Open Tibia Shaft Fractures and Soft-Tissue Coverage: The Effects of Management by an Orthopaedic Microsurgical Team.

PubMed

VandenBerg, James; Osei, Daniel; Boyer, Martin I; Gardner, Michael J; Ricci, William M; Spraggs-Hughes, Amanda; McAndrew, Christopher M

2017-06-01

To compare the timing of soft-tissue (flap) coverage and occurrence of complications before and after the establishment of an integrated orthopaedic trauma/microsurgical team. Retrospective cohort study. A single level 1 trauma center. Twenty-eight subjects (13 pre- and 15 post-integration) with open tibia shaft fractures (OTA/AO 42A, 42B, and 42C) treated with flap coverage between January 2009 and March 2015. Flap coverage for open tibia shaft fractures treated before ("preintegration") and after ("postintegration") implementation of an integrated orthopaedic trauma/microsurgical team. Time from index injury to flap coverage. The unadjusted median time to coverage was 7 days (95% confidence interval, 5.9-8.1) preintegration, and 6 days (95% confidence interval, 4.6-7.4) postintegration (P = 0.48). For preintegration, 9 (69%) of the patients experienced complications, compared with 7 (47%) postintegration (P = 0.23). After formation of an integrated orthopaedic trauma/microsurgery team, we observed a 1-day decrease in median days to coverage from index injury. Complications overall were lowered in the postintegration group, although statistically insignificant. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Confidence intervals for the population mean tailored to small sample sizes, with applications to survey sampling.

PubMed

Rosenblum, Michael A; Laan, Mark J van der

2009-01-07

The validity of standard confidence intervals constructed in survey sampling is based on the central limit theorem. For small sample sizes, the central limit theorem may give a poor approximation, resulting in confidence intervals that are misleading. We discuss this issue and propose methods for constructing confidence intervals for the population mean tailored to small sample sizes. We present a simple approach for constructing confidence intervals for the population mean based on tail bounds for the sample mean that are correct for all sample sizes. Bernstein's inequality provides one such tail bound. The resulting confidence intervals have guaranteed coverage probability under much weaker assumptions than are required for standard methods. A drawback of this approach, as we show, is that these confidence intervals are often quite wide. In response to this, we present a method for constructing much narrower confidence intervals, which are better suited for practical applications, and that are still more robust than confidence intervals based on standard methods, when dealing with small sample sizes. We show how to extend our approaches to much more general estimation problems than estimating the sample mean. We describe how these methods can be used to obtain more reliable confidence intervals in survey sampling. As a concrete example, we construct confidence intervals using our methods for the number of violent deaths between March 2003 and July 2006 in Iraq, based on data from the study "Mortality after the 2003 invasion of Iraq: A cross sectional cluster sample survey," by Burnham et al. (2006).

Health Insurance Trajectories and Long-Term Survival After Heart Transplantation.

PubMed

Tumin, Dmitry; Foraker, Randi E; Smith, Sakima; Tobias, Joseph D; Hayes, Don

2016-09-01

Health insurance status at heart transplantation influences recipient survival, but implications of change in insurance for long-term outcomes are unclear. Adults aged 18 to 64 receiving first-time orthotopic heart transplants between July 2006 and December 2013 were identified in the United Network for Organ Sharing registry. Patients surviving >1 year were categorized according to trajectory of insurance status (private compared with public) at wait listing, transplantation, and 1-year follow-up. The most common insurance trajectories were continuous private coverage (44%), continuous public coverage (27%), and transition from private to public coverage (11%). Among patients who survived to 1 year (n=9088), continuous public insurance (hazard ratio =1.36; 95% confidence interval 1.19, 1.56; P<0.001) and transition from private to public insurance (hazard ratio =1.25; 95% confidence interval 1.04, 1.50; P=0.017) were associated with increased mortality hazard relative to continuous private insurance. Supplementary analyses of 11 247 patients included all durations of post-transplant survival and examined post-transplant private-to-public and public-to-private transitions as time-varying covariates. In these analyses, transition from private to public insurance was associated with increased mortality hazard (hazard ratio =1.25; 95% confidence interval 1.07, 1.47; P=0.005), whereas transition from public to private insurance was associated with lower mortality hazard (hazard ratio =0.78; 95% confidence interval 0.62, 0.97; P=0.024). Transition from private to public insurance after heart transplantation is associated with worse long-term outcomes, compounding disparities in post-transplant survival attributed to insurance status at transplantation. By contrast, post-transplant gain of private insurance among patients receiving publicly funded heart transplants was associated with improved outcomes. © 2016 American Heart Association, Inc.

Multi-reader ROC studies with split-plot designs: a comparison of statistical methods.

PubMed

Obuchowski, Nancy A; Gallas, Brandon D; Hillis, Stephen L

2012-12-01

Multireader imaging trials often use a factorial design, in which study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of this design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper, the authors compare three methods of analysis for the split-plot design. Three statistical methods are presented: the Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean analysis-of-variance approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power, and confidence interval coverage of the three test statistics. The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% confidence intervals falls close to the nominal coverage for small and large sample sizes. The split-plot multireader, multicase study design can be statistically efficient compared to the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rates, similar power, and nominal confidence interval coverage, are available for this study design. Copyright © 2012 AUR. All rights reserved.

Impact of state Medicaid coverage on utilization of inpatient rehabilitation facilities among patients with stroke.

PubMed

Skolarus, Lesli E; Burke, James F; Morgenstern, Lewis B; Meurer, William J; Adelman, Eric E; Kerber, Kevin A; Callaghan, Brian C; Lisabeth, Lynda D

2014-08-01

Poststroke rehabilitation is associated with improved outcomes. Medicaid coverage of inpatient rehabilitation facility (IRF) admissions varies by state. We explored the role of state Medicaid IRF coverage on IRF utilization among patients with stroke. Working age ischemic stroke patients with Medicaid were identified from the 2010 Nationwide Inpatient Sample. Medicaid coverage of IRFs (yes versus no) was ascertained. Primary outcome was discharge to IRF (versus other discharge destinations). We fit a logistic regression model that included patient demographics, Medicaid coverage, comorbidities, length of stay, tissue-type plasminogen activator use, state Medicaid IRF coverage, and the interaction between patient Medicaid status and state Medicaid IRF coverage while accounting for hospital clustering. Medicaid did not cover IRFs in 4 (TN, TX, SC, WV) of 42 states. The impact of State Medicaid IRF coverage was limited to Medicaid stroke patients (P for interaction <0.01). Compared with Medicaid stroke patients in states with Medicaid IRF coverage, Medicaid stroke patients hospitalized in states without Medicaid IRF coverage were less likely to be discharged to an IRF of 11.6% (95% confidence interval, 8.5%-14.7%) versus 19.5% (95% confidence interval, 18.3%-20.8%), P<0.01 after full adjustment. State Medicaid coverage of IRFs is associated with IRF utilization among stroke patients with Medicaid. Given the increasing stroke incidence among the working age and Medicaid expansion under the Affordable Care Act, careful attention to state Medicaid policy for poststroke rehabilitation and analysis of its effects on stroke outcome disparities are warranted. © 2014 American Heart Association, Inc.

Confidence intervals for a difference between lognormal means in cluster randomization trials.

PubMed

Poirier, Julia; Zou, G Y; Koval, John

2017-04-01

Cluster randomization trials, in which intact social units are randomized to different interventions, have become popular in the last 25 years. Outcomes from these trials in many cases are positively skewed, following approximately lognormal distributions. When inference is focused on the difference between treatment arm arithmetic means, existent confidence interval procedures either make restricting assumptions or are complex to implement. We approach this problem by assuming log-transformed outcomes from each treatment arm follow a one-way random effects model. The treatment arm means are functions of multiple parameters for which separate confidence intervals are readily available, suggesting that the method of variance estimates recovery may be applied to obtain closed-form confidence intervals. A simulation study showed that this simple approach performs well in small sample sizes in terms of empirical coverage, relatively balanced tail errors, and interval widths as compared to existing methods. The methods are illustrated using data arising from a cluster randomization trial investigating a critical pathway for the treatment of community acquired pneumonia.

Bootstrap confidence intervals and bias correction in the estimation of HIV incidence from surveillance data with testing for recent infection.

PubMed

Carnegie, Nicole Bohme

2011-04-15

The incidence of new infections is a key measure of the status of the HIV epidemic, but accurate measurement of incidence is often constrained by limited data. Karon et al. (Statist. Med. 2008; 27:4617–4633) developed a model to estimate the incidence of HIV infection from surveillance data with biologic testing for recent infection for newly diagnosed cases. This method has been implemented by public health departments across the United States and is behind the new national incidence estimates, which are about 40 per cent higher than previous estimates. We show that the delta method approximation given for the variance of the estimator is incomplete, leading to an inflated variance estimate. This contributes to the generation of overly conservative confidence intervals, potentially obscuring important differences between populations. We demonstrate via simulation that an innovative model-based bootstrap method using the specified model for the infection and surveillance process improves confidence interval coverage and adjusts for the bias in the point estimate. Confidence interval coverage is about 94–97 per cent after correction, compared with 96–99 per cent before. The simulated bias in the estimate of incidence ranges from −6.3 to +14.6 per cent under the original model but is consistently under 1 per cent after correction by the model-based bootstrap. In an application to data from King County, Washington in 2007 we observe correction of 7.2 per cent relative bias in the incidence estimate and a 66 per cent reduction in the width of the 95 per cent confidence interval using this method. We provide open-source software to implement the method that can also be extended for alternate models.

Improved central confidence intervals for the ratio of Poisson means

NASA Astrophysics Data System (ADS)

Cousins, R. D.

The problem of confidence intervals for the ratio of two unknown Poisson means was "solved" decades ago, but a closer examination reveals that the standard solution is far from optimal from the frequentist point of view. We construct a more powerful set of central confidence intervals, each of which is a (typically proper) subinterval of the corresponding standard interval. They also provide upper and lower confidence limits which are more restrictive than the standard limits. The construction follows Neyman's original prescription, though discreteness of the Poisson distribution and the presence of a nuisance parameter (one of the unknown means) lead to slightly conservative intervals. Philosophically, the issue of the appropriateness of the construction method is similar to the issue of conditioning on the margins in 2×2 contingency tables. From a frequentist point of view, the new set maintains (over) coverage of the unknown true value of the ratio of means at each stated confidence level, even though the new intervals are shorter than the old intervals by any measure (except for two cases where they are identical). As an example, when the number 2 is drawn from each Poisson population, the 90% CL central confidence interval on the ratio of means is (0.169, 5.196), rather than (0.108, 9.245). In the cited literature, such confidence intervals have applications in numerous branches of pure and applied science, including agriculture, wildlife studies, manufacturing, medicine, reliability theory, and elementary particle physics.

Confidence intervals and sample size calculations for the standardized mean difference effect size between two normal populations under heteroscedasticity.

PubMed

Shieh, G

2013-12-01

The use of effect sizes and associated confidence intervals in all empirical research has been strongly emphasized by journal publication guidelines. To help advance theory and practice in the social sciences, this article describes an improved procedure for constructing confidence intervals of the standardized mean difference effect size between two independent normal populations with unknown and possibly unequal variances. The presented approach has advantages over the existing formula in both theoretical justification and computational simplicity. In addition, simulation results show that the suggested one- and two-sided confidence intervals are more accurate in achieving the nominal coverage probability. The proposed estimation method provides a feasible alternative to the most commonly used measure of Cohen's d and the corresponding interval procedure when the assumption of homogeneous variances is not tenable. To further improve the potential applicability of the suggested methodology, the sample size procedures for precise interval estimation of the standardized mean difference are also delineated. The desired precision of a confidence interval is assessed with respect to the control of expected width and to the assurance probability of interval width within a designated value. Supplementary computer programs are developed to aid in the usefulness and implementation of the introduced techniques.

A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies

PubMed Central

2014-01-01

Background The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. Methods The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. Results The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. Conclusions If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used. PMID:24552686

A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies.

PubMed

Kottas, Martina; Kuss, Oliver; Zapf, Antonia

2014-02-19

The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used.

Childhood vaccination coverage rates among military dependents in the United States.

PubMed

Dunn, Angela C; Black, Carla L; Arnold, John; Brodine, Stephanie; Waalen, Jill; Binkin, Nancy

2015-05-01

The Military Health System provides universal coverage of all recommended childhood vaccinations. Few studies have examined the effect that being insured by the Military Health System has on childhood vaccination coverage. The purpose of this study was to compare the coverage of the universally recommended vaccines among military dependents versus other insured and uninsured children using a nationwide sample of children. The National Immunization Survey is a multistage, random-digit dialing survey designed to measure vaccination coverage estimates of US children aged 19 to 35 months old. Data from 2007 through 2012 were combined to permit comparison of vaccination coverage among military dependent and all other children. Among military dependents, 28.0% of children aged 19 to 35 months were not up to date on the 4:3:1:3:3:1 vaccination series excluding Haemophilus influenzae type b vaccine compared with 21.1% of all other children (odds ratio: 1.4; 95% confidence interval: 1.2-1.6). After controlling for sociodemographic characteristics, compared with all other US children, military dependent children were more likely to be incompletely vaccinated (odds ratio: 1.3; 95% confidence interval: 1.1-1.5). Lower vaccination coverage rates among US military dependent children might be due to this population being highly mobile. However, the lack of a military-wide childhood immunization registry and incomplete documentation of vaccinations could contribute to the lower vaccination coverage rates seen in this study. These results suggest the need for further investigation to evaluate vaccination coverage of children with complete ascertainment of vaccination history, and if lower immunization rates are verified, assessment of reasons for lower vaccination coverage rates among military dependent children. Copyright © 2015 by the American Academy of Pediatrics.

Assessing Mediational Models: Testing and Interval Estimation for Indirect Effects.

PubMed

Biesanz, Jeremy C; Falk, Carl F; Savalei, Victoria

2010-08-06

Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses ( Baron & Kenny, 1986 ; Sobel, 1982 ) have in recent years been supplemented by computationally intensive methods such as bootstrapping, the distribution of the product methods, and hierarchical Bayesian Markov chain Monte Carlo (MCMC) methods. These different approaches for assessing mediation are illustrated using data from Dunn, Biesanz, Human, and Finn (2007). However, little is known about how these methods perform relative to each other, particularly in more challenging situations, such as with data that are incomplete and/or nonnormal. This article presents an extensive Monte Carlo simulation evaluating a host of approaches for assessing mediation. We examine Type I error rates, power, and coverage. We study normal and nonnormal data as well as complete and incomplete data. In addition, we adapt a method, recently proposed in statistical literature, that does not rely on confidence intervals (CIs) to test the null hypothesis of no indirect effect. The results suggest that the new inferential method-the partial posterior p value-slightly outperforms existing ones in terms of maintaining Type I error rates while maximizing power, especially with incomplete data. Among confidence interval approaches, the bias-corrected accelerated (BC a ) bootstrapping approach often has inflated Type I error rates and inconsistent coverage and is not recommended; In contrast, the bootstrapped percentile confidence interval and the hierarchical Bayesian MCMC method perform best overall, maintaining Type I error rates, exhibiting reasonable power, and producing stable and accurate coverage rates.

Effect Sizes and their Intervals: The Two-Level Repeated Measures Case

ERIC Educational Resources Information Center

Algina, James; Keselman, H. J.; Penfield, Randall D.

2005-01-01

Probability coverage for eight different confidence intervals (CIs) of measures of effect size (ES) in a two-level repeated measures design was investigated. The CIs and measures of ES differed with regard to whether they used least squares or robust estimates of central tendency and variability, whether the end critical points of the interval…

Statistical inference for the within-device precision of quantitative measurements in assay validation.

PubMed

Liu, Jen-Pei; Lu, Li-Tien; Liao, C T

2009-09-01

Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.

Medicaid Coverage Expansions and Cigarette Smoking Cessation Among Low-income Adults.

PubMed

Koma, Jonathan W; Donohue, Julie M; Barry, Colleen L; Huskamp, Haiden A; Jarlenski, Marian

2017-12-01

Expanding Medicaid coverage to low-income adults may have increased smoking cessation through improved access to evidence-based treatments. Our study sought to determine if states' decisions to expand Medicaid increased recent smoking cessation. Using pooled cross-sectional data from the Behavioral Risk Factor Surveillance Survey for the years 2011-2015, we examined the association between state Medicaid coverage and the probability of recent smoking cessation among low-income adults without dependent children who were current or former smokers (n=36,083). We used difference-in-differences estimation to examine the effects of Medicaid coverage on smoking cessation, comparing low-income adult smokers in states with Medicaid coverage to comparable adults in states without Medicaid coverage, with ages 18-64 years to those ages 65 years and above. Analyses were conducted for the full sample and stratified by sex. Residence in a state with Medicaid coverage among low-income adult smokers ages 18-64 years was associated with an increase in recent smoking cessation of 2.1 percentage points (95% confidence interval, 0.25-3.9). In the comparison group of individuals ages 65 years and above, residence in a state with Medicaid coverage expansion was not associated with a change in recent smoking cessation (-0.1 percentage point, 95% confidence interval, -2.1 to 1.8). Similar increases in smoking cessation among those ages 18-64 years were estimated for females and males (1.9 and 2.2 percentage point, respectively). Findings are consistent with the hypothesis that Medicaid coverage expansions may have increased smoking cessation among low-income adults without dependent children via greater access to preventive health care services, including evidence-based smoking cessation services.

Funding policies and postabortion long-acting reversible contraception: results from a cluster randomized trial.

PubMed

Rocca, Corinne H; Thompson, Kirsten M J; Goodman, Suzan; Westhoff, Carolyn L; Harper, Cynthia C

2016-06-01

Almost one-half of women having an abortion in the United States have had a previous procedure, which highlights a failure to provide adequate preventive care. Provision of intrauterine devices and implants, which have high upfront costs, can be uniquely challenging in the abortion care setting. We conducted a study of a clinic-wide training intervention on long-acting reversible contraception and examined the effect of the intervention, insurance coverage, and funding policies on the use of long-acting contraceptives after an abortion. This subanalysis of a cluster, randomized trial examines data from the 648 patients who had undergone an abortion who were recruited from 17 reproductive health centers across the United States. The trial followed participants 18-25 years old who did not desire pregnancy for a year. We measured the effect of the intervention, health insurance, and funding policies on contraceptive outcomes, which included intrauterine device and implant counseling and selection at the abortion visit, with the use of logistic regression with generalized estimating equations for clustering. We used survival analysis to model the actual initiation of these methods over 1 year. Women who obtained abortion care at intervention sites were more likely to report intrauterine device and implant counseling (70% vs 41%; adjusted odds ratio, 3.83; 95% confidence interval, 2.37-6.19) and the selection of these methods (36% vs 21%; adjusted odds ratio, 2.11; 95% confidence interval, 1.39-3.21). However, the actual initiation of methods was similar between study arms (22/100 woman-years each; adjusted hazard ratio, 0.88; 95% confidence interval, 0.51-1.51). Health insurance and funding policies were important for the initiation of intrauterine devices and implants. Compared with uninsured women, those women with public health insurance had a far higher initiation rate (adjusted hazard ratio, 2.18; 95% confidence interval, 1.31-3.62). Women at sites that provide state Medicaid enrollees abortion coverage also had a higher initiation rate (adjusted hazard ratio, 1.73; 95% confidence interval, 1.04-2.88), as did those at sites with state mandates for private health insurance to cover contraception (adjusted hazard ratio, 1.80; 95% confidence interval, 1.06-3.07). Few of the women with private insurance used it to pay for the abortion (28%), but those who did initiated long-acting contraceptive methods at almost twice the rate as women who paid for it themselves or with donated funds (adjusted hazard ratio, 1.94; 95% confidence interval, 1.10-3.43). The clinic-wide training increased long-acting reversible contraceptive counseling and selection but did not change initiation for abortion patients. Long-acting method use after abortion was associated strongly with funding. Restrictions on the coverage of abortion and contraceptives in abortion settings prevent the initiation of desired long-acting methods. Copyright © 2015 Elsevier Inc. All rights reserved.

Accuracy and Coverage of Diagnosis and Procedural Coding of Severely Injured Patients in the Finnish Hospital Discharge Register: Comparison to Patient Files and the Helsinki Trauma Registry.

PubMed

Heinänen, M; Brinck, T; Handolin, L; Mattila, V M; Söderlund, T

2017-09-01

The Finnish Hospital Discharge Register data are frequently used for research purposes. The Finnish Hospital Discharge Register has shown excellent validity in single injuries or disease groups, but no studies have assessed patients with multiple trauma diagnoses. We aimed to evaluate the accuracy and coverage of the Finnish Hospital Discharge Register but at the same time validate the data of the trauma registry of the Helsinki University Hospital's Trauma Unit. We assessed the accuracy and coverage of the Finnish Hospital Discharge Register data by comparing them to the original patient files and trauma registry files from the trauma registry of the Helsinki University Hospital's Trauma Unit. We identified a baseline cohort of patients with severe thorax injury from the trauma registry of the Helsinki University Hospital's Trauma Unit of 2013 (sample of 107 patients). We hypothesized that the Finnish Hospital Discharge Register would lack valuable information about these patients. Using patient files, we identified 965 trauma diagnoses in these 107 patients. From the Finnish Hospital Discharge Register, we identified 632 (65.5%) diagnoses and from the trauma registry of the Helsinki University Hospital's Trauma Unit, 924 (95.8%) diagnoses. A total of 170 (17.6%) trauma diagnoses were missing from the Finnish Hospital Discharge Register data and 41 (4.2%) from the trauma registry of the Helsinki University Hospital's Trauma Unit data. The coverage and accuracy of diagnoses in the Finnish Hospital Discharge Register were 65.5% (95% confidence interval: 62.5%-68.5%) and 73.8% (95% confidence interval: 70.4%-77.2%), respectively, and for the trauma registry of the Helsinki University Hospital's Trauma Unit, 95.8% (95% confidence interval: 94.5%-97.0%) and 97.6% (95% confidence interval: 96.7%-98.6%), respectively. According to patient records, these patients were subjects in 249 operations. We identified 40 (16.1%) missing operation codes from the Finnish Hospital Discharge Register and 19 (7.6%) from the trauma registry of the Helsinki University Hospital's Trauma Unit. The validity of the Finnish Hospital Discharge Register data is unsatisfactory in terms of the accuracy and coverage of diagnoses in patients with multiple trauma diagnoses. Procedural codes provide greater accuracy. We found the coverage and accuracy of the trauma registry of the Helsinki University Hospital's Trauma Unit to be excellent. Therefore, a special trauma registry, such as the trauma registry of the Helsinki University Hospital's Trauma Unit, provides much more accurate data and should be the preferred registry when extracting data for research or for administrative use, such as resource prioritizing.

Using known populations of pronghorn to evaluate sampling plans and estimators

USGS Publications Warehouse

Kraft, K.M.; Johnson, D.H.; Samuelson, J.M.; Allen, S.H.

1995-01-01

Although sampling plans and estimators of abundance have good theoretical properties, their performance in real situations is rarely assessed because true population sizes are unknown. We evaluated widely used sampling plans and estimators of population size on 3 known clustered distributions of pronghorn (Antilocapra americana). Our criteria were accuracy of the estimate, coverage of 95% confidence intervals, and cost. Sampling plans were combinations of sampling intensities (16, 33, and 50%), sample selection (simple random sampling without replacement, systematic sampling, and probability proportional to size sampling with replacement), and stratification. We paired sampling plans with suitable estimators (simple, ratio, and probability proportional to size). We used area of the sampling unit as the auxiliary variable for the ratio and probability proportional to size estimators. All estimators were nearly unbiased, but precision was generally low (overall mean coefficient of variation [CV] = 29). Coverage of 95% confidence intervals was only 89% because of the highly skewed distribution of the pronghorn counts and small sample sizes, especially with stratification. Stratification combined with accurate estimates of optimal stratum sample sizes increased precision, reducing the mean CV from 33 without stratification to 25 with stratification; costs increased 23%. Precise results (mean CV = 13) but poor confidence interval coverage (83%) were obtained with simple and ratio estimators when the allocation scheme included all sampling units in the stratum containing most pronghorn. Although areas of the sampling units varied, ratio estimators and probability proportional to size sampling did not increase precision, possibly because of the clumped distribution of pronghorn. Managers should be cautious in using sampling plans and estimators to estimate abundance of aggregated populations.

Impact of partner bereavement on quality of cardiovascular disease management.

PubMed

Shah, Sunil M; Carey, Iain M; Harris, Tess; Dewilde, Stephen; Victor, Christina R; Cook, Derek G

2013-12-24

Bereavement is a period of increased risk of cardiovascular death. There is limited understanding of the potential contribution of quality of cardiovascular disease management to this increased risk. In a UK primary-care database, 12 722 older individuals with preexisting cardiovascular disease (coronary heart disease, hypertension, diabetes mellitus, stroke) and a partner bereavement were matched with a non-bereaved control group (n=33 911). We examined key routine annual process measures of care in the year before and after bereavement and cardiovascular medication prescribing (lipid-lowering, antiplatelet, renin-angiotensin system drugs). Odds ratios for change after bereavement compared with the change in non-bereaved matched controls are presented. In the bereaved, uptake of all annual measures was lower in the year before bereavement, with improvement in the year after, whereas in the controls, uptake was relatively stable. The odds ratio for change was 1.30 (95% confidence interval, 1.15-1.46) for cholesterol measurement and 1.40 (95% confidence interval, 1.22-1.61) for blood pressure measurement. For all medication, there was a transient fall in prescribing in the peri-bereavement period lasting until about 3 months after bereavement. The odds ratio for at least 80% prescription coverage in the 30 days after bereavement was 0.80 (95% confidence interval, 0.73-0.88) for lipid-lowering medication and 0.82 (95% confidence interval, 0.74-0.91) for antiplatelet medication compared with the change in non-bereaved individuals. Lower uptake of key cardiovascular care measures in the year before bereavement and reduced medication coverage after bereavement may contribute to increased cardiovascular risk. Clinicians need to ensure that quality of cardiovascular care is maintained in the pre- and post-bereavement periods.

Population-based coverage survey results following the mass drug administration of azithromycin for the treatment of trachoma in Amhara, Ethiopia.

PubMed

Astale, Tigist; Sata, Eshetu; Zerihun, Mulat; Nute, Andrew W; Stewart, Aisha E P; Gessese, Demelash; Ayenew, Gedefaw; Melak, Berhanu; Chanyalew, Melsew; Tadesse, Zerihun; Callahan, E Kelly; Nash, Scott D

2018-02-01

Trachoma is the leading infectious cause of blindness worldwide. In communities where the district level prevalence of trachomatous inflammation-follicular among children ages 1-9 years is ≥5%, WHO recommends annual mass drug administration (MDA) of antibiotics with the aim of at least 80% coverage. Population-based post-MDA coverage surveys are essential to understand the effectiveness of MDA programs, yet published reports from trachoma programs are rare. In the Amhara region of Ethiopia, a population-based MDA coverage survey was conducted 3 weeks following the 2016 MDA to estimate the zonal prevalence of self-reported drug coverage in all 10 administrative zones. Survey households were selected using a multi-stage cluster random sampling design and all individuals in selected households were presented with a drug sample and asked about taking the drug during the campaign. Zonal estimates were weighted and confidence intervals were calculated using survey procedures. Self-reported drug coverage was then compared with regional reported administrative coverage. Region-wide, 24,248 individuals were enumerated, of which, 20,942 (86.4%) individuals were present. The regional self-reported antibiotic coverage was 76.8% (95%Confidence Interval (CI):69.3-82.9%) in the population overall and 77.4% (95%CI = 65.7-85.9%) among children ages 1-9 years old. Zonal coverage ranged from 67.8% to 90.2%. Five out of 10 zones achieved a coverage >80%. In all zones, the reported administrative coverage was greater than 90% and was considerably higher than self-reported MDA coverage. Main reasons reported for MDA campaign non-attendance included being physically unable to get to MDA site (22.5%), traveling (20.6%), and not knowing about the campaign (21.0%). MDA refusal was low (2.8%) in this population. Although self-reported MDA coverage in Amhara was greater than 80% in some zones, programmatic improvements are warranted throughout Amhara to achieve higher coverage. These results will be used to enhance community mobilization and improve training for MDA distributors and supervisors to improve coverage in future MDAs.

Empirical likelihood-based confidence intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity.

PubMed

Gengsheng Qin; Davis, Angela E; Jing, Bing-Yi

2011-06-01

For a continuous-scale diagnostic test, it is often of interest to find the range of the sensitivity of the test at the cut-off that yields a desired specificity. In this article, we first define a profile empirical likelihood ratio for the sensitivity of a continuous-scale diagnostic test and show that its limiting distribution is a scaled chi-square distribution. We then propose two new empirical likelihood-based confidence intervals for the sensitivity of the test at a fixed level of specificity by using the scaled chi-square distribution. Simulation studies are conducted to compare the finite sample performance of the newly proposed intervals with the existing intervals for the sensitivity in terms of coverage probability. A real example is used to illustrate the application of the recommended methods.

States With Medically Needy Pathways: Differences in Long-Term and Temporary Medicaid Entry for Low-Income Medicare Beneficiaries.

PubMed

Keohane, Laura M; Trivedi, Amal; Mor, Vincent

2017-10-01

Medically needy pathways may provide temporary catastrophic coverage for low-income Medicare beneficiaries who do not otherwise qualify for full Medicaid benefits. Between January 2009 and June 2010, states with medically needy pathways had a higher percentage of low-income beneficiaries join Medicaid than states without such programs (7.5% vs. 4.1%, p < .01). However, among new full Medicaid participants, living in a state with a medically needy pathway was associated with a 3.8 percentage point (adjusted 95% confidence interval [1.8, 5.8]) increase in the probability of switching to partial Medicaid and a 4.5 percentage point (adjusted 95% confidence interval [2.9, 6.2]) increase in the probability of exiting Medicaid within 12 months. The predicted risk of leaving Medicaid was greatest when new Medicaid participants used only hospital services, rather than nursing home services, in their first month of Medicaid benefits. Alternative strategies for protecting low-income Medicare beneficiaries' access to care could provide more stable coverage.

Full prescription coverage versus usual prescription coverage after coronary artery bypass graft surgery: analysis from the post-myocardial infarction free Rx event and economic evaluation (FREEE) randomized trial.

PubMed

Kulik, Alexander; Desai, Nihar R; Shrank, William H; Antman, Elliott M; Glynn, Robert J; Levin, Raisa; Reisman, Lonny; Brennan, Troyen; Choudhry, Niteesh K

2013-09-10

Eliminating out-of-pocket costs for patients after myocardial infarction (MI) improves adherence to preventive therapies and reduces clinical events. Because adherence to medical therapy is low among patients treated with coronary artery bypass graft surgery (CABG), we evaluated the impact of providing full prescription coverage to this patient subgroup. The MI Free Rx Event and Economic Evaluation (FREEE) trial randomly assigned 5855 patients with MI to full prescription coverage or usual formulary coverage for all statins, β-blockers, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers. We assessed the impact of full prescription coverage on adherence, clinical outcomes, and healthcare costs using adjusted models among the 1052 patients who underwent CABG at the index hospitalization and 4803 who did not. CABG patients were older and had more comorbid illness (P<0.01). After MI, CABG patients were significantly more likely to receive β-blockers and statins but were less likely to receive angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy (P<0.01). Receiving full drug coverage increased rates of adherence to all preventative medications after CABG (all P<0.05). Full coverage was also associated with nonsignificant reductions in the rate of major vascular events or revascularization for patients treated with CABG (hazard ratio, 0.91; 95% confidence interval, 0.66-1.25) or without CABG (hazard ratio, 0.93; 95% confidence interval, 0.82-1.06), with no interaction noted (Pint=NS). After CABG, full prescription coverage significantly reduced patient out-of-pocket spending for drugs (P=0.001) without increasing overall health expenditures (P=NS). Eliminating drug copayments after MI provides consistent benefits to patients treated with or without CABG, leading to increased medication adherence, trends toward improved clinical outcomes, and reduced patient out-of-pocket expenses.

A comparison of confidence interval methods for the concordance correlation coefficient and intraclass correlation coefficient with small number of raters.

PubMed

Feng, Dai; Svetnik, Vladimir; Coimbra, Alexandre; Baumgartner, Richard

2014-01-01

The intraclass correlation coefficient (ICC) with fixed raters or, equivalently, the concordance correlation coefficient (CCC) for continuous outcomes is a widely accepted aggregate index of agreement in settings with small number of raters. Quantifying the precision of the CCC by constructing its confidence interval (CI) is important in early drug development applications, in particular in qualification of biomarker platforms. In recent years, there have been several new methods proposed for construction of CIs for the CCC, but their comprehensive comparison has not been attempted. The methods consisted of the delta method and jackknifing with and without Fisher's Z-transformation, respectively, and Bayesian methods with vague priors. In this study, we carried out a simulation study, with data simulated from multivariate normal as well as heavier tailed distribution (t-distribution with 5 degrees of freedom), to compare the state-of-the-art methods for assigning CI to the CCC. When the data are normally distributed, the jackknifing with Fisher's Z-transformation (JZ) tended to provide superior coverage and the difference between it and the closest competitor, the Bayesian method with the Jeffreys prior was in general minimal. For the nonnormal data, the jackknife methods, especially the JZ method, provided the coverage probabilities closest to the nominal in contrast to the others which yielded overly liberal coverage. Approaches based upon the delta method and Bayesian method with conjugate prior generally provided slightly narrower intervals and larger lower bounds than others, though this was offset by their poor coverage. Finally, we illustrated the utility of the CIs for the CCC in an example of a wake after sleep onset (WASO) biomarker, which is frequently used in clinical sleep studies of drugs for treatment of insomnia.

Permutation-based inference for the AUC: A unified approach for continuous and discontinuous data.

PubMed

Pauly, Markus; Asendorf, Thomas; Konietschke, Frank

2016-11-01

We investigate rank-based studentized permutation methods for the nonparametric Behrens-Fisher problem, that is, inference methods for the area under the ROC curve. We hereby prove that the studentized permutation distribution of the Brunner-Munzel rank statistic is asymptotically standard normal, even under the alternative. Thus, incidentally providing the hitherto missing theoretical foundation for the Neubert and Brunner studentized permutation test. In particular, we do not only show its consistency, but also that confidence intervals for the underlying treatment effects can be computed by inverting this permutation test. In addition, we derive permutation-based range-preserving confidence intervals. Extensive simulation studies show that the permutation-based confidence intervals appear to maintain the preassigned coverage probability quite accurately (even for rather small sample sizes). For a convenient application of the proposed methods, a freely available software package for the statistical software R has been developed. A real data example illustrates the application. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Robust Coefficients Alpha and Omega and Confidence Intervals With Outlying Observations and Missing Data: Methods and Software.

PubMed

Zhang, Zhiyong; Yuan, Ke-Hai

2016-06-01

Cronbach's coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald's omega has been used as a popular alternative to alpha in the literature. Traditional estimation methods for alpha and omega often implicitly assume that data are complete and normally distributed. This study proposes robust procedures to estimate both alpha and omega as well as corresponding standard errors and confidence intervals from samples that may contain potential outlying observations and missing values. The influence of outlying observations and missing data on the estimates of alpha and omega is investigated through two simulation studies. Results show that the newly developed robust method yields substantially improved alpha and omega estimates as well as better coverage rates of confidence intervals than the conventional nonrobust method. An R package coefficientalpha is developed and demonstrated to obtain robust estimates of alpha and omega.

Robust Coefficients Alpha and Omega and Confidence Intervals With Outlying Observations and Missing Data

PubMed Central

Zhang, Zhiyong; Yuan, Ke-Hai

2015-01-01

Cronbach’s coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald’s omega has been used as a popular alternative to alpha in the literature. Traditional estimation methods for alpha and omega often implicitly assume that data are complete and normally distributed. This study proposes robust procedures to estimate both alpha and omega as well as corresponding standard errors and confidence intervals from samples that may contain potential outlying observations and missing values. The influence of outlying observations and missing data on the estimates of alpha and omega is investigated through two simulation studies. Results show that the newly developed robust method yields substantially improved alpha and omega estimates as well as better coverage rates of confidence intervals than the conventional nonrobust method. An R package coefficientalpha is developed and demonstrated to obtain robust estimates of alpha and omega. PMID:29795870

Generalized Bootstrap Method for Assessment of Uncertainty in Semivariogram Inference

USGS Publications Warehouse

Olea, R.A.; Pardo-Iguzquiza, E.

2011-01-01

The semivariogram and its related function, the covariance, play a central role in classical geostatistics for modeling the average continuity of spatially correlated attributes. Whereas all methods are formulated in terms of the true semivariogram, in practice what can be used are estimated semivariograms and models based on samples. A generalized form of the bootstrap method to properly model spatially correlated data is used to advance knowledge about the reliability of empirical semivariograms and semivariogram models based on a single sample. Among several methods available to generate spatially correlated resamples, we selected a method based on the LU decomposition and used several examples to illustrate the approach. The first one is a synthetic, isotropic, exhaustive sample following a normal distribution, the second example is also a synthetic but following a non-Gaussian random field, and a third empirical sample consists of actual raingauge measurements. Results show wider confidence intervals than those found previously by others with inadequate application of the bootstrap. Also, even for the Gaussian example, distributions for estimated semivariogram values and model parameters are positively skewed. In this sense, bootstrap percentile confidence intervals, which are not centered around the empirical semivariogram and do not require distributional assumptions for its construction, provide an achieved coverage similar to the nominal coverage. The latter cannot be achieved by symmetrical confidence intervals based on the standard error, regardless if the standard error is estimated from a parametric equation or from bootstrap. ?? 2010 International Association for Mathematical Geosciences.

Demography and population status of polar bears in western Hudson Bay

USGS Publications Warehouse

Lunn, Nicholas J.; Regher, Eric V; Servanty, Sabrina; Converse, Sarah J.; Richardson, Evan S.; Stirling, Ian

2013-01-01

The 2011 abundance estimate from this analysis was 806 bears with a 95% Bayesian credible interval of 653-984. This is lower than, but broadly consistent with, the abundance estimate of 1,030 (95% confidence interval = 745-1406) from a 2011 aerial survey (Stapleton et al. 2014). The capture-recapture and aerial survey approaches have different spatial and temporal coverage of the WH subpopulation and, consequently, the effective study population considered by each approach is different.

Comparing interval estimates for small sample ordinal CFA models

PubMed Central

Natesan, Prathiba

2015-01-01

Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading. Therefore, editors and policymakers should continue to emphasize the inclusion of interval estimates in research. PMID:26579002

Comparing interval estimates for small sample ordinal CFA models.

PubMed

Natesan, Prathiba

2015-01-01

Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading. Therefore, editors and policymakers should continue to emphasize the inclusion of interval estimates in research.

Mumps vaccine performance among university students during a mumps outbreak.

PubMed

Cortese, Margaret M; Jordan, Hannah T; Curns, Aaron T; Quinlan, Patricia A; Ens, Kim A; Denning, Patricia M; Dayan, Gustavo H

2008-04-15

The largest reported mumps outbreak at a US college in 19 years occurred in 2006 at a Kansas university with a 2-dose measles-mumps-rubella (MMR) vaccination policy. We assessed vaccine performance and mumps risk factors, including the possibility of waning vaccine protection. Case students were compared with a cohort of the university's approximately 19,000 undergraduates. The secondary attack rate for clinical mumps was determined among roommates exposed to case students. Time from receipt of the second dose of MMR vaccine was compared between case students and roommates without mumps. Coverage with > or =2 dose of MMR vaccine was > or =95% among 140 undergraduate case students and 444 cohort students. The secondary attack rate for clinical mumps among roommates who had received 2 doses of vaccine ranged from 2.2% to 7.7%, depending on the case definition. Compared with roommates without mumps, case students were more likely (odds ratio, 2.46; 95% confidence interval, 1.25-4.82) to have received their second dose of MMR vaccine > or =10 years earlier. The odds of being a case student increased with each 1-year increase in time from receipt of the second dose of MMR vaccine (odds ratio, 1.36; 95% confidence interval, 1.10-1.68) among case students and roommates aged 18-19 years but not among those aged > or =20 years. Students aged 18-19 years had a higher risk of mumps (risk ratio, 3.14; 95% confidence interval, 1.60-6.16), compared with students aged > or =22 years; women living in dormitories had increased risk of mumps (risk ratio, 1.95; 95% confidence interval, 1.01-3.76), compared with men not living in dormitories. High 2-dose MMR coverage protected many students from developing mumps but was not sufficient to prevent the mumps outbreak. Vaccine-induced protection may wane. Similar US settings where large numbers of young adults from wild-type naive cohorts live closely together may be at particular risk for mumps outbreaks.

Assessing equity of healthcare utilization in rural China: results from nationally representative surveys from 1993 to 2008

PubMed Central

2013-01-01

Background The phenomenon of inequitable healthcare utilization in rural China interests policymakers and researchers; however, the inequity has not been actually measured to present the magnitude and trend using nationally representative data. Methods Based on the National Health Service Survey (NHSS) in 1993, 1998, 2003, and 2008, the Probit model with the probability of outpatient visit and the probability of inpatient visit as the dependent variables is applied to estimate need-predicted healthcare utilization. Furthermore, need-standardized healthcare utilization is assessed through indirect standardization method. Concentration index is measured to reflect income-related inequity of healthcare utilization. Results The concentration index of need-standardized outpatient utilization is 0.0486[95% confidence interval (0.0399, 0.0574)], 0.0310[95% confidence interval (0.0229, 0.0390)], 0.0167[95% confidence interval (0.0069, 0.0264)] and −0.0108[95% confidence interval (−0.0213, -0.0004)] in 1993, 1998, 2003 and 2008, respectively. For inpatient service, the concentration index is 0.0529[95% confidence interval (0.0349, 0.0709)], 0.1543[95% confidence interval (0.1356, 0.1730)], 0.2325[95% confidence interval (0.2132, 0.2518)] and 0.1313[95% confidence interval (0.1174, 0.1451)] in 1993, 1998, 2003 and 2008, respectively. Conclusions Utilization of both outpatient and inpatient services was pro-rich in rural China with the exception of outpatient service in 2008. With the same needs for healthcare, rich rural residents utilized more healthcare service than poor rural residents. Compared to utilization of outpatient service, utilization of inpatient service was more inequitable. Inequity of utilization of outpatient service reduced gradually from 1993 to 2008; meanwhile, inequity of inpatient service utilization increased dramatically from 1993 to 2003 and decreased significantly from 2003 to 2008. Recent attempts in China to increase coverage of insurance and primary healthcare could be a contributing factor to counteract the inequity of outpatient utilization, but better benefit packages and delivery strategies still need to be tested and scaled up to reduce future inequity in inpatient utilization in rural China. PMID:23688260

EXACT DISTRIBUTIONS OF INTRACLASS CORRELATION AND CRONBACH'S ALPHA WITH GAUSSIAN DATA AND GENERAL COVARIANCE.

PubMed

Kistner, Emily O; Muller, Keith E

2004-09-01

Intraclass correlation and Cronbach's alpha are widely used to describe reliability of tests and measurements. Even with Gaussian data, exact distributions are known only for compound symmetric covariance (equal variances and equal correlations). Recently, large sample Gaussian approximations were derived for the distribution functions. New exact results allow calculating the exact distribution function and other properties of intraclass correlation and Cronbach's alpha, for Gaussian data with any covariance pattern, not just compound symmetry. Probabilities are computed in terms of the distribution function of a weighted sum of independent chi-square random variables. New F approximations for the distribution functions of intraclass correlation and Cronbach's alpha are much simpler and faster to compute than the exact forms. Assuming the covariance matrix is known, the approximations typically provide sufficient accuracy, even with as few as ten observations. Either the exact or approximate distributions may be used to create confidence intervals around an estimate of reliability. Monte Carlo simulations led to a number of conclusions. Correctly assuming that the covariance matrix is compound symmetric leads to accurate confidence intervals, as was expected from previously known results. However, assuming and estimating a general covariance matrix produces somewhat optimistically narrow confidence intervals with 10 observations. Increasing sample size to 100 gives essentially unbiased coverage. Incorrectly assuming compound symmetry leads to pessimistically large confidence intervals, with pessimism increasing with sample size. In contrast, incorrectly assuming general covariance introduces only a modest optimistic bias in small samples. Hence the new methods seem preferable for creating confidence intervals, except when compound symmetry definitely holds.

Mass drug administration and the sustainable control of schistosomiasis: Community health workers are vital for global elimination efforts.

PubMed

Inobaya, Marianette T; Chau, Thao N; Ng, Shu-Kay; MacDougall, Colin; Olveda, Remigio M; Tallo, Veronica L; Landicho, Jhoys M; Malacad, Carol M; Aligato, Mila F; Guevarra, Jerric R; Ross, Allen G

2018-01-01

Schistosomiasis control is centred on preventive chemotherapy through mass drug administration (MDA). However, endemic countries continue to struggle to attain target coverage rates and patient compliance. In the Philippines, barangay health workers (BHWs) play a vital role in the coordination of MDA, acting as advocates, implementers, and educators. The aim of this study was to determine whether BHW knowledge and attitudes towards schistosomiasis and MDA is sufficient and correlated with resident knowledge and drug compliance. A cross-sectional survey was conducted in 2015 among 2186 residents and 224 BHWs in the province of Northern Samar, the Philippines using a structured survey questionnaire. BHWs showed good familiarity on how schistosomiasis is acquired and diagnosed. Nevertheless, both BHWs and residents had poor awareness of the signs and symptoms of schistosomiasis, disease prevention, and treatment options. There was no correlation between the knowledge scores of the BHWs and the residents (r=0.080, p=0.722). Kruskal-Wallis analysis revealed significant differences in BHW knowledge scores between the low (3.29, 95% confidence interval 3.16-3.36), moderate (3.61, 95% confidence interval 3.49-3.69), and high (4.05, 95% confidence interval 3.77-4.13) compliance village groups (p=0.002), with the high compliance areas having the highest mean knowledge scores. This study highlights the importance of community health workers in obtaining the World Health Organization drug coverage rate of 75% and improving compliance with MDA in the community. Investing in the education of community health workers with appropriate disease-specific training is crucial if disease elimination is ultimately to be achieved. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Socioeconomic Inequalities in Statin Adherence Under Universal Coverage: Does Sex Matter?

PubMed

Aarnio, Emma; Martikainen, Janne; Winn, Aaron N; Huupponen, Risto; Vahtera, Jussi; Korhonen, Maarit J

2016-11-01

Previous research shows that low socioeconomic position (SEP; especially low income) is associated with statin nonadherence. We investigated the relationship between SEP and statin adherence in a country with universal coverage using group-based trajectory modeling in addition to the proportion of days covered. Using data from Finnish healthcare registers, we identified 116 846 individuals, aged 45 to 75 years, who initiated statin therapy for primary prevention of cardiovascular disease. We measured adherence as proportion of days covered over an 18-month period since initiation and identified different adherence patterns based on monthly adherence with group-based trajectory modeling. When adjusted for age, marital status, residential area, clinical characteristics, and copayment, low SEP was associated with statin nonadherence (proportion of days covered <80%) among men (eg, lowest versus highest income quintile: odds ratio, 1.41; 95% confidence interval, 1.32-1.50; basic versus higher-degree education: odds ratio, 1.18; 95% confidence interval, 1.13-1.24; unemployment versus employment: odds ratio, 1.17; 95% confidence interval, 1.10-1.25). Among women, the corresponding associations were different ( P <0.001 for sex-by-income quintile, sex-by-education level, and sex-by-labor market status interactions) and mainly nonsignificant. Results based on adherence trajectories showed that men in low SEP were likely to belong to trajectories presenting a fast decline in adherence. Low SEP was associated with overall and rapidly increasing statin nonadherence among men. Conversely, in women, associations between SEP and nonadherence were weak and inconsistent. Group-based trajectory modeling provided insight into the dynamics of statin adherence and its association with SEP. © 2016 American Heart Association, Inc.

Correlation Between Pediatrician Supply and Public Health in Japan as Evidenced by Vaccination Coverage in 2010: Secondary Data Analysis

PubMed Central

Sakai, Rie; Fink, Günther; Wang, Wei; Kawachi, Ichiro

2015-01-01

Background In industrialized countries, assessment of the causal effect of physician supply on population health has yielded mixed results. Since the scope of child vaccination is an indicator of preventive health service utilization, this study investigates the correlation between vaccination coverage and pediatrician supply as a reflection of overall pediatric health during a time of increasing pediatrician numbers in Japan. Methods Cross-sectional data were collected from publicly available sources for 2010. Dependent variables were vaccination coverage for measles and diphtheria, pertussis, and tetanus (DPT) by region. The primary predictor of interest was number of pediatricians per 10 000-child population (pediatrician density) at the municipality level. Multivariate logistic regression models were used to estimate associations of interest, conditional on a large range of demographic and infrastructure-related factors as covariates, including non-pediatric physician density, total population, per capita income, occupation, unemployment rate, prevalence of single motherhood, number of hospital beds per capita, length of roads, crime rate, accident rate, and metropolitan area code as urban/rural status. The percentage of the population who completed college-level education or higher in 2010 was included in the model as a proxy for education level. Results Pediatrician density was positively and significantly associated with vaccination coverage for both vaccine series. On average, each unit of pediatrician density increased odds by 1.012 for measles (95% confidence interval, 1.010–1.015) and 1.019 for DPT (95% confidence interval, 1.016–1.022). Conclusions Policies increasing pediatrician supply contribute to improved preventive healthcare services utilization, such as immunizations, and presumably improved child health status in Japan. PMID:25817986

Multiple imputation methods for bivariate outcomes in cluster randomised trials.

PubMed

DiazOrdaz, K; Kenward, M G; Gomes, M; Grieve, R

2016-09-10

Missing observations are common in cluster randomised trials. The problem is exacerbated when modelling bivariate outcomes jointly, as the proportion of complete cases is often considerably smaller than the proportion having either of the outcomes fully observed. Approaches taken to handling such missing data include the following: complete case analysis, single-level multiple imputation that ignores the clustering, multiple imputation with a fixed effect for each cluster and multilevel multiple imputation. We contrasted the alternative approaches to handling missing data in a cost-effectiveness analysis that uses data from a cluster randomised trial to evaluate an exercise intervention for care home residents. We then conducted a simulation study to assess the performance of these approaches on bivariate continuous outcomes, in terms of confidence interval coverage and empirical bias in the estimated treatment effects. Missing-at-random clustered data scenarios were simulated following a full-factorial design. Across all the missing data mechanisms considered, the multiple imputation methods provided estimators with negligible bias, while complete case analysis resulted in biased treatment effect estimates in scenarios where the randomised treatment arm was associated with missingness. Confidence interval coverage was generally in excess of nominal levels (up to 99.8%) following fixed-effects multiple imputation and too low following single-level multiple imputation. Multilevel multiple imputation led to coverage levels of approximately 95% throughout. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Meningococcal Conjugate and Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccination Among HIV-infected Youth.

PubMed

Setse, Rosanna W; Siberry, George K; Moss, William J; Wheeling, John; Bohannon, Beverly A; Dominguez, Kenneth L

2016-05-01

The meningococcal conjugate vaccine (MCV4) and the tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) were first recommended for adolescents in the US in 2005. The goal of our study was to determine MCV4 and Tdap vaccines coverage among perinatally and behaviorally HIV-infected adolescents in 2006 and to compare coverage estimates in our study population to similarly aged healthy youth in 2006. Longitudinal Epidemiologic Study to Gain Insight into HIV/AIDS in Children and Youth (LEGACY) is a retrospective cohort study of HIV-infected youth in 22 HIV specialty clinics across the US. Among LEGACY participants ≥11 years of age in 2006, we conducted a cross-sectional analysis to determine MCV4, Tdap and MCV4/Tdap vaccine coverage. We compared vaccine coverage among our study population to coverage among similarly aged youth in the 2006 National Immunization Survey for Teens (NIS-Teen Survey). Multivariable mixed effects logistic regression modeling was used to examine associations between MCV4/Tdap vaccination and mode of HIV transmission. MCV4 and Tdap coverage rates among 326 eligible participants were 31.6% and 28.8%, respectively. Among adolescents 13-17 years of age, MCV4 and Tdap coverage was significantly higher among HIV-infected youth than among youth in the 2006 NIS-Teen Survey (P <0.01). In multivariable analysis, perinatally HIV-infected youth were significantly more likely to have received MCV4/Tdap vaccination compared with their behaviorally infected counterparts (adjusted odds ratio: 5.1; 95% confidence interval: 2.0, 12.7). HIV-infected youth with CD4 cell counts of 200-499 cells/μL were more likely to have had MCV4/Tdap vaccination compared with those with CD4 counts ≥500 cells/μL (adjusted odds ratio: 2.2; 95% confidence interval: 1.2, 4.3). Participants with plasma HIV RNA viral loads of >400 copies/mL were significantly less likely to have received MCV4/Tdap vaccination (P < 0.05). MCV4 and Tdap coverage among HIV-infected youth was suboptimal but higher than for healthy adolescents in the 2006 NIS-Teen Survey. Perinatal HIV infection was associated with increased likelihood of vaccination. Specific measures are needed to improve vaccine coverage among adolescents in the US.

An evaluation of voluntary 2-dose varicella vaccination coverage in New York City public schools.

PubMed

Doll, Margaret K; Rosen, Jennifer B; Bialek, Stephanie R; Szeto, Hiram; Zimmerman, Christopher M

2015-05-01

We assessed coverage for 2-dose varicella vaccination, which is not required for school entry, among New York City public school students and examined characteristics associated with receipt of 2 doses. We measured receipt of either at least 1 or 2 doses of varicella vaccine among students aged 4 years and older in a sample of 336 public schools (n = 223 864 students) during the 2010 to 2011 school year. Data came from merged student vaccination records from 2 administrative data systems. We conducted multivariable regression to assess associations of age, gender, race/ethnicity, and school location with 2-dose prevalence. Coverage with at least 1 varicella dose was 96.2% (95% confidence interval [CI] = 96.2%, 96.3%); coverage with at least 2 doses was 64.8% (95% CI = 64.6%, 64.9%). Increasing student age, non-Hispanic White race/ethnicity, and attendance at school in Staten Island were associated with lower 2-dose coverage. A 2-dose varicella vaccine requirement for school entry would likely improve 2-dose coverage, eliminate coverage disparities, and prevent disease.

An Alternative to Cohen's Standardized Mean Difference Effect Size: A Robust Parameter and Confidence Interval in the Two Independent Groups Case

ERIC Educational Resources Information Center

Algina, James; Keselman, H. J.; Penfield, Randall D.

2005-01-01

The authors argue that a robust version of Cohen's effect size constructed by replacing population means with 20% trimmed means and the population standard deviation with the square root of a 20% Winsorized variance is a better measure of population separation than is Cohen's effect size. The authors investigated coverage probability for…

The Patient Protection and Affordable Care Act dependent coverage expansion: Disparities in impact among young adult oncology patients.

PubMed

Alvarez, Elysia M; Keegan, Theresa H; Johnston, Emily E; Haile, Robert; Sanders, Lee; Wise, Paul H; Saynina, Olga; Chamberlain, Lisa J

2018-01-01

Private health insurance is associated with improved outcomes in patients with cancer. However, to the authors' knowledge, little is known regarding the impact of the Patient Protection and Affordable Care Act Dependent Coverage Expansion (ACA-DCE), which extended private insurance to young adults (to age 26 years) beginning in 2010, on the insurance status of young adults with cancer. The current study was a retrospective, population-based analysis of hospitalized young adult oncology patients (aged 22-30 years) in California during 2006 through 2014 (11,062 patients). Multivariable regression analyses examined factors associated with having private insurance. Results were presented as adjusted odds ratios and 95% confidence intervals. A difference-in-difference analysis examined the influence of the ACA-DCE on insurance coverage by race/ethnicity and federal poverty level. Multivariable regression demonstrated that patients of black and Hispanic race/ethnicity were less likely to have private insurance before and after the ACA-DCE, compared with white patients. Younger age (22-25 years) was associated with having private insurance after implementation of the ACA-DCE (odds ratio, 1.20; 95% confidence interval, 1.06-1.35). In the difference-in-difference analysis, private insurance increased among white patients aged 22 to 25 years who were living in medium-income (2006-2009: 64.6% vs 2011-2014: 69.1%; P = .003) and high-income (80.4% vs 82%; P = .043) zip codes and among Asians aged 22 to 25 years living in high-income zip codes (73.2 vs 85.7%; P = .022). Private insurance decreased for all Hispanic patients aged 22 to 25 years between the 2 time periods. The ACA-DCE provision increased insurance coverage, but not among all patients. Private insurance increased for white and Asian patients in higher income neighborhoods, potentially widening social disparities in private insurance coverage among young adults with cancer. Cancer 2018;124:110-7. © 2017 American Cancer Society. © 2017 American Cancer Society.

Two Birds With One Stone: Estimating Population Vaccination Coverage From a Test-negative Vaccine Effectiveness Case-control Study.

PubMed

Doll, Margaret K; Morrison, Kathryn T; Buckeridge, David L; Quach, Caroline

2016-10-15

Vaccination program evaluation includes assessment of vaccine uptake and direct vaccine effectiveness (VE). Often examined separately, we propose a design to estimate rotavirus vaccination coverage using controls from a rotavirus VE test-negative case-control study and to examine coverage following implementation of the Quebec, Canada, rotavirus vaccination program. We present our assumptions for using these data as a proxy for coverage in the general population, explore effects of diagnostic accuracy on coverage estimates via simulations, and validate estimates with an external source. We found 79.0% (95% confidence interval, 74.3%, 83.0%) ≥2-dose rotavirus coverage among participants eligible for publicly funded vaccination. No differences were detected between study and external coverage estimates. Simulations revealed minimal bias in estimates with high diagnostic sensitivity and specificity. We conclude that controls from a VE case-control study may be a valuable resource of coverage information when reasonable assumptions can be made for estimate generalizability; high rotavirus coverage demonstrates success of the Quebec program. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Assessing Interval Estimation Methods for Hill Model ...

EPA Pesticide Factsheets

The Hill model of concentration-response is ubiquitous in toxicology, perhaps because its parameters directly relate to biologically significant metrics of toxicity such as efficacy and potency. Point estimates of these parameters obtained through least squares regression or maximum likelihood are commonly used in high-throughput risk assessment, but such estimates typically fail to include reliable information concerning confidence in (or precision of) the estimates. To address this issue, we examined methods for assessing uncertainty in Hill model parameter estimates derived from concentration-response data. In particular, using a sample of ToxCast concentration-response data sets, we applied four methods for obtaining interval estimates that are based on asymptotic theory, bootstrapping (two varieties), and Bayesian parameter estimation, and then compared the results. These interval estimation methods generally did not agree, so we devised a simulation study to assess their relative performance. We generated simulated data by constructing four statistical error models capable of producing concentration-response data sets comparable to those observed in ToxCast. We then applied the four interval estimation methods to the simulated data and compared the actual coverage of the interval estimates to the nominal coverage (e.g., 95%) in order to quantify performance of each of the methods in a variety of cases (i.e., different values of the true Hill model paramet

The impact of 24-hr, in-hospital pediatric critical care attending physician presence on process of care and patient outcomes*.

PubMed

Nishisaki, Akira; Pines, Jesse M; Lin, Richard; Helfaer, Mark A; Berg, Robert A; Tenhave, Thomas; Nadkarni, Vinay M

2012-07-01

Attending physicians are only required to provide in-hospital coverage during daytime hours in many pediatric intensive care units. An in-hospital 24-hr pediatric intensive care unit attending coverage model has been increasingly popular, but the impact of 24-hr, in-hospital attending coverage on care processes and outcomes has not been reported. We compared processes of care and outcomes before and after the implementation of a 24-hr in-hospital pediatric intensive care unit attending physician model. Retrospective comparison of before and after cohorts. A single large, academic tertiary medical/surgical pediatric intensive care unit. : Pediatric intensive care unit admissions in 2000-2006. Transition to 24-hr from 12-hr in-hospital pediatric critical care attending physician coverage model in January 2004. A total of 18,702 patients were admitted to intensive care unit: 8,520 in 24 hrs; 10,182 in 12 hrs. Duration of mechanical ventilation was lower (median 33 hrs [interquartile range 12-88] vs. 48 hrs [interquartile range 16-133], adjusted reduction of 35% [95% confidence interval 25%-44%], p < .001) and intensive care unit length of stay was shorter (median 2 days [interquartile range 1-4] vs. 2 days [interquartile range 1-5], adjusted p < .001) for 24 hr vs. 12 hr coverage. The reduction in mechanical ventilation hours was similar when noninvasive, mechanical ventilation was included in ventilation hours (median 42 hrs vs. 56 hrs, adjusted reduction in ventilation hours: 33% [95% confidence interval 20-45], p < .001). Intensive care unit mortality was not significantly different (2.2% vs. 2.5%, adjusted p =.23). These associations were consistent across daytime and nighttime admissions, weekend and weekday admissions, and among subgroups with higher Pediatric Risk of Mortality III scores, postsurgical patients, and histories of previous intensive care unit admission. Implementation of 24-hr in-hospital pediatric critical care attending coverage was associated with shorter duration of mechanical ventilation and shorter length of intensive care unit stay. After accounting for potential confounders, this finding was consistent across a broad spectrum of critically ill children.

Case control study of rotavirus vaccine effectiveness in Portugal during 6 years of private market use.

PubMed

Marlow, Robin; Ferreira, Muriel; Cordeiro, Eugénio; Trotter, Caroline; Januário, Luis; Finn, Adam; Rodrigues, Fernanda

2015-05-01

Although recommended by the vaccine committee of the Portuguese Paediatric Society, rotavirus vaccines have not been included in the routine immunization schedule. They have been available privately since 2006 with estimated coverage reaching approximately 30%. However, unlike other European countries using the vaccine, sentinel surveillance has detected fluctuations but no clear trends in the rate of gastrointestinal disease presentations. In this study, we set out to establish the real world effectiveness of rotavirus immunization in this low vaccine coverage setting. We carried out a test-negative case control study on a population of children attending a regional pediatric hospital, between 2006 and 2012, with symptoms of acute gastroenteritis and producing a stool sample for routine rotavirus testing. We calculated exposure odds ratio (ratio of odds of antecedent vaccination among cases compared with controls) to derive vaccine effectiveness ([1 - adjusted odds ratio]/100) against both hospital attendance and admission. Vaccine effectiveness against attendance with rotavirus acute gastroenteritis was 83.7% (95% confidence interval: 73.9-89.8) and against hospital admission was 96.1% (95% confidence interval: 83.8-99.1). No significant difference between the 2 available vaccines was detected. Both rotavirus vaccines offer a high degree of individual protection in this population.

Uninsured but Eligible Children

PubMed Central

DeVoe, Jennifer E.; Krois, Lisa; Edlund, Christine; Smith, Jeanene; Carlson, Nichole E.

2016-01-01

Background Despite expansions in public health insurance programs, millions of US children lack coverage. Nearly two-thirds of Oregon’s uninsured children seem to be eligible for public insurance. Objectives We sought to identify uninsured but eligible children and to examine how parental coverage affects children’s insurance status. Methods We collected primary data from families enrolled in Oregon’s food stamp program, which has similar eligibility requirements to public health insurance in Oregon. In this cross-sectional, multivariable analysis, results from 2861 surveys were weighted back to a population of 84,087 with nonresponse adjustment. Key predictor variables were parental insurance status and type of insurance; the outcome variable was children’s insurance status. Results Nearly 11% of children, presumed eligible for public insurance, were uninsured. Uninsurance among children was associated with being Hispanic, having an employed parent, and higher household earnings (133–185% of the federal poverty level). Children with an uninsured parent were more likely to be uninsured, compared with those who had insured parents (adjusted odds ratio 14.21, 95% confidence interval 9.23–20.34). More surprisingly, there was a higher rate of uninsured children among privately-insured parents, compared with parents covered by public insurance (adjusted odds ratio 4.39, 95% confidence interval 2.00–9.66). Conclusions Low-income Oregon parents at the higher end of the public insurance income threshold and those with private insurance were having the most difficulty keeping their children insured. These findings suggest that when parents succeed in pulling themselves out of poverty and gaining employment with private health insurance coverage, children may be getting left behind. PMID:18162849

Impact of antenatal steroids on intraventricular hemorrhage in very-low-birth weight infants.

PubMed

Wei, J C; Catalano, R; Profit, J; Gould, J B; Lee, H C

2016-05-01

To determine the association between antenatal steroids administration and intraventricular hemorrhage rates. We used cross-sectional data from the California Perinatal Quality Care Collaborative during 2007 to 2013 for infants ⩽32 weeks gestational age. Using multivariable logistic regression, we evaluated the effect of antenatal steroids on intraventricular hemorrhage, stratified by gestational age. In 25 979 very-low-birth weight infants, antenatal steroid use was associated with a reduction in incidence of any grade of intraventricular hemorrhage (odds ratio=0.68, 95% confidence interval: 0.62, 0.75) and a reduction in incidence of severe intraventricular hemorrhage (odds ratio=0.51, 95% confidence interval: 0.45, 0.58). This association was seen across gestational ages ranging from 22 to 29 weeks. Although current guidelines recommend coverage for preterm birth at 24 to 34 weeks gestation, our results suggest that treatment with antenatal steroids may be beneficial even before 24 weeks of gestational age.

SLDAssay: A software package and web tool for analyzing limiting dilution assays.

PubMed

Trumble, Ilana M; Allmon, Andrew G; Archin, Nancie M; Rigdon, Joseph; Francis, Owen; Baldoni, Pedro L; Hudgens, Michael G

2017-11-01

Serial limiting dilution (SLD) assays are used in many areas of infectious disease related research. This paper presents SLDAssay, a free and publicly available R software package and web tool for analyzing data from SLD assays. SLDAssay computes the maximum likelihood estimate (MLE) for the concentration of target cells, with corresponding exact and asymptotic confidence intervals. Exact and asymptotic goodness of fit p-values, and a bias-corrected (BC) MLE are also provided. No other publicly available software currently implements the BC MLE or the exact methods. For validation of SLDAssay, results from Myers et al. (1994) are replicated. Simulations demonstrate the BC MLE is less biased than the MLE. Additionally, simulations demonstrate that exact methods tend to give better confidence interval coverage and goodness-of-fit tests with lower type I error than the asymptotic methods. Additional advantages of using exact methods are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

An Evaluation of Voluntary 2-Dose Varicella Vaccination Coverage in New York City Public Schools

PubMed Central

Rosen, Jennifer B.; Bialek, Stephanie R.; Szeto, Hiram; Zimmerman, Christopher M.

2015-01-01

Objectives. We assessed coverage for 2-dose varicella vaccination, which is not required for school entry, among New York City public school students and examined characteristics associated with receipt of 2 doses. Methods. We measured receipt of either at least 1 or 2 doses of varicella vaccine among students aged 4 years and older in a sample of 336 public schools (n = 223 864 students) during the 2010 to 2011 school year. Data came from merged student vaccination records from 2 administrative data systems. We conducted multivariable regression to assess associations of age, gender, race/ethnicity, and school location with 2-dose prevalence. Results. Coverage with at least 1 varicella dose was 96.2% (95% confidence interval [CI] = 96.2%, 96.3%); coverage with at least 2 doses was 64.8% (95% CI = 64.6%, 64.9%). Increasing student age, non-Hispanic White race/ethnicity, and attendance at school in Staten Island were associated with lower 2-dose coverage. Conclusions. A 2-dose varicella vaccine requirement for school entry would likely improve 2-dose coverage, eliminate coverage disparities, and prevent disease. PMID:25521904

The effectiveness of vaccine day and educational interventions on influenza vaccine coverage among health care workers at long-term care facilities.

PubMed

Kimura, Akiko C; Nguyen, Christine N; Higa, Jeffrey I; Hurwitz, Eric L; Vugia, Duc J

2007-04-01

We examined barriers to influenza vaccination among long-term care facility (LTCF) health care workers in Southern California and developed simple, effective interventions to improve influenza vaccine coverage of these workers. In 2002, health care workers at LTCFs were surveyed regarding their knowledge and attitudes about influenza and the influenza vaccine. Results were used to develop 2 interventions, an educational campaign and Vaccine Day (a well-publicized day for free influenza vaccination of all employees at the worksite). Seventy facilities were recruited to participate in an intervention trial and randomly assigned to 4 study groups. The combination of Vaccine Day and an educational campaign was most effective in increasing vaccine coverage (53% coverage; prevalence ratio [PR]=1.45; 95% confidence interval [CI]=1.24, 1.71, compared with 27% coverage in the control group). Vaccine Day alone was also effective (46% coverage; PR= 1.41; 95% CI=1.17, 1.71). The educational campaign alone was not effective in improving coverage levels (34% coverage; PR=1.18; 95% CI=0.93, 1.50). Influenza vaccine coverage of LTCF health care workers can be improved by providing free vaccinations at the worksite with a well-publicized Vaccine Day.

Relaxing the rule of ten events per variable in logistic and Cox regression.

PubMed

Vittinghoff, Eric; McCulloch, Charles E

2007-03-15

The rule of thumb that logistic and Cox models should be used with a minimum of 10 outcome events per predictor variable (EPV), based on two simulation studies, may be too conservative. The authors conducted a large simulation study of other influences on confidence interval coverage, type I error, relative bias, and other model performance measures. They found a range of circumstances in which coverage and bias were within acceptable levels despite less than 10 EPV, as well as other factors that were as influential as or more influential than EPV. They conclude that this rule can be relaxed, in particular for sensitivity analyses undertaken to demonstrate adequate control of confounding.

Pregnancy and birth outcomes in couples with infertility with and without assisted reproductive technology: with an emphasis on US population-based studies.

PubMed

Luke, Barbara

2017-09-01

Infertility, defined as the inability to conceive within 1 year of unprotected intercourse, affects an estimated 80 million individuals worldwide, or 10-15% of couples of reproductive age. Assisted reproductive technology includes all infertility treatments to achieve conception; in vitro fertilization is the process by which an oocyte is fertilized by semen outside the body; non-in vitro fertilization assisted reproductive technology treatments include ovulation induction, artificial insemination, and intrauterine insemination. Use of assisted reproductive technology has risen steadily in the United States during the past 2 decades due to several reasons, including childbearing at older maternal ages and increasing insurance coverage. The number of in vitro fertilization cycles in the United States has nearly doubled from 2000 through 2013 and currently 1.7% of all live births in the United States are the result of this technology. Since the birth of the first child from in vitro fertilization >35 years ago, >5 million babies have been born from in vitro fertilization, half within the past 6 years. It is estimated that 1% of singletons, 19% of twins, and 25% of triplet or higher multiples are due to in vitro fertilization, and 4%, 21%, and 52%, respectively, are due to non-in vitro fertilization assisted reproductive technology. Higher plurality at birth results in a >10-fold increase in the risks for prematurity and low birthweight in twins vs singletons (adjusted odds ratio, 11.84; 95% confidence interval, 10.56-13.27 and adjusted odds ratio, 10.68; 95% confidence interval, 9.45-12.08, respectively). The use of donor oocytes is associated with increased risks for pregnancy-induced hypertension (adjusted odds ratio, 1.43; 95% confidence interval, 1.14-1.78) and prematurity (adjusted odds ratio, 1.43; 95% confidence interval, 1.11-1.83). The use of thawed embryos is associated with higher risks for pregnancy-induced hypertension (adjusted odds ratio, 1.30; 95% confidence interval, 1.08-1.57) and large-for-gestation birthweight (adjusted odds ratio, 1.74; 95% confidence interval, 1.45-2.08). Among singletons, in vitro fertilization is associated with increased risk of severe maternal morbidity compared with fertile deliveries (vaginal: adjusted odds ratio, 2.27; 95% confidence interval, 1.78-2.88; cesarean: adjusted odds ratio, 1.67; 95% confidence interval, 1.40-1.98, respectively) and subfertile deliveries (vaginal: adjusted odds ratio, 1.97; 95% confidence interval, 1.30-3.00; cesarean: adjusted odds ratio, 1.75; 95% confidence interval, 1.30-2.35, respectively). Among twins, cesarean in vitro fertilization deliveries have significantly greater severe maternal morbidity compared to cesarean fertile deliveries (adjusted odds ratio, 1.48; 95% confidence interval, 1.14-1.93). Subfertility, with or without in vitro fertilization or non-in vitro fertilization infertility treatments to achieve a pregnancy, is associated with increased risks of adverse maternal and perinatal outcomes. The major risk from in vitro fertilization treatments of multiple births (and the associated excess of perinatal morbidity) has been reduced over time, with fewer and better-quality embryos being transferred. Copyright © 2017. Published by Elsevier Inc.

Estimation of aquifer scale proportion using equal area grids: assessment of regional scale groundwater quality

USGS Publications Warehouse

Belitz, Kenneth; Jurgens, Bryant C.; Landon, Matthew K.; Fram, Miranda S.; Johnson, Tyler D.

2010-01-01

The proportion of an aquifer with constituent concentrations above a specified threshold (high concentrations) is taken as a nondimensional measure of regional scale water quality. If computed on the basis of area, it can be referred to as the aquifer scale proportion. A spatially unbiased estimate of aquifer scale proportion and a confidence interval for that estimate are obtained through the use of equal area grids and the binomial distribution. Traditionally, the confidence interval for a binomial proportion is computed using either the standard interval or the exact interval. Research from the statistics literature has shown that the standard interval should not be used and that the exact interval is overly conservative. On the basis of coverage probability and interval width, the Jeffreys interval is preferred. If more than one sample per cell is available, cell declustering is used to estimate the aquifer scale proportion, and Kish's design effect may be useful for estimating an effective number of samples. The binomial distribution is also used to quantify the adequacy of a grid with a given number of cells for identifying a small target, defined as a constituent that is present at high concentrations in a small proportion of the aquifer. Case studies illustrate a consistency between approaches that use one well per grid cell and many wells per cell. The methods presented in this paper provide a quantitative basis for designing a sampling program and for utilizing existing data.

Sun Protection Among New Zealand Primary School Children.

PubMed

Gage, Ryan; Leung, William; Stanley, James; Reeder, Anthony; Mackay, Christina; Smith, Moira; Barr, Michelle; Chambers, Tim; Signal, Louise

2017-12-01

Schools are an important setting for raising skin cancer prevention awareness and encouraging sun protection. We assessed the clothes worn and shade used by 1,278 children in eight schools in the Wellington region of New Zealand. These children were photographed for the Kids'Cam project between September 2014 and March 2015 during school lunch breaks. Children's mean clothing coverage (expressed as a percentage of body area covered) was calculated. Data on school sun-safety policies were obtained via telephone. Mean total body clothing coverage was 70.3% (95% confidence interval = 66.3%, 73.8%). Body regions with the lowest mean coverage were the head (15.4% coverage), neck (36.1% coverage), lower arms (46.1% coverage), hands (5.3% coverage), and calves (30.1% coverage). Children from schools with hats as part of the school uniform were significantly more likely to wear a hat (52.2%) than children from schools without a school hat (2.7%). Most children (78.4%) were not under the cover of shade. Our findings suggest that New Zealand children are not sufficiently protected from the sun at school. Schools should consider comprehensive approaches to improve sun protection, such as the provision of school hats, sun-protective uniforms, and the construction of effective shade.

Prediction of Low Community Sanitation Coverage Using Environmental and Sociodemographic Factors in Amhara Region, Ethiopia

PubMed Central

Oswald, William E.; Stewart, Aisha E. P.; Flanders, W. Dana; Kramer, Michael R.; Endeshaw, Tekola; Zerihun, Mulat; Melaku, Birhanu; Sata, Eshetu; Gessesse, Demelash; Teferi, Tesfaye; Tadesse, Zerihun; Guadie, Birhan; King, Jonathan D.; Emerson, Paul M.; Callahan, Elizabeth K.; Moe, Christine L.; Clasen, Thomas F.

2016-01-01

This study developed and validated a model for predicting the probability that communities in Amhara Region, Ethiopia, have low sanitation coverage, based on environmental and sociodemographic conditions. Community sanitation coverage was measured between 2011 and 2014 through trachoma control program evaluation surveys. Information on environmental and sociodemographic conditions was obtained from available data sources and linked with community data using a geographic information system. Logistic regression was used to identify predictors of low community sanitation coverage (< 20% versus ≥ 20%). The selected model was geographically and temporally validated. Model-predicted probabilities of low community sanitation coverage were mapped. Among 1,502 communities, 344 (22.90%) had coverage below 20%. The selected model included measures for high topsoil gravel content, an indicator for low-lying land, population density, altitude, and rainfall and had reasonable predictive discrimination (area under the curve = 0.75, 95% confidence interval = 0.72, 0.78). Measures of soil stability were strongly associated with low community sanitation coverage, controlling for community wealth, and other factors. A model using available environmental and sociodemographic data predicted low community sanitation coverage for areas across Amhara Region with fair discrimination. This approach could assist sanitation programs and trachoma control programs, scaling up or in hyperendemic areas, to target vulnerable areas with additional activities or alternate technologies. PMID:27430547

A longitudinal study of medicaid coverage for tobacco dependence treatments in Massachusetts and associated decreases in hospitalizations for cardiovascular disease.

PubMed

Land, Thomas; Rigotti, Nancy A; Levy, Douglas E; Paskowsky, Mark; Warner, Donna; Kwass, Jo-Ann; Wetherell, Leann; Keithly, Lois

2010-12-07

Insurance coverage of tobacco cessation medications increases their use and reduces smoking prevalence in a population. However, uncertainty about the impact of this coverage on health care utilization and costs is a barrier to the broader adoption of this policy, especially by publicly funded state Medicaid insurance programs. Whether a publicly funded tobacco cessation benefit leads to decreased medical claims for tobacco-related diseases has not been studied. We examined the experience of Massachusetts, whose Medicaid program adopted comprehensive coverage of tobacco cessation medications in July 2006. Over 75,000 Medicaid subscribers used the benefit in the first 2.5 years. On the basis of earlier secondary survey work, it was estimated that smoking prevalence declined among subscribers by 10% during this period. Using claims data, we compared the probability of hospitalization prior to use of the tobacco cessation pharmacotherapy benefit with the probability of hospitalization after benefit use among Massachusetts Medicaid beneficiaries, adjusting for demographics, comorbidities, seasonality, influenza cases, and the implementation of the statewide smoke-free air law using generalized estimating equations. Statistically significant annualized declines of 46% (95% confidence interval 2%-70%) and 49% (95% confidence interval 6%-72%) were observed in hospital admissions for acute myocardial infarction and other acute coronary heart disease diagnoses, respectively. There were no significant decreases in hospitalizations rates for respiratory diagnoses or seven other diagnostic groups evaluated. Among Massachusetts Medicaid subscribers, use of a comprehensive tobacco cessation pharmacotherapy benefit was associated with a significant decrease in claims for hospitalizations for acute myocardial infarction and acute coronary heart disease, but no significant change in hospital claims for other diagnoses. For low-income smokers, removing the barriers to the use of smoking cessation pharmacotherapy has the potential to decrease short-term utilization of hospital services.

A Longitudinal Study of Medicaid Coverage for Tobacco Dependence Treatments in Massachusetts and Associated Decreases in Hospitalizations for Cardiovascular Disease

PubMed Central

Land, Thomas; Rigotti, Nancy A.; Levy, Douglas E.; Paskowsky, Mark; Warner, Donna; Kwass, Jo-Ann; Wetherell, LeAnn; Keithly, Lois

2010-01-01

Background Insurance coverage of tobacco cessation medications increases their use and reduces smoking prevalence in a population. However, uncertainty about the impact of this coverage on health care utilization and costs is a barrier to the broader adoption of this policy, especially by publicly funded state Medicaid insurance programs. Whether a publicly funded tobacco cessation benefit leads to decreased medical claims for tobacco-related diseases has not been studied. We examined the experience of Massachusetts, whose Medicaid program adopted comprehensive coverage of tobacco cessation medications in July 2006. Over 75,000 Medicaid subscribers used the benefit in the first 2.5 years. On the basis of earlier secondary survey work, it was estimated that smoking prevalence declined among subscribers by 10% during this period. Methods and Findings Using claims data, we compared the probability of hospitalization prior to use of the tobacco cessation pharmacotherapy benefit with the probability of hospitalization after benefit use among Massachusetts Medicaid beneficiaries, adjusting for demographics, comorbidities, seasonality, influenza cases, and the implementation of the statewide smoke-free air law using generalized estimating equations. Statistically significant annualized declines of 46% (95% confidence interval 2%–70%) and 49% (95% confidence interval 6%–72%) were observed in hospital admissions for acute myocardial infarction and other acute coronary heart disease diagnoses, respectively. There were no significant decreases in hospitalizations rates for respiratory diagnoses or seven other diagnostic groups evaluated. Conclusions Among Massachusetts Medicaid subscribers, use of a comprehensive tobacco cessation pharmacotherapy benefit was associated with a significant decrease in claims for hospitalizations for acute myocardial infarction and acute coronary heart disease, but no significant change in hospital claims for other diagnoses. For low-income smokers, removing the barriers to the use of smoking cessation pharmacotherapy has the potential to decrease short-term utilization of hospital services. Please see later in the article for the Editors' Summary PMID:21170313

Human immunophenotyping via low-variance, low-bias, interpretive regression modeling of small, wide data sets: Application to aging and immune response to influenza vaccination.

PubMed

Holmes, Tyson H; He, Xiao-Song

2016-10-01

Small, wide data sets are commonplace in human immunophenotyping research. As defined here, a small, wide data set is constructed by sampling a small to modest quantity n,1

Human Immunophenotyping via Low-Variance, Low-Bias, Interpretive Regression Modeling of Small, Wide Data Sets: Application to Aging and Immune Response to Influenza Vaccination

PubMed Central

Holmes, Tyson H.; He, Xiao-Song

2016-01-01

Small, wide data sets are commonplace in human immunophenotyping research. As defined here, a small, wide data set is constructed by sampling a small to modest quantity n, 1 < n < 50, of human participants for the purpose of estimating many parameters p, such that n < p < 1,000. We offer a set of prescriptions that are designed to facilitate low-variance (i.e. stable), low-bias, interpretive regression modeling of small, wide data sets. These prescriptions are distinctive in their especially heavy emphasis on minimizing use of out-of-sample information for conducting statistical inference. That allows the working immunologist to proceed without being encumbered by imposed and often untestable statistical assumptions. Problems of unmeasured confounders, confidence-interval coverage, feature selection, and shrinkage/denoising are defined clearly and treated in detail. We propose an extension of an existing nonparametric technique for improved small-sample confidence-interval tail coverage from the univariate case (single immune feature) to the multivariate (many, possibly correlated immune features). An important role for derived features in the immunological interpretation of regression analyses is stressed. Areas of further research are discussed. Presented principles and methods are illustrated through application to a small, wide data set of adults spanning a wide range in ages and multiple immunophenotypes that were assayed before and after immunization with inactivated influenza vaccine (IIV). Our regression modeling prescriptions identify some potentially important topics for future immunological research. 1) Immunologists may wish to distinguish age-related differences in immune features from changes in immune features caused by aging. 2) A form of the bootstrap that employs linear extrapolation may prove to be an invaluable analytic tool because it allows the working immunologist to obtain accurate estimates of the stability of immune parameter estimates with a bare minimum of imposed assumptions. 3) Liberal inclusion of immune features in phenotyping panels can facilitate accurate separation of biological signal of interest from noise. In addition, through a combination of denoising and potentially improved confidence interval coverage, we identify some candidate immune correlates (frequency of cell subset and concentration of cytokine) with B cell response as measured by quantity of IIV-specific IgA antibody-secreting cells and quantity of IIV-specific IgG antibody-secreting cells. PMID:27196789

How to regress and predict in a Bland-Altman plot? Review and contribution based on tolerance intervals and correlated-errors-in-variables models.

PubMed

Francq, Bernard G; Govaerts, Bernadette

2016-06-30

Two main methodologies for assessing equivalence in method-comparison studies are presented separately in the literature. The first one is the well-known and widely applied Bland-Altman approach with its agreement intervals, where two methods are considered interchangeable if their differences are not clinically significant. The second approach is based on errors-in-variables regression in a classical (X,Y) plot and focuses on confidence intervals, whereby two methods are considered equivalent when providing similar measures notwithstanding the random measurement errors. This paper reconciles these two methodologies and shows their similarities and differences using both real data and simulations. A new consistent correlated-errors-in-variables regression is introduced as the errors are shown to be correlated in the Bland-Altman plot. Indeed, the coverage probabilities collapse and the biases soar when this correlation is ignored. Novel tolerance intervals are compared with agreement intervals with or without replicated data, and novel predictive intervals are introduced to predict a single measure in an (X,Y) plot or in a Bland-Atman plot with excellent coverage probabilities. We conclude that the (correlated)-errors-in-variables regressions should not be avoided in method comparison studies, although the Bland-Altman approach is usually applied to avert their complexity. We argue that tolerance or predictive intervals are better alternatives than agreement intervals, and we provide guidelines for practitioners regarding method comparison studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Substantial decline in hepatitis B virus infections following vaccine introduction in Tajikistan.

PubMed

Khetsuriani, Nino; Tishkova, Faina; Jabirov, Shamsidin; Wannemuehler, Kathleen; Kamili, Saleem; Pirova, Zulfiya; Mosina, Liudmila; Gavrilin, Eugene; Ursu, Pavel; Drobeniuc, Jan

2015-07-31

Tajikistan, considered highly endemic area for hepatitis B virus (HBV) in a pre-vaccine era, introduced hepatitis B vaccine in 2002 and reported ≥80% coverage with three doses of hepatitis B vaccine (HepB3) since 2004. However, the impact of vaccine introduction has not been assessed. We tested residual serum specimens from a 2010 national serosurvey for vaccine-preventable diseases in Tajikistan and assessed the prevalence of HBV infection across groups defined based on the birth cohorts' routine infant hepatitis B vaccination program implementation and HepB3 coverage achieved (≥80% versus <80%). Serosurvey participants were selected through stratified multi-stage cluster sampling among residents of all regions of Tajikistan aged 1-24 years. All specimens were tested for antibodies against HBV core antigen (anti-HBc) and those found positive were tested for HBV surface antigen (HBsAg). Seroprevalence and 95% confidence intervals were calculated and compared across subgroups using Satterthwaite-adjusted chi-square tests, accounting for the survey design and sampling weights. A total of 2188 samples were tested. Prevalence of HBV infection markers was lowest among cohorts with ≥80% HepB3 coverage (ages, 1-6 years): 2.1% (95% confidence interval, 1.1-4.3%) for anti-HBc, 0.4% (0.1-1.3%) for HBsAg, followed by 7.2% (4.1-12.4%) for anti-HBc and 2.1% (0.7-6.1%) for HBsAg among cohorts with <80% HepB3 coverage (ages, 7-8 years), by 12.0% (8.7-16.3%) for anti-HBc and 3.5% (2.2-5.6%) for HBsAg among children's cohorts not targeted for vaccination (ages, 9-14 years), and 28.9% (24.5-33.8%) for anti-HBc and 6.8% (4.5-10.1%) for HBsAg among unvaccinated adult cohorts (ages, 15-24 years). Differences across groups were significant (p<0.001, chi-square) for both markers. The present study demonstrates substantial impact of hepatitis B vaccine introduction on reducing HBV infections in Tajikistan. To achieve further progress in hepatitis B control, Tajikistan should maintain high routine coverage with hepatitis B vaccine, including birth dose. Published by Elsevier Ltd.

Advances in the meta-analysis of heterogeneous clinical trials II: The quality effects model.

PubMed

Doi, Suhail A R; Barendregt, Jan J; Khan, Shahjahan; Thalib, Lukman; Williams, Gail M

2015-11-01

This article examines the performance of the updated quality effects (QE) estimator for meta-analysis of heterogeneous studies. It is shown that this approach leads to a decreased mean squared error (MSE) of the estimator while maintaining the nominal level of coverage probability of the confidence interval. Extensive simulation studies confirm that this approach leads to the maintenance of the correct coverage probability of the confidence interval, regardless of the level of heterogeneity, as well as a lower observed variance compared to the random effects (RE) model. The QE model is robust to subjectivity in quality assessment down to completely random entry, in which case its MSE equals that of the RE estimator. When the proposed QE method is applied to a meta-analysis of magnesium for myocardial infarction data, the pooled mortality odds ratio (OR) becomes 0.81 (95% CI 0.61-1.08) which favors the larger studies but also reflects the increased uncertainty around the pooled estimate. In comparison, under the RE model, the pooled mortality OR is 0.71 (95% CI 0.57-0.89) which is less conservative than that of the QE results. The new estimation method has been implemented into the free meta-analysis software MetaXL which allows comparison of alternative estimators and can be downloaded from www.epigear.com. Copyright © 2015 Elsevier Inc. All rights reserved.

Environmental Chemicals in Urine and Blood: Improving Methods for Creatinine and Lipid Adjustment.

PubMed

O'Brien, Katie M; Upson, Kristen; Cook, Nancy R; Weinberg, Clarice R

2016-02-01

Investigators measuring exposure biomarkers in urine typically adjust for creatinine to account for dilution-dependent sample variation in urine concentrations. Similarly, it is standard to adjust for serum lipids when measuring lipophilic chemicals in serum. However, there is controversy regarding the best approach, and existing methods may not effectively correct for measurement error. We compared adjustment methods, including novel approaches, using simulated case-control data. Using a directed acyclic graph framework, we defined six causal scenarios for epidemiologic studies of environmental chemicals measured in urine or serum. The scenarios include variables known to influence creatinine (e.g., age and hydration) or serum lipid levels (e.g., body mass index and recent fat intake). Over a range of true effect sizes, we analyzed each scenario using seven adjustment approaches and estimated the corresponding bias and confidence interval coverage across 1,000 simulated studies. For urinary biomarker measurements, our novel method, which incorporates both covariate-adjusted standardization and the inclusion of creatinine as a covariate in the regression model, had low bias and possessed 95% confidence interval coverage of nearly 95% for most simulated scenarios. For serum biomarker measurements, a similar approach involving standardization plus serum lipid level adjustment generally performed well. To control measurement error bias caused by variations in serum lipids or by urinary diluteness, we recommend improved methods for standardizing exposure concentrations across individuals.

Initial Validation of NDVI time seriesfrom AVHRR, VEGETATION, and MODIS

NASA Technical Reports Server (NTRS)

Morisette, Jeffrey T.; Pinzon, Jorge E.; Brown, Molly E.; Tucker, Jim; Justice, Christopher O.

2004-01-01

The paper will address Theme 7: Multi-sensor opportunities for VEGETATION. We present analysis of a long-term vegetation record derived from three moderate resolution sensors: AVHRR, VEGETATION, and MODIS. While empirically based manipulation can ensure agreement between the three data sets, there is a need to validate the series. This paper uses atmospherically corrected ETM+ data available over the EOS Land Validation Core Sites as an independent data set with which to compare the time series. We use ETM+ data from 15 globally distributed sites, 7 of which contain repeat coverage in time. These high-resolution data are compared to the values of each sensor by spatially aggregating the ETM+ to each specific sensors' spatial coverage. The aggregated ETM+ value provides a point estimate for a specific site on a specific date. The standard deviation of that point estimate is used to construct a confidence interval for that point estimate. The values from each moderate resolution sensor are then evaluated with respect to that confident interval. Result show that AVHRR, VEGETATION, and MODIS data can be combined to assess temporal uncertainties and address data continuity issues and that the atmospherically corrected ETM+ data provide an independent source with which to compare that record. The final product is a consistent time series climate record that links historical observations to current and future measurements.

Disparities in access to preventive health care services among insured children in a cross sectional study.

PubMed

King, Christian

2016-07-01

Children with insurance have better access to care and health outcomes if their parents also have insurance. However, little is known about whether the type of parental insurance matters. This study attempts to determine whether the type of parental insurance affects the access to health care services of children.I used data from the 2009-2013 Medical Expenditure Panel Survey and estimated multivariate logistic regressions (N = 26,152). I estimated how family insurance coverage affects the probability that children have a usual source of care, well-child visits in the past year, unmet medical and prescription needs, less than 1 dental visit per year, and unmet dental needs.Children in families with mixed insurance (child publicly insured and parent privately insured) were less likely to have a well-child visit than children in privately insured families (odds ratio = 0.86, 95% confidence interval 0.76-0.98). When restricting the sample to publicly insured children, children with privately insured parents were less likely to have a well-child visit (odds ratio = 0.82, 95% confidence interval 0.73-0.92), less likely to have a usual source of care (odds ratio = 0.79, 95% confidence interval 0.67-0.94), and more likely to have unmet dental needs (odds ratio = 1.68, 95% confidence interval 1.10-2.58).Children in families with mixed insurance tend to fare poorly compared to children in publicly insured families. This may indicate that children in these families may be underinsured. Expanding parental eligibility for public insurance or subsidizing private insurance for children would potentially improve their access to preventive care.

Impact of Antenatal Steroids on Intraventricular Hemorrhage in Very Low Birth Weight Infants

PubMed Central

Wei, Julia C.; Catalano, Ralph; Profit, Jochen; Gould, Jeffrey B.; Lee, Henry C.

2016-01-01

Objective To determine the association between antenatal steroids administration and intraventricular hemorrhage rates. Methods We used cross-sectional data from the California Perinatal Quality Care Collaborative during 2007-2013 for infants ≤ 32 weeks gestational age. Using multivariable logistic regression, we evaluated the effect of antenatal steroids on intraventricular hemorrhage, stratified by gestational age. Results In 25,979 very low birth weight infants, antenatal steroid use was associated with a reduction in incidence of any grade of intraventricular hemorrhage (odds ratio = 0.51, 95% confidence interval: 0.45, 0.58) and a reduction in incidence of severe intraventricular hemorrhage (odds ratio = 0.62, 95% confidence interval: 0.57, 0.67). This association was seen across gestational ages ranging from 22 to 29 weeks. Conclusions While current guidelines recommend coverage for preterm birth at 24 to 34 weeks gestation, our results suggest that treatment with antenatal steroids may be beneficial even before 24 weeks of gestational age. PMID:27010109

Standard Errors and Confidence Intervals of Norm Statistics for Educational and Psychological Tests.

PubMed

Oosterhuis, Hannah E M; van der Ark, L Andries; Sijtsma, Klaas

2016-11-14

Norm statistics allow for the interpretation of scores on psychological and educational tests, by relating the test score of an individual test taker to the test scores of individuals belonging to the same gender, age, or education groups, et cetera. Given the uncertainty due to sampling error, one would expect researchers to report standard errors for norm statistics. In practice, standard errors are seldom reported; they are either unavailable or derived under strong distributional assumptions that may not be realistic for test scores. We derived standard errors for four norm statistics (standard deviation, percentile ranks, stanine boundaries and Z-scores) under the mild assumption that the test scores are multinomially distributed. A simulation study showed that the standard errors were unbiased and that corresponding Wald-based confidence intervals had good coverage. Finally, we discuss the possibilities for applying the standard errors in practical test use in education and psychology. The procedure is provided via the R function check.norms, which is available in the mokken package.

Evaluating the Impact of Guessing and Its Interactions With Other Test Characteristics on Confidence Interval Procedures for Coefficient Alpha

PubMed Central

Paek, Insu

2015-01-01

The effect of guessing on the point estimate of coefficient alpha has been studied in the literature, but the impact of guessing and its interactions with other test characteristics on the interval estimators for coefficient alpha has not been fully investigated. This study examined the impact of guessing and its interactions with other test characteristics on four confidence interval (CI) procedures for coefficient alpha in terms of coverage rate (CR), length, and the degree of asymmetry of CI estimates. In addition, interval estimates of coefficient alpha when data follow the essentially tau-equivalent condition were investigated as a supplement to the case of dichotomous data with examinee guessing. For dichotomous data with guessing, the results did not reveal salient negative effects of guessing and its interactions with other test characteristics (sample size, test length, coefficient alpha levels) on CR and the degree of asymmetry, but the effect of guessing was salient as a main effect and an interaction effect with sample size on the length of the CI estimates, making longer CI estimates as guessing increases, especially when combined with a small sample size. Other important effects (e.g., CI procedures on CR) are also discussed. PMID:29795863

Evaluation of some random effects methodology applicable to bird ringing data

USGS Publications Warehouse

Burnham, K.P.; White, Gary C.

2002-01-01

Existing models for ring recovery and recapture data analysis treat temporal variations in annual survival probability (S) as fixed effects. Often there is no explainable structure to the temporal variation in S1,..., Sk; random effects can then be a useful model: Si = E(S) + ??i. Here, the temporal variation in survival probability is treated as random with average value E(??2) = ??2. This random effects model can now be fit in program MARK. Resultant inferences include point and interval estimation for process variation, ??2, estimation of E(S) and var (E??(S)) where the latter includes a component for ??2 as well as the traditional component for v??ar(S??\\S??). Furthermore, the random effects model leads to shrinkage estimates, Si, as improved (in mean square error) estimators of Si compared to the MLE, S??i, from the unrestricted time-effects model. Appropriate confidence intervals based on the Si are also provided. In addition, AIC has been generalized to random effects models. This paper presents results of a Monte Carlo evaluation of inference performance under the simple random effects model. Examined by simulation, under the simple one group Cormack-Jolly-Seber (CJS) model, are issues such as bias of ??s2, confidence interval coverage on ??2, coverage and mean square error comparisons for inference about Si based on shrinkage versus maximum likelihood estimators, and performance of AIC model selection over three models: Si ??? S (no effects), Si = E(S) + ??i (random effects), and S1,..., Sk (fixed effects). For the cases simulated, the random effects methods performed well and were uniformly better than fixed effects MLE for the Si.

Vaccination coverage for measles, mumps and rubella in anthroposophical schools in Gelderland, The Netherlands.

PubMed

Klomp, Judith H E; van Lier, Alies; Ruijs, Wilhelmina L M

2015-06-01

Social clustering of unvaccinated children in anthroposophical schools occurs, as inferred from various measles outbreaks that can be traced to these schools. However, accurate vaccination coverage data of anthroposophical schools are not widely available. In 2012, we performed a survey to estimate the vaccination coverage in three different grades of 11 anthroposophical schools in Gelderland, The Netherlands. We also gauged the opinion on childhood vaccination of the parents and compared these with the results of a national survey. In 2014, we were also able to obtain the registered total vaccination coverage per school from the national vaccination register to compare this with our survey data. The self-reported MMR vaccination coverage (2012) in the three grades of the schools in our study was 83% (range 45-100% per school). The registered total vaccination coverage (2014) was 78% (range 59-88% per school). The 95% confidence intervals of the two different vaccination coverages overlap for all schools. The parents in this study were less convinced about the beneficial effect of vaccinations and more worried about the possible side effects of vaccination compared with parents in general. Despite high overall vaccination coverage, the WHO goal to eliminate measles and rubella will not easily be achieved when social clustering of unvaccinated children in anthroposophical schools remains. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Thyroid cancer incidence among Asian immigrants to Ontario, Canada: A population-based cohort study.

PubMed

Shah, Baiju R; Griffiths, Rebecca; Hall, Stephen F

2017-09-01

The highest rates of thyroid cancer are observed in Pacific Island nations as well as Australia and Asian countries bordering the Pacific. The objective of this study was to determine the risk for thyroid cancer among immigrants to Canada from Southeast and East Asia compared with immigrants from other regions and nonimmigrants. This was a population-based, longitudinal cohort study using health care administrative data to examine all residents of Ontario without pre-existing thyroid cancer. Individuals were followed from January 1997 or 5 years after they became eligible for health care coverage in Ontario, whichever came later. Patients were followed until March 2015 for incident-differentiated thyroid cancer, and then for recurrence. The study followed 14,659,733 individuals for a median of 17 years. Thyroid cancer incidence was 43.8 cases per 100,000 person-years among Southeast Asian immigrants, 28.6 cases per 100,000 person-years among East Asian immigrants, 21.5 cases per 100,000 person-years among other immigrants, and 14.5 cases per 100,000 person-years among nonimmigrants. Incidence was highest among immigrants from the Philippines (52.7 cases per 100,000 person-years), South Korea (33.5 cases per 100,000 person-years), and China (30.0 cases per 100,000 person-years). Adjusted hazard ratios for thyroid cancer compared with nonimmigrants were 2.66 (95% confidence interval, 2.48-2.84) for Southeast Asian immigrants, 1.87 (95% confidence interval, 1.75-2.00) for East Asian immigrants, and 1.51 (95% confidence interval, 1.45-1.57) for other immigrants. Immigrants were more likely to have papillary histology and stage I cancer. East Asian immigrants, but not Southeast Asian immigrants, had a lower risk of recurrence (hazard ratio, 0.73 [95% confidence interval, 0.57-0.94] and 1.01 [95% confidence interval, 0.81-1.26], respectively). Immigrants from Southeast and East Asia had markedly higher thyroid cancer incidence than nonimmigrants. At particularly elevated risk were immigrants from the Philippines, South Korea, and China. Cancer 2017;123:3320-5. © 2017 American Cancer Society. © 2017 American Cancer Society.

Inequities in mental health care after health care system reform in Chile.

PubMed

Araya, Ricardo; Rojas, Graciela; Fritsch, Rosemarie; Frank, Richard; Lewis, Glyn

2006-01-01

We compared differences in mental health needs and provision of mental health services among residents of Santiago, Chile, with private and public health insurance coverage. We conducted a cross-sectional survey of a random sample of adults. Presence of mental disorders and use of health care services were assessed via structured interviews. Individuals were classified as having public, private, or no health insurance coverage. Among individuals with mental disorders, only 20% (95% confidence interval [CI]=16%, 24%) had consulted a professional about these problems. A clear mismatch was found between need and provision of services. Participants with public insurance coverage exhibited the highest prevalence of mental disorders but the lowest rates of consultation; participants with private coverage exhibited exactly the opposite pattern. After adjustment for age, income, and severity of symptoms, private insurance coverage (odds ratio [OR]=2.72; 95% CI=1.6, 4.6) and higher disability level (OR=1.27, 95% CI=1.1, 1.5) were the only factors associated with increased frequency of mental health consultation. The health reforms that have encouraged the growth of the private health sector in Chile also have increased risk segmentation within the health system, accentuating inequalities in health care provision.

Determinants and Coverage of Vaccination in Children in Western Kenya from a 2003 Cross-Sectional Survey

PubMed Central

Calhoun, Lisa M.; van Eijk, Anna M.; Lindblade, Kim A.; Odhiambo, Frank O.; Wilson, Mark L.; Winterbauer, Elizabeth; Slutsker, Laurence; Hamel, Mary J.

2014-01-01

This study assesses full and timely vaccination coverage and factors associated with full vaccination in children ages 12–23 months in Gem, Nyanza Province, Kenya in 2003. A simple random sample of 1,769 households was selected, and guardians were invited to bring children under 5 years of age to participate in a survey. Full vaccination coverage was 31.1% among 244 children. Only 2.2% received all vaccinations in the target month for each vaccination. In multivariate logistic regression, children of mothers of higher parity (odds ratio [OR] = 0.27, 95% confidence interval [95% CI] = 0.13–0.65, P ≤ 0.01), children of mothers with lower maternal education (OR = 0.35, 95% CI = 0.13–0.97, P ≤ 0.05), or children in households with the spouse absent versus present (OR = 0.40, 95% CI = 0.17–0.91, P ≤ 0.05) were less likely to be fully vaccinated. These data serve as a baseline from which changes in vaccination coverage will be measured as interventions to improve vaccination timeliness are introduced. PMID:24343886

Determinants and coverage of vaccination in children in western Kenya from a 2003 cross-sectional survey.

PubMed

Calhoun, Lisa M; van Eijk, Anna M; Lindblade, Kim A; Odhiambo, Frank O; Wilson, Mark L; Winterbauer, Elizabeth; Slutsker, Laurence; Hamel, Mary J

2014-02-01

This study assesses full and timely vaccination coverage and factors associated with full vaccination in children ages 12-23 months in Gem, Nyanza Province, Kenya in 2003. A simple random sample of 1,769 households was selected, and guardians were invited to bring children under 5 years of age to participate in a survey. Full vaccination coverage was 31.1% among 244 children. Only 2.2% received all vaccinations in the target month for each vaccination. In multivariate logistic regression, children of mothers of higher parity (odds ratio [OR] = 0.27, 95% confidence interval [95% CI] = 0.13-0.65, P ≤ 0.01), children of mothers with lower maternal education (OR = 0.35, 95% CI = 0.13-0.97, P ≤ 0.05), or children in households with the spouse absent versus present (OR = 0.40, 95% CI = 0.17-0.91, P ≤ 0.05) were less likely to be fully vaccinated. These data serve as a baseline from which changes in vaccination coverage will be measured as interventions to improve vaccination timeliness are introduced.

Abstract: Inference and Interval Estimation for Indirect Effects With Latent Variable Models.

PubMed

Falk, Carl F; Biesanz, Jeremy C

2011-11-30

Models specifying indirect effects (or mediation) and structural equation modeling are both popular in the social sciences. Yet relatively little research has compared methods that test for indirect effects among latent variables and provided precise estimates of the effectiveness of different methods. This simulation study provides an extensive comparison of methods for constructing confidence intervals and for making inferences about indirect effects with latent variables. We compared the percentile (PC) bootstrap, bias-corrected (BC) bootstrap, bias-corrected accelerated (BC a ) bootstrap, likelihood-based confidence intervals (Neale & Miller, 1997), partial posterior predictive (Biesanz, Falk, and Savalei, 2010), and joint significance tests based on Wald tests or likelihood ratio tests. All models included three reflective latent variables representing the independent, dependent, and mediating variables. The design included the following fully crossed conditions: (a) sample size: 100, 200, and 500; (b) number of indicators per latent variable: 3 versus 5; (c) reliability per set of indicators: .7 versus .9; (d) and 16 different path combinations for the indirect effect (α = 0, .14, .39, or .59; and β = 0, .14, .39, or .59). Simulations were performed using a WestGrid cluster of 1680 3.06GHz Intel Xeon processors running R and OpenMx. Results based on 1,000 replications per cell and 2,000 resamples per bootstrap method indicated that the BC and BC a bootstrap methods have inflated Type I error rates. Likelihood-based confidence intervals and the PC bootstrap emerged as methods that adequately control Type I error and have good coverage rates.

Interval estimation and optimal design for the within-subject coefficient of variation for continuous and binary variables

PubMed Central

Shoukri, Mohamed M; Elkum, Nasser; Walter, Stephen D

2006-01-01

Background In this paper we propose the use of the within-subject coefficient of variation as an index of a measurement's reliability. For continuous variables and based on its maximum likelihood estimation we derive a variance-stabilizing transformation and discuss confidence interval construction within the framework of a one-way random effects model. We investigate sample size requirements for the within-subject coefficient of variation for continuous and binary variables. Methods We investigate the validity of the approximate normal confidence interval by Monte Carlo simulations. In designing a reliability study, a crucial issue is the balance between the number of subjects to be recruited and the number of repeated measurements per subject. We discuss efficiency of estimation and cost considerations for the optimal allocation of the sample resources. The approach is illustrated by an example on Magnetic Resonance Imaging (MRI). We also discuss the issue of sample size estimation for dichotomous responses with two examples. Results For the continuous variable we found that the variance stabilizing transformation improves the asymptotic coverage probabilities on the within-subject coefficient of variation for the continuous variable. The maximum like estimation and sample size estimation based on pre-specified width of confidence interval are novel contribution to the literature for the binary variable. Conclusion Using the sample size formulas, we hope to help clinical epidemiologists and practicing statisticians to efficiently design reliability studies using the within-subject coefficient of variation, whether the variable of interest is continuous or binary. PMID:16686943

Health workers' attitudes, perceptions and knowledge of influenza immunization in Lima, Peru: A mixed methods study.

PubMed

Bazán, Magdalena; Villacorta, Erika; Barbagelatta, Gisella; Jimenez, M Michelle; Goya, Cecilia; Bartolini, Rosario M; Penny, Mary E

2017-05-19

Vaccination against seasonal influenza in health workers is recommended but coverage is variable. This study aimed to determine coverage of influenza vaccination among health workers in Lima, Peru in 2010; explore barriers and enabling elements for vaccination; and suggest strategies to improve coverage. Qualitative interviews informed the development of a survey instrument that consisted of open and close-ended questions. Sub-analyses were done by occupational group and results were calculated as percentages for each possible response with confidence intervals of 95%. Coverage of the influenza vaccination was 77.2%. Vaccinated staff were less likely to have permanent contracts (p=0.0150) and vaccination coverage was lower in physicians (p=0.0001). Over 90% cited protection of themselves, families and patients as reasons for vaccination and 48% mentioned peer encouragement. Fear of adverse events (47%) and organizational barriers (>30%) were reasons for non-vaccination. To improve coverage, highest priority was given to strategies providing more information. Key factors in driving health worker vaccination include desire for protection and peer encouragement. Perceptual barriers based on a misunderstanding of the epidemiology of influenza and vaccination could be overcome by targeted education and information. Organizational barriers require attention to how vaccination is implemented within health facilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Robust power spectral estimation for EEG data

PubMed Central

Melman, Tamar; Victor, Jonathan D.

2016-01-01

Background Typical electroencephalogram (EEG) recordings often contain substantial artifact. These artifacts, often large and intermittent, can interfere with quantification of the EEG via its power spectrum. To reduce the impact of artifact, EEG records are typically cleaned by a preprocessing stage that removes individual segments or components of the recording. However, such preprocessing can introduce bias, discard available signal, and be labor-intensive. With this motivation, we present a method that uses robust statistics to reduce dependence on preprocessing by minimizing the effect of large intermittent outliers on the spectral estimates. New method Using the multitaper method[1] as a starting point, we replaced the final step of the standard power spectrum calculation with a quantile-based estimator, and the Jackknife approach to confidence intervals with a Bayesian approach. The method is implemented in provided MATLAB modules, which extend the widely used Chronux toolbox. Results Using both simulated and human data, we show that in the presence of large intermittent outliers, the robust method produces improved estimates of the power spectrum, and that the Bayesian confidence intervals yield close-to-veridical coverage factors. Comparison to existing method The robust method, as compared to the standard method, is less affected by artifact: inclusion of outliers produces fewer changes in the shape of the power spectrum as well as in the coverage factor. Conclusion In the presence of large intermittent outliers, the robust method can reduce dependence on data preprocessing as compared to standard methods of spectral estimation. PMID:27102041

Robust power spectral estimation for EEG data.

PubMed

Melman, Tamar; Victor, Jonathan D

2016-08-01

Typical electroencephalogram (EEG) recordings often contain substantial artifact. These artifacts, often large and intermittent, can interfere with quantification of the EEG via its power spectrum. To reduce the impact of artifact, EEG records are typically cleaned by a preprocessing stage that removes individual segments or components of the recording. However, such preprocessing can introduce bias, discard available signal, and be labor-intensive. With this motivation, we present a method that uses robust statistics to reduce dependence on preprocessing by minimizing the effect of large intermittent outliers on the spectral estimates. Using the multitaper method (Thomson, 1982) as a starting point, we replaced the final step of the standard power spectrum calculation with a quantile-based estimator, and the Jackknife approach to confidence intervals with a Bayesian approach. The method is implemented in provided MATLAB modules, which extend the widely used Chronux toolbox. Using both simulated and human data, we show that in the presence of large intermittent outliers, the robust method produces improved estimates of the power spectrum, and that the Bayesian confidence intervals yield close-to-veridical coverage factors. The robust method, as compared to the standard method, is less affected by artifact: inclusion of outliers produces fewer changes in the shape of the power spectrum as well as in the coverage factor. In the presence of large intermittent outliers, the robust method can reduce dependence on data preprocessing as compared to standard methods of spectral estimation. Copyright © 2016 Elsevier B.V. All rights reserved.

Exemptions From Mandatory Immunization After Legally Mandated Parental Counseling.

PubMed

Omer, Saad B; Allen, Kristen; Chang, D H; Guterman, L Beryl; Bednarczyk, Robert A; Jordan, Alex; Buttenheim, Alison; Jones, Malia; Hannan, Claire; deHart, M Patricia; Salmon, Daniel A

2018-01-01

The success of health care provider counseling-based interventions to address vaccine hesitancy is not clear. In 2011, Washington State implemented Senate Bill 5005 (SB5005), requiring counseling and a signed form from a licensed health care provider to obtain an exemption. Evaluating the impact of a counseling intervention can provide important insight into population-level interventions that focus on interpersonal communication by a health care provider. We used segmented regression and interaction and aggregation indices to assess the impact of SB5005 on immunization coverage and exemption rates in Washington State from school years 1997-1998 through 2013-2014. After SB5005 was implemented, there was a significant relative decrease of 40.2% (95% confidence interval: -43.6% to -36.6%) in exemption rates. This translates to a significant absolute reduction of 2.9 percentage points (95% confidence interval: -4.2% to -1.7%) in exemption rates. There were increases in vaccine coverage for all vaccines required for school entrance, with the exception of the hepatitis B vaccine. The probability that kindergarteners without exemptions would encounter kindergarteners with exemptions (interaction index) decreased, and the probability that kindergarteners with exemptions would encounter other such kindergarteners (aggregation index) also decreased after SB5005. Moreover, SB5005 was associated with a decline in geographic clustering of vaccine exemptors. States in the United States and jurisdictions in other countries should consider adding parental counseling by health care provider as a requirement for obtaining exemptions to vaccination requirements. Copyright © 2018 by the American Academy of Pediatrics.

Does the covariance structure matter in longitudinal modelling for the prediction of future CD4 counts?

PubMed

Taylor, J M; Law, N

1998-10-30

We investigate the importance of the assumed covariance structure for longitudinal modelling of CD4 counts. We examine how individual predictions of future CD4 counts are affected by the covariance structure. We consider four covariance structures: one based on an integrated Ornstein-Uhlenbeck stochastic process; one based on Brownian motion, and two derived from standard linear and quadratic random-effects models. Using data from the Multicenter AIDS Cohort Study and from a simulation study, we show that there is a noticeable deterioration in the coverage rate of confidence intervals if we assume the wrong covariance. There is also a loss in efficiency. The quadratic random-effects model is found to be the best in terms of correctly calibrated prediction intervals, but is substantially less efficient than the others. Incorrectly specifying the covariance structure as linear random effects gives too narrow prediction intervals with poor coverage rates. Fitting using the model based on the integrated Ornstein-Uhlenbeck stochastic process is the preferred one of the four considered because of its efficiency and robustness properties. We also use the difference between the future predicted and observed CD4 counts to assess an appropriate transformation of CD4 counts; a fourth root, cube root and square root all appear reasonable choices.

Utilization of the Local Government Health Insurance Scheme (JKA) for Maternal Health Services Among Women Living in Underdeveloped Areas of Aceh Province, Indonesia.

PubMed

Kesuma, Zurnila Marli; Chongsuvivatwong, Virasakdi

2015-04-01

Aceh province of Indonesia created its own health coverage scheme called Jaminan Kesehatan Aceh (JKA) to cover Aceh's populations who were not registered under insurance for the poor (Jamkesmas). This study aims to compare the utilization rate of maternal health care (MHC) services and contraceptive prevalence rate (CPR) before JKA, during the transition period, and after JKA had been established. A cross-sectional household survey was conducted from June 2011 to July 2012. Utilization of MHC services and CPR during the 3 periods was assessed using a questionnaire. The Mantel-Haenszel χ(2) test was used to examine the association between period and coverage. Generalized estimating equations (GEEs) were used to examine utilization and type of service, period of service, and type of scheme. Coverage of utilization of skilled birth attendants significantly improved among the JKA holders (odds ratio = 1.84; 95% confidence interval = 1.18-2.89). JKA, thus, has shown its positive impact. © 2014 APJPH.

Ranking Businesses and Municipal Locations by Spatiotemporal Cardiac Arrest Risk to Guide Public Defibrillator Placement.

PubMed

Sun, Christopher L F; Brooks, Steven C; Morrison, Laurie J; Chan, Timothy C Y

2017-03-21

Efforts to guide automated external defibrillator placement for out-of-hospital cardiac arrest (OHCA) treatment have focused on identifying broadly defined location categories without considering hours of operation. Broad location categories may be composed of many businesses with varying accessibility. Identifying specific locations for automated external defibrillator deployment incorporating operating hours and time of OHCA occurrence may improve automated external defibrillator accessibility. We aim to identify specific businesses and municipal locations that maximize OHCA coverage on the basis of spatiotemporal assessment of OHCA risk in the immediate vicinity of franchise locations. This study was a retrospective population-based cohort study using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public OHCAs occurring in Toronto, ON, Canada, from January 2007 through December 2015. We identified 41 unique businesses and municipal location types with ≥20 locations in Toronto from the YellowPages, Canadian Franchise Association, and the City of Toronto Open Data Portal. We obtained their geographic coordinates and hours of operation from Web sites, by phone, or in person. We determined the number of OHCAs that occurred within 100 m of each location when it was open (spatiotemporal coverage) for Toronto overall and downtown. The businesses and municipal locations were then ranked by spatiotemporal OHCA coverage. To evaluate temporal stability of the rankings, we calculated intraclass correlation of the annual coverage values. There were 2654 nontraumatic public OHCAs. Tim Hortons ranked first in Toronto, covering 286 OHCAs. Starbucks ranked first in downtown, covering 110 OHCAs. Coffee shops and bank machines from the 5 largest Canadian banks occupied 8 of the top 10 spots in both Toronto and downtown. The rankings exhibited high temporal stability with intraclass correlation values of 0.88 (95% confidence interval, 0.83-0.93) in Toronto and 0.79 (95% confidence interval, 0.71-0.86) in downtown. We identified and ranked businesses and municipal locations by spatiotemporal OHCA risk in their immediate vicinity. This approach may help policy makers and funders to identify and prioritize potential partnerships for automated external defibrillator deployment in public-access defibrillator programs. © 2017 American Heart Association, Inc.

Marginal Structural Models for Case-Cohort Study Designs to Estimate the Association of Antiretroviral Therapy Initiation With Incident AIDS or Death

PubMed Central

Cole, Stephen R.; Hudgens, Michael G.; Tien, Phyllis C.; Anastos, Kathryn; Kingsley, Lawrence; Chmiel, Joan S.; Jacobson, Lisa P.

2012-01-01

To estimate the association of antiretroviral therapy initiation with incident acquired immunodeficiency syndrome (AIDS) or death while accounting for time-varying confounding in a cost-efficient manner, the authors combined a case-cohort study design with inverse probability-weighted estimation of a marginal structural Cox proportional hazards model. A total of 950 adults who were positive for human immunodeficiency virus type 1 were followed in 2 US cohort studies between 1995 and 2007. In the full cohort, 211 AIDS cases or deaths occurred during 4,456 person-years. In an illustrative 20% random subcohort of 190 participants, 41 AIDS cases or deaths occurred during 861 person-years. Accounting for measured confounders and determinants of dropout by inverse probability weighting, the full cohort hazard ratio was 0.41 (95% confidence interval: 0.26, 0.65) and the case-cohort hazard ratio was 0.47 (95% confidence interval: 0.26, 0.83). Standard multivariable-adjusted hazard ratios were closer to the null, regardless of study design. The precision lost with the case-cohort design was modest given the cost savings. Results from Monte Carlo simulations demonstrated that the proposed approach yields approximately unbiased estimates of the hazard ratio with appropriate confidence interval coverage. Marginal structural model analysis of case-cohort study designs provides a cost-efficient design coupled with an accurate analytic method for research settings in which there is time-varying confounding. PMID:22302074

Relationship of Hospital Staff Coverage and Delivery Room Resuscitation Practices to Birth Asphyxia.

PubMed

Tu, Joanna H; Profit, Jochen; Melsop, Kathryn; Brown, Taylor; Davis, Alexis; Main, Elliot; Lee, Henry C

2017-02-01

Objective  The objective of this study was to assess utilization of specialist coverage and checklists in perinatal settings and to examine utilization by birth asphyxia rates. Design  This is a survey study of California maternity hospitals concerning checklist use to prepare for delivery room resuscitation and 24-hour in-house specialist coverage (pediatrician/neonatologist, obstetrician, and obstetric anesthesiologist) and results linked to hospital birth asphyxia rates (preterm and low weight births were excluded). Results  Of 253 maternity hospitals, 138 responded (55%); 59 (43%) indicated checklist use, and in-house specialist coverage ranged from 38% (pediatrician/neonatologist) to 54% (anesthesiology). In-house coverage was more common in urban versus rural hospitals for all specialties ( p  < 0.0001), but checklist use was not significantly different ( p  = 0.88). Higher birth volume hospitals had more specialist coverage ( p  < 0.0001), whereas checklist use did not differ ( p  = 0.3). In-house obstetric coverage was associated with lower asphyxia rates (odds ratio: 0.34; 95% confidence interval [CI]: 0.20, 0.58) in a regression model accounting for other providers. Checklist use was not associated with birth asphyxia (odds ratio: 1.12; 95% CI: 0.75, 1.68). Conclusion  Higher birth volume and urban hospitals demonstrated greater in-house specialist coverage, but checklist use was similar across all hospitals. Current data suggest that in-house obstetric coverage has greater impact on asphyxia than other specialist coverage or checklist use. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

An empirical Bayes approach to analyzing recurring animal surveys

USGS Publications Warehouse

Johnson, D.H.

1989-01-01

Recurring estimates of the size of animal populations are often required by biologists or wildlife managers. Because of cost or other constraints, estimates frequently lack the accuracy desired but cannot readily be improved by additional sampling. This report proposes a statistical method employing empirical Bayes (EB) estimators as alternatives to those customarily used to estimate population size, and evaluates them by a subsampling experiment on waterfowl surveys. EB estimates, especially a simple limited-translation version, were more accurate and provided shorter confidence intervals with greater coverage probabilities than customary estimates.

Client-Level Coverage of Needle and Syringe Program and High-Risk Injection Behaviors: A Case Study of People Who Inject Drugs in Kermanshah, Iran.

PubMed

Noroozi, Mehdi; Mirzazadeh, Ali; Noroozi, Alireza; Mehrabi, Yadoallah; Hajebi, Ahmad; Zamani, Saman; Sharifi, Hamid; Higgs, Peter; Soori, Hamid

2015-01-01

Needle-syringe programs (NSP) have been running in Iran since 2002. However, the coverage of such program among the NSP clients at the individual level was not studies yet. This study aimed to determine the client coverage of NSP and its correlation with high injection-related risk behaviors. A cross-sectional survey was conducted in Kermanshah province, Iran, in 2014. 230 people who inject drugs (PWID) recruited from two drop-in centers (DICs) from April to September 2014, participated in a face-to-face interview to provide information related individual coverage of NSP, demographic characteristics, and injecting behaviors 30 days prior to the interview. Overall, the average of syringe coverage was 158% [95% confidence interval (CI) = 65.7-205.5], while 56% (95% CI = 40-97) have individual converge less than 100%. Needle/syringe sharing was significantly higher among individual with low NSP coverage [adjusted odds ratio (AOR) = 2.6, 95% CI = 1.3-6.2]. About 85% participants with coverage of less than 100% reported reuse of syringe within the last 30 days (AOR = 3.2, 95% CI = 1.4-7.7). PWID are different regarding their NSP individual-level converges. There are certain clusters of PWID, who do not receive sufficient number of syringes. Given that insufficient individual syringe coverage level is highly associated with injection risk behaviors, reasons for such low converge need to be assessed and addressed carefully.

Client-Level Coverage of Needle and Syringe Program and High-Risk Injection Behaviors: A Case Study of People Who Inject Drugs in Kermanshah, Iran

PubMed Central

Noroozi, Mehdi; Mirzazadeh, Ali; Noroozi, Alireza; Mehrabi, Yadoallah; Hajebi, Ahmad; Zamani, Saman; Sharifi, Hamid; Higgs, Peter; Soori, Hamid

2015-01-01

Background Needle-syringe programs (NSP) have been running in Iran since 2002. However, the coverage of such program among the NSP clients at the individual level was not studies yet. This study aimed to determine the client coverage of NSP and its correlation with high injection-related risk behaviors. Methods A cross-sectional survey was conducted in Kermanshah province, Iran, in 2014. 230 people who inject drugs (PWID) recruited from two drop-in centers (DICs) from April to September 2014, participated in a face-to-face interview to provide information related individual coverage of NSP, demographic characteristics, and injecting behaviors 30 days prior to the interview. Findings Overall, the average of syringe coverage was 158% [95% confidence interval (CI) = 65.7-205.5], while 56% (95% CI = 40-97) have individual converge less than 100%. Needle/syringe sharing was significantly higher among individual with low NSP coverage [adjusted odds ratio (AOR) = 2.6, 95% CI = 1.3-6.2]. About 85% participants with coverage of less than 100% reported reuse of syringe within the last 30 days (AOR = 3.2, 95% CI = 1.4-7.7). Conclusion PWID are different regarding their NSP individual-level converges. There are certain clusters of PWID, who do not receive sufficient number of syringes. Given that insufficient individual syringe coverage level is highly associated with injection risk behaviors, reasons for such low converge need to be assessed and addressed carefully. PMID:26885353

Age- and gender-specific time trend in risk of death of patients admitted with aneurysmal subarachnoid hemorrhage in the Netherlands.

PubMed

Nieuwkamp, Dennis J; Vaartjes, Ilonca; Algra, Ale; Bots, Michiel L; Rinkel, Gabriël J E

2013-10-01

In a meta-analysis of population-based studies, case-fatality rates of subarachnoid hemorrhage have decreased worldwide by 17% between 1973 and 2002. However, age- and gender-specific decreases could not be determined. Because >10% of patients with subarachnoid hemorrhage die before reaching the hospital, this suggests that the prognosis for hospitalized subarachnoid hemorrhage patients has improved even more. We assessed age- and gender-specific time trends of the risk of death for hospitalized subarachnoid hemorrhage patients. From the Dutch hospital discharge register (nationwide coverage), we identified 9403 patients admitted with subarachnoid hemorrhage in the Netherlands between 1997 and 2006. Changes in risk of death within this time frame and influence of age and gender were quantified with Poisson regression. The overall 30-day risk of death was 34.0% (95% confidence interval 33.1 ↔ 35.0%). After adjustment for age and gender, the annual decrease was 1.6% (95% confidence interval 0.5 ↔ 2.6%), which confers to a decrease of 13.4% (95% confidence interval 4.8 ↔ 21.2%) in the study period. The one-year risk of death decreased 2.0% per year (95% confidence interval 1.1 ↔ 2.9%). The decrease in risk of death was mainly found in the period 2003-2005, was not found for patients ≥ 65 years and was statistically significant for men, but not for women. The decrease in risk of death for patients admitted in the Netherlands with subarachnoid hemorrhage is overall considerable, but unevenly distributed over age and gender. Further research should focus on reasons for improved survival (improved diagnostics, improved treatment) and reasons why improvement has not occurred for women and for patients in older age categories. © 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.

Multipollutant measurement error in air pollution epidemiology studies arising from predicting exposures with penalized regression splines

PubMed Central

Bergen, Silas; Sheppard, Lianne; Kaufman, Joel D.; Szpiro, Adam A.

2016-01-01

Summary Air pollution epidemiology studies are trending towards a multi-pollutant approach. In these studies, exposures at subject locations are unobserved and must be predicted using observed exposures at misaligned monitoring locations. This induces measurement error, which can bias the estimated health effects and affect standard error estimates. We characterize this measurement error and develop an analytic bias correction when using penalized regression splines to predict exposure. Our simulations show bias from multi-pollutant measurement error can be severe, and in opposite directions or simultaneously positive or negative. Our analytic bias correction combined with a non-parametric bootstrap yields accurate coverage of 95% confidence intervals. We apply our methodology to analyze the association of systolic blood pressure with PM2.5 and NO2 in the NIEHS Sister Study. We find that NO2 confounds the association of systolic blood pressure with PM2.5 and vice versa. Elevated systolic blood pressure was significantly associated with increased PM2.5 and decreased NO2. Correcting for measurement error bias strengthened these associations and widened 95% confidence intervals. PMID:27789915

Strategies for Improving Vaccine Delivery: A Cluster-Randomized Trial.

PubMed

Fu, Linda Y; Zook, Kathleen; Gingold, Janet A; Gillespie, Catherine W; Briccetti, Christine; Cora-Bramble, Denice; Joseph, Jill G; Haimowitz, Rachel; Moon, Rachel Y

2016-06-01

New emphasis on and requirements for demonstrating health care quality have increased the need for evidence-based methods to disseminate practice guidelines. With regard to impact on pediatric immunization coverage, we aimed to compare a financial incentive program (pay-for-performance [P4P]) and a virtual quality improvement technical support (QITS) learning collaborative. This single-blinded (to outcomes assessor), cluster-randomized trial was conducted among unaffiliated pediatric practices across the United States from June 2013 to June 2014. Practices received either the P4P or QITS intervention. All practices received a Vaccinator Toolkit. P4P practices participated in a tiered financial incentives program for immunization coverage improvement. QITS practices participated in a virtual learning collaborative. Primary outcome was percentage of all needed vaccines received (PANVR). We also assessed immunization up-to-date (UTD) status. Data were analyzed from 3,147 patient records from 32 practices. Practices in the study arms reported similar QI activities (∼6 to 7 activities). We found no difference in PANVR between P4P and QITS (mean ± SE, 90.7% ± 1.1% vs 86.1% ± 1.3%, P = 0.46). Likewise, there was no difference in odds of being UTD between study arms (adjusted odds ratio 1.02, 95% confidence interval 0.68 to 1.52, P = .93). In within-group analysis, patients in both arms experienced nonsignificant increases in PANVR. Similarly, the change in adjusted odds of UTD over time was modest and nonsignificant for P4P but reached significance in the QITS arm (adjusted odds ratio 1.28, 95% confidence interval 1.02 to 1.60, P = .03). Participation in either a financial incentives program or a virtual learning collaborative led to self-reported improvements in immunization practices but minimal change in objectively measured immunization coverage. Copyright © 2016 by the American Academy of Pediatrics.

Inequities in Mental Health Care After Health Care System Reform in Chile

PubMed Central

Araya, Ricardo; Rojas, Graciela; Fritsch, Rosemarie; Frank, Richard; Lewis, Glyn

2006-01-01

Objectives. We compared differences in mental health needs and provision of mental health services among residents of Santiago, Chile, with private and public health insurance coverage. Methods. We conducted a cross-sectional survey of a random sample of adults. Presence of mental disorders and use of health care services were assessed via structured interviews. Individuals were classified as having public, private, or no health insurance coverage. Results. Among individuals with mental disorders, only 20% (95% confidence interval [CI]=16%, 24%) had consulted a professional about these problems. A clear mismatch was found between need and provision of services. Participants with public insurance coverage exhibited the highest prevalence of mental disorders but the lowest rates of consultation; participants with private coverage exhibited exactly the opposite pattern. After adjustment for age, income, and severity of symptoms, private insurance coverage (odds ratio [OR]=2.72; 95% CI=1.6, 4.6) and higher disability level (OR=1.27, 95% CI=1.1, 1.5) were the only factors associated with increased frequency of mental health consultation. Conclusions. The health reforms that have encouraged the growth of the private health sector in Chile also have increased risk segmentation within the health system, accentuating inequalities in health care provision. PMID:16317207

Change in Health Insurance Coverage in Massachusetts and Other New England States by Perceived Health Status: Potential Impact of Health Reform

PubMed Central

Zack, Matthew M.; Strine, Tara W.; Druss, Benjamin G.; Simoes, Eduardo

2013-01-01

Objectives. We examined the impact of Massachusetts health reform and its public health component (enacted in 2006) on change in health insurance coverage by perceived health. Methods. We used 2003–2009 Behavioral Risk Factor Surveillance System data. We used a difference-in-differences framework to examine the experience in Massachusetts to predict the outcomes of national health care reform. Results. The proportion of adults aged 18 to 64 years with health insurance coverage increased more in Massachusetts than in other New England states (4.5%; 95% confidence interval [CI] = 3.5%, 5.6%). For those with higher perceived health care need (more recent mentally and physically unhealthy days and activity limitation days [ALDs]), the postreform proportion significantly exceeded prereform (P < .001). Groups with higher perceived health care need represented a disproportionate increase in health insurance coverage in Massachusetts compared with other New England states—from 4.3% (95% CI = 3.3%, 5.4%) for fewer than 14 ALDs to 9.0% (95% CI = 4.5%, 13.5%) for 14 or more ALDs. Conclusions. On the basis of the Massachusetts experience, full implementation of the Affordable Care Act may increase health insurance coverage especially among populations with higher perceived health care need. PMID:23597359

Medicaid Coverage of Methadone Maintenance and the Use of Opioid Agonist Therapy Among Pregnant Women in Specialty Treatment.

PubMed

Bachhuber, Marcus A; Mehta, Pooja K; Faherty, Laura J; Saloner, Brendan

2017-12-01

Opioid agonist therapy (OAT) is the standard of care for pregnant women with opioid use disorder (OUD). Medicaid coverage policies may strongly influence OAT use in this group. To examine the association between Medicaid coverage of methadone maintenance and planned use of OAT in the publicly funded treatment system. Retrospective cross-sectional analysis of treatment admissions in 30 states extracted from the Treatment Episode Data Set (2013 and 2014). Medicaid-insured pregnant women with OUD (n=3354 treatment admissions). The main outcome measure was planned use of OAT on admission. The main exposure was state Medicaid coverage of methadone maintenance. Using multivariable logistic regression models adjusting for sociodemographic, substance use, and treatment characteristics, we compared the probability of planned OAT use in states with Medicaid coverage of methadone maintenance versus states without coverage. A total of 71% of pregnant women admitted to OUD treatment were 18-29 years old, 85% were white non-Hispanic, and 56% used heroin. Overall, 74% of admissions occurred in the 18 states with Medicaid coverage of methadone maintenance and 53% of admissions involved planned use of OAT. Compared with states without Medicaid coverage of methadone maintenance, admissions in states with coverage were significantly more likely to involve planned OAT use (adjusted difference: 32.9 percentage points, 95% confidence interval, 19.2-46.7). Including methadone maintenance in the Medicaid benefit is essential to increasing OAT among pregnant women with OUD and should be considered a key policy strategy to enhance outcomes for mothers and newborns.

Household coverage of Swaziland's national community health worker programme: a cross-sectional population-based study.

PubMed

Geldsetzer, Pascal; Vaikath, Maria; De Neve, Jan-Walter; Bossert, Thomas J; Sibandze, Sibusiso; Bärnighausen, Till

2017-08-01

To ascertain household coverage achieved by Swaziland's national community health worker (CHW) programme and differences in household coverage across clients' sociodemographic characteristics. Household survey from June to September 2015 in two of Swaziland's four administrative regions using two-stage cluster random sampling. Interviewers administered a questionnaire to all household members in 1542 households across 85 census enumeration areas. While the CHW programme aims to cover all households in the country, only 44.5% (95% confidence interval: 38.0% to 51.1%) reported that they had ever been visited by a CHW. In both uni- and multivariable regressions, coverage was negatively associated with household wealth (OR for most vs. least wealthy quartile: 0.30 [0.16 to 0.58], P < 0.001) and education (OR for >secondary schooling vs. no schooling: 0.65 [0.47 to 0.90], P = 0.009), and positively associated with residing in a rural area (OR: 2.95 [1.77 to 4.91], P < 0.001). Coverage varied widely between census enumeration areas. Swaziland's national CHW programme is falling far short of its coverage goal. To improve coverage, the programme would likely need to recruit additional CHWs and/or assign more households to each CHW. Alternatively, changing the programme's ambitious coverage goal to visiting only certain types of households would likely reduce existing arbitrary differences in coverage between households and communities. This study highlights the need to evaluate and reform large long-standing CHW programmes in sub-Saharan Africa. © 2017 John Wiley & Sons Ltd.

Complete immunization coverage and its determinants among children in Malaysia: findings from the National Health and Morbidity Survey (NHMS) 2016.

PubMed

Lim, K K; Chan, Y Y; Noor Ani, A; Rohani, J; Siti Norfadhilah, Z A; Santhi, M R

2017-12-01

The success of the Expanded Program on Immunization among children will greatly reduce the burden of illness and disability from vaccine preventable diseases. The aim of the study was to evaluate the complete immunization coverage and its determinants among children aged 12-23 months in Malaysia. Cross-sectional study. Data on immunization were extracted from the 2016 National Health and Morbidity Survey. Complete immunization coverage was classified as received all recommended primary vaccine doses by the age of 12 months and verified by vaccination cards, and incompletely immunized if they received partially recommended vaccine dose or not received any recommended vaccine dose or had no vaccination card. The multiple logistic regression analyses were conducted to determine the sociodemographic factors associated with complete immunization coverage. The overall complete immunization coverage among children (verified by cards) was 86.4% (n = 8920, 95% confidence interval: 85.4-87.4). Multivariable logistic regression analyses model revealed that factors significantly associated with complete immunization coverage were ethnicity, occupation of the mother, head of household's education level, and head of household's occupation. While sex, citizenship, household income, mother's age, and marital status were not significantly associated with complete immunization coverage. According to the World Health Organization criteria, the present study demonstrated that the immunization coverage of 86.4% is still unsatisfactory. Thus, the current intervention program should be enhanced in order to achieve the 95% coverage for all antigens in the national vaccination program. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Consumer confidence in the safety of food and newspaper coverage of food safety issues: a longitudinal perspective.

PubMed

de Jonge, Janneke; Van Trijp, Hans; Renes, Reint Jan; Frewer, Lynn J

2010-01-01

This study develops a longitudinal perspective on consumer confidence in the safety of food to explore if, how, and why consumer confidence changes over time. In the first study, a theory-based monitoring instrument for consumer confidence in the safety of food was developed and validated. The monitoring instrument assesses consumer confidence together with its determinants. Model and measurement invariance were validated rigorously before developments in consumer confidence in the safety of food and its determinants were investigated over time. The results from the longitudinal analysis show that across four waves of annual data collection (2003-2006), the framework was stable and that the relative importance of the determinants of confidence was, generally, constant over time. Some changes were observed regarding the mean ratings on the latent constructs. The second study explored how newspaper coverage of food safety related issues affects consumer confidence in the safety of food through subjective consumer recall of food safety incidents. The results show that the newspaper coverage on food safety issues is positively associated with consumer recall of food safety incidents, both in terms of intensity and recency of media coverage.

Twenty-four-hour in-house neonatologist coverage and long-term neurodevelopmental outcomes of preterm infants.

PubMed

Lodha, A; Brown, N; Soraisham, A; Amin, H; Tang, S; Singhal, N

2017-08-01

To compare short- and long-term neurodevelopmental outcomes at 3 years of corrected age of preterm infants cared for by 24-hour in-house staff neonatologists and those cared for by staff neonatologists during daytime only. Retrospective analysis of prospectively collected follow-up data on all nonanomalous preterm infants from 1998 to 2004 excluding year 2001 as a washout period. Infants were divided into two groups based on care provided by staff neonatologists: 24-hour in-house coverage (24-hour coverage 1998-2000) and daytime coverage (day coverage 2002-2004). Short- and long-term outcomes were compared. A total of 387 (78%) of the screened infants were included. Twenty-four-hour coverage (n=179) and day coverage (n=208) groups had a median birth weight (BW) of 875 g (range 470-1250) and 922 g (480-1530; P=0.028), respectively, and both had a median gestational age of 27 weeks. In the day coverage group, a smaller proportion of mothers had chorioamnionitis (20% vs. 30%; P=0.025), received less antibiotics (62% vs. 73%; P=0.023), and infants had fewer cases of confirmed sepsis (14% vs. 23%; P=0.022). In the day coverage group, a larger number of infants had respiratory distress syndrome (87% vs. 77%; P=0.011) and required prolonged mechanical ventilation (median 31 vs. 21 days; P=0.002). The incidence of major neurodevelopmental impairment was not significantly different between the two groups (odds ratio 0.76; 95% confidence interval 0.34-1.65). Duration of mechanical ventilation was reduced with 24-hour in-house coverage by staff neonatologists. However, 24-hour coverage was not associated with any difference in neurodevelopmental (ND) outcomes at 3-year corrected age.

Comparing Type of Health Insurance Among Low-Income Children: A Mixed-Methods Study from Oregon

PubMed Central

Wallace, Lorraine; Selph, Shelley; Westfall, Nicholas; Crocker, Stephanie

2016-01-01

We employed a mixed-methods study of primary data from a statewide household survey and in-person interviews with parents to examine—quantitatively and qualitatively—whether low-income children experienced differences between public and private insurance coverage types. We carried out 24 in-depth interviews with a sub-sample of respondents to Oregon’s 2005 Children’s Access to Healthcare Study (CAHS), analyzed using a standard iterative process and immersion/crystallization cycles. Qualitative findings guided quantitative analyses of CAHS data that assessed associations between insurance type and parental-reported unmet children’s health care needs. Interviewees uniformly reported that stable health insurance was important, but there was no consensus regarding which type was superior. Quantitatively, there were only a few significant differences. Cross-sectionally, compared with private coverage, public coverage was associated with higher odds of unmet specialty care needs (odds ratio [OR] 3.54; 95% confidence interval [CI] 1.52–8.24). Comparing full-year coverage patterns, those with public coverage had lower odds of unmet prescription needs (OR 0.60, 95% CI 0.36–0.99) and unmet mental health counseling needs (OR 0.24, 95% CI 0.10–0.63), compared with privately covered children. Low-income Oregon parents reported few differences in their child’s experience with private versus public coverage. PMID:21052802

The Impact of Increasing Health Insurance Coverage on Disparities in Mortality: Health Care Reform in Colombia, 1998–2007

PubMed Central

Arroyave, Ivan; Cardona, Doris; Burdorf, Alex

2013-01-01

Objectives. We examined the impact of expanding health insurance coverage on socioeconomic disparities in total and cardiovascular disease mortality from 1998 to 2007 in Colombia. Methods. We used Poisson regression to analyze data from mortality registries (633 905 deaths) linked to population census data. We used the relative index of inequality to compare disparities in mortality by education between periods of moderate increase (1998–2002) and accelerated increase (2003–2007) in health insurance coverage. Results. Disparities in mortality by education widened over time. Among men, the relative index of inequality increased from 2.59 (95% confidence interval [CI] = 2.52, 2.67) in 1998–2002 to 3.07 (95% CI = 2.99, 3.15) in 2003–2007, and among women, from 2.86 (95% CI = 2.77, 2.95) to 3.12 (95% CI = 3.03, 3.21), respectively. Disparities increased yearly by 11% in men and 4% in women in 1998–2002, whereas they increased by 1% in men per year and remained stable among women in 2003–2007. Conclusions. Mortality disparities widened significantly less during the period of increased health insurance coverage than the period of no coverage change. Although expanding coverage did not eliminate disparities, it may contribute to curbing future widening of disparities. PMID:23327277

Improving Physician Recommendations for Human Papillomavirus Vaccination: The Role of Professional Organizations.

PubMed

Hswen, Yulin; Gilkey, Melissa B; Rimer, Barbara K; Brewer, Noel T

2017-01-01

To address low human papillomavirus (HPV) vaccination coverage, the American Academy of Family Physicians (AAFP) and the American Academy of Pediatrics (AAP) have launched national campaigns encouraging physicians to deliver strong HPV vaccine recommendations. We surveyed family physicians and pediatricians to examine the impact of these efforts on physicians' recommendation practices. A national sample of family physicians and pediatricians (n = 776) completed our online survey in 2014. The survey assessed reach, content, and influence of AAFP and AAP communications about HPV vaccination. The survey also assessed quality of physicians' communication practices for recommending HPV vaccination. Forty-seven percent of family physicians reported receiving information on HPV vaccination from AAFP, whereas 62% of pediatricians reported receiving information from AAP. Among physicians reached by AAFP or AAP, most reported receiving the message to give strong recommendations to adolescent boys (71%) and girls (78%). Although receiving information was not associated with HPV vaccine recommendation quality, receiving the message to give strong recommendations correlated with delivering higher-quality recommendations for boys (odds ratio, 4.19, 95% confidence interval, 2.64-6.64) and girls (odds ratio, 3.15, 95% confidence interval, 1.91-5.18). Over half of physicians reported improving their HPV vaccine communication after receiving information from AAFP (69%) or AAP (53%). Our findings suggest that it is important for AAFP and AAP to communicate the need for strong HPV vaccine recommendations. Given that many physicians reported improving their recommendation practices, professional organizations stand to contribute to increasing HPV vaccination coverage, but they will likely need to increase the intensity of quality improvement efforts to do so.

Coverage of childhood vaccination among children aged 12-23 months, Tamil Nadu, 2015, India

PubMed Central

Murhekar, Manoj V.; Kamaraj, P.; Kanagasabai, K.; Elavarasu, G.; Rajasekar, T. Daniel; Boopathi, K.; Mehendale, Sanjay

2017-01-01

Background & objectives: District-Level Household Survey-4 (DLHS-4) indicated that during 2012-2013, only 56 per cent of children aged 12-23 months in Tamil Nadu were fully vaccinated, which were lesser than those reported in earlier national surveys. We, therefore, conducted cluster surveys to estimate coverage of childhood vaccination in the State, and also to identify the factors associated with low coverage. Methods: Cross-sectional surveys were conducted in 15 strata [municipal corporation non-slum (n=1), municipal corporation slum (n=1), hilly (n=1), rural (n=6) and urban (n=6)]. From each stratum, 30 clusters were selected using probability proportional to the population size linear systematic sampling; seven children aged 12-23 months were selected from each cluster and their mothers/care-takers were interviewed to collect information about vaccination status of the child. A child was considered fully vaccinated if he/she received bacillus Calmette-Guérin (BCG), three doses of pentavalent, three doses of oral polio vaccine and one dose of measles vaccine, and appropriately vaccinated if all vaccine doses were given at right age and with right interval. Further, coverage of fully vaccinated children (FVC) as per vaccination cards or mothers’ recall, validated coverage of FVC (V-FVC) among those having cards, and coverage of appropriately vaccinated children (AVC) were estimated using survey data analysis module with appropriate sampling weights. Results: A total of 3150 children were surveyed, of them 2528 (80.3%) had vaccination card. The weighted coverage of FVC, V-FVC and AVC in the State was 79.9 per cent [95% confidence interval (CI): 78.2-81.5], 78.8 per cent (95% CI: 76.9-80.5) and 69.7 per cent (95% CI: 67.7-71.7), respectively. The coverage of individual vaccine ranged between 84 per cent (measles) and 99.8 per cent (BCG). About 12 per cent V-FVC were not vaccinated as per the vaccination schedule. Interpretation & conclusions: The coverage of FVC in Tamil Nadu was high, with about 80 per cent children completing primary vaccination. Efforts to increase vaccination coverage in the State need to focus on educating vaccinators about the need to adhere to the national vaccination schedule and strengthening supervision to ensure that children are vaccinated appropriately. PMID:28749402

Coverage of childhood vaccination among children aged 12-23 months, Tamil Nadu, 2015, India.

PubMed

Murhekar, Manoj V; Kamaraj, P; Kanagasabai, K; Elavarasu, G; Rajasekar, T Daniel; Boopathi, K; Mehendale, Sanjay

2017-03-01

District-Level Household Survey-4 (DLHS-4) indicated that during 2012-2013, only 56 per cent of children aged 12-23 months in Tamil Nadu were fully vaccinated, which were lesser than those reported in earlier national surveys. We, therefore, conducted cluster surveys to estimate coverage of childhood vaccination in the State, and also to identify the factors associated with low coverage. Cross-sectional surveys were conducted in 15 strata [municipal corporation non-slum (n=1), municipal corporation slum (n=1), hilly (n=1), rural (n=6) and urban (n=6)]. From each stratum, 30 clusters were selected using probability proportional to the population size linear systematic sampling; seven children aged 12-23 months were selected from each cluster and their mothers/care-takers were interviewed to collect information about vaccination status of the child. A child was considered fully vaccinated if he/she received bacillus Calmette-Guérin (BCG), three doses of pentavalent, three doses of oral polio vaccine and one dose of measles vaccine, and appropriately vaccinated if all vaccine doses were given at right age and with right interval. Further, coverage of fully vaccinated children (FVC) as per vaccination cards or mothers' recall, validated coverage of FVC (V-FVC) among those having cards, and coverage of appropriately vaccinated children (AVC) were estimated using survey data analysis module with appropriate sampling weights. A total of 3150 children were surveyed, of them 2528 (80.3%) had vaccination card. The weighted coverage of FVC, V-FVC and AVC in the State was 79.9 per cent [95% confidence interval (CI): 78.2-81.5], 78.8 per cent (95% CI: 76.9-80.5) and 69.7 per cent (95% CI: 67.7-71.7), respectively. The coverage of individual vaccine ranged between 84 per cent (measles) and 99.8 per cent (BCG). About 12 per cent V-FVC were not vaccinated as per the vaccination schedule. The coverage of FVC in Tamil Nadu was high, with about 80 per cent children completing primary vaccination. Efforts to increase vaccination coverage in the State need to focus on educating vaccinators about the need to adhere to the national vaccination schedule and strengthening supervision to ensure that children are vaccinated appropriately.

State Medicaid Coverage, ESRD Incidence, and Access to Care

PubMed Central

Goldstein, Benjamin A.; Hall, Yoshio N.; Mitani, Aya A.; Winkelmayer, Wolfgang C.

2014-01-01

The proportion of low-income nonelderly adults covered by Medicaid varies widely by state. We sought to determine whether broader state Medicaid coverage, defined as the proportion of each state’s low-income nonelderly adult population covered by Medicaid, associates with lower state-level incidence of ESRD and greater access to care. The main outcomes were incidence of ESRD and five indicators of access to care. We identified 408,535 adults aged 20–64 years, who developed ESRD between January 1, 2001, and December 31, 2008. Medicaid coverage among low-income nonelderly adults ranged from 12.2% to 66.0% (median 32.5%). For each additional 10% of the low-income nonelderly population covered by Medicaid, there was a 1.8% (95% confidence interval, 1.0% to 2.6%) decrease in ESRD incidence. Among nonelderly adults with ESRD, gaps in access to care between those with private insurance and those with Medicaid were narrower in states with broader coverage. For a 50-year-old white woman, the access gap to the kidney transplant waiting list between Medicaid and private insurance decreased by 7.7 percentage points in high (>45%) versus low (<25%) Medicaid coverage states. Similarly, the access gap to transplantation decreased by 4.0 percentage points and the access gap to peritoneal dialysis decreased by 3.8 percentage points in high Medicaid coverage states. In conclusion, states with broader Medicaid coverage had a lower incidence of ESRD and smaller insurance-related access gaps. PMID:24652791

Contraception Insurance Coverage and Receipt of Long-Acting Reversible Contraception or Depot Medroxyprogesterone Acetate on the Day of Abortion.

PubMed

Krashin, Jamie W; Stuart, Gretchen S; Garrett, Joanne; Spector, Hannah; Bryant, Amy G; Charm, Samantha; Morse, Jessica E

2017-07-01

To evaluate whether contraceptive insurance coverage for women who present for an abortion is associated with obtaining long-acting reversible contraception or depot medroxyprogesterone acetate (DMPA) on the day the abortion is completed. We conducted a prospective cohort study of women presenting for medical or surgical abortion at a single health center in North Carolina. Eligible women were 18 years or older and fluent in English or Spanish. Data were from participant questionnaires, medical charts, and financial records. Our main exposure was whether the woman had insurance coverage for contraception at clinic intake. Our primary outcome was receiving DMPA, an intrauterine device, or a contraceptive subdermal implant on the same day of their surgical abortion or at the visit that determined their medication abortion was complete. We used univariable, bivariable, and multivariable analysis to report our findings. Five hundred seventy-five women enrolled in our cohort between September 2015 and April 2016. One hundred twenty-eight (22%) had insurance coverage and 447 (78%) did not. In the group with insurance coverage for contraception, 38% (49/128) received a long-acting reversible contraception method or DMPA compared with 7% (33/447) in the group without insurance coverage for contraception. After adjusting for confounding, women with contraceptive coverage were more than five times as likely to receive immediate postabortion contraception with one of these methods compared with women without coverage (relative risk 5.6, 95% confidence interval 3.8-8.3). Women with contraceptive insurance coverage on the day of their abortion were more likely to leave the abortion clinic with an intrauterine device or implant in place or receive DMPA injection compared with women without coverage.

Timeliness and completeness of measles vaccination among children in rural areas of Guangxi, China: A stratified three-stage cluster survey.

PubMed

Tang, Xianyan; Geater, Alan; McNeil, Edward; Zhou, Hongxia; Deng, Qiuyun; Dong, Aihu

2017-07-01

Large-scale outbreaks of measles occurred in 2013 and 2014 in rural Guangxi, a region in Southwest China with high coverage for measles-containing vaccine (MCV). This study aimed to estimate the timely vaccination coverage, the timely-and-complete vaccination coverage, and the median delay period for MCV among children aged 18-54 months in rural Guangxi. Based on quartiles of measles incidence during 2011-2013, a stratified three-stage cluster survey was conducted from June through August 2015. Using weighted estimation and finite population correction, vaccination coverage and 95% confidence intervals (CIs) were calculated. Weighted Kaplan-Meier analyses were used to estimate the median delay periods for the first (MCV1) and second (MCV2) doses of the vaccine. A total of 1216 children were surveyed. The timely vaccination coverage rate was 58.4% (95% CI, 54.9%-62.0%) for MCV1, and 76.9% (95% CI, 73.6%-80.0%) for MCV2. The timely-and-complete vaccination coverage rate was 47.4% (95% CI, 44.0%-51.0%). The median delay period was 32 (95% CI, 27-38) days for MCV1, and 159 (95% CI, 118-195) days for MCV2. The timeliness and completeness of measles vaccination was low, and the median delay period was long among children in rural Guangxi. Incorporating the timeliness and completeness into official routine vaccination coverage statistics may help appraise the coverage of vaccination in China. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Using digital surveillance to examine the impact of public figure pancreatic cancer announcements on media and search query outcomes.

PubMed

Noar, Seth M; Ribisl, Kurt M; Althouse, Benjamin M; Willoughby, Jessica Fitts; Ayers, John W

2013-12-01

Announcements of cancer diagnoses from public figures may stimulate cancer information seeking and media coverage about cancer. This study used digital surveillance to quantify the effects of pancreatic cancer public figure announcements on online cancer information seeking and cancer media coverage. We compiled a list of public figures (N = 25) who had been diagnosed with or had died from pancreatic cancer between 2006 and 2011. We specified interrupted time series models using data from Google Trends to examine search query shifts for pancreatic cancer and other cancers. Weekly media coverage archived on Google News were also analyzed. Most public figures' pancreatic cancer announcements corresponded with no appreciable change in pancreatic cancer search queries or media coverage. In contrast, Patrick Swayze's diagnosis was associated with a 285% (95% confidence interval [CI]: 212 to 360) increase in pancreatic cancer search queries, though it was only weakly associated with increases in pancreatic cancer media coverage. Steve Jobs's death was associated with a 197% (95% CI: 131 to 266) increase in pancreatic cancer queries and a 3517% (95% CI: 2882 to 4492) increase in pancreatic cancer media coverage. In general, a doubling in pancreatic cancer-specific media coverage corresponded with a 325% increase in pancreatic cancer queries. Digital surveillance is an important tool for future cancer control research and practice. The current application of these methods suggested that pancreatic cancer announcements (diagnosis or death) by particular public figures stimulated media coverage of and online information seeking for pancreatic cancer.

Estimation of measles vaccination coverage using the Lot Quality Assurance Sampling (LQAS) method--Tamilnadu, India, 2002-2003.

PubMed

Sivasankaran, Saravanan; Manickam, P; Ramakrishnan, R; Hutin, Y; Gupte, M D

2006-04-28

As part of the global strategic plan to reduce the number of measles deaths in India, the state of Tamilnadu aims at > or =95% measles vaccination coverage. A study was conducted to measure overall coverage levels for the Poondi Primary Health Center (PPHC), a rural health-care facility in Tiruvallur District, and to determine whether any of the PPHC's six health subcenters had coverage levels <95%. The Lot Quality Assurance Sampling (LQAS) method was used to identify health subcenters in the PPHC area with measles vaccination coverage levels <95% among children aged 12-23 months. Lemeshow and Taber sampling plans were used to determine that the measles vaccination status of 73 children aged 12--23 months had to be assessed in each health subcenter coverage area, with a 5% level of significance and a decision value of two. If more than two children were unvaccinated, the null hypothesis (i.e., that coverage in the health subcenter was low [<95%]) was not rejected. If the number of unvaccinated children was two or fewer, the null hypothesis was rejected, and coverage in the subcenter was considered to be good (i.e., > or =95%). All data were pooled in a stratified sample to estimate overall total coverage in the PPHC area. For two (33.3%) of the six health subcenters, more than two children were unvaccinated (i.e., coverage was <95%). Combining results from all six health subcenters generated a coverage estimate of 97.7% (95% confidence interval = 95.7-98.8) on the basis of 428 (97.7%) of 438 children identified as vaccinated. LQAS techniques proved useful in identifying small health areas with lower vaccination coverage, which helps to target interventions. Monthly review of vaccination coverage by subcenter and village is recommended to identify pockets of unvaccinated children and to maintain uniform high coverage in the PPHC area.

Rapid assessment of cataract surgical coverage in rural Zululand.

PubMed

Rotchford, A P; Johnson, G J

2000-10-01

Cataract surgical coverage (CSC) is a useful indicator of the degree of success of a cataract intervention programme. However, because previously described methods are time-consuming and labour-intensive, they are rarely performed. This study describes a simple and inexpensive assessment of CSC based on screening of pensioners at pension delivery sites in a rural district. Random cluster-based cross-sectional survey. State pension distribution sites in Hlabisa, a rural district in KwaZulu-Natal, South Africa. 562 old-age pensioners. Subjects found to be blind (visual acuity < 3/60) and those reporting a history of eye surgery were examined using a torch and direct ophthalmoscope by an ophthalmologist. Cases of blindness due to operable cataract and post-cataract surgical subjects were identified. CSC was found to be 38.5% (95% confidence interval 29.1-47.9%). Blindness prevalence was 10.3%, with 69.0% due to cataract.

Sampling Theory and Confidence Intervals for Effect Sizes: Using ESCI To Illustrate "Bouncing"; Confidence Intervals.

ERIC Educational Resources Information Center

Du, Yunfei

This paper discusses the impact of sampling error on the construction of confidence intervals around effect sizes. Sampling error affects the location and precision of confidence intervals. Meta-analytic resampling demonstrates that confidence intervals can haphazardly bounce around the true population parameter. Special software with graphical…

On Some Confidence Intervals for Estimating the Mean of a Skewed Population

ERIC Educational Resources Information Center

Shi, W.; Kibria, B. M. Golam

2007-01-01

A number of methods are available in the literature to measure confidence intervals. Here, confidence intervals for estimating the population mean of a skewed distribution are considered. This note proposes two alternative confidence intervals, namely, Median t and Mad t, which are simple adjustments to the Student's t confidence interval. In…

Comparison of Mass Azithromycin Coverage Targets of Children in Niger: A Cluster-Randomized Trachoma Trial.

PubMed

Oldenburg, Catherine E; Amza, Abdou; Kadri, Boubacar; Nassirou, Beido; Cotter, Sun Y; Stoller, Nicole E; West, Sheila K; Bailey, Robin L; Porco, Travis C; Gaynor, Bruce D; Keenan, Jeremy D; Lietman, Thomas M

2018-02-01

Repeated oral azithromycin distribution targeted only to children has proven effective in reducing the ocular Chlamydia that causes trachoma. Here, we assess whether an enhanced coverage target of at least 90% of children is superior to the World Health Organization recommendation of at least 80%. Twenty-four trachoma-endemic communities in Matamèye, Niger, were randomized to a single day of azithromycin distribution aiming for at least 80% coverage or up to 4 days of treatment and > 90% coverage of children under age 12. All distributions were biannual. Children < 5 years of age and adults > 15 years were monitored for ocular Chlamydia infection by polymerase chain reaction every 6 months for 36 months in children and at baseline and 36 months in adults. Ocular Chlamydia prevalence in children decreased from 24.9% (95% confidence interval [CI] 15.9-33.8%) to 4.4% (95% CI 0.6-8.2%, P < 0.001) at 36 months in the standard coverage arm and from 15.6% (95% CI 10.0-21.2%) to 3.3% (95% CI 1.0-5.5%; P < 0.001) in the enhanced coverage arm. Enhanced coverage reduced ocular Chlamydia prevalence in children more quickly over time compared with standard ( P = 0.04). There was no difference between arms at 36 months in children (2.4% lower with enhanced coverage, 95% CI 7.7-12.5%; P = 0.60). No infection was detected in adults at 36 months. Increasing antibiotic coverage among children from 80% to 90% may yield only short term improvements for trachoma control programs. Targeting treatment to children alone may be sufficient for trachoma control in this setting.

Healthcare Coverage for HIV Provider Visits Before and After Implementation of the Affordable Care Act

PubMed Central

Berry, Stephen A.; Fleishman, John A.; Yehia, Baligh R.; Cheever, Laura W.; Hauck, Heather; Korthuis, P. Todd; Mathews, W. Christopher; Keruly, Jeanne; Nijhawan, Ank E.; Agwu, Allison L.; Somboonwit, Charurut; Moore, Richard D.; Gebo, Kelly A.

2016-01-01

Background. Before implementation of the Patient Protection and Affordable Care Act (ACA) in 2014, 100 000 persons living with human immunodeficiency virus (HIV) (PLWH) lacked healthcare coverage and relied on a safety net of Ryan White HIV/AIDS Program support, local charities, or uncompensated care (RWHAP/Uncomp) to cover visits to HIV providers. We compared HIV provider coverage before (2011–2013) versus after (first half of 2014) ACA implementation among a total of 28 374 PLWH followed up in 4 sites in Medicaid expansion states (California, Oregon, and Maryland), 4 in a state (New York) that expanded Medicaid in 2001, and 2 in nonexpansion states (Texas and Florida). Methods. Multivariate multinomial logistic models were used to assess changes in RWHAP/Uncomp, Medicaid, and private insurance coverage, using Medicare as a referent. Results. In expansion state sites, RWHAP/Uncomp coverage decreased (unadjusted, 28% before and 13% after ACA; adjusted relative risk ratio [ARRR], 0.44; 95% confidence interval [CI], .40–.48). Medicaid coverage increased (23% and 38%; ARRR, 1.82; 95% CI, 1.70–1.94), and private coverage was unchanged (21% and 19%; 0.96; .89–1.03). In New York sites, both RWHAP/Uncomp (20% and 19%) and Medicaid (50% and 50%) coverage were unchanged, while private coverage decreased (13% and 12%; ARRR, 0.86; 95% CI, .80–.92). In nonexpansion state sites, RWHAP/Uncomp (57% and 52%) and Medicaid (18% and 18%) coverage were unchanged, while private coverage increased (4% and 7%; ARRR, 1.79; 95% CI, 1.62–1.99). Conclusions. In expansion state sites, half of PLWH relying on RWHAP/Uncomp coverage shifted to Medicaid, while in New York and nonexpansion state sites, reliance on RWHAP/Uncomp remained constant. In the first half of 2014, the ACA did not eliminate the need for RWHAP safety net provider visit coverage. PMID:27143660

Examples of S1 coverage intervals with very good and very bad long-run success rate

NASA Astrophysics Data System (ADS)

Giaquinto, Nicola; Fabbiano, Laura

2016-04-01

The paper illustrates, by means of selected examples, the merits and the limits of the method for computing coverage intervals described in the Supplement 1 to the GUM. The assessment of coverage intervals is done by evaluating their long-run success rate. Three pairs of examples are presented, relative to three different ways of generating incomplete knowledge about quantities: toss of dice, presence of additive noise, quantization. In all the pairs of examples, the first one results in a coverage interval with a long-run success rate equal to the coverage probability (set to 95%); the second one, instead, yields an interval with a success rate near to zero. The paper shows that the propagation mechanism of the Supplement 1, while working well in certain special cases, yields unacceptable results in others, and that the problematic issues cannot be neglected. The conclusion is that, if a Bayesian approach to uncertainty evaluation is adopted, the propagation is a particularly delicate issue.

Acellular dermal matrix and subepithelial connective tissue grafts for root coverage: A systematic review

PubMed Central

Gallagher, Sarah Ivy; Matthews, Debora Candace

2017-01-01

Background: The aim of this systematic review was to evaluate whether patients with gingival recession would benefit from an acellular dermal matrix graft (ADMG) in ways that are comparable to the gold standard of the subepithelial connective tissue graft (SCTG). Materials and Methods: A systematic review and meta-analysis comparing ADMG to SCTG for the treatment of Miller Class I and II recession defects was conducted according to PRISMA guidelines. PubMed, Excerpta Medica Database, and Cochrane Central Register of Controlled Trials databases were searched up to March 2016 for controlled trials with minimum 6 months duration. The primary outcome was root coverage; secondary outcomes included attachment level change, keratinized tissue (KT) change, and patient-based outcomes. Both authors independently assessed the quality of each included trial and extracted the relevant data. Results: From 158 potential titles, 17 controlled trials were included in the meta-analysis. There were no differences between ADMG and SCTG for mean root coverage, percent root coverage, and clinical attachment level gain. ADMG was statistically better than SCTG for gain in width of KT (−0.43 mm; 95% confidence interval: −0.72, −0.15). Only one study compared patient-based outcomes. Conclusion: This review found that an ADMG would be a suitable root coverage substitute for an SCTG when avoidance of the second surgical site is preferred. PMID:29551861

Outcomes for Spine Stereotactic Body Radiation Therapy and an Analysis of Predictors of Local Recurrence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishop, Andrew J.; Tao, Randa; Rebueno, Neal C.

Purpose: To investigate local control, survival outcomes, and predictors of local relapse for patients treated with spine stereotactic body radiation therapy. Methods and Materials: We reviewed the records of 332 spinal metastases consecutively treated with stereotactic body radiation therapy between 2002 and 2012. The median follow-up for all living patients was 33 months (range, 0-111 months). Endpoints were overall survival and local control (LC); recurrences were classified as either in-field or marginal. Results: The 1-year actuarial LC and overall survival rates were 88% and 64%, respectively. Patients with local relapses had poorer dosimetric coverage of the gross tumor volume (GTV) compared withmore » patients without recurrence (minimum dose [Dmin] biologically equivalent dose [BED] 23.9 vs 35.1 Gy, P<.001; D98 BED 41.8 vs 48.1 Gy, P=.001; D95 BED 47.2 vs 50.5 Gy, P=.004). Furthermore, patients with marginal recurrences had poorer prescription coverage of the GTV (86% vs 93%, P=.01) compared with those with in-field recurrences, potentially because of more upfront spinal canal disease (78% vs 24%, P=.001). Using a Cox regression univariate analysis, patients with a GTV BED Dmin ≥33.4 Gy (median dose) (equivalent to 14 Gy in 1 fraction) had a significantly higher 1-year LC rate (94% vs 80%, P=.001) compared with patients with a lower GTV BED Dmin; this factor was the only significant variable on multivariate Cox analysis associated with LC (P=.001, hazard ratio 0.29, 95% confidence interval 0.14-0.60) and also was the only variable significant in a separate competing risk multivariate model (P=.001, hazard ratio 0.30, 95% confidence interval 0.15-0.62). Conclusions: Stereotactic body radiation therapy offers durable control for spinal metastases, but there is a subset of patients that recur locally. Patients with local relapse had significantly poorer tumor coverage, which was likely attributable to treatment planning directives that prioritized the spinal cord constraints over tumor coverage. When possible, we recommend maintaining a GTV Dmin above 14 Gy in 1 fraction and 21 Gy in 3 fractions.« less

Sociodemographic predictors of variation in coverage of the national shingles vaccination programme in England, 2014/15.

PubMed

Ward, Charlotte; Byrne, Lisa; White, Joanne M; Amirthalingam, Gayatri; Tiley, Karen; Edelstein, Michael

2017-04-25

In September 2013, England introduced a shingles vaccination programme to reduce incidence and severity of shingles in the elderly. This study aims to assess variation in vaccine coverage with regards to selected sociodemographic factors to inform activities for improving equity of the programme. Eligible 70year-olds were identified from a national vaccine coverage dataset in 2014/15 that includes 95% of GPs in England. NHS England Local Team (LT) and index of multiple deprivation (IMD) scores were assigned to patients based on GP-postcode. Vaccine coverage (%) with 95% confidence intervals (CIs), were calculated overall and by LT, ethnicity and IMD, using binomial regression. Of 502,058 eligible adults, 178,808 (35.6%) had ethnicity recorded. Crude vaccine coverage was 59.5% (95%CI: 59.3-59.7). Coverage was lowest in London (49.6% coverage, 95%CI: 49.0-50.2), and compared to this coverage was significantly higher in all other LTs (+6.3 to +10.4, p<0.001) after adjusting for ethnicity and IMD. Coverage decreased with increasing deprivation and was 8.2% lower in the most deprived (95%CI: 7.3-9.1) compared with the least deprived IMD quintile (64.1% coverage, 95%CI: 63.6-64.6), after adjustment for ethnicity and LT. Compared with White-British (60.7% coverage, 95%CI: 60.5-61.0), other ethnic groups had between 4.0% (Indian) and 21.8% (Mixed: White and Black African) lower coverage. After adjusting for IMD and LT, significantly lower coverage by ethnicity persisted in all groups, except in Mixed: Other, Indian and Bangladeshi compared with White-British. After taking geography and deprivation into account, shingles vaccine coverage varied by ethnicity. White-British, Indian and Bangladeshi groups had highest coverage; Mixed: White and Black African, and Black-other ethnicities had the lowest. Patients' ethnicity and IMD are predictors of coverage which contribute to, but do not wholly account for, geographical variation coverage. Interventions to address service-related, sociodemographic and ethnic inequalities in shingles vaccine coverage are required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental Chemicals in Urine and Blood: Improving Methods for Creatinine and Lipid Adjustment

PubMed Central

O’Brien, Katie M.; Upson, Kristen; Cook, Nancy R.; Weinberg, Clarice R.

2015-01-01

Background Investigators measuring exposure biomarkers in urine typically adjust for creatinine to account for dilution-dependent sample variation in urine concentrations. Similarly, it is standard to adjust for serum lipids when measuring lipophilic chemicals in serum. However, there is controversy regarding the best approach, and existing methods may not effectively correct for measurement error. Objectives We compared adjustment methods, including novel approaches, using simulated case–control data. Methods Using a directed acyclic graph framework, we defined six causal scenarios for epidemiologic studies of environmental chemicals measured in urine or serum. The scenarios include variables known to influence creatinine (e.g., age and hydration) or serum lipid levels (e.g., body mass index and recent fat intake). Over a range of true effect sizes, we analyzed each scenario using seven adjustment approaches and estimated the corresponding bias and confidence interval coverage across 1,000 simulated studies. Results For urinary biomarker measurements, our novel method, which incorporates both covariate-adjusted standardization and the inclusion of creatinine as a covariate in the regression model, had low bias and possessed 95% confidence interval coverage of nearly 95% for most simulated scenarios. For serum biomarker measurements, a similar approach involving standardization plus serum lipid level adjustment generally performed well. Conclusions To control measurement error bias caused by variations in serum lipids or by urinary diluteness, we recommend improved methods for standardizing exposure concentrations across individuals. Citation O’Brien KM, Upson K, Cook NR, Weinberg CR. 2016. Environmental chemicals in urine and blood: improving methods for creatinine and lipid adjustment. Environ Health Perspect 124:220–227; http://dx.doi.org/10.1289/ehp.1509693 PMID:26219104

Correcting bias due to missing stage data in the non-parametric estimation of stage-specific net survival for colorectal cancer using multiple imputation.

PubMed

Falcaro, Milena; Carpenter, James R

2017-06-01

Population-based net survival by tumour stage at diagnosis is a key measure in cancer surveillance. Unfortunately, data on tumour stage are often missing for a non-negligible proportion of patients and the mechanism giving rise to the missingness is usually anything but completely at random. In this setting, restricting analysis to the subset of complete records gives typically biased results. Multiple imputation is a promising practical approach to the issues raised by the missing data, but its use in conjunction with the Pohar-Perme method for estimating net survival has not been formally evaluated. We performed a resampling study using colorectal cancer population-based registry data to evaluate the ability of multiple imputation, used along with the Pohar-Perme method, to deliver unbiased estimates of stage-specific net survival and recover missing stage information. We created 1000 independent data sets, each containing 5000 patients. Stage data were then made missing at random under two scenarios (30% and 50% missingness). Complete records analysis showed substantial bias and poor confidence interval coverage. Across both scenarios our multiple imputation strategy virtually eliminated the bias and greatly improved confidence interval coverage. In the presence of missing stage data complete records analysis often gives severely biased results. We showed that combining multiple imputation with the Pohar-Perme estimator provides a valid practical approach for the estimation of stage-specific colorectal cancer net survival. As usual, when the percentage of missing data is high the results should be interpreted cautiously and sensitivity analyses are recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measles susceptibility in young Thai men suggests need for young adult measles vaccination: a cross sectional study.

PubMed

Gonwong, Siriphan; Chuenchitra, Thippawan; Khantapura, Patchariya; Islam, Dilara; Mason, Carl J

2016-04-11

Measles remains a major public health concern in Thailand despite the introduction of vaccination since 1984. Similar to other countries, Thailand has experienced numerous measles outbreaks including adult communities such as university student dormitories, prisons, refugee camps, and military recruit camps. These outbreaks raise questions on the seroprotective antibody level in Thai adults. To better understand measles susceptibility in young Thai adults, a retrospective measles seroprevalence study on repository serum specimens obtained with informed consent from young Thai men entering the Royal Thai Army (RTA) during 2007-2008 was conducted. A total of 7760 stratified randomized samples were chosen by residence province. Measles IgG titer was measured using a commercial IgG quantitative ELISA kit following the manufacturer's instructions. An antibody level ≥ 250 International Units per Liter (IU/L) was interpreted as seropositive. The overall measles seroprevalence was 78.5 % (95 % Confidence Interval: 77.6-79.4 %) with geometric mean titer of 738 IU/L (95 % Confidence Interval: 716-760 IU/L). The measles seroprevalence by province ranged from 59.6 % to 93.1 %. A trend of decreasing seroprevalence in the younger cohorts despite increasing immunization coverage was found. Lower seroprevalence than vaccination coverage was observed in the youngest age group. To achieve long term measles control and elimination, an integrated two doses vaccination strategy has been implemented in children in Thailand. This nationwide measles seroprevalence study in young adult RTA recruits found a measles seroprevalence lower than WHO's recommendation for measles outbreak prevention and elimination. These results raise concerns for measles control in Thailand. Supplementary immunization in young adults is essential especially in high-risk and densely populated communities to establish herd immunity for outbreak prevention and elimination.

Changes in prescription contraceptive use, 1995-2002: the effect of insurance status.

PubMed

Culwell, Kelly R; Feinglass, Joe

2007-12-01

To examine changes in prescription contraception use between 1995 and 2002 by insurance status among women at risk for unintended pregnancy. Data from the National Survey of Family Growth, including 4,767 women at risk of unintended pregnancy in 1995 and 3,569 in 2002, were used to evaluate changes in primary contraception methods by health insurance status and year of survey. Logistic regression models tested differences in the likelihood of prescription contraceptive use among privately insured, publicly insured, and uninsured women in each year, after controlling for age, race and ethnicity, education, income, employment, marital status, number of children, religion, and self reported overall health. Overall prescription contraceptive use increased between 1995 and 2002 by 3% (48.9% to 51.9%, P=.049). Nonuse of contraception also increased (11.6% to 16.1%, P<.001). The change in the likelihood of prescription contraceptive use was greatest and only significant among privately insured women (+5.5%, P=.002). In multiple regression analysis, women in 1995 were 10% less likely to report use of prescription contraceptives compared with women in 2002 (relative risk 0.90, 95% confidence interval 0.82-0.98), and uninsured women were more than 20% less likely to report prescription contraceptive use compared with privately insured women (relative risk 0.78, 95% confidence interval 0.67-0.90). Prescription contraceptive use increased most significantly among privately insured women between 1995 and 2002, potentially reflecting state mandates enacted during that period requiring contraceptive coverage by private insurers. It is important for clinicians to understand these differences and address issues of insurance coverage with patients when discussing contraceptive options. III.

Variance estimation when using inverse probability of treatment weighting (IPTW) with survival analysis.

PubMed

Austin, Peter C

2016-12-30

Propensity score methods are used to reduce the effects of observed confounding when using observational data to estimate the effects of treatments or exposures. A popular method of using the propensity score is inverse probability of treatment weighting (IPTW). When using this method, a weight is calculated for each subject that is equal to the inverse of the probability of receiving the treatment that was actually received. These weights are then incorporated into the analyses to minimize the effects of observed confounding. Previous research has found that these methods result in unbiased estimation when estimating the effect of treatment on survival outcomes. However, conventional methods of variance estimation were shown to result in biased estimates of standard error. In this study, we conducted an extensive set of Monte Carlo simulations to examine different methods of variance estimation when using a weighted Cox proportional hazards model to estimate the effect of treatment. We considered three variance estimation methods: (i) a naïve model-based variance estimator; (ii) a robust sandwich-type variance estimator; and (iii) a bootstrap variance estimator. We considered estimation of both the average treatment effect and the average treatment effect in the treated. We found that the use of a bootstrap estimator resulted in approximately correct estimates of standard errors and confidence intervals with the correct coverage rates. The other estimators resulted in biased estimates of standard errors and confidence intervals with incorrect coverage rates. Our simulations were informed by a case study examining the effect of statin prescribing on mortality. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

A Profile of Indian Health Service Emergency Departments.

PubMed

Bernard, Kenneth; Hasegawa, Kohei; Sullivan, Ashley; Camargo, Carlos

2017-06-01

The Indian Health Service provides health care to eligible American Indians and Alaskan Natives. No published data exist on emergency services offered by this unique health care system. We seek to determine the characteristics and capabilities of Indian Health Service emergency departments (EDs). All Indian Health Service EDs were surveyed about demographics and operational characteristics for 2014 with the National Emergency Department Inventory survey (available at http://www.emnet-nedi.org/). Of the forty eligible sites, there were 34 respondents (85% response rate). Respondents reported a total of 637,523 ED encounters, ranging from 521 to 63,200 visits per site. Overall, 85% (95% confidence interval 70% to 94%) had continuous physician coverage. Of all physicians staffing the ED, a median of 13% (interquartile range 0% to 50%) were board certified or board prepared in emergency medicine. Overall, 50% (95% confidence interval 34% to 66%) of respondents reported that their ED was operating over capacity. Indian Health Service EDs varied widely in visit volume, with many operating over capacity. Most were not staffed by board-certified or -prepared emergency physicians. Most lacked access to specialty consultation and telemedicine capabilities. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Immunization coverage among Hispanic ancestry, 2003 National Immunization Survey.

PubMed

Darling, Natalie J; Barker, Lawrence E; Shefer, Abigail M; Chu, Susan Y

2005-12-01

The Hispanic population is increasing and heterogeneous (Hispanic refers to persons of Spanish, Hispanic, or Latino descent). The objective was to examine immunization rates among Hispanic ancestry for the 4:3:1:3:3 series (> or = 4 doses diphtheria, tetanus toxoids, and pertussis vaccine; > or = 3 doses poliovirus vaccine; > or = 1 doses measles-containing vaccine; > or = 3 doses Haemophilus influenzae type b vaccine; and > or = 3 doses hepatitis B vaccine). The National Immunization Survey measures immunization coverage among 19- to 35-month-old U.S. children. Coverage was compared from combined 2001-2003 data among Hispanics and non-Hispanic whites using t-tests, and among Hispanic ancestry using a chi-square test. Hispanics were categorized as Mexican, Mexican American, Central American, South American, Puerto Rican, Cuban, Spanish Caribbean (primarily Dominican Republic), other, and multiple ancestry. Children of Hispanic ancestry increased from 21% in 1999 to 25% in 2003. These Hispanic children were less well immunized than non-Hispanic whites (77.0%, +/-2.1% [95% confidence interval] compared to 82.5%, +/-1.1% (95% CI) > in 2003). Immunization coverage did not vary significantly among Hispanics of varying ancestries (p=0.26); however, there was substantial geographic variability. In some areas, immunization coverage among Hispanics was significantly higher than non-Hispanic whites. Hispanic children were less well immunized than non-Hispanic whites; however, coverage varied notably by geographic area. Although a chi-square test found no significant differences in coverage among Hispanic ancestries, the range of coverage, 79.2%, +/-5.1% for Cuban Americans to 72.1%, +/-2.4% for Mexican descent, may suggest a need for improved and more localized monitoring among Hispanic communities.

Effect of maternal HIV status on vaccination coverage among sub-Saharan African children: A socio-ecological analysis.

PubMed

Adetokunboh, Olatunji O; Uthman, Olalekan A; Wiysonge, Charles S

2018-05-02

We investigated the relationship between maternal HIV status and uptake of the full series of three doses of diphtheria-tetanus-pertussis containing vaccines (DTP3) in sub-Saharan African children. We used data obtained from demographic and health surveys conducted in sub-Saharan Africa. We conducted meta-analysis and calculated pooled odds ratios (OR) for the association between maternal HIV status and DTP3 vaccination status for each country. A total of 4,187 out of 5,537 children of women living with HIV received DTP3 (75.6%), compared to 71,290 of 113,513 (62.8%) children of HIV negative women. National DTP3 coverage among children of HIV-positive women varied between 24% and 96% while among children of HIV negative women it was between 26% and 92%. Overall pooled result showed no significant difference in DTP3 coverage between the two groups (OR = 1.05; 95% confidence interval 0.91 - 1.22), with statistically significant heterogeneity (Chi 2 = 91.63, P = 0.000, I 2 = 71.6%). There was no significant association between DTP3 coverage and maternal HIV status in sub-Saharan Africa. However, DTP3 coverage for both HIV-exposed and non-exposed children were below the required target. Meta-regression revealed no significant association between DTP3 coverage and country characteristics (e.g. HIV prevalence among women, antiretroviral therapy coverage, gross domestic product per capita, human development index, adult literacy rate and sub-region). Improved prevention of mother-to-child transmission services might have contributed to some extent to the higher DTP3 vaccination coverage among the HIV-exposed children. There is also need to address barriers impeding uptake of vaccination among HIV-exposed and non-exposed children.

Coverage and Consumption of Micronutrient Powders, Fortified Staples, and Iodized Salt Among Children Aged 6 to 23 Months in Selected Neighborhoods of Nairobi County, Kenya.

PubMed

Leyvraz, Magali; David-Kigaru, Dorcus M; Macharia-Mutie, Catherine; Aaron, Grant J; Roefs, Marlene; Tumilowicz, Alison

2018-03-01

Intake of micronutrient-rich foods among children aged 6 to 23 months in Nairobi is low. This study aimed to assess existing coverage and utilization of micronutrient powders (MNPs), fortified staples, and iodized salt among children aged 6 to 23 months prior to implementation of an MNP program. A cross-sectional survey among caregivers of children aged 6 to 23 months (n = 618) was implemented in 7 neighborhoods within Nairobi County, representing the implementation area of the new MNP program. Results for MNP coverage and utilization showed 28.5% of all caregivers were aware of MNP, 18.5% had ever received MNP for their child, and 10.8% had fed MNP to their child in the previous 7 days. Effective coverage (ie, the child had been given the MNP at least 3 times in the previous 7 days) was 5.8%. Effective coverage of infants and young children with poor feeding practices was significantly lower as compared to those with non-poor feeding practices (coverage ratio, 0.34; confidence interval, 0.12-0.70). Most households purchased iodized salt (96.9%), fortified oil (61.0%), and fortified maize flour (93.9%). An estimated 23.9% of vitamin A requirements of children (6-23 months) were provided from fortified oil and 50.7% of iron from fortified maize flour. Most households consumed processed milk (81%). Coverage of MNPs in the surveyed neighborhoods was low. Coverage of fortified salt, oil, and maize flour was high and provided significant amount of micronutrients to children. Processed milk has potential as a vehicle for food fortification.

Impact of Medicare Part D on Antidepressant Treatment, Medication Choice and Adherence among Older Adults with Depression

PubMed Central

Donohue, Julie M.; Zhang, Yuting; Men, Aiju; Perera, Subashan; Lave, Judith R.; Hanlon, Joseph T.; Reynolds, Charles F.

2010-01-01

Objectives Depression in older adults is often undertreated due, in part, to medication costs. We examined the impact of improved prescription drug coverage under Medicare Part D on use of antidepressants, medication choice and adherence. Design, Setting and Participants Observational claims-based study of older adults with depression (ICD-9: 296.2, 296.3, 311, 300.4) continuously enrolled in a Medicare managed care plan between 2004–2007. Three groups with limited ($150 or $350 quarterly caps) or no drug coverage in 2004–2005 obtained Part D benefits in 2006. A comparison group had stable employer-sponsored coverage throughout. Measurements Any antidepressant prescription fill, antidepressant choice (tricyclics or monoamine oxidase inhibitors vs. newer antidepressants), and adherence (80% of days covered) in the first 6 months of treatment. Results Part D was associated with increased odds of any antidepressant use among those who previously lacked coverage [Odds Ratio (OR) 1.61, 95% confidence interval (CI) 1.41–1.85] but odds of use did not change among those with limited prior coverage. Use of older antidepressant agents did not change with Part D. All three groups whose coverage improved with Part D had significantly higher odds of 80% of days covered with an antidepressant [OR=1.86 (95% CI, 1.44–2.39) for No coverage, 1.74 (95% CI, 1.25–3.42) for $150 cap; and 1.19 (95% CI 1.06–1.34) for the $350 cap groups]. Conclusions Medicare Part D was associated with improvements in antidepressant use and adherence in depressed older adults who previously had no or limited drug coverage but not with changes in use of older agents. PMID:22123272

Likelihood ratio meta-analysis: New motivation and approach for an old method.

PubMed

Dormuth, Colin R; Filion, Kristian B; Platt, Robert W

2016-03-01

A 95% confidence interval (CI) in an updated meta-analysis may not have the expected 95% coverage. If a meta-analysis is simply updated with additional data, then the resulting 95% CI will be wrong because it will not have accounted for the fact that the earlier meta-analysis failed or succeeded to exclude the null. This situation can be avoided by using the likelihood ratio (LR) as a measure of evidence that does not depend on type-1 error. We show how an LR-based approach, first advanced by Goodman, can be used in a meta-analysis to pool data from separate studies to quantitatively assess where the total evidence points. The method works by estimating the log-likelihood ratio (LogLR) function from each study. Those functions are then summed to obtain a combined function, which is then used to retrieve the total effect estimate, and a corresponding 'intrinsic' confidence interval. Using as illustrations the CAPRIE trial of clopidogrel versus aspirin in the prevention of ischemic events, and our own meta-analysis of higher potency statins and the risk of acute kidney injury, we show that the LR-based method yields the same point estimate as the traditional analysis, but with an intrinsic confidence interval that is appropriately wider than the traditional 95% CI. The LR-based method can be used to conduct both fixed effect and random effects meta-analyses, it can be applied to old and new meta-analyses alike, and results can be presented in a format that is familiar to a meta-analytic audience. Copyright © 2016 Elsevier Inc. All rights reserved.

Blood Pressure, Antihypertensive Polypharmacy, Frailty, and Risk for Serious Fall Injuries Among Older Treated Adults With Hypertension.

PubMed

Bromfield, Samantha G; Ngameni, Cedric-Anthony; Colantonio, Lisandro D; Bowling, C Barrett; Shimbo, Daichi; Reynolds, Kristi; Safford, Monika M; Banach, Maciej; Toth, Peter P; Muntner, Paul

2017-08-01

Antihypertensive medication and low systolic blood pressure (BP) and diastolic BP have been associated with an increased falls risk in some studies. Many older adults have indicators of frailty, which may increase their risk for falls. We contrasted the association of systolic BP, diastolic BP, number of antihypertensive medication classes taken, and indicators of frailty with risk for serious fall injuries among 5236 REGARDS study (Reasons for Geographic and Racial Difference in Stroke) participants ≥65 years taking antihypertensive medication at baseline with Medicare fee-for-service coverage. Systolic BP and diastolic BP were measured, and antihypertensive medication classes being taken assessed through a pill bottle review during a study visit. Indicators of frailty included low body mass index, cognitive impairment, depressive symptoms, exhaustion, impaired mobility, and history of falls. Serious fall injuries were defined as fall-related fractures, brain injuries, or joint dislocations using Medicare claims through December 31, 2014. Over a median of 6.4 years, 802 (15.3%) participants had a serious fall injury. The multivariable-adjusted hazard ratio for a serious fall injury among participants with 1, 2, or ≥3 indicators of frailty versus no frailty indicators was 1.18 (95% confidence interval, 0.99-1.40), 1.49 (95% confidence interval, 1.19-1.87), and 2.04 (95% confidence interval, 1.56-2.67), respectively. Systolic BP, diastolic BP, and number of antihypertensive medication classes being taken at baseline were not associated with risk for serious fall injuries after multivariable adjustment. In conclusion, indicators of frailty, but not BP or number of antihypertensive medication classes, were associated with increased risk for serious fall injuries among older adults taking antihypertensive medication. © 2017 American Heart Association, Inc.

speed-ne: Software to simulate and estimate genetic effective population size (Ne ) from linkage disequilibrium observed in single samples.

PubMed

Hamilton, Matthew B; Tartakovsky, Maria; Battocletti, Amy

2018-05-01

The genetic effective population size, N e , can be estimated from the average gametic disequilibrium (r2^) between pairs of loci, but such estimates require evaluation of assumptions and currently have few methods to estimate confidence intervals. speed-ne is a suite of matlab computer code functions to estimate Ne^ from r2^ with a graphical user interface and a rich set of outputs that aid in understanding data patterns and comparing multiple estimators. speed-ne includes functions to either generate or input simulated genotype data to facilitate comparative studies of Ne^ estimators under various population genetic scenarios. speed-ne was validated with data simulated under both time-forward and time-backward coalescent models of genetic drift. Three classes of estimators were compared with simulated data to examine several general questions: what are the impacts of microsatellite null alleles on Ne^, how should missing data be treated, and does disequilibrium contributed by reduced recombination among some loci in a sample impact Ne^. Estimators differed greatly in precision in the scenarios examined, and a widely employed Ne^ estimator exhibited the largest variances among replicate data sets. speed-ne implements several jackknife approaches to estimate confidence intervals, and simulated data showed that jackknifing over loci and jackknifing over individuals provided ~95% confidence interval coverage for some estimators and should be useful for empirical studies. speed-ne provides an open-source extensible tool for estimation of Ne^ from empirical genotype data and to conduct simulations of both microsatellite and single nucleotide polymorphism (SNP) data types to develop expectations and to compare Ne^ estimators. © 2018 John Wiley & Sons Ltd.

Reducing the width of confidence intervals for the difference between two population means by inverting adaptive tests.

PubMed

O'Gorman, Thomas W

2018-05-01

In the last decade, it has been shown that an adaptive testing method could be used, along with the Robbins-Monro search procedure, to obtain confidence intervals that are often narrower than traditional confidence intervals. However, these confidence interval limits require a great deal of computation and some familiarity with stochastic search methods. We propose a method for estimating the limits of confidence intervals that uses only a few tests of significance. We compare these limits to those obtained by a lengthy Robbins-Monro stochastic search and find that the proposed method is nearly as accurate as the Robbins-Monro search. Adaptive confidence intervals that are produced by the proposed method are often narrower than traditional confidence intervals when the distributions are long-tailed, skewed, or bimodal. Moreover, the proposed method of estimating confidence interval limits is easy to understand, because it is based solely on the p-values from a few tests of significance.

Two Highly Immunized Hilly Areas versus Double Measles Outbreak Investigations in District Kangra, Himachal Pradesh, India, in 2006

PubMed Central

Gupta, Surender N; Gupta, Naveen

2009-01-01

Background: We investigated two sequential outbreaks of measles in seven villages of Kangra, to confirm the diagnosis and to formulate recommendations for prevention and control. Methods: We defined a case of measles as occurrence of fever with rash in a child aged six months to 17 years during the period 3rd September to 23rd November 2006. We collected information on age, sex, residence, date of onset, symptoms, signs, treatment taken, traveling history and vaccination status. We described the outbreak by time, place and person. We estimated vaccine coverage and efficacy in the affected villages. We confirmed diagnosis clinically, serologically and through genotyping of the virus. Results: We identified 69 cases. Overall attack rates ranged between 4.2% and 6%. All case patients were between 6 years to 11 years of age. Age-specific attack rate in double outbreaks ranged in between 1.7% and 21.6%, the highest being in the age range 11–17 years. No deaths or complications were reported. The epidemic curve was suggestive of typical propagated pattern. The first outbreak imported virus after an interschool game competition (relative risk, 6.44%; 95% confidence interval, 3.81–10.91); followed by the second outbreak, in which people exchanged foods in the festival in one infected village of the first outbreak (relative risk, 5.3; 95% confidence interval, 1.90–14.77; P <.001). The calculated immunization coverage (93%) coincided nearly with administrative claims. The vaccine efficacies were estimated to be 85% and 81% in the first and second outbreaks respectively. Eleven of the 16 case patients were tested for measles IgM antibodies, while two nasopharyngeal swabs were positive by polymerase chain reaction (PCR) and are genotyped D4 measles strain. Vitamin A supplementations were only given in four villages. Conclusion: Measles outbreaks were confirmed in high–immunization-coverage areas. We recommended (i) second dose opportunity for measles in Himachal Pradesh and (ii) vitamin A supplementation to all the case patients. PMID:20300381

Retrospective measles outbreak investigation: Sudan, 2004.

PubMed

Coronado, Fátima; Musa, Nisreen; El Tayeb, El Sayed Ahmed; Haithami, Salah; Dabbagh, Alya; Mahoney, Frank; Nandy, Robin; Cairns, Lisa

2006-10-01

Recent population-based studies of measles incidence and deaths in Sudan are not available. To determine the epidemiology and case-fatality rate (CFR) of measles, we conducted a retrospective outbreak investigation in two states in northern Sudan. Of 1144 case-patients identified, 92% were <15 years; 48.6% were vaccinated; and 62% received vitamin A before illness. Ten measles-associated deaths were identified (CFR 0.9%; 95% confidence interval 0.16-1.91). CFR determined by this investigation is lower than expected for the region but remains 10 times higher than that in developed countries. Measles control should be strengthened by improving vaccine coverage, measles surveillance and case-management.

Constructing Confidence Intervals for Reliability Coefficients Using Central and Noncentral Distributions.

ERIC Educational Resources Information Center

Weber, Deborah A.

Greater understanding and use of confidence intervals is central to changes in statistical practice (G. Cumming and S. Finch, 2001). Reliability coefficients and confidence intervals for reliability coefficients can be computed using a variety of methods. Estimating confidence intervals includes both central and noncentral distribution approaches.…

Can 3-dimensional power Doppler indices improve the prenatal diagnosis of a potentially morbidly adherent placenta in patients with placenta previa?

PubMed

Haidar, Ziad A; Papanna, Ramesha; Sibai, Baha M; Tatevian, Nina; Viteri, Oscar A; Vowels, Patricia C; Blackwell, Sean C; Moise, Kenneth J

2017-08-01

Traditionally, 2-dimensional ultrasound parameters have been used for the diagnosis of a suspected morbidly adherent placenta previa. More objective techniques have not been well studied yet. The objective of the study was to determine the ability of prenatal 3-dimensional power Doppler analysis of flow and vascular indices to predict the morbidly adherent placenta objectively. A prospective cohort study was performed in women between 28 and 32 gestational weeks with known placenta previa. Patients underwent a two-dimensional gray-scale ultrasound that determined management decisions. 3-Dimensional power Doppler volumes were obtained during the same examination and vascular, flow, and vascular flow indices were calculated after manual tracing of the viewed placenta in the sweep; data were blinded to obstetricians. Morbidly adherent placenta was confirmed by histology. Severe morbidly adherent placenta was defined as increta/percreta on histology, blood loss >2000 mL, and >2 units of PRBC transfused. Sensitivities, specificities, predictive values, and likelihood ratios were calculated. Student t and χ 2 tests, logistic regression, receiver-operating characteristic curves, and intra- and interrater agreements using Kappa statistics were performed. The following results were found: (1) 50 women were studied: 23 had morbidly adherent placenta, of which 12 (52.2%) were severe morbidly adherent placenta; (2) 2-dimensional parameters diagnosed morbidly adherent placenta with a sensitivity of 82.6% (95% confidence interval, 60.4-94.2), a specificity of 88.9% (95% confidence interval, 69.7-97.1), a positive predictive value of 86.3% (95% confidence interval, 64.0-96.4), a negative predictive value of 85.7% (95% confidence interval, 66.4-95.3), a positive likelihood ratio of 7.4 (95% confidence interval, 2.5-21.9), and a negative likelihood ratio of 0.2 (95% confidence interval, 0.08-0.48); (3) mean values of the vascular index (32.8 ± 7.4) and the vascular flow index (14.2 ± 3.8) were higher in morbidly adherent placenta (P < .001); (4) area under the receiver-operating characteristic curve for the vascular and vascular flow indices were 0.99 and 0.97, respectively; (5) the vascular index ≥21 predicted morbidly adherent placenta with a sensitivity and a specificity of 95% (95% confidence interval, 88.2-96.9) and 91%, respectively (95% confidence interval, 87.5-92.4), 92% positive predictive value (95% confidence interval, 85.5-94.3), 90% negative predictive value (95% confidence interval, 79.9-95.3), positive likelihood ratio of 10.55 (95% confidence interval, 7.06-12.75), and negative likelihood ratio of 0.05 (95% confidence interval, 0.03-0.13); and (6) for the severe morbidly adherent placenta, 2-dimensional ultrasound had a sensitivity of 33.3% (95% confidence interval, 11.3-64.6), a specificity of 81.8% (95% confidence interval, 47.8-96.8), a positive predictive value of 66.7% (95% confidence interval, 24.1-94.1), a negative predictive value of 52.9% (95% confidence interval, 28.5-76.1), a positive likelihood ratio of 1.83 (95% confidence interval, 0.41-8.11), and a negative likelihood ratio of 0.81 (95% confidence interval, 0.52-1.26). A vascular index ≥31 predicted the diagnosis of a severe morbidly adherent placenta with a 100% sensitivity (95% confidence interval, 72-100), a 90% specificity (95% confidence interval, 81.7-93.8), an 88% positive predictive value (95% confidence interval, 55.0-91.3), a 100% negative predictive value (95% confidence interval, 90.9-100), a positive likelihood ratio of 10.0 (95% confidence interval, 3.93-16.13), and a negative likelihood ratio of 0 (95% confidence interval, 0-0.34). Intrarater and interrater agreements were 94% (P < .001) and 93% (P < .001), respectively. The vascular index accurately predicts the morbidly adherent placenta in patients with placenta previa. In addition, 3-dimensional power Doppler vascular and vascular flow indices were more predictive of severe cases of morbidly adherent placenta compared with 2-dimensional ultrasound. This objective technique may limit the variations in diagnosing morbidly adherent placenta because of the subjectivity of 2-dimensional ultrasound interpretations. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of lack of insurance, poverty and paediatrician supply on immunization rates among children 19-35 months of age in the United States.

PubMed

Becton, James L; Cheng, Lee; Nieman, Linda Z

2008-04-01

Previous studies found that the increasing number of paediatricians in the United States was associated with improved childhood immunization coverage, while the increasing poverty level and the lack of health insurance reduced access to health care. We evaluated whether changes in the number of paediatricians, poverty level and health insurance affected national childhood immunization coverage in the state levels of the United States. Data were collected primarily from the US National Immunization Surveys, series 4:3:1:3:3 from years 1995 and 2003. Ordinal logistic regression analysis was used to analyse the relationships among variables. Over 8 years studied, immunization coverage increased for children aged 19-35 months from 52.3% to 79.8% in the 50 states. The average number of paediatricians per 1000 births increased 28.7% while the percentage of children without health insurance declined 15.6%, and the percentage of children who lived in poverty level declined 17.3%. In 1995, the states with higher immunization coverage were associated with higher numbers of paediatricians [odds ratio (OR), 32.73; 95% confidence interval (CI), 5.96-179.77]. In 2003, the higher numbers of paediatricians still played a role in the increased immunization coverage (OR, 4.69; 95% CI, 1.01-21.78); however, the higher rate of uninsured children in 2003 had an even greater effect upon immunization coverage. Compared with states with lower rates of uninsured children, states with intermediate and higher rates of uninsured children had sixfold (OR, 0.16; 95% CI, 0.03-0.81) and 16-fold (OR, 0.06; 95% CI, 0.01-0.40) decreased childhood immunization coverage, respectively. Between 1995 and 2003 in the United States, the lack of health insurance became more prominent than the supply of paediatricians in affecting immunization coverage for children aged 19-35 months. Future improvements in insurance coverage for children will likely lead to greater immunization coverage.

Seasonal influenza vaccination coverage and its determinants among nursing homes personnel in western France.

PubMed

Elias, Christelle; Fournier, Anna; Vasiliu, Anca; Beix, Nicolas; Demillac, Rémi; Tillaut, Hélène; Guillois, Yvonnick; Eyebe, Serge; Mollo, Bastien; Crépey, Pascal

2017-07-07

Influenza-associated deaths is an important risk for the elderly in nursing homes (NHs) worldwide. Vaccination coverage among residents is high but poorly effective due to immunosenescence. Hence, vaccination of personnel is an efficient way to protect residents. Our objective was to quantify the seasonal influenza vaccination (IV) coverage among NH for elderly workers and identify its determinants in France. We conducted a cross-sectional study in March 2016 in a randomized sample of NHs of the Ille-et-Vilaine department of Brittany, in western France. A standardized questionnaire was administered to a randomized sample of NH workers for face-to-face interviews. General data about the establishment was also collected. Among the 33 NHs surveyed, IV coverage for the 2015-2016 season among permanent workers was estimated at 20% (95% Confidence Interval (CI) 15.3%-26.4%) ranging from 0% to 69% depending on the establishments surveyed. Moreover, IV was associated with having previously experienced a "severe" influenza episode in the past (Prevalence Ratio 1.48, 95% CI 1.01-2.17), and varied by professional categories (p < 0.004) with better coverage among administrative staff. Better knowledge about influenza prevention tools was also correlated (p < 0.001) with a higher IV coverage. Individual perceptions of vaccination benefits had a significant influence on the IV coverage (p < 0.001). Although IV coverage did not reach a high rate, our study showed that personnel considered themselves sufficiently informed about IV. IV coverage remains low in the NH worker population in Ille-et-Vilaine and also possibly in France. Strong variations of IV coverage among NHs suggest that management and working environment play an important role. To overcome vaccine "hesitancy", specific communication tools may be required to be adapted to the various NH professionals to improve influenza prevention.

State Medicaid Coverage of Medically Necessary Abortions and Severe Maternal Morbidity and Maternal Mortality.

PubMed

Jarlenski, Marian; Hutcheon, Jennifer A; Bodnar, Lisa M; Simhan, Hyagriv N

2017-05-01

To estimate the association between state Medicaid coverage of medically necessary abortion and severe maternal morbidity and in-hospital maternal mortality in the United States. We used data on pregnancy-related hospitalizations from the Nationwide Inpatient Sample from 2000 to 2011 (weighted n=38,016,845). State-level Medicaid coverage of medically necessary abortion for each year was determined from Guttmacher Institute reports. We used multivariable logistic regression to examine the association between state Medicaid coverage of abortion and severe maternal morbidity and in-hospital maternal mortality, overall and stratified by payer. The unadjusted rate of severe maternal morbidity was lower among Medicaid-paid hospitalizations in states with Medicaid coverage of medically necessary abortion relative to those in states without such coverage (62.4 compared with 69.3 per 10,000). Among Medicaid-paid hospitalizations in states with Medicaid coverage of medically necessary abortion, there were 8.5 per 10,000 fewer cases (95% confidence interval [CI] 4.0-16.5) of severe maternal morbidity in adjusted analyses relative to those in states without such Medicaid coverage. Similarly, there were 10.3 per 10,000 fewer cases (95% CI 3.5-17.2) of severe maternal morbidity in adjusted analyses among private insurance-paid hospitalizations in states with Medicaid coverage of medically necessary abortion relative to those in states without such Medicaid coverage. The adjusted rate of in-hospital maternal mortality was not different for Medicaid-paid hospitalizations in states with and without Medicaid coverage of medically necessary abortion (9.2 and 9.0 per 100,000, respectively) nor for private insurance-paid hospitalizations (5.6 and 6.1 per 100,000, respectively). State Medicaid coverage of medically necessary abortion was associated with an average 16% decreased risk of severe maternal morbidity. An association between state Medicaid coverage of medically necessary abortion and a reduced risk of severe maternal morbidity was observed in women covered by both Medicaid and private insurance. Results suggest that Medicaid coverage of medically necessary abortion is not harmful to maternal health.

Tetanus toxoid coverage as an indicator of serological protection against neonatal tetanus.

PubMed Central

Deming, Michael S.; Roungou, Jean-Baptiste; Kristiansen, Max; Heron, Iver; Yango, Alphonse; Guenengafo, Alexis; Ndamobissi, Robert

2002-01-01

OBJECTIVE: A Multiple-Indicator Cluster Survey (MICS) was conducted at mid-decade in more than 60 developing countries to measure progress towards the year 2000 World Summit for Children goals. These goals included the protection of at least 90% of children against neonatal tetanus through the immunization of their mothers, as measured by tetanus toxoid (TT) coverage. In the Central African Republic (CAR), serological testing was added to the MICS to understand better the relationship between survey estimates of TT coverage and the prevalence of serological protection. METHODS: In the CAR MICS, mothers of children younger than one year of age gave verbal histories of the TT vaccinations they had received, using the MICS TT questionnaire. A subsample of mothers was tested for tetanus antitoxin, using a double-antigen enzyme-linked immunoadsorbent assay (ELISA). Seropositivity was defined as a titre of > or =0.01 IU/ml, and TT coverage was defined as the proportion of mothers protected at delivery, according to their history of TT vaccinations. FINDINGS: Among the 222 mothers in the subsample, weighted TT coverage was 74.4% (95% Confidence Interval (CI); 67.0% - 81.7%) and tetanus antitoxin seroprevalence was 88.7% (95% CI; 83.2% - 94.2%). The weighted median antitoxin titre was 0.35 IU/ml. CONCLUSIONS: Tetanus toxoid coverage in the CAR was lower than the prevalence of serological protection against neonatal tetanus. If this relationship holds for other countries, TT coverage estimates from the MICS may underestimate the extent to which the year 2000 goal for protecting children against neonatal tetanus was reached. We also showed that a high level of serological protection had been achieved in a country facing major public health challenges and resource constraints. PMID:12378286

Human papillomavirus vaccine delivery strategies that achieved high coverage in low- and middle-income countries.

PubMed

LaMontagne, D Scott; Barge, Sandhya; Le, Nga Thi; Mugisha, Emmanuel; Penny, Mary E; Gandhi, Sanjay; Janmohamed, Amynah; Kumakech, Edward; Mosqueira, N Rocio; Nguyen, Nghi Quy; Paul, Proma; Tang, Yuxiao; Minh, Tran Hung; Uttekar, Bella Patel; Jumaan, Aisha O

2011-11-01

To assess human papillomavirus (HPV) vaccination coverage after demonstration projects conducted in India, Peru, Uganda and Viet Nam by PATH and national governments and to explore the reasons for vaccine acceptance or refusal. Vaccines were delivered through schools or health centres or in combination with other health interventions, and either monthly or through campaigns at fixed time points. Using a two-stage cluster sample design, the authors selected households in demonstration project areas and interviewed over 7000 parents or guardians of adolescent girls to assess coverage and acceptability. They defined full vaccination as the receipt of all three vaccine doses and used an open-ended question to explore acceptability. Vaccination coverage in school-based programmes was 82.6% (95% confidence interval, CI: 79.3-85.6) in Peru, 88.9% (95% CI: 84.7-92.4) in 2009 in Uganda and 96.1% (95% CI: 93.0-97.8) in 2009 in Viet Nam. In India, a campaign approach achieved 77.2% (95% CI: 72.4-81.6) to 87.8% (95% CI: 84.3-91.3) coverage, whereas monthly delivery achieved 68.4% (95% CI: 63.4-73.4) to 83.3% (95% CI: 79.3-87.3) coverage. More than two thirds of respondents gave as reasons for accepting the HPV vaccine that: (i) it protects against cervical cancer; (ii) it prevents disease, or (iii) vaccines are good. Refusal was more often driven by programmatic considerations (e.g. school absenteeism) than by opposition to the vaccine. High coverage with HPV vaccine among young adolescent girls was achieved through various delivery strategies in the developing countries studied. Reinforcing positive motivators for vaccine acceptance is likely to facilitate uptake.

Coverage of a national cardiovascular risk assessment and management programme (NHS Health Check): Retrospective database study.

PubMed

Chang, Kiara Chu-Mei; Soljak, Michael; Lee, John Tayu; Woringer, Maria; Johnston, Desmond; Khunti, Kamlesh; Majeed, Azeem; Millett, Christopher

2015-09-01

To determine coverage of NHS Health Check, a national cardiovascular risk assessment programme in England, in the first four years after implementation, and to examine prevalence of high cardiovascular disease (CVD) risk and uptake of statins in high risk patients. Study sample was 95,571 patients in England aged 40-74years continuously registered with 509 practices in the Clinical Practice Research Datalink between April 2009 and March 2013. Multilevel logistic regression models were used to assess predictors of Health Check attendance; elevated CVD risk factors and statin prescribing among attendees. Programme coverage was 21.4% over four years, with large variations between practices (0%-72.7%) and regions (9.4%-30.7%). Coverage was higher in older patients (adjusted odds ratio 2.88, 95% confidence interval 2.49-3.31 for patients 70-74years) and in patients with a family history of premature coronary heart disease (2.37, 2.22-2.53), but lower in Black Africans (0.75, 0.61-0.92) and Chinese (0.68, 0.47-0.96) compared with White British. Coverage was similar in patients living in deprived and affluent areas. Prevalence of high CVD risk (QRISK2≥20%) among attendees was 4.6%. One third (33.6%) of attendees at high risk were prescribed a statin after Health Checks. Coverage of the programme and statin prescribing in high risk individuals was low. Coverage was similar in deprived and affluent groups but lower in some ethnic minority groups, possibly widening inequalities. These findings raise a question about whether recommendations by WHO to develop CVD risk assessment programmes internationally will deliver anticipated health benefits. Copyright © 2015. Published by Elsevier Inc.

Can influenza vaccination coverage among healthcare workers influence the risk of nosocomial influenza-like illness in hospitalized patients?

PubMed

Amodio, E; Restivo, V; Firenze, A; Mammina, C; Tramuto, F; Vitale, F

2014-03-01

Approximately 20% of healthcare workers are infected with influenza each year, causing nosocomial outbreaks and staff shortages. Despite influenza vaccination of healthcare workers representing the most effective preventive strategy, coverage remains low. To analyse the risk of nosocomial influenza-like illness (NILI) among patients admitted to an acute care hospital in relation to influenza vaccination coverage among healthcare workers. Data collected over seven consecutive influenza seasons (2005-2012) in an Italian acute care hospital were analysed retrospectively. Three different sources of data were used: hospital discharge records; influenza vaccination coverage among healthcare workers; and incidence of ILI in the general population. Clinical modification codes from the International Classification of Diseases, 9(th) Revision were used to define NILI. Overall, 62,343 hospitalized patients were included in the study, 185 (0.03%) of whom were identified as NILI cases. Over the study period, influenza vaccination coverage among healthcare workers decreased from 13.2% to 3.1% (P < 0.001), whereas the frequency of NILI in hospitalized patients increased from 1.1‰ to 5.7‰ (P < 0.001). A significant inverse association was observed between influenza vaccination coverage among healthcare workers and rate of NILI among patients (adjusted odds ratio 0.97, 95% confidence interval 0.94-0.99). Increasing influenza vaccination coverage among healthcare workers could reduce the risk of NILI in patients hospitalized in acute hospitals. This study offers a reliable and cost-saving methodology that could help hospital management to assess and make known the benefits of influenza vaccination among healthcare workers. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Coverage of pilot parenteral vaccination campaign against canine rabies in N'Djaména, Chad.

PubMed Central

Kayali, U.; Mindekem, R.; Yémadji, N.; Vounatsou, P.; Kaninga, Y.; Ndoutamia, A. G.; Zinsstag, J.

2003-01-01

Canine rabies, and thus human exposure to rabies, can be controlled through mass vaccination of the animal reservoir if dog owners are willing to cooperate. Inaccessible, ownerless dogs, however, reduce the vaccination coverage achieved in parenteral campaigns. This study aimed to estimate the vaccination coverage in dogs in three study zones of N'Djaména, Chad, after a pilot free parenteral mass vaccination campaign against rabies. We used a capture-mark-recapture approach for population estimates, with a Bayesian, Markov chain, Monte Carlo method to estimate the total number of owned dogs, and the ratio of ownerless to owned dogs to calculate vaccination coverage. When we took into account ownerless dogs, the vaccination coverage in the dog populations was 87% (95% confidence interval (CI), 84-89%) in study zone I, 71% (95% CI, 64-76%) in zone II, and 64% (95% CI, 58-71%) in zone III. The proportions of ownerless dogs to owned dogs were 1.1% (95% CI, 0-3.1%), 7.6% (95% CI, 0.7-16.5%), and 10.6% (95% CI, 1.6-19.1%) in the three study zones, respectively. Vaccination coverage in the three populations of owned dogs was 88% (95% CI, 84-92%) in zone I, 76% (95% CI, 71-81%) in zone II, and 70% (95% CI, 66-76%) in zone III. Participation of dog owners in the free campaign was high, and the number of inaccessible ownerless dogs was low. High levels of vaccination coverage could be achieved with parenteral mass vaccination. Regular parenteral vaccination campaigns to cover all of N'Djaména should be considered as an ethical way of preventing human rabies when post-exposure treatment is of limited availability and high in cost. PMID:14758434

Human papillomavirus vaccine delivery strategies that achieved high coverage in low- and middle-income countries

PubMed Central

Barge, Sandhya; Le, Nga Thi; Mugisha, Emmanuel; Penny, Mary E; Gandhi, Sanjay; Janmohamed, Amynah; Kumakech, Edward; Mosqueira, N Rocio; Nguyen, Nghi Quy; Paul, Proma; Tang, Yuxiao; Minh, Tran Hung; Uttekar, Bella Patel; Jumaan, Aisha O

2011-01-01

Abstract Objective To assess human papillomavirus (HPV) vaccination coverage after demonstration projects conducted in India, Peru, Uganda and Viet Nam by PATH and national governments and to explore the reasons for vaccine acceptance or refusal. Methods Vaccines were delivered through schools or health centres or in combination with other health interventions, and either monthly or through campaigns at fixed time points. Using a two-stage cluster sample design, the authors selected households in demonstration project areas and interviewed over 7000 parents or guardians of adolescent girls to assess coverage and acceptability. They defined full vaccination as the receipt of all three vaccine doses and used an open-ended question to explore acceptability. Findings Vaccination coverage in school-based programmes was 82.6% (95% confidence interval, CI: 79.3–85.6) in Peru, 88.9% (95% CI: 84.7–92.4) in 2009 in Uganda and 96.1% (95% CI: 93.0–97.8) in 2009 in Viet Nam. In India, a campaign approach achieved 77.2% (95% CI: 72.4–81.6) to 87.8% (95% CI: 84.3–91.3) coverage, whereas monthly delivery achieved 68.4% (95% CI: 63.4–73.4) to 83.3% (95% CI: 79.3–87.3) coverage. More than two thirds of respondents gave as reasons for accepting the HPV vaccine that: (i) it protects against cervical cancer; (ii) it prevents disease, or (iii) vaccines are good. Refusal was more often driven by programmatic considerations (e.g. school absenteeism) than by opposition to the vaccine. Conclusion High coverage with HPV vaccine among young adolescent girls was achieved through various delivery strategies in the developing countries studied. Reinforcing positive motivators for vaccine acceptance is likely to facilitate uptake. PMID:22084528

Influenza vaccine coverage, influenza-associated morbidity and all-cause mortality in Catalonia (Spain).

PubMed

Muñoz, M Pilar; Soldevila, Núria; Martínez, Anna; Carmona, Glòria; Batalla, Joan; Acosta, Lesly M; Domínguez, Angela

2011-07-12

The objective of this work was to study the behaviour of influenza with respect to morbidity and all-cause mortality in Catalonia, and their association with influenza vaccination coverage. The study was carried out over 13 influenza seasons, from epidemiological week 40 of 1994 to week 20 of 2007, and included confirmed cases of influenza and all-cause mortality. Two generalized linear models were fitted: influenza-associated morbidity was modelled by Poisson regression and all-cause mortality by negative binomial regression. The seasonal component was modelled with the periodic function formed by the sum of the sinus and cosines. Expected influenza mortality during periods of influenza virus circulation was estimated by Poisson regression and its confidence intervals using the Bootstrap approach. Vaccination coverage was associated with a reduction in influenza-associated morbidity (p<0.001), but not with a reduction in all-cause mortality (p=0.149). In the case of influenza-associated morbidity, an increase of 5% in vaccination coverage represented a reduction of 3% in the incidence rate of influenza. There was a positive association between influenza-associated morbidity and all-cause mortality. Excess mortality attributable to influenza epidemics was estimated as 34.4 (95% CI: 28.4-40.8) weekly deaths. In conclusion, all-cause mortality is a good indicator of influenza surveillance and vaccination coverage is associated with a reduction in influenza-associated morbidity but not with all-cause mortality. Copyright © 2011 Elsevier Ltd. All rights reserved.

Introduction to Sample Size Choice for Confidence Intervals Based on "t" Statistics

ERIC Educational Resources Information Center

Liu, Xiaofeng Steven; Loudermilk, Brandon; Simpson, Thomas

2014-01-01

Sample size can be chosen to achieve a specified width in a confidence interval. The probability of obtaining a narrow width given that the confidence interval includes the population parameter is defined as the power of the confidence interval, a concept unfamiliar to many practitioners. This article shows how to utilize the Statistical Analysis…

An Introduction to Confidence Intervals for Both Statistical Estimates and Effect Sizes.

ERIC Educational Resources Information Center

Capraro, Mary Margaret

This paper summarizes methods of estimating confidence intervals, including classical intervals and intervals for effect sizes. The recent American Psychological Association (APA) Task Force on Statistical Inference report suggested that confidence intervals should always be reported, and the fifth edition of the APA "Publication Manual"…

Evaluation of confidence intervals for a steady-state leaky aquifer model

USGS Publications Warehouse

Christensen, S.; Cooley, R.L.

1999-01-01

The fact that dependent variables of groundwater models are generally nonlinear functions of model parameters is shown to be a potentially significant factor in calculating accurate confidence intervals for both model parameters and functions of the parameters, such as the values of dependent variables calculated by the model. The Lagrangian method of Vecchia and Cooley [Vecchia, A.V. and Cooley, R.L., Water Resources Research, 1987, 23(7), 1237-1250] was used to calculate nonlinear Scheffe-type confidence intervals for the parameters and the simulated heads of a steady-state groundwater flow model covering 450 km2 of a leaky aquifer. The nonlinear confidence intervals are compared to corresponding linear intervals. As suggested by the significant nonlinearity of the regression model, linear confidence intervals are often not accurate. The commonly made assumption that widths of linear confidence intervals always underestimate the actual (nonlinear) widths was not correct. Results show that nonlinear effects can cause the nonlinear intervals to be asymmetric and either larger or smaller than the linear approximations. Prior information on transmissivities helps reduce the size of the confidence intervals, with the most notable effects occurring for the parameters on which there is prior information and for head values in parameter zones for which there is prior information on the parameters.The fact that dependent variables of groundwater models are generally nonlinear functions of model parameters is shown to be a potentially significant factor in calculating accurate confidence intervals for both model parameters and functions of the parameters, such as the values of dependent variables calculated by the model. The Lagrangian method of Vecchia and Cooley was used to calculate nonlinear Scheffe-type confidence intervals for the parameters and the simulated heads of a steady-state groundwater flow model covering 450 km2 of a leaky aquifer. The nonlinear confidence intervals are compared to corresponding linear intervals. As suggested by the significant nonlinearity of the regression model, linear confidence intervals are often not accurate. The commonly made assumption that widths of linear confidence intervals always underestimate the actual (nonlinear) widths was not correct. Results show that nonlinear effects can cause the nonlinear intervals to be asymmetric and either larger or smaller than the linear approximations. Prior information on transmissivities helps reduce the size of the confidence intervals, with the most notable effects occurring for the parameters on which there is prior information and for head values in parameter zones for which there is prior information on the parameters.

[Factors associated with the use of dental health services].

PubMed

Dho, María Silvina

2018-02-01

This paper seeks to analyze the factors associated with the use of dental health services (UDHS) by adults in the city of Corrientes, Argentina. A cross-sectional study was conducted. Information concerning the study variables was collected via a home survey. The sample size was established with a 95% confidence interval level (381 individuals). A simple random sampling design was used, which was complemented with a non-probability quota sampling. The data was analyzed using SPSS version 21.0 and Epidat version 3.1 softwares. Socio-economic level, dental health coverage, perception of oral health care, perception of oral health, knowledge about oral health, and oral hygiene habits were significantly associated with the UDHS over the last twelve months. These same factors, excluding dental health coverage and knowledge about oral health, were associated with the UDHS for routine dental check-ups. Measures should be implemented to increase the UDHS for prevention purposes in men and women of all socio-economic levels, particularly in less-privileged individuals.

Efficiently estimating salmon escapement uncertainty using systematically sampled data

USGS Publications Warehouse

Reynolds, Joel H.; Woody, Carol Ann; Gove, Nancy E.; Fair, Lowell F.

2007-01-01

Fish escapement is generally monitored using nonreplicated systematic sampling designs (e.g., via visual counts from towers or hydroacoustic counts). These sampling designs support a variety of methods for estimating the variance of the total escapement. Unfortunately, all the methods give biased results, with the magnitude of the bias being determined by the underlying process patterns. Fish escapement commonly exhibits positive autocorrelation and nonlinear patterns, such as diurnal and seasonal patterns. For these patterns, poor choice of variance estimator can needlessly increase the uncertainty managers have to deal with in sustaining fish populations. We illustrate the effect of sampling design and variance estimator choice on variance estimates of total escapement for anadromous salmonids from systematic samples of fish passage. Using simulated tower counts of sockeye salmon Oncorhynchus nerka escapement on the Kvichak River, Alaska, five variance estimators for nonreplicated systematic samples were compared to determine the least biased. Using the least biased variance estimator, four confidence interval estimators were compared for expected coverage and mean interval width. Finally, five systematic sampling designs were compared to determine the design giving the smallest average variance estimate for total annual escapement. For nonreplicated systematic samples of fish escapement, all variance estimators were positively biased. Compared to the other estimators, the least biased estimator reduced bias by, on average, from 12% to 98%. All confidence intervals gave effectively identical results. Replicated systematic sampling designs consistently provided the smallest average estimated variance among those compared.

Sample size planning for composite reliability coefficients: accuracy in parameter estimation via narrow confidence intervals.

PubMed

Terry, Leann; Kelley, Ken

2012-11-01

Composite measures play an important role in psychology and related disciplines. Composite measures almost always have error. Correspondingly, it is important to understand the reliability of the scores from any particular composite measure. However, the point estimates of the reliability of composite measures are fallible and thus all such point estimates should be accompanied by a confidence interval. When confidence intervals are wide, there is much uncertainty in the population value of the reliability coefficient. Given the importance of reporting confidence intervals for estimates of reliability, coupled with the undesirability of wide confidence intervals, we develop methods that allow researchers to plan sample size in order to obtain narrow confidence intervals for population reliability coefficients. We first discuss composite reliability coefficients and then provide a discussion on confidence interval formation for the corresponding population value. Using the accuracy in parameter estimation approach, we develop two methods to obtain accurate estimates of reliability by planning sample size. The first method provides a way to plan sample size so that the expected confidence interval width for the population reliability coefficient is sufficiently narrow. The second method ensures that the confidence interval width will be sufficiently narrow with some desired degree of assurance (e.g., 99% assurance that the 95% confidence interval for the population reliability coefficient will be less than W units wide). The effectiveness of our methods was verified with Monte Carlo simulation studies. We demonstrate how to easily implement the methods with easy-to-use and freely available software. ©2011 The British Psychological Society.

Improved confidence intervals when the sample is counted an integer times longer than the blank.

PubMed

Potter, William Edward; Strzelczyk, Jadwiga Jodi

2011-05-01

Past computer solutions for confidence intervals in paired counting are extended to the case where the ratio of the sample count time to the blank count time is taken to be an integer, IRR. Previously, confidence intervals have been named Neyman-Pearson confidence intervals; more correctly they should have been named Neyman confidence intervals or simply confidence intervals. The technique utilized mimics a technique used by Pearson and Hartley to tabulate confidence intervals for the expected value of the discrete Poisson and Binomial distributions. The blank count and the contribution of the sample to the gross count are assumed to be Poisson distributed. The expected value of the blank count, in the sample count time, is assumed known. The net count, OC, is taken to be the gross count minus the product of IRR with the blank count. The probability density function (PDF) for the net count can be determined in a straightforward manner.

Vaccination and All-Cause Child Mortality From 1985 to 2011: Global Evidence From the Demographic and Health Surveys

PubMed Central

McGovern, Mark E.; Canning, David

2015-01-01

Based on models with calibrated parameters for infection, case fatality rates, and vaccine efficacy, basic childhood vaccinations have been estimated to be highly cost effective. We estimated the association of vaccination with mortality directly from survey data. Using 149 cross-sectional Demographic and Health Surveys, we determined the relationship between vaccination coverage and the probability of dying between birth and 5 years of age at the survey cluster level. Our data included approximately 1 million children in 68,490 clusters from 62 countries. We considered the childhood measles, bacillus Calmette-Guérin, diphtheria-pertussis-tetanus, polio, and maternal tetanus vaccinations. Using modified Poisson regression to estimate the relative risk of child mortality in each cluster, we also adjusted for selection bias that resulted from the vaccination status of dead children not being reported. Childhood vaccination, and in particular measles and tetanus vaccination, is associated with substantial reductions in childhood mortality. We estimated that children in clusters with complete vaccination coverage have a relative risk of mortality that is 0.73 (95% confidence interval: 0.68, 0.77) times that of children in a cluster with no vaccinations. Although widely used, basic vaccines still have coverage rates well below 100% in many countries, and our results emphasize the effectiveness of increasing coverage rates in order to reduce child mortality. PMID:26453618

The Effect of Various Types of Motorcycle Helmets on Cervical Spine Injury in Head Injury Patients: A Multicenter Study in Taiwan

PubMed Central

Lin, Mau-Roung; Chu, Shu-Fen; Tsai, Shin-Han; Bai, Chyi-Huey; Chiu, Wen-Ta

2015-01-01

Introduction. The relationship between cervical spine injury (CSI) and helmet in head injury (HI) patients following motorcycle crashes is crucial. Controversy still exists; therefore we evaluated the effect of various types of helmets on CSI in HI patients following motorcycle crashes and researched the mechanism of this effect. Patients and Methods. A total of 5225 patients of motorcycle crashes between 2000 and 2009 were extracted from the Head Injury Registry in Taiwan. These patients were divided into case and control groups according to the presence of concomitant CSI. Helmet use and types were separately compared between the two groups and the odds ratio of CSI was obtained by using multiple logistic regression analysis. Results. We observed that 173 (3.3%) of the HI patients were associated with CSI. The HI patients using a helmet (odds ratio (OR) = 0.31, 95% confidence interval (CI) = 0.19−0.49), full-coverage helmet (0.19, 0.10−0.36), and partial-coverage helmet (0.35, 0.21−0.56) exhibited a significantly decreased rate of CSI compared with those without a helmet. Conclusion. Wearing full-coverage and partial-coverage helmets significantly reduced the risk of CSI among HI patients following motorcycle crashes. This effect may be due to the smooth surface and hard padding materials of helmet. PMID:25705663

No lasting legacy: no change in reporting of women's sports in the British print media with the London 2012 Olympics and Paralympics

PubMed Central

Packer, C.; Geh, D.J.; Goulden, O.W.; Jordan, A.M.; Withers, G.K.; Wagstaff, A.J.; Bellwood, R.A.; Binmore, C.L.; Webster, C.L.

2015-01-01

Background The proportion of media sports coverage devoted to women is reported at between 1 and 6%. Our survey examines and compares reporting patterns before and after the 2012 Olympics and Paralympics. Methods We collected data on sports coverage in six national newspapers on 3 weekend days in February and March 2012, and in February 2013; ∼5 months before the opening of the 2012 Olympic Games and 5 months after the closing of the Paralympic Games. Results In 2012, 39 of 876 articles in national newspapers (4.5%) related to women's sports, compared with 22 of 755 (2.9%) in 2013; a non-significant reduction in coverage [difference 1.54%, 95% confidence interval (CI) −0.28 to 3.36). In 2012, 24 of 647 pictures (3.7%) related to women's activities, compared with 10 of 738 (1.4%) in 2013; a significant reduction in coverage (difference 2.35%; 95% CI 0.68–4.03). The median area per article was significantly greater for men in both years. Conclusions We found a continuing bias towards men's sport in the media analysed and no evidence of improvement either before or after the 2012 Olympics and Paralympics. Increased support of women's sport in the print media could benefit individuals and influence the health of the population. PMID:24618182

Exact Scheffé-type confidence intervals for output from groundwater flow models: 2. Combined use of hydrogeologic information and calibration data

USGS Publications Warehouse

Cooley, Richard L.

1993-01-01

Calibration data (observed values corresponding to model-computed values of dependent variables) are incorporated into a general method of computing exact Scheffé-type confidence intervals analogous to the confidence intervals developed in part 1 (Cooley, this issue) for a function of parameters derived from a groundwater flow model. Parameter uncertainty is specified by a distribution of parameters conditioned on the calibration data. This distribution was obtained as a posterior distribution by applying Bayes' theorem to the hydrogeologically derived prior distribution of parameters from part 1 and a distribution of differences between the calibration data and corresponding model-computed dependent variables. Tests show that the new confidence intervals can be much smaller than the intervals of part 1 because the prior parameter variance-covariance structure is altered so that combinations of parameters that give poor model fit to the data are unlikely. The confidence intervals of part 1 and the new confidence intervals can be effectively employed in a sequential method of model construction whereby new information is used to reduce confidence interval widths at each stage.

Graphing within-subjects confidence intervals using SPSS and S-Plus.

PubMed

Wright, Daniel B

2007-02-01

Within-subjects confidence intervals are often appropriate to report and to display. Loftus and Masson (1994) have reported methods to calculate these, and their use is becoming common. In the present article, procedures for calculating within-subjects confidence intervals in SPSS and S-Plus are presented (an R version is on the accompanying Web site). The procedure in S-Plus allows the user to report the bias corrected and adjusted bootstrap confidence intervals as well as the standard confidence intervals based on traditional methods. The presented code can be easily altered to fit the individual user's needs.

A pragmatic, randomized, controlled study evaluating the impact of access to smoking cessation pharmacotherapy coverage on the proportion of successful quitters in a Canadian population of smokers motivated to quit (ACCESSATION).

PubMed

Selby, Peter; Brosky, Gerald; Oh, Paul; Raymond, Vincent; Arteaga, Carmen; Ranger, Suzanne

2014-05-07

Many smokers find the cost of smoking cessation medications a barrier. Financial coverage for these medications increases utilization of pharmacotherapies. This study assesses whether financial coverage increases the proportion of successful quitters. A pragmatic, open-label, randomized, controlled trial was conducted in 58 Canadian sites between March 2009 and September 2010. Smokers (≥10 cigarettes/day) without insurance coverage who were motivated to quit within 14 days were randomized (1:1) in a blinded manner to receive either full coverage eligibility for 26 weeks or no coverage. Pharmacotherapies covered were varenicline, bupropion, or nicotine patches/gum. Investigators/subjects were unblinded to study group assignment after randomization and prior to choosing a smoking cessation method(s). All subjects received brief smoking cessation counseling. The primary outcome measure was self-reported 7-day point prevalence of abstinence (PPA) at week 26. Of the 1380 randomized subjects (coverage, 696; no coverage, 684), 682 (98.0%) and 435 (63.6%), respectively, were dispensed at least one smoking cessation medication dose. The 7-day PPA at week 26 was higher in the full coverage versus no coverage group: 20.8% (n = 145) and 13.9% (n = 95), respectively; odds ratio (OR) = 1.64, 95% confidence interval (CI) 1.23-2.18; p = 0.001. Urine cotinine-confirmed 7-day PPA at week 26 was 15.7% (n = 109) and 10.1% (n = 69), respectively; OR = 1.68, 95% CI 1.21-2.33; p = 0.002. After pharmacotherapy, coverage eligibility was withdrawn from the full coverage group, continuous abstinence between weeks 26 and 52 was 6.6% (n = 46) and 5.6% (n = 38), in the full coverage and no coverage groups, respectively; OR = 1.19, 95% CI 0.76-1.87; p = 0.439. In this study, the adoption of a smoking cessation medication coverage drug policy was an effective intervention to improve 26-week quit rates in Canada. The advantages were lost once coverage was discontinued. Further study is required on the duration of coverage to prevent relapse to smoking. (clinicaltrials.gov identifier: NCT00818207; the study was sponsored by Pfizer Inc.).

Explorations in Statistics: Confidence Intervals

ERIC Educational Resources Information Center

Curran-Everett, Douglas

2009-01-01

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This third installment of "Explorations in Statistics" investigates confidence intervals. A confidence interval is a range that we expect, with some level of confidence, to include the true value of a population parameter…

Risk of Mycobacterium tuberculosis infection in Somalia: national tuberculin survey 2006.

PubMed

Munim, A; Rajab, Y; Barker, A; Daniel, M; Williams, B

2008-01-01

To estimate the annual risk of tuberculosis (TB) infection (ARTI) in Somalia a tuberculin survey was conducted in February/March 2006. Stratified cluster sampling was carried out within the 18 regions and 101 randomly selected primary schools. Tuberculin testing was done in 10 680 grade 1 schoolchildren. Transverse tuberculin reaction size was measured 72 hours later. The number of children with a satisfactory test read was 10 364. The overall BCG coverage was 54%. Based on frequency distribution of tuberculin reaction sizes, the ARTI in Somalia was estimated at 2.2% (confidence interval: 1.5%-3.2%). There was an annual decline of 2.6% comparing with a previous study in 1956.

Affordable Care Act Qualified Health Plan Coverage: Association With Improved HIV Viral Suppression for AIDS Drug Assistance Program Clients in a Medicaid Nonexpansion State

PubMed Central

McManus, Kathleen A.; Rhodes, Anne; Bailey, Steven; Yerkes, Lauren; Engelhard, Carolyn L.; Ingersoll, Karen S.; Stukenborg, George J.; Dillingham, Rebecca

2016-01-01

Background. With the Patient Protection and Affordable Care Act, many state AIDS Drug Assistance Programs (ADAPs) shifted their healthcare delivery model from direct medication provision to purchasing qualified health plans (QHPs). The objective of this study was to characterize the demographic and healthcare delivery factors associated with Virginia ADAP clients' QHP enrollment and to assess the relationship between QHP coverage and human immunodeficiency virus (HIV) viral suppression. Methods. The cohort included persons living with HIV who were enrolled in the Virginia ADAP (n = 3933). Data were collected from 1 January 2013 through 31 December 2014. Multivariable binary logistic regression was conducted to assess for associations with QHP enrollment and between QHP coverage and viral load (VL) suppression. Results. In the cohort, 47.1% enrolled in QHPs, and enrollment varied significantly based on demographic and healthcare delivery factors. In multivariable binary logistic regression, controlling for time, age, sex, race/ethnicity, and region, factors significantly associated with achieving HIV viral suppression included QHP coverage (adjusted odds ratio, 1.346; 95% confidence interval, 1.041–1.740; P = .02), an initially undetectable VL (2.809; 2.174–3.636; P < .001), HIV rather than AIDS disease status (1.377; 1.049–1.808; P = .02), and HIV clinic (P < .001). Conclusions. QHP coverage was associated with viral suppression, an essential outcome for individuals and for public health. Promoting QHP coverage in clinics that provide care to persons living with HIV may offer a new opportunity to increase rates of viral suppression. PMID:27143661

Coverage of hospital-based cataract surgery and barriers to the uptake of surgery among cataract blind persons in nigeria: the Nigeria National Blindness and Visual Impairment Survey.

PubMed

Abubakar, Tafida; Gudlavalleti, Murthy V S; Sivasubramaniam, Selvaraj; Gilbert, Clare E; Abdull, Mohammed M; Imam, Abdullahi U

2012-04-01

To determine cataract surgical coverage, and barriers to modern cataract surgery in Nigeria. Multistage stratified cluster random sampling was used to identify a nationally representative sample of 15,027 persons aged 40+ years. All underwent visual acuity testing, frequency doubling technology visual field testing, autorefraction, and measurement of best corrected vision if <6/12 in one or both eyes. An ophthalmologist examined the anterior segment and fundus through an undilated pupil for all participants. Participants were examined by a second ophthalmologist using a slit lamp and dilated fundus examination using a 90 diopter condensing lens if vision was <6/12 in one or both eyes, there were optic disc changes suggestive of glaucoma, and 1 in 7 participants regardless of findings. All those who had undergone cataract surgery were asked where and when this had taken place. Individuals who were severely visually impaired or blind from unoperated cataract were asked to explain why they had not undergone surgery. A total of 13,591 participants were examined (response rate 89.9%). Prevalence of cataract surgery was 1.6% (95% confidence interval 1.4-1.8), significantly higher among those aged ≥70 years. Cataract surgical coverage (persons) in Nigeria was 38.3%. Coverage was 1.7 times higher among males than females. Coverage was only 9.1% among women in the South-South geopolitical zone. Over one third of those who were cataract blind said they could not afford surgery (36%). Cataract surgical coverage in Nigeria was among the lowest in the world. Urgent initiatives are necessary to improve surgical output and access to surgery.

Repeat retail clinic visits: impact of insurance coverage and age of patient.

PubMed

Angstman, Kurt B; Bernard, Matthew E; Rohrer, James E; Garrison, Gregory M; Maclaughlin, Kathy L

2012-12-01

As retail clinics provide a less costly alternative for health care, it would be reasonable to expect an increase in multiple (repeat) retail visits by those patients who may have expenses for receiving primary care. If costs were not a significant factor, then repeat visits should not be significantly different between these patients and those with coverage for primary care visits. The hypothesis for this study was that patients with the potential for out-of-pocket expenses would have a higher frequency of repeat retail clinic visits within 180 days compared to those with primary care coverage. A retrospective chart review was conducted of 5703 patients utilizing a retail clinic in Rochester, Minnesota from January 1, 2009 through June 30, 2009. The first visit to the retail clinic was considered the index visit and the chart was reviewed for repeat retail clinic visits within the next 180 days. Using a multiple logistic regression model, the odds of a pediatric patient (N=2344) having a repeat retail visit within 180 days of the index visit were not significantly impacted by insurance coverage (P=0.4209). Of the 3359 adult patients, those with unknown coverage had a 25.6% higher odds ratio of repeat retail clinic visits than those with insurance coverage (odds ratio 1.2557, confidence interval 1.0421-1.5131). This study suggested that when cost is an issue, the adult patient may favor retail clinics for episodic, low-acuity health care. In contrast, the pediatric population did not, suggesting that other factors, such as convenience, may play more of a role in the choice of episodic health care for this age group.

Increased immunization coverage addresses the equity gap in Nepal

PubMed Central

Nelin, Viktoria; Raaijmakers, Hendrikus; Kim, Hyung Joon; Singh, Chahana; Målqvist, Mats

2017-01-01

Abstract Objective To compare immunization coverage and equity distribution of coverage between 2001 and 2014 in Nepal. Methods We used data from the Demographic and Health Surveys carried out in 2001, 2006 and 2011 together with data from the 2014 Multiple Indicator Cluster Survey. We calculated the proportion, in mean percentage, of children who had received bacille Calmette–Guérin (BCG) vaccine, three doses of polio vaccine, three doses of diphtheria–pertussis–tetanus (DPT) vaccine and measles vaccine. To measure inequities between wealth quintiles, we calculated the slope index of inequality (SII) and relative index of inequality (RII) for all surveys. Findings From 2001 to 2014, the proportion of children who received all vaccines at the age of 12 months increased from 68.8% (95% confidence interval, CI: 67.5–70.1) to 82.4% (95% CI: 80.7–84.0). While coverage of BCG, DPT and measles immunization statistically increased during the study period, the proportion of children who received the third dose of polio vaccine decreased from 93.3% (95% CI: 92.7–93.9) to 88.1% (95% CI: 86.8–89.3). The poorest wealth quintile showed the greatest improvement in immunization coverage, from 58% to 77.9%, while the wealthiest quintile only improved from 84.8% to 86.0%. The SII for children who received all vaccines improved from 0.070 (95% CI: 0.061–0.078) to 0.026 (95% CI: 0.013–0.039) and RII improved from 1.13 to 1.03. Conclusion The improvement in immunization coverage between 2001 and 2014 in Nepal can mainly be attributed to the interventions targeting the disadvantaged populations. PMID:28479621

Individual and socioeconomic factors associated with childhood immunization coverage in Nigeria

PubMed Central

Oleribe, Obinna; Kumar, Vibha; Awosika-Olumo, Adebowale; Taylor-Robinson, Simon David

2017-01-01

Introduction Immunization is the world’s most successful and cost-effective public health intervention as it prevents over 2 million deaths annually. However, over 2 million deaths still occur yearly from Vaccine preventable diseases, the majority of which occur in sub-Saharan Africa. Nigeria is a major contributor of global childhood deaths from VPDs. Till date, Nigeria still has wild polio virus in circulation. The objective of this study was to identify the individual and socioeconomic factors associated with immunization coverage in Nigeria through a secondary dataset analysis of Nigeria Demographic and Health Survey (NDHS), 2013. Methods A quantitative analysis of the 2013 NDHS dataset was performed. Ethical approvals were obtained from Walden University IRB and the National Health Research Ethics Committee of Nigeria. The dataset was downloaded, validated for completeness and analyzed using univariate, bivariate and multivariate statistics. Results Of 27,571 children aged 0 to 59 months, 22.1% had full vaccination, and 29% never received any vaccination. Immunization coverage was significantly associated with childbirth order, delivery place, child number, and presence or absence of a child health card. Maternal age, geographical location, education, religion, literacy, wealth index, marital status, and occupation were significantly associated with immunization coverage. Paternal education, occupation, and age were also significantly associated with coverage. Respondent's age, educational attainment and wealth index remained significantly related to immunization coverage at 95% confidence interval in multivariate analysis. Conclusion The study highlights child, parental and socioeconomic barriers to successful immunization programs in Nigeria. These findings need urgent attention, given the re-emergence of wild poliovirus in Nigeria. An effective, efficient, sustainable, accessible, and acceptable immunization program for children should be designed, developed and undertaken in Nigeria with adequate strategies put in place to implement them. PMID:28690734

Individual and socioeconomic factors associated with childhood immunization coverage in Nigeria.

PubMed

Oleribe, Obinna; Kumar, Vibha; Awosika-Olumo, Adebowale; Taylor-Robinson, Simon David

2017-01-01

Immunization is the world's most successful and cost-effective public health intervention as it prevents over 2 million deaths annually. However, over 2 million deaths still occur yearly from Vaccine preventable diseases, the majority of which occur in sub-Saharan Africa. Nigeria is a major contributor of global childhood deaths from VPDs. Till date, Nigeria still has wild polio virus in circulation. The objective of this study was to identify the individual and socioeconomic factors associated with immunization coverage in Nigeria through a secondary dataset analysis of Nigeria Demographic and Health Survey (NDHS), 2013. A quantitative analysis of the 2013 NDHS dataset was performed. Ethical approvals were obtained from Walden University IRB and the National Health Research Ethics Committee of Nigeria. The dataset was downloaded, validated for completeness and analyzed using univariate, bivariate and multivariate statistics. Of 27,571 children aged 0 to 59 months, 22.1% had full vaccination, and 29% never received any vaccination. Immunization coverage was significantly associated with childbirth order, delivery place, child number, and presence or absence of a child health card. Maternal age, geographical location, education, religion, literacy, wealth index, marital status, and occupation were significantly associated with immunization coverage. Paternal education, occupation, and age were also significantly associated with coverage. Respondent's age, educational attainment and wealth index remained significantly related to immunization coverage at 95% confidence interval in multivariate analysis. The study highlights child, parental and socioeconomic barriers to successful immunization programs in Nigeria. These findings need urgent attention, given the re-emergence of wild poliovirus in Nigeria. An effective, efficient, sustainable, accessible, and acceptable immunization program for children should be designed, developed and undertaken in Nigeria with adequate strategies put in place to implement them.

Using an R Shiny to Enhance the Learning Experience of Confidence Intervals

ERIC Educational Resources Information Center

Williams, Immanuel James; Williams, Kelley Kim

2018-01-01

Many students find understanding confidence intervals difficult, especially because of the amalgamation of concepts such as confidence levels, standard error, point estimates and sample sizes. An R Shiny application was created to assist the learning process of confidence intervals using graphics and data from the US National Basketball…

The effect of health-facility admission and skilled birth attendant coverage on maternal survival in India: a case-control analysis.

PubMed

Montgomery, Ann L; Fadel, Shaza; Kumar, Rajesh; Bondy, Sue; Moineddin, Rahim; Jha, Prabhat

2014-01-01

Research in areas of low skilled attendant coverage found that maternal mortality is paradoxically higher in women who seek obstetric care. We estimated the effect of health-facility admission on maternal survival, and how this effect varies with skilled attendant coverage across India. Using unmatched population-based case-control analysis of national datasets, we compared the effect of health-facility admission at any time (antenatal, intrapartum, postpartum) on maternal deaths (cases) to women reporting pregnancies (controls). Probability of maternal death decreased with increasing skilled attendant coverage, among both women who were and were not admitted to a health-facility, however, the risk of death among women who were admitted was higher (at 50% coverage, OR = 2.32, 95% confidence interval 1.85-2.92) than among those women who were not; while at higher levels of coverage, the effect of health-facility admission was attenuated. In a secondary analysis, the probability of maternal death decreased with increasing coverage among both women admitted for delivery or delivered at home but there was no effect of admission for delivery on mortality risk (50% coverage, OR = 1.0, 0.80-1.25), suggesting that poor quality of obstetric care may have attenuated the benefits of facility-based care. Subpopulation analysis of obstetric hemorrhage cases and report of 'excessive bleeding' in controls showed that the probability of maternal death decreased with increasing skilled attendant coverage; but the effect of health-facility admission was attenuated (at 50% coverage, OR = 1.47, 0.95-1.79), suggesting that some of the effect in the main model can be explained by women arriving at facility with complications underway. Finally, highest risk associated with health-facility admission was clustered in women with education ≤ 8 years. The effect of health-facility admission did vary by skilled attendant coverage, and this effect appears to be driven partially by reverse causality; however, inequitable access to and possibly poor quality of healthcare for primary and emergency services appears to play a role in maternal survival as well.

Alternative Confidence Interval Methods Used in the Diagnostic Accuracy Studies

PubMed Central

Gülhan, Orekıcı Temel

2016-01-01

Background/Aim. It is necessary to decide whether the newly improved methods are better than the standard or reference test or not. To decide whether the new diagnostics test is better than the gold standard test/imperfect standard test, the differences of estimated sensitivity/specificity are calculated with the help of information obtained from samples. However, to generalize this value to the population, it should be given with the confidence intervals. The aim of this study is to evaluate the confidence interval methods developed for the differences between the two dependent sensitivity/specificity values on a clinical application. Materials and Methods. In this study, confidence interval methods like Asymptotic Intervals, Conditional Intervals, Unconditional Interval, Score Intervals, and Nonparametric Methods Based on Relative Effects Intervals are used. Besides, as clinical application, data used in diagnostics study by Dickel et al. (2010) has been taken as a sample. Results. The results belonging to the alternative confidence interval methods for Nickel Sulfate, Potassium Dichromate, and Lanolin Alcohol are given as a table. Conclusion. While preferring the confidence interval methods, the researchers have to consider whether the case to be compared is single ratio or dependent binary ratio differences, the correlation coefficient between the rates in two dependent ratios and the sample sizes. PMID:27478491

Alternative Confidence Interval Methods Used in the Diagnostic Accuracy Studies.

PubMed

Erdoğan, Semra; Gülhan, Orekıcı Temel

2016-01-01

Background/Aim. It is necessary to decide whether the newly improved methods are better than the standard or reference test or not. To decide whether the new diagnostics test is better than the gold standard test/imperfect standard test, the differences of estimated sensitivity/specificity are calculated with the help of information obtained from samples. However, to generalize this value to the population, it should be given with the confidence intervals. The aim of this study is to evaluate the confidence interval methods developed for the differences between the two dependent sensitivity/specificity values on a clinical application. Materials and Methods. In this study, confidence interval methods like Asymptotic Intervals, Conditional Intervals, Unconditional Interval, Score Intervals, and Nonparametric Methods Based on Relative Effects Intervals are used. Besides, as clinical application, data used in diagnostics study by Dickel et al. (2010) has been taken as a sample. Results. The results belonging to the alternative confidence interval methods for Nickel Sulfate, Potassium Dichromate, and Lanolin Alcohol are given as a table. Conclusion. While preferring the confidence interval methods, the researchers have to consider whether the case to be compared is single ratio or dependent binary ratio differences, the correlation coefficient between the rates in two dependent ratios and the sample sizes.

Modified Confidence Intervals for the Mean of an Autoregressive Process.

DTIC Science & Technology

1985-08-01

Validity of the method 45 3.6 Theorem 47 4 Derivation of corrections 48 Introduction 48 The zero order pivot 50 4.1 Algorithm 50 CONTENTS The first...of standard confidence intervals. There are several standard methods of setting confidence intervals in simulations, including the regener- ative... method , batch means, and time series methods . We-will focus-s on improved confidence intervals for the mean of an autoregressive process, and as such our

Determinants of Health Insurance Coverage among People Aged 45 and over in China: Who Buys Public, Private and Multiple Insurance

PubMed Central

Jin, Yinzi; Hou, Zhiyuan; Zhang, Donglan

2016-01-01

Background China is reforming and restructuring its health insurance system to achieve the goal of universal coverage. This study aims to understand the determinants of public, private and multiple insurance coverage among people of retirement-age in China. Methods We used data from the China Health and Retirement Longitudinal Survey 2011 and 2013, a nationally representative survey of Chinese people aged 45 and over. Multinomial logit regression was performed to identify the determinants of public, private and multiple health insurance coverage. We also conducted logit regression to examine the association between public insurance coverage and demand for private insurance. Results In 2013, 94.5% of this population had at least one type of public insurance, and 12.2% purchased private insurance. In general, we found that rural residents were less likely to be uninsured (Relative Risk Ratio (RRR) = 0.40, 95% Confidence Interval (CI): 0.34–0.47) and were less likely to buy private insurance (RRR = 0.22, 95% CI: 0.16–0.31). But rural-to-urban migrants were more likely to be uninsured (RRR = 1.39, 95% CI: 1.24–1.57). Public health insurance coverage may crowd out private insurance market (Odds Ratio = 0.55, 95% CI: 0.48–0.63), particularly among enrollees of Urban Resident Basic Medical Insurance. There exists a huge socioeconomic disparity in both public and private insurance coverage. Conclusion The migrants, the poor and the vulnerable remained in the edge of the system. The growing private insurance market did not provide sufficient financial protection and did not cover the people with the greatest need. To achieve universal coverage and reduce socioeconomic disparity, China should integrate the urban and rural public insurance schemes across regions and remove the barriers for the middle-income and low-income to access private insurance. PMID:27564320

Cancer trial enrollment after state-mandated reimbursement.

PubMed

Gross, C P; Murthy, V; Li, Y; Kaluzny, A D; Krumholz, H M

2004-07-21

Recruitment of patients into cancer research studies is exceedingly difficult, particularly for early phase trials. Payer reimbursement policies are a frequently cited barrier. We examined whether state policies that ensure coverage of routine medical care costs for cancer trial participants are associated with an increase in clinical trial enrollment. We used logistic Poisson regressions to analyze enrollment in National Cancer Institute phase II and phase III Clinical Trials Cooperative Group trials and compared changes in trial enrollment rates between 1996 and 2001 of privately insured cancer patients who resided in the four states that enacted coverage policies in 1999 with enrollment rates in states without such policies. All statistical tests were two-sided. Trial enrollment rates increased in the coverage and noncoverage states by 24.9% (95% confidence interval [CI] = 22.8% to 27.0%) and 28.8% (95% CI = 27.7% to 29.8%) per year, respectively, from 1996 through 2001. After implementation of the coverage policies in 1999 in four states, there was a 21.7% (95% CI = 3.8% to 42.6%) annual increase in phase II trial enrollment in coverage states, compared with a 15.6% (95% CI = 8.8% to 21.8%) annual decrease in noncoverage states (P<.001). After accounting for secular trend, cancer type, and race in multivariable analyses, the odds ratio (OR) for a phase II trial participant residing in a coverage versus a noncoverage state after 1999 was 1.59 per year (95% CI = 1.22 to 2.07; P =.001). In a multivariable analysis of phase III trial participation, there was a decrease in the odds of residing in a coverage state after 1999 (OR = 0.90, 95% CI = 0.84 to 0.98; P =.011). State coverage policies were associated with a statistically significant increase in phase II cancer trial participation and did not increase phase III cancer trial enrollment.

Associations between key intervention coverage and child mortality: an analysis of 241 sub-national regions of sub-Saharan Africa.

PubMed

Akachi, Yoko; Steenland, Maria; Fink, Günther

2017-12-21

Reducing child mortality remains a key objective in the Sustainable Development Goals. Although remarkable progress has been made with respect to under-5 mortality over the last 25 years, little is known regarding the relative contributions of public health interventions and general improvements in socioeconomic status during this time period. We combined all available data from the Demographic and Health Survey (DHS) to construct a longitudinal, multi-level dataset with information on subnational-level key intervention coverage, household socioeconomic status and child health outcomes in sub-Saharan Africa. The dataset covers 562 896 child records and 769 region-year observations across 24 countries. We used multi-level multivariable logistics regression models to assess the associations between child mortality and changes in the coverage of 17 key reproductive, maternal, newborn and child health interventions such as bednets, water and sanitation infrastructure, vaccination and breastfeeding practices, as well as concurrent improvements in social and economic development. Full vaccination coverage was associated with a 30% decrease in the odds of child mortality [odds ratio (OR) 0.698, 95% confidence interval (CI) 0.564, 0.864], and continued breastfeeding was associated with a 24% decrease in the odds of child mortality (OR 0.759, 95% CI 0.642, 0.898). Our results suggest that changes in vaccination coverage, as well as increases in female education and economic development, made the largest contributions to the positive mortality trends observed. Breastfeeding was associated with child survival but accounts for little of the observed declines in mortality due to declining coverage levels during our study period. Our findings suggest that a large amount of progress has been made with respect to coverage levels of key health interventions. Whereas all socioeconomic variables considered appear to strongly predict health outcomes, the same was true only for very few health coverage indicators. © The Author(s) 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Trends and racial and ethnic disparities in the prevalence of pregestational type 1 and type 2 diabetes in Northern California: 1996-2014.

PubMed

Peng, Tiffany Y; Ehrlich, Samantha F; Crites, Yvonne; Kitzmiller, John L; Kuzniewicz, Michael W; Hedderson, Monique M; Ferrara, Assiamira

2017-02-01

Despite concern for adverse perinatal outcomes in women with diabetes mellitus before pregnancy, recent data on the prevalence of pregestational type 1 and type 2 diabetes mellitus in the United States are lacking. The purpose of this study was to estimate changes in the prevalence of overall pregestational diabetes mellitus (all types) and pregestational type 1 and type 2 diabetes mellitus and to estimate whether changes varied by race-ethnicity from 1996-2014. We conducted a cohort study among 655,428 pregnancies at a Northern California integrated health delivery system from 1996-2014. Logistic regression analyses provided estimates of prevalence and trends. The age-adjusted prevalence (per 100 deliveries) of overall pregestational diabetes mellitus increased from 1996-1999 to 2012-2014 (from 0.58 [95% confidence interval, 0.54-0.63] to 1.06 [95% confidence interval, 1.00-1.12]; P trend <.0001). Significant increases occurred in all racial-ethnic groups; the largest relative increase was among Hispanic women (121.8% [95% confidence interval, 84.4-166.7]); the smallest relative increase was among non-Hispanic white women (49.6% [95% confidence interval, 27.5-75.4]). The age-adjusted prevalence of pregestational type 1 and type 2 diabetes mellitus increased from 0.14 (95% confidence interval, 0.12-0.16) to 0.23 (95% confidence interval, 0.21-0.27; P trend <.0001) and from 0.42 (95% confidence interval, 0.38-0.46) to 0.78 (95% confidence interval, 0.73-0.83; P trend <.0001), respectively. The greatest relative increase in the prevalence of type 1 diabetes mellitus was in non-Hispanic white women (118.4% [95% confidence interval, 70.0-180.5]), who had the lowest increases in the prevalence of type 2 diabetes mellitus (13.6% [95% confidence interval, -8.0 to 40.1]). The greatest relative increase in the prevalence of type 2 diabetes mellitus was in Hispanic women (125.2% [95% confidence interval, 84.8-174.4]), followed by African American women (102.0% [95% confidence interval, 38.3-194.3]) and Asian women (93.3% [95% confidence interval, 48.9-150.9]). The prevalence of overall pregestational diabetes mellitus and pregestational type 1 and type 2 diabetes mellitus increased from 1996-1999 to 2012-2014 and racial-ethnic disparities were observed, possibly because of differing prevalence of maternal obesity. Targeted prevention efforts, preconception care, and disease management strategies are needed to reduce the burden of diabetes mellitus and its sequelae. Copyright © 2016 Elsevier Inc. All rights reserved.

Effectiveness of a new long-lasting insecticidal nets delivery model in two rural districts of Mozambique: a before-after study.

PubMed

Arroz, Jorge A H; Candrinho, Baltazar; Mendis, Chandana; Varela, Pablo; Pinto, João; Martins, Maria do Rosário O

2018-02-05

In 2015, Mozambique piloted a new model of long-lasting insecticidal nets (LLINs) delivery in a campaign. The new delivery model was used in two rural districts were, and two others were considered as control, maintaining the old delivery model. The aim of this study is to compare the coverage of ownership and use of LLINs in intervention and control districts in Mozambique. A before-after design with control group was carried out 6 months after LLINs distribution. Using systematic probabilistic sampling, 1547 households were surveyed by means of a questionnaire. To find associations between the district categories (intervention and control) and the main outcomes of the study (LLIN ownership, use, and universal coverage achievement), odds ratio (OR) and respective confidence intervals were calculated. Of the 760 households surveyed in the intervention districts, 98.8% had at least one LLIN; of the 787 households surveyed in the control districts, 89.6% had at least one LLIN [OR: 9.7, 95% (CI 4.84-19.46)]. Around 95 and 87% of households owning at least one LLIN reported having slept under the LLIN the previous night in the intervention and control districts, respectively [OR: 3.2; 95% (CI 2.12-4.69)]. Seventy-one percent of the households surveyed achieved universal coverage in the intervention districts against 59.6% in the control districts [OR: 1.6; 95% (CI 1.33-2.03)]. The universal coverage campaign piloted with the new delivery model has increased LLINs ownership, use, and progression for reaching universal coverage targets in the community.

Association between sudden infant death syndrome and diphtheria-tetanus-pertussis immunisation: an ecological study.

PubMed

Müller-Nordhorn, Jacqueline; Hettler-Chen, Chih-Mei; Keil, Thomas; Muckelbauer, Rebecca

2015-01-28

Sudden infant death syndrome (SIDS) continues to be one of the main causes of infant mortality in the United States. The objective of this study was to analyse the association between diphtheria-tetanus-pertussis (DTP) immunisation and SIDS over time. The Centers for Disease Control and Prevention provided the number of cases of SIDS and live births per year (1968-2009), allowing the calculation of SIDS mortality rates. Immunisation coverage was based on (1) the United States Immunization Survey (1968-1985), (2) the National Health Interview Survey (1991-1993), and (3) the National Immunization Survey (1994-2009). We used sleep position data from the National Infant Sleep Position Survey. To determine the time points at which significant changes occurred and to estimate the annual percentage change in mortality rates, we performed joinpoint regression analyses. We fitted a Poisson regression model to determine the association between SIDS mortality rates and DTP immunisation coverage (1975-2009). SIDS mortality rates increased significantly from 1968 to 1971 (+27% annually), from 1971 to 1974 (+47%), and from 1974 to 1979 (+3%). They decreased from 1979 to 1991 (-1%) and from 1991 to 2001 (-8%). After 2001, mortality rates remained constant. DTP immunisation coverage was inversely associated with SIDS mortality rates. We observed an incidence rate ratio of 0.92 (95% confidence interval: 0.87 to 0.97) per 10% increase in DTP immunisation coverage after adjusting for infant sleep position. Increased DTP immunisation coverage is associated with decreased SIDS mortality. Current recommendations on timely DTP immunisation should be emphasised to prevent not only specific infectious diseases but also potentially SIDS.

Human Papillomavirus Vaccination Uptake before and after the Affordable Care Act: Variation According to Insurance Status, Race, and Education (NHANES 2006-2014).

PubMed

Corriero, Rosemary; Gay, Jennifer L; Robb, Sara Wagner; Stowe, Ellen W

2018-02-01

The purpose of the study was to compare human papillomavirus (HPV) vaccination rates before and after Affordable Care Act (ACA) implementation among women, and examine differences according to insurance status and other sociodemographic variables. This was a cross-sectional analysis of the National Health and Nutrition Examination Survey questionnaire data. Participants (n = 4599) were from a random sample of the United States population. HPV vaccination status and number of doses received according to age, income, education, race, and insurance coverage. Over time, the proportion of women reporting HPV vaccination increased from 16.4% to 27.6%, and reporting vaccination completion (3 doses) increased from 56.8% to 67.2%. After ACA implementation, respondents were 3.3 times more likely to be vaccinated compared with before ACA implementation (95% confidence interval [CI], 2.0-5.5) adjusting for age, race, and insurance coverage. Similarly, respondents were more likely to have received 2 (odds ratio, 2.8; 95% CI, 1.5-5.3) or 3 doses (odds ratio, 5.8; 95% CI, 2.5-13.6). Vaccination uptake increased in a comparison of waves of data from before and after ACA implementation. This increase in vaccination coverage could be related to the increased preventative service coverage, which includes vaccines, required by the ACA. Future studies might focus on the role insurance has on vaccination uptake, and meeting Healthy People 2020 objectives for vaccination coverage. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

The Medicare Drug Benefit (Part D) and Treatment of Heart Failure in Older Adults

PubMed Central

Donohue, Julie M.; Zhang, Yuting; Lave, Judith R.; Gellad, Walid F.; Men, Aiju; Perera, Subashan; Hanlon, Joseph T.

2010-01-01

Background Adherence to pharmacotherapy for heart failure is poor among older adults due, in part, to high prescription drug costs. We examined the impact of improvements in drug coverage under Medicare Part D on utilization of, and adherence to, medications for heart failure in older adults. Methods We used a quasi-experimental approach to analyze pharmacy claims for 6,950 individuals age≥65 years with heart failure enrolled in a Medicare managed care organization two years before and after Part D’s implementation. We compared prescription fill patterns among individuals who moved from limited (quarterly benefits caps of $150 or $350) or no drug coverage to Part D in 2006 to those who had generous employer-sponsored coverage throughout the study period. Results Individuals who previously lacked drug coverage filled approximately 6 more heart failure prescriptions annually after Part D (Adjusted Ratio of Prescription Counts = 1.36, 95% Confidence Interval=CI=1.29-1.44; p<0.0001 relative to the comparison group). Those previously lacking drug coverage were more likely to fill prescriptions for an angiotensin converting enzyme inhibitor/angiotensin II receptor blocker plus a beta blocker after Part D (adjusted ratio of odds ratios=AROR=1.73; 95% CI=1.42-2.10; p<0.0001), and more likely to be adherent to such pharmacotherapy (AROR=2.95; 95% CI=1.85-4.69; p<0.0001) relative to the comparison group. Conclusions Medicare Part D was associated with improved access to medications and adherence to pharmacotherapy in older adults with heart failure. PMID:20598987

The P Value Problem in Otolaryngology: Shifting to Effect Sizes and Confidence Intervals.

PubMed

Vila, Peter M; Townsend, Melanie Elizabeth; Bhatt, Neel K; Kao, W Katherine; Sinha, Parul; Neely, J Gail

2017-06-01

There is a lack of reporting effect sizes and confidence intervals in the current biomedical literature. The objective of this article is to present a discussion of the recent paradigm shift encouraging the use of reporting effect sizes and confidence intervals. Although P values help to inform us about whether an effect exists due to chance, effect sizes inform us about the magnitude of the effect (clinical significance), and confidence intervals inform us about the range of plausible estimates for the general population mean (precision). Reporting effect sizes and confidence intervals is a necessary addition to the biomedical literature, and these concepts are reviewed in this article.

Intimate Partner Violence and Adherence to HIV Pre-exposure Prophylaxis (PrEP) in African Women in HIV Serodiscordant Relationships: A Prospective Cohort Study

PubMed Central

Haberer, Jessica; Celum, Connie; Mugo, Nelly; Ware, Norma C.; Cohen, Craig R.; Tappero, Jordan W.; Kiarie, James; Ronald, Allan; Mujugira, Andrew; Tumwesigye, Elioda; Were, Edwin; Irungu, Elizabeth; Baeten, Jared M.

2016-01-01

Background: Intimate partner violence (IPV) is associated with higher HIV incidence, reduced condom use, and poor adherence to antiretroviral therapy and other medications. IPV may also affect adherence to pre-exposure prophylaxis (PrEP). Methods: We analyzed data from 1785 HIV-uninfected women enrolled in a clinical trial of PrEP among African HIV serodiscordant couples. Experience of verbal, physical, or economic IPV was assessed at monthly visits by face-to-face interviews. Low PrEP adherence was defined as clinic-based pill count coverage <80% or plasma tenofovir levels <40 ng/mL. The association between IPV and low adherence was analyzed using generalized estimating equations, adjusting for potential confounders. In-depth interview transcripts were examined to explain how IPV could impact adherence. Results: Sixteen percent of women reported IPV during a median of 34.8 months of follow-up (interquartile range 27.0–35.0). Overall, 7% of visits had pill count coverage <80%, and 32% had plasma tenofovir <40 ng/mL. Women reporting IPV in the past 3 months had increased risk of low adherence by pill count (adjusted risk ratio 1.49, 95% confidence interval: 1.17 to 1.89) and by plasma tenofovir (adjusted risk ratio 1.51, 95% confidence interval: 1.06 to 2.15). Verbal, economic, and physical IPV were all associated with low adherence. However, the impact of IPV diminished and was not statistically significant 3 months after the reported exposure. In qualitative interviews, women identified several ways in which IPV affected adherence, including stress and forgetting, leaving home without pills, and partners throwing pills away. Conclusions: Women who reported recent IPV in the Partners PrEP Study were at increased risk of low PrEP adherence. Strategies to mitigate PrEP nonadherence in the context of IPV should be evaluated. PMID:27243900

Changes in antidepressant use by young people and suicidal behavior after FDA warnings and media coverage: quasi-experimental study.

PubMed

Lu, Christine Y; Zhang, Fang; Lakoma, Matthew D; Madden, Jeanne M; Rusinak, Donna; Penfold, Robert B; Simon, Gregory; Ahmedani, Brian K; Clarke, Gregory; Hunkeler, Enid M; Waitzfelder, Beth; Owen-Smith, Ashli; Raebel, Marsha A; Rossom, Rebecca; Coleman, Karen J; Copeland, Laurel A; Soumerai, Stephen B

2014-06-18

To investigate if the widely publicized warnings in 2003 from the US Food and Drug Administration about a possible increased risk of suicidality with antidepressant use in young people were associated with changes in antidepressant use, suicide attempts, and completed suicides among young people. Quasi-experimental study assessing changes in outcomes after the warnings, controlling for pre-existing trends. Automated healthcare claims data (2000-10) derived from the virtual data warehouse of 11 health plans in the US Mental Health Research Network. Study cohorts included adolescents (around 1.1 million), young adults (around 1.4 million), and adults (around 5 million). Rates of antidepressant dispensings, psychotropic drug poisonings (a validated proxy for suicide attempts), and completed suicides. Trends in antidepressant use and poisonings changed abruptly after the warnings. In the second year after the warnings, relative changes in antidepressant use were -31.0% (95% confidence interval -33.0% to -29.0%) among adolescents, -24.3% (-25.4% to -23.2%) among young adults, and -14.5% (-16.0% to -12.9%) among adults. These reflected absolute reductions of 696, 1216, and 1621 dispensings per 100,000 people among adolescents, young adults, and adults, respectively. Simultaneously, there were significant, relative increases in psychotropic drug poisonings in adolescents (21.7%, 95% confidence interval 4.9% to 38.5%) and young adults (33.7%, 26.9% to 40.4%) but not among adults (5.2%, -6.5% to 16.9%). These reflected absolute increases of 2 and 4 poisonings per 100,000 people among adolescents and young adults, respectively (approximately 77 additional poisonings in our cohort of 2.5 million young people). Completed suicides did not change for any age group. Safety warnings about antidepressants and widespread media coverage decreased antidepressant use, and there were simultaneous increases in suicide attempts among young people. It is essential to monitor and reduce possible unintended consequences of FDA warnings and media reporting. © Lu et al 2014.

Completeness and accuracy of the wisconsin immunization registry: an evaluation coinciding with the beginning of meaningful use.

PubMed

Koepke, Ruth; Petit, Ashley B; Ayele, Roman A; Eickhoff, Jens C; Schauer, Stephanie L; Verdon, Matthew J; Hopfensperger, Daniel J; Conway, James H; Davis, Jeffrey P

2015-01-01

Vaccination coverage rates can be improved through the application of complete and accurate immunization information systems (IISs). Evaluate the completeness and accuracy of Wisconsin's IIS, the Wisconsin Immunization Registry (WIR). Cross-sectional evaluation, comparing vaccination medical records (MRs) from provider clinics with WIR records. Medical records of patients born during 2009 were randomly selected from 251 Wisconsin clinics associated with the Vaccines for Children Program. Completeness: percentage of patients with client records in the WIR, percentage of patients up-to-date (%UTD) with the 4:3:1:3:3:1:4 vaccination series, and percentage of patients' MR vaccinations matched by administration date (±10 days) and type to vaccinations documented in the WIR. Accuracy: percentages of matched vaccinations with the same administration date, same trade name (TN), and same lot number. Of the 1863 selected patient MRs, 98% (n = 1833) had WIR client records and 97% of their 30 899 vaccinations were documented in the WIR. The %UTD was 49.3% using the MR only, 76.5% using the WIR only, and 75.2% as estimated by the National Immunization Survey. Among matched vaccinations, 99% had the same administration date, 96% had the same TN, and 95% had the same lot number. Compared with patients from clinics that entered data into the WIR using data exchange from electronic health records, patients from clinics that entered data using the Web-based user interface were less likely to have client records in the WIR (odds ratio: 0.3; 95% confidence interval: 0.1-0.9) and less likely to have accurate TNs (odds ratio: 0.3; 95% confidence interval: 0.1-0.5). The WIR was complete and accurate among this sample of children born during 2009 and provided a vaccination coverage assessment similar to the National Immunization Survey. Our results provide support for the expectation that meaningful use and other initiatives that increase data exchange from electronic health records to IISs will improve IIS data quality.

Anticipated changes in reimbursements for US outpatient emergency department encounters after health reform.

PubMed

Galarraga, Jessica E; Pines, Jesse M

2014-04-01

We study how reimbursements to emergency departments (EDs) for outpatient visits may be affected by the insurance coverage expansion of the Patient Protection and Affordable Care Act as previously uninsured patients gain coverage either through the Medicaid expansion or through health insurance exchanges. We conducted a secondary analysis of data (2005 to 2010) from the Medical Expenditure Panel Survey. We specified multiple linear regression models to examine differences in the payments, charges, and reimbursement ratios by insurance category. Comparisons were made between 2 groups to reflect likely movements in insurance status after the Patient Protection and Affordable Care Act implementation: (1) the uninsured who will be Medicaid eligible afterward versus Medicaid insured, and (2) the uninsured who will be Medicaid ineligible afterward versus the privately insured. From 2005 to 2010, as a percentage of total ED charges, outpatient ED encounters for Medicaid beneficiaries reimbursed 17% more than for uninsured individuals who will become Medicaid eligible after Patient Protection and Affordable Care Act implementation: 40.0% versus 34.0%, mean absolute difference=5.9%, 95% confidence interval 5.7% to 6.2%. During the same period, the privately insured reimbursed 39% more than for uninsured individuals who will not be Medicaid eligible after Patient Protection and Affordable Care Act implementation: 54.0% versus 38.8%, mean absolute difference=15.2%, 95% confidence interval 12.8% to 17.6%. Assuming historical reimbursement patterns remain after Patient Protection and Affordable Care Act implementation, outpatient ED encounters could reimburse considerably more for both the previously uninsured patients who will obtain Medicaid insurance and for those who move into private insurance products through health insurance exchanges. Although our study does provide insight into the future, multiple factors will ultimately influence reimbursements after implementation of the act. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Confidence Intervals for Error Rates Observed in Coded Communications Systems

NASA Astrophysics Data System (ADS)

Hamkins, J.

2015-05-01

We present methods to compute confidence intervals for the codeword error rate (CWER) and bit error rate (BER) of a coded communications link. We review several methods to compute exact and approximate confidence intervals for the CWER, and specifically consider the situation in which the true CWER is so low that only a handful, if any, codeword errors are able to be simulated. In doing so, we answer the question of how long an error-free simulation must be run in order to certify that a given CWER requirement is met with a given level of confidence, and discuss the bias introduced by aborting a simulation after observing the first codeword error. Next, we turn to the lesser studied problem of determining confidence intervals for the BER of coded systems. Since bit errors in systems that use coding or higher-order modulation do not occur independently, blind application of a method that assumes independence leads to inappropriately narrow confidence intervals. We present a new method to compute the confidence interval properly, using the first and second sample moments of the number of bit errors per codeword. This is the first method we know of to compute a confidence interval for the BER of a coded or higher-order modulation system.

Human papillomavirus vaccination among adolescents in Georgia.

PubMed

Underwood, Natasha L; Weiss, Paul; Gargano, Lisa M; Seib, Katherine; Rask, Kimberly J; Morfaw, Christopher; Murray, Dennis; DiClemente, Ralph J; Hughes, James M; Sales, Jessica M

2015-01-01

Human papillomavirus (HPV) vaccination coverage for adolescent females and males remains low in the United States. We conducted a 3-arm randomized controlled trial (RCT) conducted in middle and high schools in eastern Georgia from 2011-2013 to determine the effect of 2 educational interventions used to increase adolescent vaccination coverage for the 4 recommended adolescent vaccines: Tdap, MCV4, HPV and influenza. As part of this RCT, this article focuses on: 1) describing initiation and completion of HPV vaccine series among a diverse population of male and female adolescents; 2) assessing parental attitudes toward HPV vaccine; and 3) examining correlates of HPV vaccine series initiation and completion. Parental attitude score was the strongest predictor of HPV vaccine initiation among adolescents (adjusted odds ratio (aOR): 2.08; 95% confidence interval (CI): 1.80, 2.39). Other correlates that significantly predicted HPV series initiation were gender, study year, and intervention arm. Parental attitudes remained a significant predictor of receipt of 3 doses of HPV vaccine along with gender, race, school type and insurance type. This study demonstrates that positive parental attitudes are important predictors of HPV vaccination and critical to increasing coverage rates. Our findings suggest that more research is needed to understand how parental attitudes are developed and evolve over time.

Quantile regression models of animal habitat relationships

USGS Publications Warehouse

Cade, Brian S.

2003-01-01

Typically, all factors that limit an organism are not measured and included in statistical models used to investigate relationships with their environment. If important unmeasured variables interact multiplicatively with the measured variables, the statistical models often will have heterogeneous response distributions with unequal variances. Quantile regression is an approach for estimating the conditional quantiles of a response variable distribution in the linear model, providing a more complete view of possible causal relationships between variables in ecological processes. Chapter 1 introduces quantile regression and discusses the ordering characteristics, interval nature, sampling variation, weighting, and interpretation of estimates for homogeneous and heterogeneous regression models. Chapter 2 evaluates performance of quantile rankscore tests used for hypothesis testing and constructing confidence intervals for linear quantile regression estimates (0 ≤ τ ≤ 1). A permutation F test maintained better Type I errors than the Chi-square T test for models with smaller n, greater number of parameters p, and more extreme quantiles τ. Both versions of the test required weighting to maintain correct Type I errors when there was heterogeneity under the alternative model. An example application related trout densities to stream channel width:depth. Chapter 3 evaluates a drop in dispersion, F-ratio like permutation test for hypothesis testing and constructing confidence intervals for linear quantile regression estimates (0 ≤ τ ≤ 1). Chapter 4 simulates from a large (N = 10,000) finite population representing grid areas on a landscape to demonstrate various forms of hidden bias that might occur when the effect of a measured habitat variable on some animal was confounded with the effect of another unmeasured variable (spatially and not spatially structured). Depending on whether interactions of the measured habitat and unmeasured variable were negative (interference interactions) or positive (facilitation interactions), either upper (τ > 0.5) or lower (τ < 0.5) quantile regression parameters were less biased than mean rate parameters. Sampling (n = 20 - 300) simulations demonstrated that confidence intervals constructed by inverting rankscore tests provided valid coverage of these biased parameters. Quantile regression was used to estimate effects of physical habitat resources on a bivalve mussel (Macomona liliana) in a New Zealand harbor by modeling the spatial trend surface as a cubic polynomial of location coordinates.

Association Between the Opening of Retail Clinics and Low-Acuity Emergency Department Visits.

PubMed

Martsolf, Grant; Fingar, Kathryn R; Coffey, Rosanna; Kandrack, Ryan; Charland, Tom; Eibner, Christine; Elixhauser, Anne; Steiner, Claudia; Mehrotra, Ateev

2017-04-01

We assess whether the opening of retail clinics near emergency departments (ED) is associated with decreased ED utilization for low-acuity conditions. We used data from the Healthcare Cost and Utilization Project State Emergency Department Databases for 2,053 EDs in 23 states from 2007 to 2012. We used Poisson regression models to examine the association between retail clinic penetration and the rate of ED visits for 11 low-acuity conditions. Retail clinic "penetration" was measured as the percentage of the ED catchment area that overlapped with the 10-minute drive radius of a retail clinic. Rate ratios were calculated for a 10-percentage-point increase in retail clinic penetration per quarter. During the course of a year, this represents the effect of an increase in retail clinic penetration rate from 0% to 40%, which was approximately the average penetration rate observed in 2012. Among all patients, retail clinic penetration was not associated with a reduced rate of low-acuity ED visits (rate ratio=0.999; 95% confidence interval=0.997 to 1.000). Among patients with private insurance, there was a slight decrease in low-acuity ED visits (rate ratio=0.997; 95% confidence interval=0.994 to 0.999). For the average ED in a given quarter, this would equal a 0.3% reduction (95% confidence interval 0.1% to 0.6%) in low-acuity ED visits among the privately insured if retail clinic penetration rate increased by 10 percentage points per quarter. With increased patient demand resulting from the expansion of health insurance coverage, retail clinics may emerge as an important care location, but to date, they have not been associated with a meaningful reduction in low-acuity ED visits. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

No lasting legacy: no change in reporting of women's sports in the British print media with the London 2012 Olympics and Paralympics.

PubMed

Packer, C; Geh, D J; Goulden, O W; Jordan, A M; Withers, G K; Wagstaff, A J; Bellwood, R A; Binmore, C L; Webster, C L

2015-03-01

The proportion of media sports coverage devoted to women is reported at between 1 and 6%. Our survey examines and compares reporting patterns before and after the 2012 Olympics and Paralympics. We collected data on sports coverage in six national newspapers on 3 weekend days in February and March 2012, and in February 2013; ∼5 months before the opening of the 2012 Olympic Games and 5 months after the closing of the Paralympic Games. In 2012, 39 of 876 articles in national newspapers (4.5%) related to women's sports, compared with 22 of 755 (2.9%) in 2013; a non-significant reduction in coverage [difference 1.54%, 95% confidence interval (CI) -0.28 to 3.36). In 2012, 24 of 647 pictures (3.7%) related to women's activities, compared with 10 of 738 (1.4%) in 2013; a significant reduction in coverage (difference 2.35%; 95% CI 0.68-4.03). The median area per article was significantly greater for men in both years. We found a continuing bias towards men's sport in the media analysed and no evidence of improvement either before or after the 2012 Olympics and Paralympics. Increased support of women's sport in the print media could benefit individuals and influence the health of the population. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health.

Integrating antiretroviral therapy into antenatal care and maternal and child health settings: a systematic review and meta-analysis

PubMed Central

Hoos, David; Beqiri, Alba; Lorenz-Dehne, Karl; McClure, Craig; Duncombe, Chris

2013-01-01

Abstract Objective To determine whether integrating antiretroviral therapy (ART) into antenatal care (ANC) and maternal and child health (MCH) clinics could improve programmatic and patient outcomes. Methods The authors systematically searched PubMed, Embase, African Index Medicus and LiLACS for randomized controlled trials, prospective cohort studies, or retrospective cohort studies comparing outcomes in ANC or MCH clinics that had and had not integrated ART. The outcomes of interest were ART coverage, ART enrolment, ART retention, mortality and transmission of human immunodeficiency virus (HIV). Findings Four studies met the inclusion criteria. All were conducted in ANC clinics. Increased enrolment of pregnant women in ART was observed in ANC clinics that had integrated ART (relative risk, RR: 2.09; 95% confidence interval, CI; 1.78–2.46; I2: 15%). Increased ART coverage was also noted in such clinics (RR: 1.37; 95% CI: 1.05–1.79; I2: 83%). Sensitivity analyses revealed a trend for the national prevalence of HIV infection to explain the heterogeneity in the size of the effect of ART integration on ART coverage (P = 0.13). Retention in ART was similar in ANC clinics with and without ART integration. Conclusion Although few data were available, ART integration in ANC clinics appears to lead to higher rates of ART enrolment and ART coverage. Rates of retention in ART remain similar to those observed in referral-based models. PMID:23397350

Minimax confidence intervals in geomagnetism

NASA Technical Reports Server (NTRS)

Stark, Philip B.

1992-01-01

The present paper uses theory of Donoho (1989) to find lower bounds on the lengths of optimally short fixed-length confidence intervals (minimax confidence intervals) for Gauss coefficients of the field of degree 1-12 using the heat flow constraint. The bounds on optimal minimax intervals are about 40 percent shorter than Backus' intervals: no procedure for producing fixed-length confidence intervals, linear or nonlinear, can give intervals shorter than about 60 percent the length of Backus' in this problem. While both methods rigorously account for the fact that core field models are infinite-dimensional, the application of the techniques to the geomagnetic problem involves approximations and counterfactual assumptions about the data errors, and so these results are likely to be extremely optimistic estimates of the actual uncertainty in Gauss coefficients.

Using Screencast Videos to Enhance Undergraduate Students' Statistical Reasoning about Confidence Intervals

ERIC Educational Resources Information Center

Strazzeri, Kenneth Charles

2013-01-01

The purposes of this study were to investigate (a) undergraduate students' reasoning about the concepts of confidence intervals (b) undergraduate students' interactions with "well-designed" screencast videos on sampling distributions and confidence intervals, and (c) how screencast videos improve undergraduate students' reasoning ability…

Frequentist Model Averaging in Structural Equation Modelling.

PubMed

Jin, Shaobo; Ankargren, Sebastian

2018-06-04

Model selection from a set of candidate models plays an important role in many structural equation modelling applications. However, traditional model selection methods introduce extra randomness that is not accounted for by post-model selection inference. In the current study, we propose a model averaging technique within the frequentist statistical framework. Instead of selecting an optimal model, the contributions of all candidate models are acknowledged. Valid confidence intervals and a [Formula: see text] test statistic are proposed. A simulation study shows that the proposed method is able to produce a robust mean-squared error, a better coverage probability, and a better goodness-of-fit test compared to model selection. It is an interesting compromise between model selection and the full model.

Path Loss Prediction Over the Lunar Surface Utilizing a Modified Longley-Rice Irregular Terrain Model

NASA Technical Reports Server (NTRS)

Foore, Larry; Ida, Nathan

2007-01-01

This study introduces the use of a modified Longley-Rice irregular terrain model and digital elevation data representative of an analogue lunar site for the prediction of RF path loss over the lunar surface. The results are validated by theoretical models and past Apollo studies. The model is used to approximate the path loss deviation from theoretical attenuation over a reflecting sphere. Analysis of the simulation results provides statistics on the fade depths for frequencies of interest, and correspondingly a method for determining the maximum range of communications for various coverage confidence intervals. Communication system engineers and mission planners are provided a link margin and path loss policy for communication frequencies of interest.

CALCULATION OF NONLINEAR CONFIDENCE AND PREDICTION INTERVALS FOR GROUND-WATER FLOW MODELS.

USGS Publications Warehouse

Cooley, Richard L.; Vecchia, Aldo V.

1987-01-01

A method is derived to efficiently compute nonlinear confidence and prediction intervals on any function of parameters derived as output from a mathematical model of a physical system. The method is applied to the problem of obtaining confidence and prediction intervals for manually-calibrated ground-water flow models. To obtain confidence and prediction intervals resulting from uncertainties in parameters, the calibrated model and information on extreme ranges and ordering of the model parameters within one or more independent groups are required. If random errors in the dependent variable are present in addition to uncertainties in parameters, then calculation of prediction intervals also requires information on the extreme range of error expected. A simple Monte Carlo method is used to compute the quantiles necessary to establish probability levels for the confidence and prediction intervals. Application of the method to a hypothetical example showed that inclusion of random errors in the dependent variable in addition to uncertainties in parameters can considerably widen the prediction intervals.

Effects of income and dental insurance coverage on need for dental care in Canada.

PubMed

Duncan, Laura; Bonner, Ashley

2014-01-01

To estimate the strength of the associations among income, dental insurance coverage and need for dental care (both urgent and nonurgent) in Canada. Multinomial logistic models were fit to data from the 2009 Canadian Health Measures Survey to test unadjusted associations among household income, dental insurance coverage and the need for urgent and nonurgent dental care. Adjusted associations, controlling for socio-demographic variables (age, sex, immigration status, education and province of residence) and oral health habits (brushing, flossing and visits to the dentist) were also evaluated. In the unadjusted model, need for treatment was lower among people with dental insurance than among those without insurance coverage (for urgent treatment: odds ratio [OR] 0.76, 95% confidence interval [CI] 0.66-0.89; for nonurgent treatment: OR 0.59, 95% CI 0.50-0.70). In addition, there was an income gradient, whereby people with higher income had less need for dental treatment (for urgent treatment: OR 0.99, 95% CI 0.99-1.00; for nonurgent treatment: OR 0.99, 95% CI 0.98-0.99). Controlling for socio-demographic and oral health variables decreased the magnitude of the association between dental insurance coverage and need for treatment (for urgent treatment: OR 0.80, 95% CI 0.68-0.95; for nonurgent treatment: OR 0.76, 95% CI 0.63-0.92). An interaction term between dental coverage and income was significant in relation to the need for nonurgent treatment: among lower-income individuals, having insurance slightly decreased the odds of needing nonurgent treatment, with this decrease in odds becoming greater for middle-income earners and even greater for high-income earners. Income-related inequality in need for dental care exists even in the presence of dental insurance coverage and good dental hygiene habits. These findings highlight the need for increased access to dental care for low-income populations and families living in poverty.

Evaluation of a national universal coverage campaign of long-lasting insecticidal nets in a rural district in north-west Tanzania.

PubMed

West, Philippa A; Protopopoff, Natacha; Rowland, Mark W; Kirby, Matthew J; Oxborough, Richard M; Mosha, Franklin W; Malima, Robert; Kleinschmidt, Immo

2012-08-10

Insecticide-treated nets (ITN) are one of the most effective measures for preventing malaria. Mass distribution campaigns are being used to rapidly increase net coverage in at-risk populations. This study had two purposes: to evaluate the impact of a universal coverage campaign (UCC) of long-lasting insecticidal nets (LLINs) on LLIN ownership and usage, and to identify factors that may be associated with inadequate coverage. In 2011 two cross-sectional household surveys were conducted in 50 clusters in Muleba district, north-west Tanzania. Prior to the UCC 3,246 households were surveyed and 2,499 afterwards. Data on bed net ownership and usage, demographics of household members and household characteristics including factors related to socio-economic status were gathered, using an adapted version of the standard Malaria Indicator Survey. Specific questions relating to the UCC process were asked. The proportion of households with at least one ITN increased from 62.6% (95% Confidence Interval (CI) = 60.9-64.2) before the UCC to 90.8% (95% CI = 89.0-92.3) afterwards. ITN usage in all residents rose from 40.8% to 55.7%. After the UCC 58.4% (95% CI = 54.7-62.1) of households had sufficient ITNs to cover all their sleeping places. Households with children under five years (OR = 2.4, 95% CI = 1.9-2.9) and small households (OR = 1.9, 95% CI = 1.5-2.4) were most likely to reach universal coverage. Poverty was not associated with net coverage. Eighty percent of households surveyed received LLINs from the campaign. The UCC in Muleba district of Tanzania was equitable, greatly improving LLIN ownership and, more moderately, usage. However, the goal of universal coverage in terms of the adequate provision of nets was not achieved. Multiple, continuous delivery systems and education activities are required to maintain and improve bed net ownership and usage.

Bootstrapping Confidence Intervals for Robust Measures of Association.

ERIC Educational Resources Information Center

King, Jason E.

A Monte Carlo simulation study was conducted to determine the bootstrap correction formula yielding the most accurate confidence intervals for robust measures of association. Confidence intervals were generated via the percentile, adjusted, BC, and BC(a) bootstrap procedures and applied to the Winsorized, percentage bend, and Pearson correlation…

Interpretation of Confidence Interval Facing the Conflict

ERIC Educational Resources Information Center

Andrade, Luisa; Fernández, Felipe

2016-01-01

As literature has reported, it is usual that university students in statistics courses, and even statistics teachers, interpret the confidence level associated with a confidence interval as the probability that the parameter value will be between the lower and upper interval limits. To confront this misconception, class activities have been…

Evaluating Independent Proportions for Statistical Difference, Equivalence, Indeterminacy, and Trivial Difference Using Inferential Confidence Intervals

ERIC Educational Resources Information Center

Tryon, Warren W.; Lewis, Charles

2009-01-01

Tryon presented a graphic inferential confidence interval (ICI) approach to analyzing two independent and dependent means for statistical difference, equivalence, replication, indeterminacy, and trivial difference. Tryon and Lewis corrected the reduction factor used to adjust descriptive confidence intervals (DCIs) to create ICIs and introduced…

Comparison of Random Forest and Parametric Imputation Models for Imputing Missing Data Using MICE: A CALIBER Study

PubMed Central

Shah, Anoop D.; Bartlett, Jonathan W.; Carpenter, James; Nicholas, Owen; Hemingway, Harry

2014-01-01

Multivariate imputation by chained equations (MICE) is commonly used for imputing missing data in epidemiologic research. The “true” imputation model may contain nonlinearities which are not included in default imputation models. Random forest imputation is a machine learning technique which can accommodate nonlinearities and interactions and does not require a particular regression model to be specified. We compared parametric MICE with a random forest-based MICE algorithm in 2 simulation studies. The first study used 1,000 random samples of 2,000 persons drawn from the 10,128 stable angina patients in the CALIBER database (Cardiovascular Disease Research using Linked Bespoke Studies and Electronic Records; 2001–2010) with complete data on all covariates. Variables were artificially made “missing at random,” and the bias and efficiency of parameter estimates obtained using different imputation methods were compared. Both MICE methods produced unbiased estimates of (log) hazard ratios, but random forest was more efficient and produced narrower confidence intervals. The second study used simulated data in which the partially observed variable depended on the fully observed variables in a nonlinear way. Parameter estimates were less biased using random forest MICE, and confidence interval coverage was better. This suggests that random forest imputation may be useful for imputing complex epidemiologic data sets in which some patients have missing data. PMID:24589914

Comparison of random forest and parametric imputation models for imputing missing data using MICE: a CALIBER study.

PubMed

Shah, Anoop D; Bartlett, Jonathan W; Carpenter, James; Nicholas, Owen; Hemingway, Harry

2014-03-15

Multivariate imputation by chained equations (MICE) is commonly used for imputing missing data in epidemiologic research. The "true" imputation model may contain nonlinearities which are not included in default imputation models. Random forest imputation is a machine learning technique which can accommodate nonlinearities and interactions and does not require a particular regression model to be specified. We compared parametric MICE with a random forest-based MICE algorithm in 2 simulation studies. The first study used 1,000 random samples of 2,000 persons drawn from the 10,128 stable angina patients in the CALIBER database (Cardiovascular Disease Research using Linked Bespoke Studies and Electronic Records; 2001-2010) with complete data on all covariates. Variables were artificially made "missing at random," and the bias and efficiency of parameter estimates obtained using different imputation methods were compared. Both MICE methods produced unbiased estimates of (log) hazard ratios, but random forest was more efficient and produced narrower confidence intervals. The second study used simulated data in which the partially observed variable depended on the fully observed variables in a nonlinear way. Parameter estimates were less biased using random forest MICE, and confidence interval coverage was better. This suggests that random forest imputation may be useful for imputing complex epidemiologic data sets in which some patients have missing data.

Evaluation of impact of measles rubella campaign on vaccination coverage and routine immunization services in Bangladesh.

PubMed

Uddin, Md Jasim; Adhikary, Gourab; Ali, Md Wazed; Ahmed, Shahabuddin; Shamsuzzaman, Md; Odell, Chris; Hashiguchi, Lauren; Lim, Stephen S; Alam, Nurul

2016-08-12

Like other countries in Asia, measles-rubella (MR) vaccine coverage in Bangladesh is suboptimal whereas 90-95 % coverage is needed for elimination of these diseases. The Ministry of Health and Family Welfare (MOHFW) of the Government of Bangladesh implemented MR campaign in January-February 2014 to increase MR vaccination coverage. Strategically, the MOHFW used both routine immunization centres and educational institutions for providing vaccine to the children aged 9 months to <15 years. The evaluation was carried out to assess the impact of the campaign on MR vaccination and routine immunization services. Both quantitative and qualitative evaluations were done before and after implementation of the campaign. Quantitative data were presented with mean (standard deviation, SD) for continuous variables and with proportion for categorical variables. The overall and age- and sex-specific coverage rates were calculated for each region and then combined. Categorical variables were compared by chi-square statistics. Multiple logistic regression analysis were performed to estimate odds ratios (OR) and 95 % confidence intervals (CI) of coverage associated with covariates, with adjustment for other covariates. Qualitative data were analyzed using content analysis. The evaluations found MR coverage was very low (<13 %) before the campaign and it rose to 90 % after the campaign. The pre-post campaign difference in MR coverage in each stratum was highly significant (p < 0.001). The campaign achieved high coverage despite relatively low level (23 %) of interpersonal communication with caregivers through registration process. Child registration was associated with higher MR coverage (OR 2.91, 95 % CI 1.91-4.44). Children who attended school were more likely to be vaccinated (OR 8.97, 95 % CI 6.17-13.04) compared to those who did not attend school. Children of caregivers with primary or secondary or higher education had higher coverage compared to children of caregivers with no formal education. Most caregivers mentioned contribution of the campaign in vaccination for the children not previously vaccinated. The results of the evaluation indicated that the campaign was successful in terms of improving MR coverage and routine immunization services. The evaluation provided an important guideline for future evaluation of similar efforts in Bangladesh and elsewhere.

Race, Ethnicity, Language, Social Class, and Health Communication Inequalities: A Nationally-Representative Cross-Sectional Study

PubMed Central

Viswanath, Kasisomayajula; Ackerson, Leland K.

2011-01-01

Background While mass media communications can be an important source of health information, there are substantial social disparities in health knowledge that may be related to media use. The purpose of this study is to investigate how the use of cancer-related health communications is patterned by race, ethnicity, language, and social class. Methodology/Principal Findings In a nationally-representative cross-sectional telephone survey, 5,187 U.S. adults provided information about demographic characteristics, cancer information seeking, and attention to and trust in health information from television, radio, newspaper, magazines, and the Internet. Cancer information seeking was lowest among Spanish-speaking Hispanics (odds ratio: 0.42; 95% confidence interval: 0.28–0.63) compared to non-Hispanic whites. Spanish-speaking Hispanics were more likely than non-Hispanic whites to pay attention to (odds ratio: 3.10; 95% confidence interval: 2.07–4.66) and trust (odds ratio: 2.61; 95% confidence interval: 1.53–4.47) health messages from the radio. Non-Hispanic blacks were more likely than non-Hispanic whites to pay attention to (odds ratio: 2.39; 95% confidence interval: 1.88–3.04) and trust (odds ratio: 2.16; 95% confidence interval: 1.61–2.90) health messages on television. Those who were college graduates tended to pay more attention to health information from newspapers (odds ratio: 1.98; 95% confidence interval: 1.42–2.75), magazines (odds ratio: 1.86; 95% confidence interval: 1.32–2.60), and the Internet (odds ratio: 4.74; 95% confidence interval: 2.70–8.31) and had less trust in cancer-related health information from television (odds ratio: 0.44; 95% confidence interval: 0.32–0.62) and radio (odds ratio: 0.54; 95% confidence interval: 0.34–0.86) compared to those who were not high school graduates. Conclusions/Significance Health media use is patterned by race, ethnicity, language and social class. Providing greater access to and enhancing the quality of health media by taking into account factors associated with social determinants may contribute to addressing social disparities in health. PMID:21267450

Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.

PubMed

Virk, Jasveer; Liew, Zeyan; Olsen, Jørn; Nohr, Ellen A; Catov, Janet M; Ritz, Beate

2016-08-01

To evaluate whether early folic acid supplementation during pregnancy prevents diagnosis of autism spectrum disorders in offspring. Information on autism spectrum disorder diagnosis was obtained from the National Hospital Register and the Central Psychiatric Register. We estimated risk ratios for autism spectrum disorders for children whose mothers took folate or multivitamin supplements from 4 weeks prior from the last menstrual period through to 8 weeks after the last menstrual period (-4 to 8 weeks) by three 4-week periods. We did not find an association between early folate or multivitamin intake for autism spectrum disorder (folic acid-adjusted risk ratio: 1.06, 95% confidence interval: 0.82-1.36; multivitamin-adjusted risk ratio: 1.00, 95% confidence interval: 0.82-1.22), autistic disorder (folic acid-adjusted risk ratio: 1.18, 95% confidence interval: 0.76-1.84; multivitamin-adjusted risk ratio: 1.22, 95% confidence interval: 0.87-1.69), Asperger's syndrome (folic acid-adjusted risk ratio: 0.85, 95% confidence interval: 0.46-1.53; multivitamin-adjusted risk ratio: 0.95, 95% confidence interval: 0.62-1.46), or pervasive developmental disorder-not otherwise specified (folic acid-adjusted risk ratio: 1.07, 95% confidence interval: 0.75-1.54; multivitamin: adjusted risk ratio: 0.87, 95% confidence interval: 0.65-1.17) compared with women reporting no supplement use in the same period. We did not find any evidence to corroborate previous reports of a reduced risk for autism spectrum disorders in offspring of women using folic acid supplements in early pregnancy. © The Author(s) 2015.

Applying Bootstrap Resampling to Compute Confidence Intervals for Various Statistics with R

ERIC Educational Resources Information Center

Dogan, C. Deha

2017-01-01

Background: Most of the studies in academic journals use p values to represent statistical significance. However, this is not a good indicator of practical significance. Although confidence intervals provide information about the precision of point estimation, they are, unfortunately, rarely used. The infrequent use of confidence intervals might…

Reporting Confidence Intervals and Effect Sizes: Collecting the Evidence

ERIC Educational Resources Information Center

Zientek, Linda Reichwein; Ozel, Z. Ebrar Yetkiner; Ozel, Serkan; Allen, Jeff

2012-01-01

Confidence intervals (CIs) and effect sizes are essential to encourage meta-analytic thinking and to accumulate research findings. CIs provide a range of plausible values for population parameters with a degree of confidence that the parameter is in that particular interval. CIs also give information about how precise the estimates are. Comparison…

Confidence Intervals for Effect Sizes: Applying Bootstrap Resampling

ERIC Educational Resources Information Center

Banjanovic, Erin S.; Osborne, Jason W.

2016-01-01

Confidence intervals for effect sizes (CIES) provide readers with an estimate of the strength of a reported statistic as well as the relative precision of the point estimate. These statistics offer more information and context than null hypothesis statistic testing. Although confidence intervals have been recommended by scholars for many years,…

Accuracy in parameter estimation for targeted effects in structural equation modeling: sample size planning for narrow confidence intervals.

PubMed

Lai, Keke; Kelley, Ken

2011-06-01

In addition to evaluating a structural equation model (SEM) as a whole, often the model parameters are of interest and confidence intervals for those parameters are formed. Given a model with a good overall fit, it is entirely possible for the targeted effects of interest to have very wide confidence intervals, thus giving little information about the magnitude of the population targeted effects. With the goal of obtaining sufficiently narrow confidence intervals for the model parameters of interest, sample size planning methods for SEM are developed from the accuracy in parameter estimation approach. One method plans for the sample size so that the expected confidence interval width is sufficiently narrow. An extended procedure ensures that the obtained confidence interval will be no wider than desired, with some specified degree of assurance. A Monte Carlo simulation study was conducted that verified the effectiveness of the procedures in realistic situations. The methods developed have been implemented in the MBESS package in R so that they can be easily applied by researchers. © 2011 American Psychological Association

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant, Stephen R.; Walker, Gary V.; Koshy, Matthew

Purpose: The Patient Protection and Affordable Care Act looks to expand both private and Medicaid insurance. To evaluate how these changes may affect the field of radiation oncology, we evaluated the association of insurance status with the use of brachytherapy in cancers for which this treatment technique is used. Methods and Materials: A total of 190,467 patients met the inclusion criteria, of whom 95,292 (50.0%) had breast cancer, 61,096 (32.1%) had prostate cancer, 28,194 (14.8%) had endometrial cancer, and 5885 (3.1%) had cervical cancer. A multivariate logistic regression model was used to determine the association between insurance status and receiptmore » of brachytherapy among patients treated definitively for prostate and cervical cancer or postoperatively for breast and endometrial cancer. Results: The rates of non-Medicaid insurance were 49.9% (cervical), 85.3% (endometrial), 87.4% (breast), and 90.9% (prostate) (P<.001). In a logistic regression, patients who received radiation therapy were less likely to receive brachytherapy if they had Medicaid coverage (odds ratio [OR] 0.57, 95% confidence interval [CI] 0.53-0.61, P<.001) or did not have insurance coverage (OR 0.50, 95% CI 0.45-0.56, P<.001) compared with those with non-Medicaid insurance. On subset analysis, patients with Medicaid coverage or without insurance coverage were significantly less likely to receive brachytherapy than were those with non-Medicaid insurance for all 4 sites, except for patients with endometrial cancer. Conclusions: Despite being a cost-effective treatment modality, brachytherapy is less often used in the definitive or postoperative management of cancer in patients with Medicaid coverage or without insurance. Upcoming health policy changes resulting in the expansion of private insurance and Medicaid will likely increase access to and demand for brachytherapy.« less

Importance of employee vaccination against influenza in preventing cases in long-term care facilities.

PubMed

Wendelboe, Aaron M; Avery, Catherine; Andrade, Bernardo; Baumbach, Joan; Landen, Michael G

2011-10-01

Employees of long-term care facilities (LTCFs) who have contact with residents should be vaccinated against influenza annually to reduce influenza incidence among residents. This investigation estimated the magnitude of the benefit of this recommendation. The New Mexico Department of Health implemented active surveillance in all of its 75 LTCFs during influenza seasons 2006-2007 and 2007-2008. Information about the number of laboratory-confirmed cases of influenza and the proportion vaccinated of both residents and direct-care employees in each facility was collected monthly. LTCFs reporting at least 1 case of influenza (defined alternately by laboratory confirmation or symptoms of influenza-like illness [ILI]) among residents were compared with LTCFs reporting no cases of influenza. Regression modeling was used to obtain adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the association between employee vaccination coverage and the occurrence of influenza outbreaks. Covariates included vaccination coverage among residents, the staff-to-resident ratio, and the proportion of filled beds. Seventeen influenza outbreaks were reported during this 2-year period of surveillance. Eleven of these were laboratory confirmed (n = 21 residents) and 6 were defined by ILI (n = 40 residents). Mean influenza vaccination coverage among direct-care employees was 51% in facilities reporting outbreaks and 60% in facilities not reporting outbreaks (P = .12). Increased vaccination coverage among direct-care employees was associated with fewer reported outbreaks of laboratory-confirmed influenza (aOR, 0.97 [95% CI, 0.95-0.99]) and ILI (aOR, 0.98 [95% CI, 0.96-1.00]). High vaccination coverage among direct-care employees helps to prevent influenza in LTCFs.

Reduction in child mortality in Ethiopia: analysis of data from demographic and health surveys.

PubMed

Doherty, Tanya; Rohde, Sarah; Besada, Donela; Kerber, Kate; Manda, Samuel; Loveday, Marian; Nsibande, Duduzile; Daviaud, Emmanuelle; Kinney, Mary; Zembe, Wanga; Leon, Natalie; Rudan, Igor; Degefie, Tedbabe; Sanders, David

2016-12-01

To examine changes in under-5 mortality, coverage of child survival interventions and nutritional status of children in Ethiopia between 2000 and 2011. Using the Lives Saved Tool, the impact of changes in coverage of child survival interventions on under-5 lives saved was estimated. Estimates of child mortality were generated using three Ethiopia Demographic and Health Surveys undertaken between 2000 and 2011. Coverage indicators for high impact child health interventions were calculated and the Lives Saved Tool (LiST) was used to estimate child lives saved in 2011. The mortality rate in children younger than 5 years decreased rapidly from 218 child deaths per 1000 live births (95% confidence interval 183 to 252) in the period 1987-1991 to 88 child deaths per 1000 live births in the period 2007-2011 (78 to 98). The prevalence of moderate or severe stunting in children aged 6-35 months also declined significantly. Improvements in the coverage of interventions relevant to child survival in rural areas of Ethiopia between 2000 and 2011 were found for tetanus toxoid, DPT3 and measles vaccination, oral rehydration solution (ORS) and care-seeking for suspected pneumonia. The LiST analysis estimates that there were 60 700 child deaths averted in 2011, primarily attributable to decreases in wasting rates (18%), stunting rates (13%) and water, sanitation and hygiene (WASH) interventions (13%). Improvements in the nutritional status of children and increases in coverage of high impact interventions most notably WASH and ORS have contributed to the decline in under-5 mortality in Ethiopia. These proximal determinants however do not fully explain the mortality reduction which is plausibly also due to the synergistic effect of major child health and nutrition policies and delivery strategies.

Seroprevalence and Determinants of Immunity to Diphtheria for Children Living in Two Districts of Contrasting Incidence During an Outbreak in East Java, Indonesia.

PubMed

Hughes, Gareth J; Mikhail, Amy F W; Husada, Dominicus; Irawan, Eveline; Kafatos, George; Bracebridge, Samantha; Pebody, Richard; Efstratiou, Androulla

2015-11-01

In 2012, an ongoing outbreak of diphtheria in Indonesia was focused in the province of East Java. There was a need to assess vaccine coverage and immunity gaps in children. We conducted a cross-sectional seroprevalence and vaccine coverage survey of children 1-15 years of age in 2 districts of East Java: one of high incidence (on the island of Madura) and one of low incidence (on the mainland). From each district, we sampled 150 children (10 children per year of age). Sera and throat swabs were taken to determine immunity and carriage status. Immunity was defined as ≥0.1 international unit/mL of antibody to diphtheria toxin. A total of 297 children were selected to participate in the study. Coverage of three doses of combined vaccine for diphtheria, tetanus and pertussis was significantly lower (P < 0.001) in the high incidence district compared with the low [57%, 95% confidence interval (CI): 36-78 vs. 97%, 95% CI: 93-100]. Despite this higher vaccine coverage, seroprevalence of immunity was lower in the low incidence district compared with the high (71%, 95% CI: 63-80 vs. 83%, 95% CI: 76-90). Immunity in the high incidence district was associated with increased age, increased prevalence of toxigenic Corynebacterium diphtheriae carriers and with receipt of multiple (and likely more recent) boosters. Significant variation exists in vaccine coverage and seroprevalence of immunity to diphtheria in East Java. Immunity in high incidence districts is likely because of natural immunity acquired through exposure to toxigenic C. diphtheriae. Booster vaccines are essential for achieving protective levels of immunity.

Coverage and determinants of childhood immunization in Nigeria: A systematic review and meta-analysis.

PubMed

Adeloye, Davies; Jacobs, Wura; Amuta, Ann O; Ogundipe, Oluwatomisin; Mosaku, Oluwaseun; Gadanya, Muktar A; Oni, Gbolahan

2017-05-19

The proportion of fully immunized children in Nigeria is reportedly low. There are concerns over national immunization data quality, with this possibly limiting country-wide response. We reviewed publicly available evidence on routine immunization across Nigeria to estimate national and zonal coverage of childhood immunization and associated determinants. A systematic search of Medline, EMBASE, Global Health and African Journals Online (AJOL) was conducted. We included population-based studies on childhood immunization in Nigeria. A random effects meta-analysis was conducted on extracted crude rates to arrive at national and zonal pooled estimates for the country. Our search returned 646 hits. 21 studies covering 25 sites and 26,960 children were selected. The estimated proportion of fully immunized children in Nigeria was 34.4% (95% confidence interval [CI]: 27.0-41.9), with South-south zone having the highest at 51.5% (95% CI: 20.5-82.6), and North-west the lowest at 9.5% (95% CI: 4.6-14.4). Mother's social engagements (OR=4.0, 95% CI: 1.9-8.1) and vaccines unavailability (OR=3.9, 95% CI: 1.2-12.3) were mostly reported for low coverage. Other leading determinants were vaccine safety concerns (OR=3.0, 95% CI: 0.9-9.4), mother's low education (OR=2.5, 95% CI: 1.8-3.6) and poor information (OR=2.0, 95% CI: 0.8-4.7). Our study suggests a low coverage of childhood immunization in Nigeria. Due to the paucity of data in the Northern states, we are still uncertain of the quality of evidence presented. It is hoped that this study will prompt the needed research, public health and policy changes toward increased evenly-spread coverage of childhood immunization in the country. Copyright © 2017 Elsevier Ltd. All rights reserved.

Commentary on Holmes et al. (2007): resolving the debate on when extinction risk is predictable.

PubMed

Ellner, Stephen P; Holmes, Elizabeth E

2008-08-01

We reconcile the findings of Holmes et al. (Ecology Letters, 10, 2007, 1182) that 95% confidence intervals for quasi-extinction risk were narrow for many vertebrates of conservation concern, with previous theory predicting wide confidence intervals. We extend previous theory, concerning the precision of quasi-extinction estimates as a function of population dynamic parameters, prediction intervals and quasi-extinction thresholds, and provide an approximation that specifies the prediction interval and threshold combinations where quasi-extinction estimates are precise (vs. imprecise). This allows PVA practitioners to define the prediction interval and threshold regions of safety (low risk with high confidence), danger (high risk with high confidence), and uncertainty.

Maternal and neonatal outcomes of antenatal anemia in a Scottish population: a retrospective cohort study.

PubMed

Rukuni, Ruramayi; Bhattacharya, Sohinee; Murphy, Michael F; Roberts, David; Stanworth, Simon J; Knight, Marian

2016-05-01

Antenatal anemia is a major public health problem in the UK, yet there is limited high quality evidence for associated poor clinical outcomes. The objectives of this study were to estimate the incidence and clinical outcomes of antenatal anemia in a Scottish population. A retrospective cohort study of 80 422 singleton pregnancies was conducted using data from the Aberdeen Maternal and Neonatal Databank between 1995 and 2012. Antenatal anemia was defined as haemoglobin ≤ 10 g/dl during pregnancy. Incidence was calculated with 95% confidence intervals and compared over time using a chi-squared test for trend. Multivariable logistic regression was used to adjust for confounding variables. Results are presented as adjusted odds ratios with 95% confidence interval. The overall incidence of antenatal anemia was 9.3 cases/100 singleton pregnancies (95% confidence interval 9.1-9.5), decreasing from 16.9/100 to 4.1/100 singleton pregnancies between 1995 and 2012 (p < 0.001). Maternal anemia was associated with antepartum hemorrhage (adjusted odds ratio 1.26, 95% confidence interval 1.17-1.36), postpartum infection (adjusted odds ratio 1.89, 95% confidence interval 1.39-2.57), transfusion (adjusted odds ratio 1.87, 95% confidence interval 1.65-2.13) and stillbirth (adjusted odds ratio 1.42, 95% confidence interval 1.04-1.94), reduced odds of postpartum hemorrhage (adjusted odds ratio 0.92, 95% confidence interval 0.86-0.98) and low birthweight (adjusted odds ratio 0.77, 95% confidence interval 0.69-0.86). No other outcomes were statistically significant. This study shows the incidence of antenatal anemia is decreasing steadily within this Scottish population. However, given that anemia is a readily correctable risk factor for major causes of morbidity and mortality in the UK, further work is required to investigate appropriate preventive measures. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

Opioid analgesia in mechanically ventilated children: results from the multicenter Measuring Opioid Tolerance Induced by Fentanyl study.

PubMed

Anand, Kanwaljeet J S; Clark, Amy E; Willson, Douglas F; Berger, John; Meert, Kathleen L; Zimmerman, Jerry J; Harrison, Rick; Carcillo, Joseph A; Newth, Christopher J L; Bisping, Stephanie; Holubkov, Richard; Dean, J Michael; Nicholson, Carol E

2013-01-01

To examine the clinical factors associated with increased opioid dose among mechanically ventilated children in the pediatric intensive care unit. Prospective, observational study with 100% accrual of eligible patients. Seven pediatric intensive care units from tertiary-care children's hospitals in the Collaborative Pediatric Critical Care Research Network. Four hundred nineteen children treated with morphine or fentanyl infusions. None. Data on opioid use, concomitant therapy, demographic and explanatory variables were collected. Significant variability occurred in clinical practices, with up to 100-fold differences in baseline opioid doses, average daily or total doses, or peak infusion rates. Opioid exposure for 7 or 14 days required doubling of the daily opioid dose in 16% patients (95% confidence interval 12%-19%) and 20% patients (95% confidence interval 16%-24%), respectively. Among patients receiving opioids for longer than 3 days (n = 225), this occurred in 28% (95% confidence interval 22%-33%) and 35% (95% confidence interval 29%-41%) by 7 or 14 days, respectively. Doubling of the opioid dose was more likely to occur following opioid infusions for 7 days or longer (odds ratio 7.9, 95% confidence interval 4.3-14.3; p < 0.001) or co-therapy with midazolam (odds ratio 5.6, 95% confidence interval 2.4-12.9; p < 0.001), and it was less likely to occur if morphine was used as the primary opioid (vs. fentanyl) (odds ratio 0.48, 95% confidence interval 0.25-0.92; p = 0.03), for patients receiving higher initial doses (odds ratio 0.96, 95% confidence interval 0.95-0.98; p < 0.001), or if patients had prior pediatric intensive care unit admissions (odds ratio 0.37, 95% confidence interval 0.15-0.89; p = 0.03). Mechanically ventilated children require increasing opioid doses, often associated with prolonged opioid exposure or the need for additional sedation. Efforts to reduce prolonged opioid exposure and clinical practice variation may prevent the complications of opioid therapy.

Applications of asymptotic confidence intervals with continuity corrections for asymmetric comparisons in noninferiority trials.

PubMed

Soulakova, Julia N; Bright, Brianna C

2013-01-01

A large-sample problem of illustrating noninferiority of an experimental treatment over a referent treatment for binary outcomes is considered. The methods of illustrating noninferiority involve constructing the lower two-sided confidence bound for the difference between binomial proportions corresponding to the experimental and referent treatments and comparing it with the negative value of the noninferiority margin. The three considered methods, Anbar, Falk-Koch, and Reduced Falk-Koch, handle the comparison in an asymmetric way, that is, only the referent proportion out of the two, experimental and referent, is directly involved in the expression for the variance of the difference between two sample proportions. Five continuity corrections (including zero) are considered with respect to each approach. The key properties of the corresponding methods are evaluated via simulations. First, the uncorrected two-sided confidence intervals can, potentially, have smaller coverage probability than the nominal level even for moderately large sample sizes, for example, 150 per group. Next, the 15 testing methods are discussed in terms of their Type I error rate and power. In the settings with a relatively small referent proportion (about 0.4 or smaller), the Anbar approach with Yates' continuity correction is recommended for balanced designs and the Falk-Koch method with Yates' correction is recommended for unbalanced designs. For relatively moderate (about 0.6) and large (about 0.8 or greater) referent proportion, the uncorrected Reduced Falk-Koch method is recommended, although in this case, all methods tend to be over-conservative. These results are expected to be used in the design stage of a noninferiority study when asymmetric comparisons are envisioned. Copyright © 2013 John Wiley & Sons, Ltd.

Confidence Intervals for the Mean: To Bootstrap or Not to Bootstrap

ERIC Educational Resources Information Center

Calzada, Maria E.; Gardner, Holly

2011-01-01

The results of a simulation conducted by a research team involving undergraduate and high school students indicate that when data is symmetric the student's "t" confidence interval for a mean is superior to the studied non-parametric bootstrap confidence intervals. When data is skewed and for sample sizes n greater than or equal to 10,…

Confidence Intervals Make a Difference: Effects of Showing Confidence Intervals on Inferential Reasoning

ERIC Educational Resources Information Center

Hoekstra, Rink; Johnson, Addie; Kiers, Henk A. L.

2012-01-01

The use of confidence intervals (CIs) as an addition or as an alternative to null hypothesis significance testing (NHST) has been promoted as a means to make researchers more aware of the uncertainty that is inherent in statistical inference. Little is known, however, about whether presenting results via CIs affects how readers judge the…

Using Asymptotic Results to Obtain a Confidence Interval for the Population Median

ERIC Educational Resources Information Center

Jamshidian, M.; Khatoonabadi, M.

2007-01-01

Almost all introductory and intermediate level statistics textbooks include the topic of confidence interval for the population mean. Almost all these texts introduce the median as a robust measure of central tendency. Only a few of these books, however, cover inference on the population median and in particular confidence interval for the median.…

ScoreRel CI: An Excel Program for Computing Confidence Intervals for Commonly Used Score Reliability Coefficients

ERIC Educational Resources Information Center

Barnette, J. Jackson

2005-01-01

An Excel program developed to assist researchers in the determination and presentation of confidence intervals around commonly used score reliability coefficients is described. The software includes programs to determine confidence intervals for Cronbachs alpha, Pearson r-based coefficients such as those used in test-retest and alternate forms…

Confidence intervals from single observations in forest research

Treesearch

Harry T. Valentine; George M. Furnival; Timothy G. Gregoire

1991-01-01

A procedure for constructing confidence intervals and testing hypothese from a single trial or observation is reviewed. The procedure requires a prior, fixed estimate or guess of the outcome of an experiment or sampling. Two examples of applications are described: a confidence interval is constructed for the expected outcome of a systematic sampling of a forested tract...

Depressive symptoms in nonresident african american fathers and involvement with their sons.

PubMed

Davis, R Neal; Caldwell, Cleopatra Howard; Clark, Sarah J; Davis, Matthew M

2009-12-01

Our objective was to determine whether paternal depressive symptoms were associated with less father involvement among African American fathers not living with their children (ie, nonresident fathers). We analyzed survey data for 345 fathers enrolled in a program for nonresident African American fathers and their preteen sons. Father involvement included measures of contact, closeness, monitoring, communication, and conflict. We used bivariate analyses and multivariate logistic regression analysis to examine associations between father involvement and depressive symptoms. Thirty-six percent of fathers reported moderate depressive symptoms, and 11% reported severe depressive symptoms. In bivariate analyses, depressive symptoms were associated with less contact, less closeness, low monitoring, and increased conflict. In multivariate analyses controlling for basic demographic features, fathers with moderate depressive symptoms were more likely to have less contact (adjusted odds ratio: 1.7 [95% confidence interval: 1.1-2.8]), less closeness (adjusted odds ratio: 2.1 [95% confidence interval: 1.3-3.5]), low monitoring (adjusted odds ratio: 2.7 [95% confidence interval: 1.4-5.2]), and high conflict (adjusted odds ratio: 2.1 [95% confidence interval: 1.2-3.6]). Fathers with severe depressive symptoms also were more likely to have less contact (adjusted odds ratio: 3.1 [95% confidence interval: 1.4-7.2]), less closeness (adjusted odds ratio: 2.6 [95% confidence interval: 1.2-5.7]), low monitoring (adjusted odds ratio: 2.8 [95% confidence interval: 1.1-7.1]), and high conflict (adjusted odds ratio: 2.6 [95% confidence interval: 1.1-5.9]). Paternal depressive symptoms may be an important, but modifiable, barrier for nonresident African American fathers willing to be more involved with their children.

Ethnic variations in morbidity and mortality from lower respiratory tract infections: a retrospective cohort study.

PubMed

Simpson, Colin R; Steiner, Markus Fc; Cezard, Genevieve; Bansal, Narinder; Fischbacher, Colin; Douglas, Anne; Bhopal, Raj; Sheikh, Aziz

2015-10-01

There is evidence of substantial ethnic variations in asthma morbidity and the risk of hospitalisation, but the picture in relation to lower respiratory tract infections is unclear. We carried out an observational study to identify ethnic group differences for lower respiratory tract infections. A retrospective, cohort study. Scotland. 4.65 million people on whom information was available from the 2001 census, followed from May 2001 to April 2010. Hospitalisations and deaths (any time following first hospitalisation) from lower respiratory tract infections, adjusted risk ratios and hazard ratios by ethnicity and sex were calculated. We multiplied ratios and confidence intervals by 100, so the reference Scottish White population's risk ratio and hazard ratio was 100. Among men, adjusted risk ratios for lower respiratory tract infection hospitalisation were lower in Other White British (80, 95% confidence interval 73-86) and Chinese (69, 95% confidence interval 56-84) populations and higher in Pakistani groups (152, 95% confidence interval 136-169). In women, results were mostly similar to those in men (e.g. Chinese 68, 95% confidence interval 56-82), although higher adjusted risk ratios were found among women of the Other South Asians group (145, 95% confidence interval 120-175). Survival (adjusted hazard ratio) following lower respiratory tract infection for Pakistani men (54, 95% confidence interval 39-74) and women (31, 95% confidence interval 18-53) was better than the reference population. Substantial differences in the rates of lower respiratory tract infections amongst different ethnic groups in Scotland were found. Pakistani men and women had particularly high rates of lower respiratory tract infection hospitalisation. The reasons behind the high rates of lower respiratory tract infection in the Pakistani community are now required. © The Royal Society of Medicine.

Risk factors of childhood asthma in children attending Lyari General Hospital.

PubMed

Kamran, Amber; Hanif, Shahina; Murtaza, Ghulam

2015-06-01

To determine the factors associated with asthma in children. The case-control study was conducted in the paediatrics clinic of Lyari General Hospital, Karachi, from May to October 2010. Children 1-15 years of age attending the clinic represented the cases, while the control group had children who were closely related (sibling or cousin) to the cases but did not have the symptoms of disease at the time. Data was collected through a proforma and analysed using SPSS 10. Of the total 346 subjects, 173(50%) each comprised the two groups. According to univariable analysis the risk factors were presence of at least one smoker (odds ratio: 3.6; 95% confidence interval: 2.3-5.8), resident of kacha house (odds ratio: 16.2; 95% confidence interval: 3.8-69.5),living in room without windows (odds ratio: 9.3; 95% confidence interval: 2.1-40.9) and living in houses without adequate sunlight (odds ratio: 1.6; 95% confidence interval: 1.2-2.4).Using multivariable modelling, family history of asthma (odds ratio: 5.9; 95% confidence interval: 3.1-11.6), presence of at least one smoker at home (odds ratio: 4.1; 95% confidence interval: 2.3-7.2), people living in a room without a window (odds ratio: 5.5; 95% confidence interval: 1.15-26.3) and people living in an area without adequate sunlight (odds ratio: 2.2; 95% confidence interval: 1.13-4.31) were found to be independent risk factors of asthma in children adjusting for age, gender and history of weaning. Family history of asthma, children living with at least one smoker at home, room without windows and people living in an area without sunlight were major risk factors of childhood asthma.

Calculation of Confidence Intervals for the Maximum Magnitude of Earthquakes in Different Seismotectonic Zones of Iran

NASA Astrophysics Data System (ADS)

Salamat, Mona; Zare, Mehdi; Holschneider, Matthias; Zöller, Gert

2017-03-01

The problem of estimating the maximum possible earthquake magnitude m_max has attracted growing attention in recent years. Due to sparse data, the role of uncertainties becomes crucial. In this work, we determine the uncertainties related to the maximum magnitude in terms of confidence intervals. Using an earthquake catalog of Iran, m_max is estimated for different predefined levels of confidence in six seismotectonic zones. Assuming the doubly truncated Gutenberg-Richter distribution as a statistical model for earthquake magnitudes, confidence intervals for the maximum possible magnitude of earthquakes are calculated in each zone. While the lower limit of the confidence interval is the magnitude of the maximum observed event,the upper limit is calculated from the catalog and the statistical model. For this aim, we use the original catalog which no declustering methods applied on as well as a declustered version of the catalog. Based on the study by Holschneider et al. (Bull Seismol Soc Am 101(4):1649-1659, 2011), the confidence interval for m_max is frequently unbounded, especially if high levels of confidence are required. In this case, no information is gained from the data. Therefore, we elaborate for which settings finite confidence levels are obtained. In this work, Iran is divided into six seismotectonic zones, namely Alborz, Azerbaijan, Zagros, Makran, Kopet Dagh, Central Iran. Although calculations of the confidence interval in Central Iran and Zagros seismotectonic zones are relatively acceptable for meaningful levels of confidence, results in Kopet Dagh, Alborz, Azerbaijan and Makran are not that much promising. The results indicate that estimating m_max from an earthquake catalog for reasonable levels of confidence alone is almost impossible.

Risk factors for low birth weight according to the multiple logistic regression model. A retrospective cohort study in José María Morelos municipality, Quintana Roo, Mexico.

PubMed

Franco Monsreal, José; Tun Cobos, Miriam Del Ruby; Hernández Gómez, José Ricardo; Serralta Peraza, Lidia Esther Del Socorro

2018-01-17

Low birth weight has been an enigma for science over time. There have been many researches on its causes and its effects. Low birth weight is an indicator that predicts the probability of a child surviving. In fact, there is an exponential relationship between weight deficit, gestational age, and perinatal mortality. Multiple logistic regression is one of the most expressive and versatile statistical instruments available for the analysis of data in both clinical and epidemiology settings, as well as in public health. To assess in a multivariate fashion the importance of 17 independent variables in low birth weight (dependent variable) of children born in the Mayan municipality of José María Morelos, Quintana Roo, Mexico. Analytical observational epidemiological cohort study with retrospective temporality. Births that met the inclusion criteria occurred in the "Hospital Integral Jose Maria Morelos" of the Ministry of Health corresponding to the Maya municipality of Jose Maria Morelos during the period from August 1, 2014 to July 31, 2015. The total number of newborns recorded was 1,147; 84 of which (7.32%) had low birth weight. To estimate the independent association between the explanatory variables (potential risk factors) and the response variable, a multiple logistic regression analysis was performed using the IBM SPSS Statistics 22 software. In ascending numerical order values of odds ratio > 1 indicated the positive contribution of explanatory variables or possible risk factors: "unmarried" marital status (1.076, 95% confidence interval: 0.550 to 2.104); age at menarche ≤ 12 years (1.08, 95% confidence interval: 0.64 to 1.84); history of abortion(s) (1.14, 95% confidence interval: 0.44 to 2.93); maternal weight < 50 kg (1.51, 95% confidence interval: 0.83 to 2.76); number of prenatal consultations ≤ 5 (1.86, 95% confidence interval: 0.94 to 3.66); maternal age ≥ 36 years (3.5, 95% confidence interval: 0.40 to 30.47); maternal age ≤ 19 years (3.59, 95% confidence interval: 0.43 to 29.87); number of deliveries = 1 (3.86, 95% confidence interval: 0.33 to 44.85); personal pathological history (4.78, 95% confidence interval: 2.16 to 10.59); pathological obstetric history (5.01, 95% confidence interval: 1.66 to 15.18); maternal height < 150 cm (5.16, 95% confidence interval: 3.08 to 8.65); number of births ≥ 5 (5.99, 95% confidence interval: 0.51 to 69.99); and smoking (15.63, 95% confidence interval: 1.07 to 227.97). Four of the independent variables (personal pathological history, obstetric pathological history, maternal stature <150 centimeters and smoking) showed a significant positive contribution, thus they can be considered as clear risk factors for low birth weight. The use of the logistic regression model in the Mayan municipality of José María Morelos, will allow estimating the probability of low birth weight for each pregnant woman in the future, which will be useful for the health authorities of the region.

Reliability of confidence intervals calculated by bootstrap and classical methods using the FIA 1-ha plot design

Treesearch

H. T. Schreuder; M. S. Williams

2000-01-01

In simulation sampling from forest populations using sample sizes of 20, 40, and 60 plots respectively, confidence intervals based on the bootstrap (accelerated, percentile, and t-distribution based) were calculated and compared with those based on the classical t confidence intervals for mapped populations and subdomains within those populations. A 68.1 ha mapped...

Confidence Intervals for Proportion Estimates in Complex Samples. Research Report. ETS RR-06-21

ERIC Educational Resources Information Center

Oranje, Andreas

2006-01-01

Confidence intervals are an important tool to indicate uncertainty of estimates and to give an idea of probable values of an estimate if a different sample from the population was drawn or a different sample of measures was used. Standard symmetric confidence intervals for proportion estimates based on a normal approximation can yield bounds…

A Comparison of Methods for Estimating Confidence Intervals for Omega-Squared Effect Size

ERIC Educational Resources Information Center

Finch, W. Holmes; French, Brian F.

2012-01-01

Effect size use has been increasing in the past decade in many research areas. Confidence intervals associated with effect sizes are encouraged to be reported. Prior work has investigated the performance of confidence interval estimation with Cohen's d. This study extends this line of work to the analysis of variance case with more than two…

The impact of sanitation interventions on latrine coverage and latrine use: A systematic review and meta-analysis.

PubMed

Garn, Joshua V; Sclar, Gloria D; Freeman, Matthew C; Penakalapati, Gauthami; Alexander, Kelly T; Brooks, Patrick; Rehfuess, Eva A; Boisson, Sophie; Medlicott, Kate O; Clasen, Thomas F

2017-04-01

An estimated 2.4 billion people still lack access to improved sanitation and 946 million still practice open defecation. The World Health Organization (WHO) commissioned this review to assess the impact of sanitation on coverage and use, as part of its effort to develop a set of guidelines on sanitation and health. We systematically reviewed the literature and used meta-analysis to quantitatively characterize how different sanitation interventions impact latrine coverage and use. We also assessed both qualitative and quantitative studies to understand how different structural and design characteristics of sanitation are associated with individual latrine use. A total of 64 studies met our eligibility criteria. Of 27 intervention studies that reported on household latrine coverage and provided a point estimate with confidence interval, the average increase in coverage was 14% (95% CI: 10%, 19%). The intervention types with the largest absolute increases in coverage included the Indian government's "Total Sanitation Campaign" (27%; 95% CI: 14%, 39%), latrine subsidy/provision interventions (16%; 95% CI: 8%, 24%), latrine subsidy/provision interventions that also incorporated education components (17%; 95% CI: -5%, 38%), sewerage interventions (14%; 95% CI: 1%, 28%), sanitation education interventions (14%; 95% CI: 3%, 26%), and community-led total sanitation interventions (12%; 95% CI: -2%, 27%). Of 10 intervention studies that reported on household latrine use, the average increase was 13% (95% CI: 4%, 21%). The sanitation interventions and contexts in which they were implemented varied, leading to high heterogeneity across studies. We found 24 studies that examined the association between structural and design characteristics of sanitation facilities and facility use. These studies reported that better maintenance, accessibility, privacy, facility type, cleanliness, newer latrines, and better hygiene access were all frequently associated with higher use, whereas poorer sanitation conditions were associated with lower use. Our results indicate that most sanitation interventions only had a modest impact on increasing latrine coverage and use. A further understanding of how different sanitation characteristics and sanitation interventions impact coverage and use is essential in order to more effectively attain sanitation access for all, eliminate open defecation, and ultimately improve health. Copyright © 2016 Elsevier GmbH. All rights reserved.

Vaccination and all-cause child mortality from 1985 to 2011: global evidence from the Demographic and Health Surveys.

PubMed

McGovern, Mark E; Canning, David

2015-11-01

Based on models with calibrated parameters for infection, case fatality rates, and vaccine efficacy, basic childhood vaccinations have been estimated to be highly cost effective. We estimated the association of vaccination with mortality directly from survey data. Using 149 cross-sectional Demographic and Health Surveys, we determined the relationship between vaccination coverage and the probability of dying between birth and 5 years of age at the survey cluster level. Our data included approximately 1 million children in 68,490 clusters from 62 countries. We considered the childhood measles, bacillus Calmette-Guérin, diphtheria-pertussis-tetanus, polio, and maternal tetanus vaccinations. Using modified Poisson regression to estimate the relative risk of child mortality in each cluster, we also adjusted for selection bias that resulted from the vaccination status of dead children not being reported. Childhood vaccination, and in particular measles and tetanus vaccination, is associated with substantial reductions in childhood mortality. We estimated that children in clusters with complete vaccination coverage have a relative risk of mortality that is 0.73 (95% confidence interval: 0.68, 0.77) times that of children in a cluster with no vaccinations. Although widely used, basic vaccines still have coverage rates well below 100% in many countries, and our results emphasize the effectiveness of increasing coverage rates in order to reduce child mortality. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Multi-Reader ROC studies with Split-Plot Designs: A Comparison of Statistical Methods

PubMed Central

Obuchowski, Nancy A.; Gallas, Brandon D.; Hillis, Stephen L.

2012-01-01

Rationale and Objectives Multi-reader imaging trials often use a factorial design, where study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of the design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper we compare three methods of analysis for the split-plot design. Materials and Methods Three statistical methods are presented: Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean ANOVA approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power and confidence interval coverage of the three test statistics. Results The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% CIs fall close to the nominal coverage for small and large sample sizes. Conclusions The split-plot MRMC study design can be statistically efficient compared with the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rate, similar power, and nominal CI coverage, are available for this study design. PMID:23122570

[Musculoskeletal pain in Central American workers: results of the First Survey on Working Conditions and Health in Central America].

PubMed

Rojas, Marianela; Gimeno, David; Vargas-Prada, Sergio; Benavides, Fernando G

2015-08-01

Examine the prevalence of musculoskeletal pain (MSP) in the six Spanish-speaking countries of Central America using a single standardized instrument, the First Survey on Working Conditions and Health in Central America in workers from all manual and non-manual labor sectors, using social security coverage as an indicator of formal versus informal employment. The workers (n = 12 024) were surveyed in their homes. The age-adjusted prevalence of MSP during the previous month was calculated for pain in the back (upper, or cervical; middle, or thoracic; and lower, or lumbar) and arm joints (shoulder, elbow, and wrist). Prevalence was estimated by sex, occupation (manual or non-manual), economic sector (agriculture, industry, or services), and social security coverage. Poisson regression models were used to calculate the prevalence rates and 95% confidence intervals, with stratification by country and anatomical site. By sites, the age-adjusted prevalence of cervical-dorsal MSP was the highest, especially in El Salvador (47.8%) and Nicaragua (45.9%), and lumbar MSP was less prevalent, especially in Panama (12.8%) and Guatemala (14.8%). After additional adjustments, the prevalence of MSP was higher in women and manual workers for all the sites and in all the countries. There were no differences in MSP in terms of social security coverage or sector of economic activity. The high prevalence of MSP in Central America, regardless of sector of activity or social security coverage, indicates that the prevention of MSP should be a priority in occupational health programs in low- and middle-income countries, especially for women and manual workers.

Patient, surgeon, and hospital disparities associated with benign hysterectomy approach and perioperative complications.

PubMed

Mehta, Ambar; Xu, Tim; Hutfless, Susan; Makary, Martin A; Sinno, Abdulrahman K; Tanner, Edward J; Stone, Rebecca L; Wang, Karen; Fader, Amanda N

2017-05-01

Hysterectomy is among the most common major surgical procedures performed in women. Approximately 450,000 hysterectomy procedures are performed each year in the United States for benign indications. However, little is known regarding contemporary US hysterectomy trends for women with benign disease with respect to operative technique and perioperative complications, and the association between these 2 factors with patient, surgeon, and hospital characteristics. We sought to describe contemporary hysterectomy trends and explore associations between patient, surgeon, and hospital characteristics with surgical approach and perioperative complications. Hysterectomies performed for benign indications by general gynecologists from July 2012 through September 2014 were analyzed in the all-payer Maryland Health Services Cost Review Commission database. We excluded hysterectomies performed by gynecologic oncologists, reproductive endocrinologists, and female pelvic medicine and reconstructive surgeons. We included both open hysterectomies and those performed by minimally invasive surgery, which included vaginal hysterectomies. Perioperative complications were defined using the Agency for Healthcare Research and Quality patient safety indicators. Surgeon hysterectomy volume during the 2-year study period was analyzed (0-5 cases annually = very low, 6-10 = low, 11-20 = medium, and ≥21 = high). We utilized logistic regression and negative binomial regression to identify patient, surgeon, and hospital characteristics associated with minimally invasive surgery utilization and perioperative complications, respectively. A total of 5660 hospitalizations were identified during the study period. Most patients (61.5%) had an open hysterectomy; 38.5% underwent a minimally invasive surgery procedure (25.1% robotic, 46.6% laparoscopic, 28.3% vaginal). Most surgeons (68.2%) were very low- or low-volume surgeons. Factors associated with a lower likelihood of undergoing minimally invasive surgery included older patient age (reference 45-64 years; 20-44 years: adjusted odds ratio, 1.16; 95% confidence interval, 1.05-1.28), black race (reference white; adjusted odds ratio, 0.70; 95% confidence interval, 0.63-0.78), Hispanic ethnicity (adjusted odds ratio, 0.62; 95% confidence interval, 0.48-0.80), smaller hospital (reference large; small: adjusted odds ratio, 0.26; 95% confidence interval, 0.15-0.45; medium: adjusted odds ratio, 0.87; 95% confidence interval, 0.79-0.96), medium hospital hysterectomy volume (reference ≥200 hysterectomies; 100-200: adjusted odds ratio, 0.78; 95% confidence interval, 0.71-0.87), and medium vs high surgeon volume (reference high; medium: adjusted odds ratio, 0.87; 95% confidence interval, 0.78-0.97). Complications occurred in 25.8% of open and 8.2% of minimally invasive hysterectomies (P < .0001). Minimally invasive hysterectomy (adjusted odds ratio, 0.22; 95% confidence interval, 0.17-0.27) and large hysterectomy volume hospitals (reference ≥200 hysterectomies; 1-100: adjusted odds ratio, 2.26; 95% confidence interval, 1.60-3.20; 101-200: adjusted odds ratio, 1.63; 95% confidence interval, 1.23-2.16) were associated with fewer complications, while patient payer, including Medicare (reference private; adjusted odds ratio, 1.86; 95% confidence interval, 1.33-2.61), Medicaid (adjusted odds ratio, 1.63; 95% confidence interval, 1.30-2.04), and self-pay status (adjusted odds ratio, 2.41; 95% confidence interval, 1.40-4.12), and very-low and low surgeon hysterectomy volume (reference ≥21 cases; 1-5 cases: adjusted odds ratio, 1.73; 95% confidence interval, 1.22-2.47; 6-10 cases: adjusted odds ratio, 1.60; 95% confidence interval, 1.11-2.23) were associated with perioperative complications. Use of minimally invasive hysterectomy for benign indications remains variable, with most patients undergoing open, more morbid procedures. Older and black patients and smaller hospitals are associated with open hysterectomy. Patient race and payer status, hysterectomy approach, and surgeon volume were associated with perioperative complications. Hysterectomies performed for benign indications by high-volume surgeons or by minimally invasive techniques may represent an opportunity to reduce preventable harm. Copyright © 2017 Elsevier Inc. All rights reserved.

Xenogenic collagen matrix or autologous connective tissue graft as adjunct to coronally advanced flaps for coverage of multiple adjacent gingival recession: Randomized trial assessing non-inferiority in root coverage and superiority in oral health-related quality of life.

PubMed

Tonetti, Maurizio S; Cortellini, Pierpaolo; Pellegrini, Gaia; Nieri, Michele; Bonaccini, Daniele; Allegri, Mario; Bouchard, Philippe; Cairo, Francesco; Conforti, Gianpaolo; Fourmousis, Ioannis; Graziani, Filippo; Guerrero, Adrian; Halben, Jan; Malet, Jacques; Rasperini, Giulio; Topoll, Heinz; Wachtel, Hannes; Wallkamm, Beat; Zabalegui, Ion; Zuhr, Otto

2018-01-01

To evaluate the non-inferiority of the adjunct of a xenogeneic collagen matrix (CMX) or connective tissue graft (CTG) to coronally advanced flaps (CAF) for coverage of multiple adjacent recessions and compare superiority in patient-reported outcomes (PROM). One hundred and eighty-seven subjects (92 CMX) with 485 recessions in 14 centres were randomized and followed up for 6 months. Patients filled daily diaries for 15 days to monitor patient-reported experience. The primary outcome was changed in position of the gingival margin. Multilevel analysis used centre, subject and tooth as levels and baseline parameters as covariates. Average baseline recession was 2.5 ± 1.0 mm. The surgery was 15.7 min shorter (95%CI from 11.9 to 19.6, p < .0001) and perceived lighter (11.9 VAS units, 95%CI from 4.6 to 19.1, p = .0014) in CMX subjects. Time to recovery was 1.8 days shorter in CMX. Six-month root coverage was 1.7 ± 1.1 mm for CMX and 2.1 ± 1.0 mm for CTG (difference of 0.44 mm, 95%CI from 0.25 to 0.63 mm). The upper limit of the confidence interval was over the non-inferiority margin of 0.25 mm. Odds of complete root coverage were significantly higher for CTG (OR = 4.0, 95% CI 1.8-8.8). Replacing CTG with CMX shortens time to recovery and decreases morbidity, but the tested generation of devices is probably inferior to autologous CTG in terms of root coverage. Significant variability in PROMs was observed among centres. © 2017 The Authors. Journal of Clinical Periodontology Published by John Wiley & Sons Ltd.

Modeling the Impact on HIV Incidence of Combination Prevention Strategies among Men Who Have Sex with Men in Beijing, China

PubMed Central

Lou, Jie; Blevins, Meridith; Ruan, Yuhua; Vermund, Sten H.; Tang, Sanyi; Webb, Glenn F.; Shepherd, Bryan E.; He, Xiong; Lu, Hongyan; Shao, Yiming; Qian, Han-Zhu

2014-01-01

Objective To project the HIV/AIDS epidemics among men who have sex with men (MSM) under different combinations of HIV testing and linkage to care (TLC) interventions including antiretroviral therapy (ART) in Beijing, China. Design Mathematical modeling. Methods Using a mathematical model to fit prevalence estimates from 2000–2010, we projected trends in HIV prevalence and incidence during 2011–2020 under five scenarios: (S1) current intervention levels by averaging 2000–2010 coverage; (S2) increased ART coverage with current TLC; (S3) increased TLC/ART coverage; (S4) increased condom use; and (S5) increased TLC/ART plus increased condom use. Results The basic reproduction number based upon the current level of interventions is significantly higher than 1 ( confidence interval (CI), 1.83–2.35), suggesting that the HIV epidemic will continue to increase to 2020. Compared to the 2010 prevalence of 7.8%, the projected HIV prevalence in 2020 for the five prevention scenarios will be: (S1) Current coverage: 21.4% (95% CI, 9.9–31.7%); (S2) Increased ART: 19.9% (95% CI, 9.9–28.4%); (S3) Increased TLC/ART: 14.5% (95% CI, 7.0–23.8%); (S4) Increased condom use: 13.0% (95% CI, 9.8–28.4%); and (S5) Increased TLC/ART and condom use: 8.7% (95% CI, 5.4–11.5%). HIV epidemic will continue to rise () for S1–S4 even with hyperbolic coverage in the sensitivity analysis, and is expected to decline () for S5. Conclusion Our transmission model suggests that Beijing MSM will have a rapidly rising HIV epidemic. Even enhanced levels of TLC/ART will not interrupt epidemic expansion, despite optimistic assumptions for coverage. Promoting condom use is a crucial component of combination interventions. PMID:24626165

Association between the Part D coverage gap and adverse health outcomes.

PubMed

Polinski, Jennifer M; Shrank, William H; Glynn, Robert J; Huskamp, Haiden A; Christopher Roebuck, M; Schneeweiss, Sebastian

2012-08-01

To determine whether Part D coverage gap entry is associated with risk of death or hospitalization for cardiovascular outcomes. Prospective cohort study. Beneficiaries entered the study upon reaching the coverage gap spending threshold and were observed until an outcome reaching the threshold for catastrophic coverage occurred or year's end. Nine thousand four hundred thirty-six exposed individuals (those who were responsible for drug costs in the gap) were compared with 9,436 unexposed individuals (those who received financial assistance) based on propensity score (PS) or high-dimensional propensity score (hdPS). Medicare Part D drug insurance. Three hundred three thousand nine hundred seventy-eight Medicare beneficiaries aged 65 and older in 2006 and 2007 with linked prescription and medical claims who enrolled in stand-alone Part D or retiree drug plans and reached the gap spending threshold. Rates of death and hospitalization for any of five cardiovascular outcomes, including acute coronary syndrome with revascularization (ACS), after reaching the coverage gap spending threshold were compared using Cox proportional hazards models. In PS-matched analyses, exposed beneficiaries had higher, albeit not significantly so, hazard of death (hazard ratio (HR) = 1.25, 95% confidence interval (CI) = 0.98-1.59) and ACS (HR = 1.16, 95% CI = 0.83-1.62) than unexposed beneficiaries. hdPS-matched analyses minimized residual confounding and confirmed results (death: HR = 0.99, 95% CI = 0.78-1.24; ACS: HR = 1.07, 95% CI = 0.81-1.41). Exposed beneficiaries were no more or less likely to experience other outcomes than were those who were unexposed. During the short-term coverage gap period, having no financial assistance to pay for drugs was not associated with greater risk of death or hospitalization for cardiovascular causes, although long-term health consequences remain unclear. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

Income-related inequality in health insurance coverage: analysis of China Health and Nutrition Survey of 2006 and 2009.

PubMed

Liu, Jinan; Shi, Lizheng; Meng, Qingyue; Khan, M Mahmud

2012-08-14

China introduced the urban resident basic medical insurance (URBMI) in 2007 to cover children and urban unemployed adults, in addition to the new cooperative medical scheme (NCMS) for rural residents in 2003 and the basic health insurance scheme (BHIS) for urban employees in 1998. This study examined whether the overall income-related inequality in health insurance coverage improved during 2006 and 2009 in China. The China Health and Nutrition Survey (CHNS) data of 2006 and 2009 were used to create the concentration curve and the concentration index. GEE logistic regression was used to model the health insurance coverage as dependent variable and household income per capita as independent variable, controlling for individuals' age, gender, marital status, educational attainment, employment status, year 2009 (Y2009), household size, retirement status, and geographic variations. The change in the income-related inequality in 2009 was estimated using the interaction term of income*Y2009. In 2006, 49.7% (4,712/9,476) respondents had health insurance: 13.4% with BHIS and 28.4% with NCMS. In 2009, 90.8% (8,964/9,863) had health insurance: 10.1% with URBMI, 18.3% with BHIS, and 57.6% with NCMS. The BHIS, URBMI, and NCMS programs had different patterns of population coverage over 10 income deciles. The concentration index was 0.15 in 2006 and 0.04 in 2009. The dominance test showed that the concentration curves were significantly different between 2006 and 2009 (p < 0.05). An income increase per capita by 10,000 RMB was associated with 25.5% more likely to have health insurance coverage (odds ratio = 1.255, 95% confidence interval: [1.130-1.393]). In 2009, there was significant improvement in the income-related inequality (p < 0.001). Comparing 2009 to 2006, the income inequality in health insurance coverage was largely corrected in China through rapid expansion of CHNS in rural areas and initiation of URBMI in urban areas.

Opioid Analgesics and Adverse Outcomes among Hemodialysis Patients.

PubMed

Ishida, Julie H; McCulloch, Charles E; Steinman, Michael A; Grimes, Barbara A; Johansen, Kirsten L

2018-05-07

Patients on hemodialysis frequently experience pain and may be particularly vulnerable to opioid-related complications. However, data evaluating the risks of opioid use in patients on hemodialysis are limited. Using the US Renal Data System, we conducted a cohort study evaluating the association between opioid use (modeled as a time-varying exposure and expressed in standardized oral morphine equivalents) and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture among 140,899 Medicare-covered adults receiving hemodialysis in 2011. We evaluated risk according to average daily total opioid dose (>60 mg, ≤60 mg, and per 60-mg dose increment) and specific agents (per 60-mg dose increment). The median age was 61 years old, 52% were men, and 50% were white. Sixty-four percent received opioids, and 17% had an episode of altered mental status (15,658 events), fall (7646 events), or fracture (4151 events) in 2011. Opioid use was associated with risk for all outcomes in a dose-dependent manner: altered mental status (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.23 to 1.34; higher dose: hazard ratio, 1.67; 95% confidence interval, 1.56 to 1.78; hazard ratio, 1.29 per 60 mg; 95% confidence interval, 1.26 to 1.33), fall (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.21 to 1.36; higher dose: hazard ratio, 1.45; 95% confidence interval, 1.31 to 1.61; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.03 to 1.05), and fracture (lower dose: hazard ratio, 1.44; 95% confidence interval, 1.33 to 1.56; higher dose: hazard ratio, 1.65; 95% confidence interval, 1.44 to 1.89; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.04 to 1.05). All agents were associated with a significantly higher hazard of altered mental status, and several agents were associated with a significantly higher hazard of fall and fracture. Opioids were associated with adverse outcomes in patients on hemodialysis, and this risk was present even at lower dosing and for agents that guidelines have recommended for use. Copyright © 2018 by the American Society of Nephrology.

Pregnancy outcome in joint hypermobility syndrome and Ehlers-Danlos syndrome.

PubMed

Sundelin, Heléne E K; Stephansson, Olof; Johansson, Kari; Ludvigsson, Jonas F

2017-01-01

An increased risk of preterm birth in women with joint hypermobility syndrome or Ehlers-Danlos syndrome is suspected. In this nationwide cohort study from 1997 through 2011, women with either joint hypermobility syndrome or Ehlers-Danlos syndrome or both disorders were identified through the Swedish Patient Register, and linked to the Medical Birth Register. Thereby, 314 singleton births to women with joint hypermobility syndrome/Ehlers-Danlos syndrome before delivery were identified. These births were compared with 1 247 864 singleton births to women without a diagnosis of joint hypermobility syndrome/Ehlers-Danlos syndrome. We used logistic regression, adjusted for maternal age, smoking, parity, and year of birth, to calculate adjusted odds ratios for adverse pregnancy outcomes. Maternal joint hypermobility syndrome/Ehlers-Danlos syndrome was not associated with any of our outcomes: preterm birth (adjusted odds ratio = 0.6, 95% confidence interval 0.3-1.2), preterm premature rupture of membranes (adjusted odds ratio = 0.8; 95% confidence interval 0.3-2.2), cesarean section (adjusted odds ratio = 0.9, 95% confidence interval 0.7-1.2), stillbirth (adjusted odds ratio = 1.1, 95% confidence interval 0.2-7.9), low Apgar score (adjusted odds ratio = 1.6, 95% confidence interval 0.7-3.6), small for gestational age (adjusted odds ratio = 0.9, 95% confidence interval 0.4-1.8) or large for gestational age (adjusted odds ratio = 1.2, 95% confidence interval 0.6-2.1). Examining only women with Ehlers-Danlos syndrome (n = 62), we found a higher risk of induction of labor (adjusted odds ratio = 2.6; 95% confidence interval 1.4-4.6) and amniotomy (adjusted odds ratio = 3.8; 95% confidence interval 2.0-7.1). No excess risks for adverse pregnancy outcome were seen in joint hypermobility syndrome. Women with joint hypermobility syndrome/Ehlers-Danlos syndrome do not seem to be at increased risk of adverse pregnancy outcome. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

Comprehension of confidence intervals - development and piloting of patient information materials for people with multiple sclerosis: qualitative study and pilot randomised controlled trial.

PubMed

Rahn, Anne C; Backhus, Imke; Fuest, Franz; Riemann-Lorenz, Karin; Köpke, Sascha; van de Roemer, Adrianus; Mühlhauser, Ingrid; Heesen, Christoph

2016-09-20

Presentation of confidence intervals alongside information about treatment effects can support informed treatment choices in people with multiple sclerosis. We aimed to develop and pilot-test different written patient information materials explaining confidence intervals in people with relapsing-remitting multiple sclerosis. Further, a questionnaire on comprehension of confidence intervals was developed and piloted. We developed different patient information versions aiming to explain confidence intervals. We used an illustrative example to test three different approaches: (1) short version, (2) "average weight" version and (3) "worm prophylaxis" version. Interviews were conducted using think-aloud and teach-back approaches to test feasibility and analysed using qualitative content analysis. To assess comprehension of confidence intervals, a six-item multiple choice questionnaire was developed and tested in a pilot randomised controlled trial using the online survey software UNIPARK. Here, the average weight version (intervention group) was tested against a standard patient information version on confidence intervals (control group). People with multiple sclerosis were invited to take part using existing mailing-lists of people with multiple sclerosis in Germany and were randomised using the UNIPARK algorithm. Participants were blinded towards group allocation. Primary endpoint was comprehension of confidence intervals, assessed with the six-item multiple choice questionnaire with six points representing perfect knowledge. Feasibility of the patient information versions was tested with 16 people with multiple sclerosis. For the pilot randomised controlled trial, 64 people with multiple sclerosis were randomised (intervention group: n = 36; control group: n = 28). More questions were answered correctly in the intervention group compared to the control group (mean 4.8 vs 3.8, mean difference 1.1 (95 % CI 0.42-1.69), p = 0.002). The questionnaire's internal consistency was moderate (Cronbach's alpha = 0.56). The pilot-phase shows promising results concerning acceptability and feasibility. Pilot randomised controlled trial results indicate that the patient information is well understood and that knowledge gain on confidence intervals can be assessed with a set of six questions. German Clinical Trials Register: DRKS00008561 . Registered 8th of June 2015.

Ethnic Differences in Incidence and Outcomes of Childhood Nephrotic Syndrome.

PubMed

Banh, Tonny H M; Hussain-Shamsy, Neesha; Patel, Viral; Vasilevska-Ristovska, Jovanka; Borges, Karlota; Sibbald, Cathryn; Lipszyc, Deborah; Brooke, Josefina; Geary, Denis; Langlois, Valerie; Reddon, Michele; Pearl, Rachel; Levin, Leo; Piekut, Monica; Licht, Christoph P B; Radhakrishnan, Seetha; Aitken-Menezes, Kimberly; Harvey, Elizabeth; Hebert, Diane; Piscione, Tino D; Parekh, Rulan S

2016-10-07

Ethnic differences in outcomes among children with nephrotic syndrome are unknown. We conducted a longitudinal study at a single regional pediatric center comparing ethnic differences in incidence from 2001 to 2011 census data and longitudinal outcomes, including relapse rates, time to first relapse, frequently relapsing disease, and use of cyclophosphamide. Among 711 children, 24% were European, 33% were South Asian, 10% were East/Southeast Asian, and 33% were of other origins. Over 10 years, the overall incidence increased from 1.99/100,000 to 4.71/100,000 among children ages 1-18 years old. In 2011, South Asians had a higher incidence rate ratio of 6.61 (95% confidence interval, 3.16 to 15.1) compared with Europeans. East/Southeast Asians had a similar incidence rate ratio (0.76; 95% confidence interval, 0.13 to 2.94) to Europeans. We determined outcomes in 455 children from the three largest ethnic groups with steroid-sensitive disease over a median of 4 years. South Asian and East/Southeast Asian children had significantly lower odds of frequently relapsing disease at 12 months (South Asian: adjusted odds ratio; 0.55; 95% confidence interval, 0.39 to 0.77; East/Southeast Asian: adjusted odds ratio; 0.42; 95% confidence interval, 0.34 to 0.51), fewer subsequent relapses (South Asian: adjusted odds ratio; 0.64; 95% confidence interval, 0.50 to 0.81; East/Southeast Asian: adjusted odds ratio; 0.47; 95% confidence interval, 0.24 to 0.91), lower risk of a first relapse (South Asian: adjusted hazard ratio, 0.74; 95% confidence interval, 0.67 to 0.83; East/Southeast Asian: adjusted hazard ratio, 0.65; 95% CI, 0.63 to 0.68), and lower use of cyclophosphamide (South Asian: adjusted hazard ratio, 0.82; 95% confidence interval, 0.53 to 1.28; East/Southeast Asian: adjusted hazard ratio, 0.54; 95% confidence interval, 0.41 to 0.71) compared with European children. Despite the higher incidence among South Asians, South and East/Southeast Asian children have significantly less complicated clinical outcomes compared with Europeans. Copyright © 2016 by the American Society of Nephrology.

The transmissibility and control of pandemic influenza A (H1N1) virus.

PubMed

Yang, Yang; Sugimoto, Jonathan D; Halloran, M Elizabeth; Basta, Nicole E; Chao, Dennis L; Matrajt, Laura; Potter, Gail; Kenah, Eben; Longini, Ira M

2009-10-30

Pandemic influenza A (H1N1) 2009 (pandemic H1N1) is spreading throughout the planet. It has become the dominant strain in the Southern Hemisphere, where the influenza season has now ended. Here, on the basis of reported case clusters in the United States, we estimated the household secondary attack rate for pandemic H1N1 to be 27.3% [95% confidence interval (CI) from 12.2% to 50.5%]. From a school outbreak, we estimated that a typical schoolchild infects 2.4 (95% CI from 1.8 to 3.2) other children within the school. We estimated the basic reproductive number, R0, to range from 1.3 to 1.7 and the generation interval to range from 2.6 to 3.2 days. We used a simulation model to evaluate the effectiveness of vaccination strategies in the United States for fall 2009. If a vaccine were available soon enough, vaccination of children, followed by adults, reaching 70% overall coverage, in addition to high-risk and essential workforce groups, could mitigate a severe epidemic.

Statistical inference for extended or shortened phase II studies based on Simon's two-stage designs.

PubMed

Zhao, Junjun; Yu, Menggang; Feng, Xi-Ping

2015-06-07

Simon's two-stage designs are popular choices for conducting phase II clinical trials, especially in the oncology trials to reduce the number of patients placed on ineffective experimental therapies. Recently Koyama and Chen (2008) discussed how to conduct proper inference for such studies because they found that inference procedures used with Simon's designs almost always ignore the actual sampling plan used. In particular, they proposed an inference method for studies when the actual second stage sample sizes differ from planned ones. We consider an alternative inference method based on likelihood ratio. In particular, we order permissible sample paths under Simon's two-stage designs using their corresponding conditional likelihood. In this way, we can calculate p-values using the common definition: the probability of obtaining a test statistic value at least as extreme as that observed under the null hypothesis. In addition to providing inference for a couple of scenarios where Koyama and Chen's method can be difficult to apply, the resulting estimate based on our method appears to have certain advantage in terms of inference properties in many numerical simulations. It generally led to smaller biases and narrower confidence intervals while maintaining similar coverages. We also illustrated the two methods in a real data setting. Inference procedures used with Simon's designs almost always ignore the actual sampling plan. Reported P-values, point estimates and confidence intervals for the response rate are not usually adjusted for the design's adaptiveness. Proper statistical inference procedures should be used.

Imputation for multisource data with comparison and assessment techniques

DOE PAGES

Casleton, Emily Michele; Osthus, David Allen; Van Buren, Kendra Lu

2017-12-27

Missing data are prevalent issue in analyses involving data collection. The problem of missing data is exacerbated for multisource analysis, where data from multiple sensors are combined to arrive at a single conclusion. In this scenario, it is more likely to occur and can lead to discarding a large amount of data collected; however, the information from observed sensors can be leveraged to estimate those values not observed. We propose two methods for imputation of multisource data, both of which take advantage of potential correlation between data from different sensors, through ridge regression and a state-space model. These methods, asmore » well as the common median imputation, are applied to data collected from a variety of sensors monitoring an experimental facility. Performance of imputation methods is compared with the mean absolute deviation; however, rather than using this metric to solely rank themethods,we also propose an approach to identify significant differences. Imputation techniqueswill also be assessed by their ability to produce appropriate confidence intervals, through coverage and length, around the imputed values. Finally, performance of imputed datasets is compared with a marginalized dataset through a weighted k-means clustering. In general, we found that imputation through a dynamic linearmodel tended to be the most accurate and to produce the most precise confidence intervals, and that imputing the missing values and down weighting them with respect to observed values in the analysis led to the most accurate performance.« less

The effect of physician staffing model on patient outcomes in a medical progressive care unit.

PubMed

Yoo, E J; Damaghi, N; Shakespeare, W G; Sherman, M S

2016-04-01

Although evidence supports the impact of intensivist physician staffing in improving intensive care unit (ICU) outcomes, the optimal coverage for progressive care units (PCU) is unknown. We sought to determine how physician staffing models influence outcomes for intermediate care patients. We conducted a retrospective observational comparison of patients admitted to the medical PCU of an academic hospital during 12-month periods of high-intensity and low-intensity staffing. A total of 318 PCU patients were eligible for inclusion (143 high-intensity and 175 low-intensity). We found that low-intensity patients were more often stepped up from the emergency department and floor, whereas high-intensity patients were ICU transfers (61% vs 42%, P = .001). However, Mortality Probability Model scoring was similar between the 2 groups. In adjusted analysis, there was no association between intensity of staffing and hospital mortality (odds ratio, 0.84; 95% confidence interval, 0.36-1.99; P = .69) or PCU mortality (odds ratio, 0.96; 95% confidence interval, 0.38-2.45; P = .69). There was also no difference in subsequent ICU admission rates or in PCU length of stay. We found no evidence that high-intensity intensivist physician staffing improves outcomes for intermediate care patients. In a strained critical care system, our study raises questions about the role of the intensivist in the graded care options between intensive and conventional ward care. Copyright © 2015 Elsevier Inc. All rights reserved.

Imputation for multisource data with comparison and assessment techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casleton, Emily Michele; Osthus, David Allen; Van Buren, Kendra Lu

Missing data are prevalent issue in analyses involving data collection. The problem of missing data is exacerbated for multisource analysis, where data from multiple sensors are combined to arrive at a single conclusion. In this scenario, it is more likely to occur and can lead to discarding a large amount of data collected; however, the information from observed sensors can be leveraged to estimate those values not observed. We propose two methods for imputation of multisource data, both of which take advantage of potential correlation between data from different sensors, through ridge regression and a state-space model. These methods, asmore » well as the common median imputation, are applied to data collected from a variety of sensors monitoring an experimental facility. Performance of imputation methods is compared with the mean absolute deviation; however, rather than using this metric to solely rank themethods,we also propose an approach to identify significant differences. Imputation techniqueswill also be assessed by their ability to produce appropriate confidence intervals, through coverage and length, around the imputed values. Finally, performance of imputed datasets is compared with a marginalized dataset through a weighted k-means clustering. In general, we found that imputation through a dynamic linearmodel tended to be the most accurate and to produce the most precise confidence intervals, and that imputing the missing values and down weighting them with respect to observed values in the analysis led to the most accurate performance.« less

Facebook and Twitter vaccine sentiment in response to measles outbreaks.

PubMed

Deiner, Michael S; Fathy, Cherie; Kim, Jessica; Niemeyer, Katherine; Ramirez, David; Ackley, Sarah F; Liu, Fengchen; Lietman, Thomas M; Porco, Travis C

2017-11-01

Social media posts regarding measles vaccination were classified as pro-vaccination, expressing vaccine hesitancy, uncertain, or irrelevant. Spearman correlations with Centers for Disease Control and Prevention-reported measles cases and differenced smoothed cumulative case counts over this period were reported (using time series bootstrap confidence intervals). A total of 58,078 Facebook posts and 82,993 tweets were identified from 4 January 2009 to 27 August 2016. Pro-vaccination posts were correlated with the US weekly reported cases (Facebook: Spearman correlation 0.22 (95% confidence interval: 0.09 to 0.34), Twitter: 0.21 (95% confidence interval: 0.06 to 0.34)). Vaccine-hesitant posts, however, were uncorrelated with measles cases in the United States (Facebook: 0.01 (95% confidence interval: -0.13 to 0.14), Twitter: 0.0011 (95% confidence interval: -0.12 to 0.12)). These findings may result from more consistent social media engagement by individuals expressing vaccine hesitancy, contrasted with media- or event-driven episodic interest on the part of individuals favoring current policy.

Exact Scheffé-type confidence intervals for output from groundwater flow models: 1. Use of hydrogeologic information

USGS Publications Warehouse

Cooley, Richard L.

1993-01-01

A new method is developed to efficiently compute exact Scheffé-type confidence intervals for output (or other function of parameters) g(β) derived from a groundwater flow model. The method is general in that parameter uncertainty can be specified by any statistical distribution having a log probability density function (log pdf) that can be expanded in a Taylor series. However, for this study parameter uncertainty is specified by a statistical multivariate beta distribution that incorporates hydrogeologic information in the form of the investigator's best estimates of parameters and a grouping of random variables representing possible parameter values so that each group is defined by maximum and minimum bounds and an ordering according to increasing value. The new method forms the confidence intervals from maximum and minimum limits of g(β) on a contour of a linear combination of (1) the quadratic form for the parameters used by Cooley and Vecchia (1987) and (2) the log pdf for the multivariate beta distribution. Three example problems are used to compare characteristics of the confidence intervals for hydraulic head obtained using different weights for the linear combination. Different weights generally produced similar confidence intervals, whereas the method of Cooley and Vecchia (1987) often produced much larger confidence intervals.

A confidence interval analysis of sampling effort, sequencing depth, and taxonomic resolution of fungal community ecology in the era of high-throughput sequencing.

PubMed

Oono, Ryoko

2017-01-01

High-throughput sequencing technology has helped microbial community ecologists explore ecological and evolutionary patterns at unprecedented scales. The benefits of a large sample size still typically outweigh that of greater sequencing depths per sample for accurate estimations of ecological inferences. However, excluding or not sequencing rare taxa may mislead the answers to the questions 'how and why are communities different?' This study evaluates the confidence intervals of ecological inferences from high-throughput sequencing data of foliar fungal endophytes as case studies through a range of sampling efforts, sequencing depths, and taxonomic resolutions to understand how technical and analytical practices may affect our interpretations. Increasing sampling size reliably decreased confidence intervals across multiple community comparisons. However, the effects of sequencing depths on confidence intervals depended on how rare taxa influenced the dissimilarity estimates among communities and did not significantly decrease confidence intervals for all community comparisons. A comparison of simulated communities under random drift suggests that sequencing depths are important in estimating dissimilarities between microbial communities under neutral selective processes. Confidence interval analyses reveal important biases as well as biological trends in microbial community studies that otherwise may be ignored when communities are only compared for statistically significant differences.

The Applicability of Confidence Intervals of Quantiles for the Generalized Logistic Distribution

NASA Astrophysics Data System (ADS)

Shin, H.; Heo, J.; Kim, T.; Jung, Y.

2007-12-01

The generalized logistic (GL) distribution has been widely used for frequency analysis. However, there is a little study related to the confidence intervals that indicate the prediction accuracy of distribution for the GL distribution. In this paper, the estimation of the confidence intervals of quantiles for the GL distribution is presented based on the method of moments (MOM), maximum likelihood (ML), and probability weighted moments (PWM) and the asymptotic variances of each quantile estimator are derived as functions of the sample sizes, return periods, and parameters. Monte Carlo simulation experiments are also performed to verify the applicability of the derived confidence intervals of quantile. As the results, the relative bias (RBIAS) and relative root mean square error (RRMSE) of the confidence intervals generally increase as return period increases and reverse as sample size increases. And PWM for estimating the confidence intervals performs better than the other methods in terms of RRMSE when the data is almost symmetric while ML shows the smallest RBIAS and RRMSE when the data is more skewed and sample size is moderately large. The GL model was applied to fit the distribution of annual maximum rainfall data. The results show that there are little differences in the estimated quantiles between ML and PWM while distinct differences in MOM.

A confidence interval analysis of sampling effort, sequencing depth, and taxonomic resolution of fungal community ecology in the era of high-throughput sequencing

PubMed Central

2017-01-01

High-throughput sequencing technology has helped microbial community ecologists explore ecological and evolutionary patterns at unprecedented scales. The benefits of a large sample size still typically outweigh that of greater sequencing depths per sample for accurate estimations of ecological inferences. However, excluding or not sequencing rare taxa may mislead the answers to the questions ‘how and why are communities different?’ This study evaluates the confidence intervals of ecological inferences from high-throughput sequencing data of foliar fungal endophytes as case studies through a range of sampling efforts, sequencing depths, and taxonomic resolutions to understand how technical and analytical practices may affect our interpretations. Increasing sampling size reliably decreased confidence intervals across multiple community comparisons. However, the effects of sequencing depths on confidence intervals depended on how rare taxa influenced the dissimilarity estimates among communities and did not significantly decrease confidence intervals for all community comparisons. A comparison of simulated communities under random drift suggests that sequencing depths are important in estimating dissimilarities between microbial communities under neutral selective processes. Confidence interval analyses reveal important biases as well as biological trends in microbial community studies that otherwise may be ignored when communities are only compared for statistically significant differences. PMID:29253889

Exact one-sided confidence bounds for the risk ratio in 2 x 2 tables with structural zero.

PubMed

Lloyd, Chris J; Moldovan, Max V

2007-12-01

This paper examines exact one-sided confidence limits for the risk ratio in a 2 x 2 table with structural zero. Starting with four approximate lower and upper limits, we adjust each using the algorithm of Buehler (1957) to arrive at lower (upper) limits that have exact coverage properties and are as large (small) as possible subject to coverage, as well as an ordering, constraint. Different Buehler limits are compared by their mean size, since all are exact in their coverage. Buehler limits based on the signed root likelihood ratio statistic are found to have the best performance and recommended for practical use. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Primary repair of penetrating colon injuries: a systematic review.

PubMed

Singer, Marc A; Nelson, Richard L

2002-12-01

Primary repair of penetrating colon injuries is an appealing management option; however, uncertainty about its safety persists. This study was conducted to compare the morbidity and mortality of primary repair with fecal diversion in the management of penetrating colon injuries by use of a meta-analysis of randomized, prospective trials. We searched for prospective, randomized trials in MEDLINE (1966 to November 2001), the Cochrane Library, and EMBase using the terms colon, penetrating, injury, colostomy, prospective, and randomized. Studies were included if they were randomized, controlled trials that compared the outcomes of primary repair with fecal diversion in the management of penetrating colon injuries. Five studies were included. Reviewers performed data extraction independently. Outcomes evaluated from each trial included mortality, total complications, infectious complications, intra-abdominal infections, wound complications, penetrating abdominal trauma index, and length of stay. Peto odds ratios for combined effect were calculated with a 95 percent confidence interval for each outcome. Heterogeneity was also assessed for each outcome. The penetrating abdominal trauma index of included subjects did not differ significantly between studies. Mortality was not significantly different between groups (odds ratio, 1.70; 95 percent confidence interval, 0.51-5.66). However, total complications (odds ratio, 0.28; 95 percent confidence interval, 0.18-0.42), total infectious complications (odds ratio, 0.41; 95 percent confidence interval, 0.27-0.63), abdominal infections including dehiscence (odds ratio, 0.59; 95 percent confidence interval, 0.38-0.94), abdominal infections excluding dehiscence (odds ratio, 0.52; 95 percent confidence interval, 0.31-0.86), wound complications including dehiscence (odds ratio, 0.55; 95 percent confidence interval, 0.34-0.89), and wound complications excluding dehiscence (odds ratio, 0.43; 95 percent confidence interval, 0.25-0.76) all significantly favored primary repair. Meta-analysis of currently published randomized, controlled trials favors primary repair over fecal diversion for penetrating colon injuries.

Bullying and mental health and suicidal behaviour among 14- to 15-year-olds in a representative sample of Australian children.

PubMed

Ford, Rebecca; King, Tania; Priest, Naomi; Kavanagh, Anne

2017-09-01

To provide the first Australian population-based estimates of the association between bullying and adverse mental health outcomes and suicidality among Australian adolescents. Analysis of data from 3537 adolescents, aged 14-15 years from Wave 6 of the K-cohort of Longitudinal Study of Australian Children was conducted. We used Poisson and linear regression to estimate associations between bullying type (none, relational-verbal, physical, both types) and role (no role, victim, bully, victim and bully), and mental health (measured by the Strengths and Difficulties Questionnaire, symptoms of anxiety and depression) and suicidality. Adolescents involved in bullying had significantly increased Strengths and Difficulties Questionnaire, depression and anxiety scores in all bullying roles and types. In terms of self-harm and suicidality, bully-victims had the highest risk of self-harm (prevalence rate ratio 4.7, 95% confidence interval [3.26, 6.83]), suicidal ideation (prevalence rate ratio 4.3, 95% confidence interval [2.83, 6.49]), suicidal plan (prevalence rate ratio 4.1, 95% confidence interval [2.54, 6.58]) and attempts (prevalence rate ratio 2.7, 95% confidence interval [1.39, 5.13]), followed by victims then bullies. The experience of both relational-verbal and physical bullying was associated with the highest risk of self-harm (prevalence rate ratio 4.6, 95% confidence interval [3.15, 6.60]), suicidal ideation or plans (prevalence rate ratio 4.6, 95% confidence interval [3.05, 6.95]; and 4.8, 95% confidence interval [3.01, 7.64], respectively) or suicide attempts (prevalence rate ratio 3.5, 95% confidence interval [1.90, 6.30]). This study presents the first national, population-based estimates of the associations between bullying by peers and mental health outcomes in Australian adolescents. The markedly increased risk of poor mental health outcomes, self-harm and suicidal ideation and behaviours among adolescents who experienced bullying highlights the importance of addressing bullying in school settings.

Ethnic variations in morbidity and mortality from lower respiratory tract infections: a retrospective cohort study

PubMed Central

Steiner, Markus FC; Cezard, Genevieve; Bansal, Narinder; Fischbacher, Colin; Douglas, Anne; Bhopal, Raj; Sheikh, Aziz

2015-01-01

Objective There is evidence of substantial ethnic variations in asthma morbidity and the risk of hospitalisation, but the picture in relation to lower respiratory tract infections is unclear. We carried out an observational study to identify ethnic group differences for lower respiratory tract infections. Design A retrospective, cohort study. Setting Scotland. Participants 4.65 million people on whom information was available from the 2001 census, followed from May 2001 to April 2010. Main outcome measures Hospitalisations and deaths (any time following first hospitalisation) from lower respiratory tract infections, adjusted risk ratios and hazard ratios by ethnicity and sex were calculated. We multiplied ratios and confidence intervals by 100, so the reference Scottish White population’s risk ratio and hazard ratio was 100. Results Among men, adjusted risk ratios for lower respiratory tract infection hospitalisation were lower in Other White British (80, 95% confidence interval 73–86) and Chinese (69, 95% confidence interval 56–84) populations and higher in Pakistani groups (152, 95% confidence interval 136–169). In women, results were mostly similar to those in men (e.g. Chinese 68, 95% confidence interval 56–82), although higher adjusted risk ratios were found among women of the Other South Asians group (145, 95% confidence interval 120–175). Survival (adjusted hazard ratio) following lower respiratory tract infection for Pakistani men (54, 95% confidence interval 39–74) and women (31, 95% confidence interval 18–53) was better than the reference population. Conclusions Substantial differences in the rates of lower respiratory tract infections amongst different ethnic groups in Scotland were found. Pakistani men and women had particularly high rates of lower respiratory tract infection hospitalisation. The reasons behind the high rates of lower respiratory tract infection in the Pakistani community are now required. PMID:26152675

Diagnostic accuracy of the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis.

PubMed

Faes, L; Bodmer, N S; Bachmann, L M; Thiel, M A; Schmid, M K

2014-07-01

To clarify the screening potential of the Amsler grid and preferential hyperacuity perimetry (PHP) in detecting or ruling out wet age-related macular degeneration (AMD). Medline, Scopus and Web of Science (by citation of reference) were searched. Checking of reference lists of review articles and of included articles complemented electronic searches. Papers were selected, assessed, and extracted in duplicate. Systematic review and meta-analysis. Twelve included studies enrolled 903 patients and allowed constructing 27 two-by-two tables. Twelve tables reported on the Amsler grid and its modifications, twelve tables reported on the PHP, one table assessed the MCPT and two tables assessed the M-charts. All but two studies had a case-control design. The pooled sensitivity of studies assessing the Amsler grid was 0.78 (95% confidence intervals; 0.64-0.87), and the pooled specificity was 0.97 (95% confidence intervals; 0.91-0.99). The corresponding positive and negative likelihood ratios were 23.1 (95% confidence intervals; 8.4-64.0) and 0.23 (95% confidence intervals; 0.14-0.39), respectively. The pooled sensitivity of studies assessing the PHP was 0.85 (95% confidence intervals; 0.80-0.89), and specificity was 0.87 (95% confidence intervals; 0.82-0.91). The corresponding positive and negative likelihood ratios were 6.7 (95% confidence intervals; 4.6-9.8) and 0.17 (95% confidence intervals; 0.13-0.23). No pooling was possible for MCPT and M-charts. Results from small preliminary studies show promising test performance characteristics both for the Amsler grid and PHP to rule out wet AMD in the screening setting. To what extent these findings can be transferred to a real clinic practice still needs to be established.

Rapid assessment of avoidable blindness in Bhutan.

PubMed

Lepcha, Nor Tshering; Chettri, Chandra Kumar; Getshen, Kunzang; Rai, Bhim Bahadur; Ramaswamy, Shamanna Bindiganavale; Saibaba, Saravanan; Nirmalan, Praveen Kumar; Demarchis, Emilia Hansson; Tabin, Geoffrey; Morley, Michael; Morley, Katharine

2013-08-01

To conduct a rapid assessment of avoidable blindness survey in Bhutan to obtain estimates of blindness, visual impairment, and cataract surgical coverage, outcomes and barriers among persons ≥50 years old. A total of 82 clusters of 50 people ≥50 years were selected using probability proportionate to size sampling. Eligible participants were selected from households using compact segment sampling, and underwent ophthalmic examination for visual acuity, followed by penlight and direct ophthalmoscopy. Participants with cataract were interviewed regarding surgical outcomes and barriers to surgery. Overall, 4046 of 4100 persons enumerated (98.7%) underwent ophthalmic examination. Adjusting for age and sex, the prevalence of bilaterally blind persons with available correction was 1.5% (95% confidence interval 1.09-1.89). Most blindness (67.1%) and severe visual impairment (74.1%) resulted from cataract, but 22.1% resulted from posterior segment pathology. Cataract surgical coverage for bilaterally blind persons was 72.7%. Almost 90% of patients reported moderate or good satisfaction, despite poor surgical outcomes in 23.6%. The prevalence of blindness in people aged ≥50 years in Bhutan was relatively low when compared with neighboring countries and World Health Organization sub-region estimates. Areas for improvement include community outreach, surgical outcomes, and posterior segment diseases.

The prognostic value of the QT interval and QT interval dispersion in all-cause and cardiac mortality and morbidity in a population of Danish citizens.

PubMed

Elming, H; Holm, E; Jun, L; Torp-Pedersen, C; Køber, L; Kircshoff, M; Malik, M; Camm, J

1998-09-01

To evaluate the prognostic value of the QT interval and QT interval dispersion in total and in cardiovascular mortality, as well as in cardiac morbidity, in a general population. The QT interval was measured in all leads from a standard 12-lead ECG in a random sample of 1658 women and 1797 men aged 30-60 years. QT interval dispersion was calculated from the maximal difference between QT intervals in any two leads. All cause mortality over 13 years, and cardiovascular mortality as well as cardiac morbidity over 11 years, were the main outcome parameters. Subjects with a prolonged QT interval (430 ms or more) or prolonged QT interval dispersion (80 ms or more) were at higher risk of cardiovascular death and cardiac morbidity than subjects whose QT interval was less than 360 ms, or whose QT interval dispersion was less than 30 ms. Cardiovascular death relative risk ratios, adjusted for age, gender, myocardial infarct, angina pectoris, diabetes mellitus, arterial hypertension, smoking habits, serum cholesterol level, and heart rate were 2.9 for the QT interval (95% confidence interval 1.1-7.8) and 4.4 for QT interval dispersion (95% confidence interval 1.0-19-1). Fatal and non-fatal cardiac morbidity relative risk ratios were similar, at 2.7 (95% confidence interval 1.4-5.5) for the QT interval and 2.2 (95% confidence interval 1.1-4.0) for QT interval dispersion. Prolongation of the QT interval and QT interval dispersion independently affected the prognosis of cardiovascular mortality and cardiac fatal and non-fatal morbidity in a general population over 11 years.

Is essential newborn care provided by institutions and after home births? Analysis of prospective data from community trials in rural South Asia

PubMed Central

2014-01-01

Background Provision of essential newborn care (ENC) can save many newborn lives in poor resource settings but coverage is far from universal and varies by country and place of delivery. Understanding gaps in current coverage and where coverage is good, in different contexts and places of delivery, could make a valuable contribution to the future design of interventions to reduce neonatal mortality. We sought to describe the coverage of essential newborn care practices for births in institutions, at home with a skilled birth attendant, and at home without a skilled birth attendant (SBA) in rural areas of Bangladesh, Nepal, and India. Methods We used data from the control arms of four cluster randomised controlled trials in Bangladesh, Eastern India and from Makwanpur and Dhanusha districts in Nepal, covering periods from 2001 to 2011. We used these data to identify essential newborn care practices as defined by the World Health Organization. Each birth was allocated to one of three delivery types: home birth without an SBA, home birth with an SBA, or institutional delivery. For each study, we calculated the observed proportion of births that received each care practice by delivery type with 95% confidence intervals, adjusted for clustering and, where appropriate, stratification. Results After exclusions, we analysed data for 8939 births from Eastern India, 27 553 births from Bangladesh, 6765 births from Makwanpur and 15 344 births from Dhanusha. Across all study areas, coverage of essential newborn care practices was highest in institutional deliveries, and lowest in home non-SBA deliveries. However, institutional deliveries did not provide universal coverage of the recommended practices, with relatively low coverage (20%-70%) across all study areas for immediate breastfeeding and thermal care. Institutions in Bangladesh had the highest coverage for almost all care practices except thermal care. Across all areas, fewer than 20% of home non-SBA deliveries used a clean delivery kit, the use of plastic gloves was very low and coverage of recommended thermal care was relatively poor. There were large differences between study areas in handwashing, immediate breastfeeding and delayed bathing. Conclusions There remains substantial scope for health facilities to improve thermal care for the newborn and to encourage immediate and exclusive breastfeeding. For unattended home deliveries, increased handwashing, use of clean delivery kits and basic thermal care offer great scope for improvement. PMID:24606612

The free vaccination policy of influenza in Beijing, China: The vaccine coverage and its associated factors.

PubMed

Lv, Min; Fang, Renfei; Wu, Jiang; Pang, Xinghuo; Deng, Ying; Lei, Trudy; Xie, Zheng

2016-04-19

In order to improve influenza vaccination coverage, the coverage rate and reasons for non-vaccination need to be determined. In 2007, the Beijing Government published a policy providing free influenza vaccinations to elderly people living in Beijing who are older than 60. This study examines the vaccination coverage after the policy was carried out and factors influencing vaccination among the elderly in Beijing. A cross-sectional survey was conducted through the use of questionnaires in 2013. A total of 1673 eligible participants were selected by multistage stratified random sampling in Beijing using anonymous questionnaires in-person. They were surveyed to determine vaccination status and social demographic information. The influenza vaccination coverage was 38.7% among elderly people in Beijing in 2012. The most common reason for not being vaccinated was people thinking they did not need to have a flu shot. After controlling for age, gender, income, self-reported health status, and the acceptance of health promotion, the rate in rural areas was 2.566 (95% confidence interval [CI], 1.801-3.655, P<0.010) times greater than that in urban areas. Different mechanisms of health education and health promotion have different influences on vaccination uptake. Those whom received information through television, community boards, or doctors were more likely to get vaccinated compared to those who did not (Odds Ratio [OR]=1.403, P<0.010; OR=1.812, P<0.010; OR=2.647, P<0.010). The influenza vaccine coverage in Beijing is much lower than that of developed countries with similar policies. The rural-urban disparity in coverage rate (64.1% versus 33.5%), may be explained by differing health provision systems and personal attitudes toward free services due to socioeconomic factors. Methods for increasing vaccination levels include increasing the focus on primary care and health education programs, particularly recommendations from doctors, to the distinct target populations, especially with a focus on expanding these efforts in urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effective coverage of essential inpatient care for small and sick newborns in a high mortality urban setting: a cross-sectional study in Nairobi City County, Kenya.

PubMed

Murphy, Georgina A V; Gathara, David; Mwachiro, Jacintah; Abuya, Nancy; Aluvaala, Jalemba; English, Mike

2018-05-22

Effective coverage requires that those in need can access skilled care supported by adequate resources. There are, however, few studies of effective coverage of facility-based neonatal care in low-income settings, despite the recognition that improving newborn survival is a global priority. We used a detailed retrospective review of medical records for neonatal admissions to public, private not-for-profit (mission) and private-for-profit (private) sector facilities providing 24×7 inpatient neonatal care in Nairobi City County to estimate the proportion of small and sick newborns receiving nationally recommended care across six process domains. We used our findings to explore the relationship between facility measures of structure and process and estimate effective coverage. Of 33 eligible facilities, 28 (four public, six mission and 18 private), providing an estimated 98.7% of inpatient neonatal care in the county, agreed to partake. Data from 1184 admission episodes were collected. Overall performance was lowest (weighted mean score 0.35 [95% confidence interval or CI: 0.22-0.48] out of 1) for correct prescription of fluid and feed volumes and best (0.86 [95% CI: 0.80-0.93]) for documentation of demographic characteristics. Doses of gentamicin, when prescribed, were at least 20% higher than recommended in 11.7% cases. Larger (often public) facilities tended to have higher process and structural quality scores compared with smaller, predominantly private, facilities. We estimate effective coverage to be 25% (estimate range: 21-31%). These newborns received high-quality inpatient care, while almost half (44.5%) of newborns needed care but did not receive it and a further 30.4% of newborns received an inadequate service. Failure to receive services and gaps in quality of care both contribute to a shortfall in effective coverage in Nairobi City County. Three-quarters of small and sick newborns do not have access to high-quality facility-based care. Substantial improvements in effective coverage will be required to tackle high neonatal mortality in this urban setting with high levels of poverty.

Cluster Survey Evaluation of a Measles Vaccination Campaign in Jharkhand, India, 2012

PubMed Central

Scobie, Heather M.; Ray, Arindam; Routray, Satyabrata; Bose, Anindya; Bahl, Sunil; Sosler, Stephen; Wannemuehler, Kathleen; Kumar, Rakesh; Haldar, Pradeep; Anand, Abhijeet

2015-01-01

Introduction India was the last country in the world to implement a two-dose strategy for measles-containing vaccine (MCV) in 2010. As part of measles second-dose introduction, phased measles vaccination campaigns were conducted during 2010–2013, targeting 131 million children 9 months to <10 years of age. We performed a post-campaign coverage survey to estimate measles vaccination coverage in Jharkhand state. Methods A multi-stage cluster survey was conducted 2 months after the phase 2 measles campaign occurred in 19 of 24 districts of Jharkhand during November 2011–March 2012. Vaccination status of children 9 months to <10 years of age was documented based on vaccination card or mother’s recall. Coverage estimates and 95% confidence intervals (95% CI) for 1,018 children were calculated using survey methods. Results In the Jharkhand phase 2 campaign, MCV coverage among children aged 9 months to <10 years was 61.0% (95% CI: 54.4–67.7%). Significant differences in coverage were observed between rural (65.0%; 95% CI: 56.8–73.2%) and urban areas (45.6%; 95% CI: 37.3–53.9%). Campaign awareness among mothers was low (51.5%), and the most commonly reported reason for non-vaccination was being unaware of the campaign (69.4%). At the end of the campaign, 53.7% (95% CI: 46.5–60.9%) of children 12 months to <10 years of age received ≥2 MCV doses, while a large proportion of children remained under-vaccinated (34.0%, 95% CI: 28.0–40.0%) or unvaccinated (12.3%, 95% CI: 9.3–16.2%). Conclusions Implementation of the national measles campaign was a significant achievement towards measles elimination in India. In Jharkhand, campaign performance was below the target coverage of ≥90% set by the Government of India, and challenges in disseminating campaign messages were identified. Efforts towards increasing two-dose MCV coverage are needed to achieve the recently adopted measles elimination goal in India and the South-East Asia region. PMID:26010084

Intakes of magnesium, potassium, and calcium and the risk of stroke among men.

PubMed

Adebamowo, Sally N; Spiegelman, Donna; Flint, Alan J; Willett, Walter C; Rexrode, Kathryn M

2015-10-01

Intakes of magnesium, potassium, and calcium have been inversely associated with the incidence of hypertension, a known risk factor for stroke. However, only a few studies have examined intakes of these cations in relation to risk of stroke. The aim of this study was to investigate whether high intake of magnesium, potassium, and calcium is associated with reduced stroke risk among men. We prospectively examined the associations between intakes of magnesium, potassium, and calcium from diet and supplements, and the risk of incident stroke among 42 669 men in the Health Professionals Follow-up Study, aged 40 to 75 years and free of diagnosed cardiovascular disease and cancer at baseline in 1986. We calculated the hazard ratio of total, ischemic, and haemorrhagic strokes by quintiles of each cation intake, and of a combined dietary score of all three cations, using multivariate Cox proportional hazard models. During 24 years of follow-up, 1547 total stroke events were documented. In multivariate analyses, the relative risks and 95% confidence intervals of total stroke for men in the highest vs. lowest quintile were 0·87 (95% confidence interval, 0·74-1·02; P, trend = 0·04) for dietary magnesium, 0·89 (95% confidence interval, 0·76-1·05; P, trend = 0·10) for dietary potassium, and 0·89 (95% confidence interval, 0·75-1·04; P, trend = 0·25) for dietary calcium intake. The relative risk of total stroke for men in the highest vs. lowest quintile was 0·74 (95% confidence interval, 0·59-0·93; P, trend = 0·003) for supplemental magnesium, 0·66 (95% confidence interval, 0·50-0·86; P, trend = 0·002) for supplemental potassium, and 1·01 (95% confidence interval, 0·84-1·20; P, trend = 0·83) for supplemental calcium intake. For total intake (dietary and supplemental), the relative risk of total stroke for men in the highest vs. lowest quintile was 0·83 (95% confidence interval, 0·70-0·99; P, trend = 0·04) for magnesium, 0·88 (95% confidence interval, 0·75-4; P, trend = 6) for potassium, and 3 (95% confidence interval, 79-09; P, trend = 84) for calcium. Men in the highest quintile for a combined dietary score of all three cations had a multivariate relative risk of 0·79 (95% confidence interval, 0·67-0·92; P, trend = 0·008) for total stroke, compared with those in the lowest. A diet rich in magnesium, potassium, and calcium may contribute to reduced risk of stroke among men. Because of significant collinearity, the independent contribution of each cation is difficult to define. © 2015 World Stroke Organization.

Neuraxial analgesia to increase the success rate of external cephalic version: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Magro-Malosso, Elena Rita; Saccone, Gabriele; Di Tommaso, Mariarosaria; Mele, Michele; Berghella, Vincenzo

2016-09-01

External cephalic version is a medical procedure in which the fetus is externally manipulated to assume the cephalic presentation. The use of neuraxial analgesia for facilitating the version has been evaluated in several randomized clinical trials, but its potential effects are still controversial. The objective of the study was to evaluate the effectiveness of neuraxial analgesia as an intervention to increase the success rate of external cephalic version. Searches were performed in electronic databases with the use of a combination of text words related to external cephalic version and neuraxial analgesia from the inception of each database to January 2016. We included all randomized clinical trials of women, with a gestational age ≥36 weeks and breech or transverse fetal presentation, undergoing external cephalic version who were randomized to neuraxial analgesia, including spinal, epidural, or combined spinal-epidural techniques (ie, intervention group) or to a control group (either intravenous analgesia or no treatment). The primary outcome was the successful external cephalic version. The summary measures were reported as relative risk or as mean differences with a 95% confidence interval. Nine randomized clinical trials (934 women) were included in this review. Women who received neuraxial analgesia had a significantly higher incidence of successful external cephalic version (58.4% vs 43.1%; relative risk, 1.44, 95% confidence interval, 1.27-1.64), cephalic presentation in labor (55.1% vs 40.2%; relative risk, 1.37, 95% confidence interval, 1.08-1.73), and vaginal delivery (54.0% vs 44.6%; relative risk, 1.21, 95% confidence interval, 1.04-1.41) compared with those who did not. Women who were randomized to the intervention group also had a significantly lower incidence of cesarean delivery (46.0% vs 55.3%; relative risk, 0.83, 95% confidence interval, 0.71-0.97), maternal discomfort (1.2% vs 9.3%; relative risk, 0.12, 95% confidence interval, 0.02-0.99), and lower pain, assessed by the visual analog scale pain score (mean difference, -4.52 points, 95% confidence interval, -5.35 to 3.69) compared with the control group. The incidences of emergency cesarean delivery (1.6% vs 2.5%; relative risk, 0.63, 95% confidence interval, 0.24-1.70), transient bradycardia (11.8% vs 8.3%; relative risk, 1.42, 95% confidence interval, 0.72-2.80), nonreassuring fetal testing, excluding transient bradycardia, after external cephalic version (6.9% vs 7.4%; relative risk, 0.93, 95% confidence interval, 0.53-1.64), and abruption placentae (0.4% vs 0.4%; relative risk, 1.01, 95% confidence interval, 0.06-16.1) were similar. Administration of neuraxial analgesia significantly increases the success rate of external cephalic version among women with malpresentation at term or late preterm, which then significantly increases the incidence of vaginal delivery. Copyright © 2016 Elsevier Inc. All rights reserved.

Add-On Antihypertensive Medications to Angiotensin-Aldosterone System Blockers in Diabetes: A Comparative Effectiveness Study.

PubMed

Schroeder, Emily B; Chonchol, Michel; Shetterly, Susan M; Powers, J David; Adams, John L; Schmittdiel, Julie A; Nichols, Gregory A; O'Connor, Patrick J; Steiner, John F

2018-05-07

In individuals with diabetes, the comparative effectiveness of add-on antihypertensive medications added to an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker on the risk of significant kidney events is unknown. We used an observational, multicenter cohort of 21,897 individuals with diabetes to compare individuals who added β -blockers, dihydropyridine calcium channel blockers, loop diuretics, or thiazide diuretics to angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. We examined the hazard of significant kidney events, cardiovascular events, and death using Cox proportional hazard models with propensity score weighting. The composite significant kidney event end point was defined as the first occurrence of a ≥30% decline in eGFR to an eGFR<60 ml/min per 1.73 m 2 , initiation of dialysis, or kidney transplant. The composite cardiovascular event end point was defined as the first occurrence of hospitalization for acute myocardial infarction, acute coronary syndrome, stroke, or congestive heart failure; coronary artery bypass grafting; or percutaneous coronary intervention, and it was only examined in those free of cardiovascular disease at baseline. Over a maximum of 5 years, there were 4707 significant kidney events, 1498 deaths, and 818 cardiovascular events. Compared with thiazide diuretics, hazard ratios for significant kidney events for β -blockers, calcium channel blockers, and loop diuretics were 0.81 (95% confidence interval, 0.74 to 0.89), 0.67 (95% confidence interval, 0.58 to 0.78), and 1.19 (95% confidence interval, 1.00 to 1.41), respectively. Compared with thiazide diuretics, hazard ratios of mortality for β -blockers, calcium channel blockers, and loop diuretics were 1.19 (95% confidence interval, 0.97 to 1.44), 0.73 (95% confidence interval, 0.52 to 1.03), and 1.67 (95% confidence interval, 1.31 to 2.13), respectively. Compared with thiazide diuretics, hazard ratios of cardiovascular events for β -blockers, calcium channel blockers, and loop diuretics compared with thiazide diuretics were 1.65 (95% confidence interval, 1.39 to 1.96), 1.05 (95% confidence interval, 0.80 to 1.39), and 1.55 (95% confidence interval, 1.05 to 2.27), respectively. Compared with thiazide diuretics, calcium channel blockers were associated with a lower risk of significant kidney events and a similar risk of cardiovascular events. Copyright © 2018 by the American Society of Nephrology.

Maternal steroid therapy for fetuses with second-degree immune-mediated congenital atrioventricular block: a systematic review and meta-analysis.

PubMed

Ciardulli, Andrea; D'Antonio, Francesco; Magro-Malosso, Elena R; Manzoli, Lamberto; Anisman, Paul; Saccone, Gabriele; Berghella, Vincenzo

2018-03-07

To explore the effect of maternal fluorinated steroid therapy on fetuses affected by second-degree immune-mediated congenital atrioventricular block. Studies reporting the outcome of fetuses with second-degree immune-mediated congenital atrioventricular block diagnosed on prenatal ultrasound and treated with fluorinated steroids compared with those not treated were included. The primary outcome was the overall progression of congenital atrioventricular block to either continuous or intermittent third-degree congenital atrioventricular block at birth. Meta-analyses of proportions using random effect model and meta-analyses using individual data random-effect logistic regression were used. Five studies (71 fetuses) were included. The progression rate to congenital atrioventricular block at birth in fetuses treated with steroids was 52% (95% confidence interval 23-79) and in fetuses not receiving steroid therapy 73% (95% confidence interval 39-94). The overall rate of regression to either first-degree, intermittent first-/second-degree or sinus rhythm in fetuses treated with steroids was 25% (95% confidence interval 12-41) compared with 23% (95% confidence interval 8-44) in those not treated. Stable (constant) second-degree congenital atrioventricular block at birth was present in 11% (95% confidence interval 2-27) of cases in the treated group and in none of the newborns in the untreated group, whereas complete regression to sinus rhythm occurred in 21% (95% confidence interval 6-42) of fetuses receiving steroids vs. 9% (95% confidence interval 0-41) of those untreated. There is still limited evidence as to the benefit of administered fluorinated steroids in terms of affecting outcome of fetuses with second-degree immune-mediated congenital atrioventricular block. © 2018 Nordic Federation of Societies of Obstetrics and Gynecology.

Active management of the third stage of labor with and without controlled cord traction: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Du, Yongming; Ye, Man; Zheng, Feiyun

2014-07-01

To determine the specific effect of controlled cord traction in the third stage of labor in the prevention of postpartum hemorrhage. We searched PubMed, Scopus and Web of Science (inception to 30 October 2013). Randomized controlled trials comparing controlled cord traction with hands-off management in the third stage of labor were included. Five randomized controlled trials involving a total of 30 532 participants were eligible. No significant difference was found between controlled cord traction and hands-off management groups with respect to the incidence of severe postpartum hemorrhage (relative risk 0.91, 95% confidence interval 0.77-1.08), need for blood transfusion (relative risk 0.96, 95% confidence interval 0.69-1.33) or therapeutic uterotonics (relative risk 0.94, 95% confidence interval 0.88-1.01). However, controlled cord traction reduced the incidence of postpartum hemorrhage in general (relative risk 0.93, 95% confidence interval 0.87-0.99; number-needed-to-treat 111, 95% confidence interval 61-666), as well manual removal of the placenta (relative risk 0.70, 95% confidence interval 0.58-0.84) and duration of the third stage of labor (mean difference -3.20, 95% confidence interval -3.21 to -3.19). Controlled cord traction appears to reduce the risk of any postpartum hemorrhage in a general sense, as well as manual removal of the placenta and the duration of the third stage of labor. However, the reduction in the occurrence of severe postpartum hemorrhage, need for additional uterotonics and blood transfusion is not statistically significant. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

Loss of DPC4/SMAD4 expression in primary gastrointestinal neuroendocrine tumors is associated with cancer-related death after resection.

PubMed

Roland, Christina L; Starker, Lee F; Kang, Y; Chatterjee, Deyali; Estrella, Jeannelyn; Rashid, Asif; Katz, Matthew H; Aloia, Thomas A; Lee, Jeffrey E; Dasari, Arvind; Yao, James C; Fleming, Jason B

2017-03-01

Gastrointestinal neuroendocrine tumors have frequent loss of DPC4/SMAD4 expression, a known tumor suppressor. The impact of SMAD4 loss on gastrointestinal neuroendocrine tumors aggressiveness or cancer-related patient outcomes is not defined. We examined the expression of SMAD4 in resected gastrointestinal neuroendocrine tumors and its impact on oncologic outcomes. Patients who underwent complete curative operative resection of gastrointestinal neuroendocrine tumors were identified retrospectively (n = 38). Immunohistochemical staining for SMAD4 expression was scored by a blinded pathologist and correlated with clinicopathologic features and oncologic outcomes. Twenty-nine percent of the gastrointestinal neuroendocrine tumors were SMAD4-negative and 71% SMAD4-positive. Median overall survival was 155 months (95% confidence interval, 102-208 months). Loss of SMAD4 was associated with both decreased median disease-free survival (28 months; 95% confidence interval, 16-40) months compared with 223 months (95% confidence interval, 3-443 months) for SMAD4-positive patients (P = .03) and decreased median disease-specific survival (SMAD4: 137 [95% confidence interval, 81-194] months versus SMAD4-positive: 204 [95% confidence interval, 143-264] months; P = .04). This translated into a decrease in median overall survival (SMAD4-negative: 125 (95% confidence interval, 51-214) months versus SMAD4-positive: 185 (95% confidence interval, 138-232) months; P = .02). Consistent with the known biology of the DPC4/SMAD4 gene, an absence of its protein expression in primary gastrointestinal neuroendocrine tumors was negatively associated with outcomes after curative operative resection. Copyright © 2016 Elsevier Inc. All rights reserved.

Calculation of the confidence intervals for transformation parameters in the registration of medical images

PubMed Central

Bansal, Ravi; Staib, Lawrence H.; Laine, Andrew F.; Xu, Dongrong; Liu, Jun; Posecion, Lainie F.; Peterson, Bradley S.

2010-01-01

Images from different individuals typically cannot be registered precisely because anatomical features within the images differ across the people imaged and because the current methods for image registration have inherent technological limitations that interfere with perfect registration. Quantifying the inevitable error in image registration is therefore of crucial importance in assessing the effects that image misregistration may have on subsequent analyses in an imaging study. We have developed a mathematical framework for quantifying errors in registration by computing the confidence intervals of the estimated parameters (3 translations, 3 rotations, and 1 global scale) for the similarity transformation. The presence of noise in images and the variability in anatomy across individuals ensures that estimated registration parameters are always random variables. We assume a functional relation among intensities across voxels in the images, and we use the theory of nonlinear, least-squares estimation to show that the parameters are multivariate Gaussian distributed. We then use the covariance matrix of this distribution to compute the confidence intervals of the transformation parameters. These confidence intervals provide a quantitative assessment of the registration error across the images. Because transformation parameters are nonlinearly related to the coordinates of landmark points in the brain, we subsequently show that the coordinates of those landmark points are also multivariate Gaussian distributed. Using these distributions, we then compute the confidence intervals of the coordinates for landmark points in the image. Each of these confidence intervals in turn provides a quantitative assessment of the registration error at a particular landmark point. Because our method is computationally intensive, however, its current implementation is limited to assessing the error of the parameters in the similarity transformation across images. We assessed the performance of our method in computing the error in estimated similarity parameters by applying that method to real world dataset. Our results showed that the size of the confidence intervals computed using our method decreased – i.e. our confidence in the registration of images from different individuals increased – for increasing amounts of blur in the images. Moreover, the size of the confidence intervals increased for increasing amounts of noise, misregistration, and differing anatomy. Thus, our method precisely quantified confidence in the registration of images that contain varying amounts of misregistration and varying anatomy across individuals. PMID:19138877

Reliability of the identification of the systemic inflammatory response syndrome in critically ill infants and children.

PubMed

Juskewitch, Justin E; Prasad, Swati; Salas, Carlos F Santillan; Huskins, W Charles

2012-01-01

To assess interobserver reliability of the identification of episodes of the systemic inflammatory response syndrome in critically ill hospitalized infants and children. Retrospective, cross-sectional study of the application of the 2005 consensus definition of systemic inflammatory response syndrome in infants and children by two independent, trained reviewers using information in the electronic medical record. Eighteen-bed pediatric multidisciplinary medical/surgical pediatric intensive care unit. A randomly selected sample of children admitted consecutively to the pediatric intensive care unit between May 1 and September 30, 2009. None. Sixty infants and children were selected from a total of 343 admitted patients. Their median age was 3.9 yrs (interquartile range, 1.5-12.7), 57% were female, and 68% were Caucasian. Nineteen (32%) children were identified by both reviewers as having an episode of systemic inflammatory response syndrome (88% agreement, 95% confidence interval 78-94; κ = 0.75, 95% confidence interval 0.59-0.92). Among these 19 children, agreement between the reviewers for individual systemic inflammatory response syndrome criteria was: temperature (84%, 95% confidence interval 60-97); white blood cell count (89%, 95% confidence interval 67-99); respiratory rate (84%, 95% confidence interval 60-97); and heart rate (68%, 95% confidence interval 33-87). Episodes of systemic inflammatory response syndrome in critically ill infants and children can be identified reproducibly using the consensus definition.

What was different about exposures reported by male Australian Gulf War veterans for the 1991 Persian Gulf War, compared with exposures reported for other deployments?

PubMed

Glass, Deborah C; Sim, Malcolm R; Kelsall, Helen L; Ikin, Jill F; McKenzie, Dean; Forbes, Andrew; Ittak, Peter

2006-07-01

This study identified chemical and environmental exposures specifically associated with the 1991 Persian Gulf War. Exposures were self-reported in a postal questionnaire, in the period of 2000-2002, by 1,424 Australian male Persian Gulf War veterans in relation to their 1991 Persian Gulf War deployment and by 625 Persian Gulf War veterans and 514 members of a military comparison group in relation to other active deployments. Six of 28 investigated exposures were experienced more frequently during the Persian Gulf War than during other deployments; these were exposure to smoke (odds ratio [OR], 4.4; 95% confidence interval, 3.0-6.6), exposure to dust (OR, 3.7; 95% confidence interval, 2.6-5.3), exposure to chemical warfare agents (OR, 3.9; 95% confidence interval, 2.1-7.9), use of respiratory protective equipment (OR, 13.6; 95% confidence interval, 7.6-26.8), use of nuclear, chemical, and biological protective suits (OR, 8.9; 95% confidence interval, 5.4-15.4), and entering/inspecting enemy equipment (OR, 3.1; 95% confidence interval, 2.1-4.8). Other chemical and environmental exposures were not specific to the Persian Gulf War deployment but were also reported in relation to other deployments. The number of exposures reported was related to service type and number of deployments but not to age or rank.

Statin therapy in lower limb peripheral arterial disease: Systematic review and meta-analysis.

PubMed

Antoniou, George A; Fisher, Robert K; Georgiadis, George S; Antoniou, Stavros A; Torella, Francesco

2014-11-01

To investigate and analyse the existing evidence supporting statin therapy in patients with lower limb atherosclerotic arterial disease. A systematic search of electronic information sources was undertaken to identify studies comparing cardiovascular outcomes in patients with lower limb peripheral arterial disease treated with a statin and those not receiving a statin. Estimates were combined applying fixed- or random-effects models. Twelve observational cohort studies and two randomised trials reporting 19,368 patients were selected. Statin therapy was associated with reduced all-cause mortality (odds ratio 0.60, 95% confidence interval 0.46-0.78) and incidence of stroke (odds ratio 0.77, 95% confidence interval 0.67-0.89). A trend towards improved cardiovascular mortality (odds ratio 0.62, 95% confidence interval 0.35-1.11), myocardial infarction (odds ratio 0.62, 95% confidence interval 0.38-1.01), and the composite of death/myocardial infarction/stroke (odds ratio 0.91, 95% confidence interval 0.81-1.03), was identified. Meta-analyses of studies performing adjustments showed decreased all-cause mortality in statin users (hazard ratio 0.77, 95% confidence interval 0.68-0.86). Evidence supporting statins' protective role in patients with lower limb peripheral arterial disease is insufficient. Statin therapy seems to be effective in reducing all-cause mortality and the incidence cerebrovascular events in patients diagnosed with peripheral arterial disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Developing appropriate methods for cost-effectiveness analysis of cluster randomized trials.

PubMed

Gomes, Manuel; Ng, Edmond S-W; Grieve, Richard; Nixon, Richard; Carpenter, James; Thompson, Simon G

2012-01-01

Cost-effectiveness analyses (CEAs) may use data from cluster randomized trials (CRTs), where the unit of randomization is the cluster, not the individual. However, most studies use analytical methods that ignore clustering. This article compares alternative statistical methods for accommodating clustering in CEAs of CRTs. Our simulation study compared the performance of statistical methods for CEAs of CRTs with 2 treatment arms. The study considered a method that ignored clustering--seemingly unrelated regression (SUR) without a robust standard error (SE)--and 4 methods that recognized clustering--SUR and generalized estimating equations (GEEs), both with robust SE, a "2-stage" nonparametric bootstrap (TSB) with shrinkage correction, and a multilevel model (MLM). The base case assumed CRTs with moderate numbers of balanced clusters (20 per arm) and normally distributed costs. Other scenarios included CRTs with few clusters, imbalanced cluster sizes, and skewed costs. Performance was reported as bias, root mean squared error (rMSE), and confidence interval (CI) coverage for estimating incremental net benefits (INBs). We also compared the methods in a case study. Each method reported low levels of bias. Without the robust SE, SUR gave poor CI coverage (base case: 0.89 v. nominal level: 0.95). The MLM and TSB performed well in each scenario (CI coverage, 0.92-0.95). With few clusters, the GEE and SUR (with robust SE) had coverage below 0.90. In the case study, the mean INBs were similar across all methods, but ignoring clustering underestimated statistical uncertainty and the value of further research. MLMs and the TSB are appropriate analytical methods for CEAs of CRTs with the characteristics described. SUR and GEE are not recommended for studies with few clusters.

Health insurance, alcohol and tobacco use among pregnant and non-pregnant women of reproductive age.

PubMed

Brown, Qiana L; Hasin, Deborah S; Keyes, Katherine M; Fink, David S; Ravenell, Orson; Martins, Silvia S

2016-09-01

Understanding the relationship between health insurance coverage and tobacco and alcohol use among reproductive age women can provide important insight into the role of access to care in preventing tobacco and alcohol use among pregnant women and women planning to become pregnant. We examined the association between health insurance coverage and both past month alcohol use and past month tobacco use in a nationally representative sample of women age 12-44 years old, by pregnancy status. The women (n=97,788) were participants in the National Survey of Drug Use and Health (NSDUH) in 2010-2013. Logistic regression models assessed the association between health insurance (insured versus uninsured), past month tobacco and alcohol use, and whether this was modified by pregnancy status. Pregnancy status significantly moderated the relationship between health insurance and tobacco use (p-value≤0.01) and alcohol use (p-value≤0.01). Among pregnant women, being insured was associated with lower odds of alcohol use (adjusted odds ratio [AOR]=0.47; 95% confidence interval [CI]=0.27-0.82), but not associated with tobacco use (AOR=1.14; 95% CI=0.73-1.76). Among non-pregnant women, being insured was associated with lower odds of tobacco use (AOR=0.67; 95% CI=0.63-0.72), but higher odds of alcohol use (AOR=1.23; 95% CI=1.15-1.32). Access to health care, via health insurance coverage is a promising method to help reduce alcohol use during pregnancy. However, despite health insurance coverage, tobacco use persists during pregnancy, suggesting missed opportunities for prevention during prenatal visits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of Health Insurance Interruption on Loss of Hypertension Control in Women With and Women Without HIV.

PubMed

Edmonds, Andrew; Ludema, Christina; Eron, Joseph J; Cole, Stephen R; Adedimeji, Adebola A; Cohen, Mardge H; Cooper, Hannah L; Fischl, Margaret; Johnson, Mallory O; Krause, Denise D; Merenstein, Dan; Milam, Joel; Wilson, Tracey E; Adimora, Adaora A

2017-12-01

Among low-income women with and without HIV, it is a priority to reduce age-related comorbidities, including hypertension and its sequelae. Because consistent health insurance access has been identified as an important factor in controlling many chronic diseases, we estimated the effects of coverage interruption on loss of hypertension control in a cohort of women in the United States. We analyzed prospective, longitudinal data from the Women's Interagency HIV Study. HIV-infected and HIV-uninfected women were included between 2005 and 2014 when they reported health insurance at consecutive biannual visits and had controlled hypertension, and were followed for any insurance break and loss of hypertension control. We estimated hazard ratios (HRs) by Cox proportional hazards regression with inverse-probability-of-treatment-and censoring weights (marginal structural models), and plotted the cumulative incidence of hypertension control loss. Among 890 HIV-infected women, the weighted HR for hypertension control loss comparing health insurance interruption to uninterrupted coverage was 1.37 (95% confidence interval [CI], 0.99-1.91). Inclusion of AIDS Drug Assistance Program (ADAP) participation with health insurance modestly increased the HR (1.47; 95% CI, 1.04-2.07). Analysis of 272 HIV-uninfected women yielded a similar HR (1.39; 95% CI, 0.88-2.21). Additionally, there were indications of uninterrupted coverage having a protective effect on hypertension when compared with the natural course in HIV-infected (HR, 0.82; 95% CI, 0.61-1.11) and HIV-uninfected (HR, 0.78; 95% CI, 0.52-1.19) women. This study provides evidence that health insurance continuity promotes hypertension control in key populations. Interventions that ensure coverage stability and ADAP access should be a policy priority.

[National survey of blindness and avoidable visual impairment in Argentina, 2013].

PubMed

Barrenechea, Rosario; de la Fuente, Inés; Plaza, Roberto Gustavo; Flores, Nadia; Segovia, Lía; Villagómez, Zaida; Camarero, Esteban Elián; Zepeda-Romero, Luz Consuelo; Lansingh, Van C; Limburg, Hans; Silva, Juan Carlos

2015-01-01

Determine the prevalence of blindness and avoidable visual impairment in Argentina, its causes, the coverage of cataract surgery, and the barriers that hinder access to these services. Cross-sectional population study conducted between May and November 2013 using the standard methodology for rapid assessment of avoidable blindness (RAAB), with a random cluster sampling of 50 people aged 50 years or more, -representative of the entire country. Participants' visual acuity (VA) was measured and the lens and posterior pole were examined by direct ophthalmoscopy. An assessment was made of the causes of having VA < 20/60, the coverage and quality of cataract surgery, and the barriers to accessing treatment. 3 770 people were assessed (92.0% of the projected number). The prevalence of blindness was 0.7% (confidence interval of 95%: 0.4-1.0%). Unoperated cataract was the main cause of blindness and severe visual impairment (44.0% and 71.1%, respectively), while the main cause of moderate visual impairment was uncorrected refractive errors (77.8%). Coverage of cataract surgery was of 97.1%, and 82.0% of operated eyes achieved VA ≥ 20/60. The main barriers to receiving this treatment were fear of the surgical procedure or of a poor result (34.9%), the cost (30.2%), and not having access to the treatment (16.3%). There is a low prevalence of blindness in the studied population and cataract is the main cause of blindness and severe visual impairment. Efforts should continue to extend coverage of cataract surgery, enhance preoperative evaluation, improve calculations of the intraocular lenses that patients need, and correct post-operative refractive errors with greater precision.

Assessment of Malawi's success in child mortality reduction through the lens of the Catalytic Initiative Integrated Health Systems Strengthening programme: Retrospective evaluation.

PubMed

Doherty, Tanya; Zembe, Wanga; Ngandu, Nobubelo; Kinney, Mary; Manda, Samuel; Besada, Donela; Jackson, Debra; Daniels, Karen; Rohde, Sarah; van Damme, Wim; Kerber, Kate; Daviaud, Emmanuelle; Rudan, Igor; Muniz, Maria; Oliphant, Nicholas P; Zamasiya, Texas; Rohde, Jon; Sanders, David

2015-12-01

Malawi is estimated to have achieved its Millennium Development Goal (MDG) 4 target. This paper explores factors influencing progress in child survival in Malawi including coverage of interventions and the role of key national policies. We performed a retrospective evaluation of the Catalytic Initiative (CI) programme of support (2007-2013). We developed estimates of child mortality using four population household surveys undertaken between 2000 and 2010. We recalculated coverage indicators for high impact child health interventions and documented child health programmes and policies. The Lives Saved Tool (LiST) was used to estimate child lives saved in 2013. The mortality rate in children under 5 years decreased rapidly in the 10 CI districts from 219 deaths per 1000 live births (95% confidence interval (CI) 189 to 249) in the period 1991-1995 to 119 deaths (95% CI 105 to 132) in the period 2006-2010. Coverage for all indicators except vitamin A supplementation increased in the 10 CI districts across the time period 2000 to 2013. The LiST analysis estimates that there were 10 800 child deaths averted in the 10 CI districts in 2013, primarily attributable to the introduction of the pneumococcal vaccine (24%) and increased household coverage of insecticide-treated bednets (19%). These improvements have taken place within a context of investment in child health policies and scale up of integrated community case management of childhood illnesses. Malawi provides a strong example for countries in sub-Saharan Africa of how high impact child health interventions implemented within a decentralised health system with an established community-based delivery platform, can lead to significant reductions in child mortality.

Neighborhood Deprivation and Childhood Asthma Outcomes, Accounting for Insurance Coverage.

PubMed

Nkoy, Flory L; Stone, Bryan L; Knighton, Andrew J; Fassl, Bernhard A; Johnson, Joseph M; Maloney, Christopher G; Savitz, Lucy A

2018-01-09

Collecting social determinants data is challenging. We assigned patients a neighborhood-level social determinant measure, the area of deprivation index (ADI), by using census data. We then assessed the association between neighborhood deprivation and asthma hospitalization outcomes and tested the influence of insurance coverage. A retrospective cohort study of children 2 to 17 years old admitted for asthma at 8 hospitals. An administrative database was used to collect patient data, including hospitalization outcomes and neighborhood deprivation status (ADI scores), which were grouped into quintiles (ADI 1, the least deprived neighborhoods; ADI 5, the most deprived neighborhoods). We used multivariable models, adjusting for covariates, to assess the associations and added a neighborhood deprivation status and insurance coverage interaction term. A total of 2270 children (median age 5 years; 40.6% girls) were admitted for asthma. We noted that higher ADI quintiles were associated with greater length of stay, higher cost, and more asthma readmissions ( P < .05 for most quintiles). Having public insurance was independently associated with greater length of stay (β: 1.171; 95% confidence interval [CI]: 1.117-1.228; P < .001), higher cost (β: 1.147; 95% CI: 1.093-1.203; P < .001), and higher readmission odds (odds ratio: 1.81; 95% CI: 1.46-2.24; P < .001). There was a significant deprivation-insurance effect modification, with public insurance associated with worse outcomes and private insurance with better outcomes across ADI quintiles ( P < .05 for most combinations). Neighborhood-level ADI measure is associated with asthma hospitalization outcomes. However, insurance coverage modifies this relationship and needs to be considered when using the ADI to identify and address health care disparities. Copyright © 2018 by the American Academy of Pediatrics.

A systematic review and meta-analysis of the effects of educating parents on the benefits and schedules of childhood vaccinations in low and middle-income countries.

PubMed

Lukusa, Lungeni Auguy; Ndze, Valantine Ngum; Mbeye, Nyanyiwe Masingi; Wiysonge, Charles Shey

2018-03-26

Public health benefits of childhood vaccinations risk being derailed by low vaccination coverage in low and middle-income countries. One reason for the low coverage is poor parental knowledge of the importance of completing vaccination schedules. We therefore assessed the effects on childhood vaccination coverage, of educating parents and other persons assuming the parental role. We prospectively registered the systematic review, published the protocol, and used standard Cochrane methods to collect and synthesise the evidence. We found six eligible randomised trials with 4248 participants. Three trials assessed health-facility based education of mothers on the importance of completing vaccination schedules; immediately after birth and three months later (one study) or during the first vaccination visit (two studies). The other trials assessed community-based education, including information campaigns on the importance of vaccines using audiotaped presentations and leaflet distributions (one study); structured group discussions on benefits and costs of childhood vaccination and local action plans for improving vaccine uptake (one study); and home-based information sessions using graphic cards showing benefits and costs of childhood vaccinations and location of vaccination centres (one study). Combining the data shows that these interventions lead to substantial improvements in childhood vaccination coverage (relative increase 36%, 95% confidence interval 14% to 62%). There was no difference between the effects of community-based and facility-based education. Therefore, education in communities and health facilities on the importance of childhood vaccinations should be integrated into all vaccination programmes in low and middle-income countries; accompanied by robust monitoring of impacts and use of data for action.

Phase Variation of NadA in Invasive Neisseria meningitidis Isolates Impacts on Coverage Estimates for 4C-MenB, a MenB vaccine.

PubMed

Green, Luke R; Lucidarme, Jay; Dave, Neelam; Chan, Hannah; Clark, Stephen; Borrow, Ray; Bayliss, Christopher D

2018-06-27

A recombinant NadA protein is one of the four major protective antigens of 4C-MenB (Bexsero®), a vaccine developed for serogroup B Neisseria meningitidis (MenB). The Meningococcal Antigen Typing System (MATS) is utilised as a high throughput assay for assessing the invasive MenB strain coverage of 4C-MenB. Where present, the nadA gene is subject to phase variable changes in transcription due to a 5'TAAA repeat tract located in a regulatory region. The promoter-containing intergenic region sequences (IGR) and 5'TAAA repeat numbers were determined for 906 invasive meningococcal disease isolates possessing the nadA gene. Exclusion of the 5'TAAA repeats reduced the number of IGR alleles from 82 to 23. Repeat numbers were associated with low and high levels of NadA expression by Western blotting and ELISA. Low expression repeat numbers were present in 83% of 179 MenB isolates with NadA-2/3 or Nad-1 peptide variants and 68% of 480 MenW ST-11 complex isolates with Nad-2/3 peptide variants. For isolates with vaccine-compatible NadA variants, 93% of MATS negative isolates were associated with low expression repeat numbers whereas 63% of isolates with MATS RP scores above the 95% confidence interval for the positive bactericidal threshold had high expression repeat numbers. Analysis of the 5'TAAA repeat number has potential as a rapid, high throughput method for assessing strain coverage for the NadA-component of 4C-MenB. A key application will be assessing coverage in meningococcal disease cases where confirmation is by PCR only and MATS cannot be applied. Copyright © 2018 Green et al.

Assessment of Malawi’s success in child mortality reduction through the lens of the Catalytic Initiative Integrated Health Systems Strengthening programme: Retrospective evaluation

PubMed Central

Doherty, Tanya; Zembe, Wanga; Ngandu, Nobubelo; Kinney, Mary; Manda, Samuel; Besada, Donela; Jackson, Debra; Daniels, Karen; Rohde, Sarah; van Damme, Wim; Kerber, Kate; Daviaud, Emmanuelle; Rudan, Igor; Muniz, Maria; Oliphant, Nicholas P; Zamasiya, Texas; Rohde, Jon; Sanders, David

2015-01-01

Background Malawi is estimated to have achieved its Millennium Development Goal (MDG) 4 target. This paper explores factors influencing progress in child survival in Malawi including coverage of interventions and the role of key national policies. Methods We performed a retrospective evaluation of the Catalytic Initiative (CI) programme of support (2007–2013). We developed estimates of child mortality using four population household surveys undertaken between 2000 and 2010. We recalculated coverage indicators for high impact child health interventions and documented child health programmes and policies. The Lives Saved Tool (LiST) was used to estimate child lives saved in 2013. Results The mortality rate in children under 5 years decreased rapidly in the 10 CI districts from 219 deaths per 1000 live births (95% confidence interval (CI) 189 to 249) in the period 1991–1995 to 119 deaths (95% CI 105 to 132) in the period 2006–2010. Coverage for all indicators except vitamin A supplementation increased in the 10 CI districts across the time period 2000 to 2013. The LiST analysis estimates that there were 10 800 child deaths averted in the 10 CI districts in 2013, primarily attributable to the introduction of the pneumococcal vaccine (24%) and increased household coverage of insecticide–treated bednets (19%). These improvements have taken place within a context of investment in child health policies and scale up of integrated community case management of childhood illnesses. Conclusions Malawi provides a strong example for countries in sub–Saharan Africa of how high impact child health interventions implemented within a decentralised health system with an established community–based delivery platform, can lead to significant reductions in child mortality. PMID:26649176

Adjusting for Confounding in Early Postlaunch Settings: Going Beyond Logistic Regression Models.

PubMed

Schmidt, Amand F; Klungel, Olaf H; Groenwold, Rolf H H

2016-01-01

Postlaunch data on medical treatments can be analyzed to explore adverse events or relative effectiveness in real-life settings. These analyses are often complicated by the number of potential confounders and the possibility of model misspecification. We conducted a simulation study to compare the performance of logistic regression, propensity score, disease risk score, and stabilized inverse probability weighting methods to adjust for confounding. Model misspecification was induced in the independent derivation dataset. We evaluated performance using relative bias confidence interval coverage of the true effect, among other metrics. At low events per coefficient (1.0 and 0.5), the logistic regression estimates had a large relative bias (greater than -100%). Bias of the disease risk score estimates was at most 13.48% and 18.83%. For the propensity score model, this was 8.74% and >100%, respectively. At events per coefficient of 1.0 and 0.5, inverse probability weighting frequently failed or reduced to a crude regression, resulting in biases of -8.49% and 24.55%. Coverage of logistic regression estimates became less than the nominal level at events per coefficient ≤5. For the disease risk score, inverse probability weighting, and propensity score, coverage became less than nominal at events per coefficient ≤2.5, ≤1.0, and ≤1.0, respectively. Bias of misspecified disease risk score models was 16.55%. In settings with low events/exposed subjects per coefficient, disease risk score methods can be useful alternatives to logistic regression models, especially when propensity score models cannot be used. Despite better performance of disease risk score methods than logistic regression and propensity score models in small events per coefficient settings, bias, and coverage still deviated from nominal.

The Effects of an Integrated Community Case Management Strategy on the Appropriate Treatment of Children and Child Mortality in Kono District, Sierra Leone: A Program Evaluation.

PubMed

Ratnayake, Ruwan; Ratto, Jeffrey; Hardy, Colleen; Blanton, Curtis; Miller, Laura; Choi, Mary; Kpaleyea, John; Momoh, Pheabean; Barbera, Yolanda

2017-09-01

Integrated community case management (iCCM) aims to reduce child mortality in areas with poor access to health care. iCCM was implemented in 2009 in Kono district, Sierra Leone, a postconflict area with high under-five mortality rates (U5MRs). We evaluated iCCM's impact and effects on child health using cluster surveys in 2010 (midterm) and 2013 (endline) to compare indicators on child mortality, coverage of appropriate treatment, timely access to care, quality of care, and recognition of community health workers (CHWs). The sample size was powered to detect a 28% decline in U5MR. Clusters were selected proportional to population size. All households were sampled to measure mortality and systematic random sampling was used to measure coverage in a subset of households. We used program data to evaluate utilization and access; 5,257 (2010) and 3,649 (2013) households were surveyed. U5MR did not change significantly (4.54 [95% confidence interval [CI]: 3.47-5.60] to 3.95 [95% CI: 3.06-4.83] deaths per 1,000 per month ( P = 0.4)) though a relative change smaller than 28% could not be detected. CHWs were the first source of care for 52% (2010) and 50.9% (2013) of children. Coverage of appropriate treatment of fever by CHWs or peripheral health units increased from 45.5% [95% CI: 39.2-52.0] to 58.2% [95% CI: 50.5-65.5] ( P = 0.01); changes for diarrhea and pneumonia were not significant. The continued reliance on the CHW as the first source of care and improved coverage for the appropriate treatment of fever support iCCM's role in Kono district.

Developing Appropriate Methods for Cost-Effectiveness Analysis of Cluster Randomized Trials

PubMed Central

Gomes, Manuel; Ng, Edmond S.-W.; Nixon, Richard; Carpenter, James; Thompson, Simon G.

2012-01-01

Aim. Cost-effectiveness analyses (CEAs) may use data from cluster randomized trials (CRTs), where the unit of randomization is the cluster, not the individual. However, most studies use analytical methods that ignore clustering. This article compares alternative statistical methods for accommodating clustering in CEAs of CRTs. Methods. Our simulation study compared the performance of statistical methods for CEAs of CRTs with 2 treatment arms. The study considered a method that ignored clustering—seemingly unrelated regression (SUR) without a robust standard error (SE)—and 4 methods that recognized clustering—SUR and generalized estimating equations (GEEs), both with robust SE, a “2-stage” nonparametric bootstrap (TSB) with shrinkage correction, and a multilevel model (MLM). The base case assumed CRTs with moderate numbers of balanced clusters (20 per arm) and normally distributed costs. Other scenarios included CRTs with few clusters, imbalanced cluster sizes, and skewed costs. Performance was reported as bias, root mean squared error (rMSE), and confidence interval (CI) coverage for estimating incremental net benefits (INBs). We also compared the methods in a case study. Results. Each method reported low levels of bias. Without the robust SE, SUR gave poor CI coverage (base case: 0.89 v. nominal level: 0.95). The MLM and TSB performed well in each scenario (CI coverage, 0.92–0.95). With few clusters, the GEE and SUR (with robust SE) had coverage below 0.90. In the case study, the mean INBs were similar across all methods, but ignoring clustering underestimated statistical uncertainty and the value of further research. Conclusions. MLMs and the TSB are appropriate analytical methods for CEAs of CRTs with the characteristics described. SUR and GEE are not recommended for studies with few clusters. PMID:22016450

Performance-based financing for improving HIV/AIDS service delivery: a systematic review.

PubMed

Suthar, Amitabh B; Nagata, Jason M; Nsanzimana, Sabin; Bärnighausen, Till; Negussie, Eyerusalem K; Doherty, Meg C

2017-01-04

Although domestic HIV/AIDS financing is increasing, international HIV/AIDS financing has plateaued. Providing incentives for the health system (i.e. performance-based financing [PBF]) may help countries achieve more with available resources. We systematically reviewed effects of PBF on HIV/AIDS service delivery to inform WHO guidelines. PubMed, WHO Index Medicus, conference databases, and clinical trial registries were searched in April 2015 for randomised trials, comparative contemporaneous studies, or time-series studies. Studies evaluating PBF in people with HIV were included when they reported service quality, access, or cost. Meta-analyses were not possible due to limited data. This study is registered with PROSPERO, number CRD42015023207. Four studies, published from 2009 to 2015 and including 173,262 people, met the eligibility criteria. All studies were from Sub-Saharan Africa. PBF did not improve individual testing coverage (relative risk [RR], 1.00, 95% confidence interval [CI] 0.89 to 1.13), improved couples testing coverage (RR 1.11, 95% CI 1.02 to 1.20), and improved pregnant women testing coverage (RR 1.29, 95% CI 1.28-1.30). PBF improved coverage of antiretrovirals in pregnant women (RR 1.55, 95% CI 1.50 to 1.59), infants (RR 1.92, 95% CI 1.84 to 2.01), and adults (RR 1.74, 1.64 to 1.85). PBF reduced attrition (RR 0.84, 95% CI 0.74 to 0.96) and treatment failure (odds ratio 0.55, 95% CI 0.32 to 0.97). Potential harms were not reported. Although the limited data suggests PBF positively affected HIV service access and quality, critical health system and governance knowledge gaps remain. More research is needed to inform national policymaking.

On the appropriateness of applying chi-square distribution based confidence intervals to spectral estimates of helicopter flyover data

NASA Technical Reports Server (NTRS)

Rutledge, Charles K.

1988-01-01

The validity of applying chi-square based confidence intervals to far-field acoustic flyover spectral estimates was investigated. Simulated data, using a Kendall series and experimental acoustic data from the NASA/McDonnell Douglas 500E acoustics test, were analyzed. Statistical significance tests to determine the equality of distributions of the simulated and experimental data relative to theoretical chi-square distributions were performed. Bias and uncertainty errors associated with the spectral estimates were easily identified from the data sets. A model relating the uncertainty and bias errors to the estimates resulted, which aided in determining the appropriateness of the chi-square distribution based confidence intervals. Such confidence intervals were appropriate for nontonally associated frequencies of the experimental data but were inappropriate for tonally associated estimate distributions. The appropriateness at the tonally associated frequencies was indicated by the presence of bias error and noncomformity of the distributions to the theoretical chi-square distribution. A technique for determining appropriate confidence intervals at the tonally associated frequencies was suggested.

Examples of measurement uncertainty evaluations in accordance with the revised GUM

NASA Astrophysics Data System (ADS)

Runje, B.; Horvatic, A.; Alar, V.; Medic, S.; Bosnjakovic, A.

2016-11-01

The paper presents examples of the evaluation of uncertainty components in accordance with the current and revised Guide to the expression of uncertainty in measurement (GUM). In accordance with the proposed revision of the GUM a Bayesian approach was conducted for both type A and type B evaluations.The law of propagation of uncertainty (LPU) and the law of propagation of distribution applied through the Monte Carlo method, (MCM) were used to evaluate associated standard uncertainties, expanded uncertainties and coverage intervals. Furthermore, the influence of the non-Gaussian dominant input quantity and asymmetric distribution of the output quantity y on the evaluation of measurement uncertainty was analyzed. In the case when the probabilistically coverage interval is not symmetric, the coverage interval for the probability P is estimated from the experimental probability density function using the Monte Carlo method. Key highlights of the proposed revision of the GUM were analyzed through a set of examples.

Magnitude and determinants of diabetic retinopathy among persons with diabetes registered at employee health department of a tertiary Eye Hospital of central Saudi Arabia

PubMed Central

Khandekar, Rajiv; Al Hassan, Arif; Al Dhibi, Hassan; Al Bahlal, Abdullah; Al-Futais, Muneera

2015-01-01

Background: To estimate the magnitude and determinants of diabetic retinopathy (DR) among persons with diabetes registered at the employee health department of King Khaled Eye Specialist Hospital (KKESH). Methods: A retrospective review of medical records was conducted in 2013–14 at KKESH. The case record review extracted demographic, profile of diabetes, diabetic complications, and different blood indices to determine the status of potential risk factors. Ocular profile, especially DR was also noted. Results: Our cohort had 94 staff with diabetes. Eye examination was carried out in 51 (54.8%) of them. The rate of DR was 52% (95% confidence interval (CI) 28–66). Sight-threatening diabetic retinopathy (STDR) (proliferative DR and/or diabetic macular edema) was present in 40% of those examined. Good glycemic control was noted in 42% of participants. Duration of diabetes was associated with DR (P = 0.04). Good glycemic control was negatively associated to DR (odds ratio = 0.2 [95% CI 0.04–0.6]). The coverage of eye screening was 55% only. Laser treatment was given to 80% of STDR cases. The lens opacity and glaucoma rate was 15% and 8.3%, respectively. Conclusions: Low coverage for eye screening and laser treatment to diabetics among the staff of an eye hospital is a matter of concern. The underlying causes of low coverage of screening, digital fundus photography as a screening tool and management should be addressed. PMID:26903721

Stigma as a barrier to treatment for child acute malnutrition in Marsabit County, Kenya.

PubMed

Bliss, Jessica Robin; Njenga, Martin; Stoltzfus, Rebecca Joyce; Pelletier, David Louis

2016-01-01

Acute malnutrition affects millions of children each year, yet global coverage of life-saving treatment through the community-based management of acute malnutrition (CMAM) is estimated to be below 15%. We investigated the potential role of stigma as a barrier to accessing CMAM. We surveyed caregivers bringing children to rural health facilities in Marsabit County, Kenya, divided into three strata based on the mid-upper arm circumference of the child: normal status (n = 327), moderate acute malnutrition (MAM, n = 241) and severe acute malnutrition (SAM, n = 143). We used multilevel mixed effects logistic regression to estimate the odds of reporting shame as a barrier to accessing health care. We found that the most common barriers to accessing child health care were those known to be universally problematic: women's time and labour constraints. These constituted the top five most frequently reported barriers regardless of child acute malnutrition status. In contrast, the odds of reporting shame as a barrier were 3.64 (confidence interval: 1.66-8.03, P < 0.05) times higher in caregivers of MAM and SAM children relative to those of normal children. We conclude that stigma is an under-recognized barrier to accessing CMAM and may constrain programme coverage. In light of the large gap in coverage of CMAM, there is an urgent need to understand the sources of acute malnutrition-associated stigma and adopt effective means of de-stigmatization. © 2015 John Wiley & Sons Ltd.

Magnitude and determinants of diabetic retinopathy among persons with diabetes registered at employee health department of a tertiary Eye Hospital of central Saudi Arabia.

PubMed

Khandekar, Rajiv; Al Hassan, Arif; Al Dhibi, Hassan; Al Bahlal, Abdullah; Al-Futais, Muneera

2015-01-01

To estimate the magnitude and determinants of diabetic retinopathy (DR) among persons with diabetes registered at the employee health department of King Khaled Eye Specialist Hospital (KKESH). A retrospective review of medical records was conducted in 2013-14 at KKESH. The case record review extracted demographic, profile of diabetes, diabetic complications, and different blood indices to determine the status of potential risk factors. Ocular profile, especially DR was also noted. Our cohort had 94 staff with diabetes. Eye examination was carried out in 51 (54.8%) of them. The rate of DR was 52% (95% confidence interval (CI) 28-66). Sight-threatening diabetic retinopathy (STDR) (proliferative DR and/or diabetic macular edema) was present in 40% of those examined. Good glycemic control was noted in 42% of participants. Duration of diabetes was associated with DR (P = 0.04). Good glycemic control was negatively associated to DR (odds ratio = 0.2 [95% CI 0.04-0.6]). The coverage of eye screening was 55% only. Laser treatment was given to 80% of STDR cases. The lens opacity and glaucoma rate was 15% and 8.3%, respectively. Low coverage for eye screening and laser treatment to diabetics among the staff of an eye hospital is a matter of concern. The underlying causes of low coverage of screening, digital fundus photography as a screening tool and management should be addressed.

A comparison of statistical methods for evaluating matching performance of a biometric identification device: a preliminary report

NASA Astrophysics Data System (ADS)

Schuckers, Michael E.; Hawley, Anne; Livingstone, Katie; Mramba, Nona

2004-08-01

Confidence intervals are an important way to assess and estimate a parameter. In the case of biometric identification devices, several approaches to confidence intervals for an error rate have been proposed. Here we evaluate six of these methods. To complete this evaluation, we simulate data from a wide variety of parameter values. This data are simulated via a correlated binary distribution. We then determine how well these methods do at what they say they do: capturing the parameter inside the confidence interval. In addition, the average widths of the various confidence intervals are recorded for each set of parameters. The complete results of this simulation are presented graphically for easy comparison. We conclude by making a recommendation regarding which method performs best.

Coverage, efficacy or dosing interval: which factor predominantly influences the impact of routine childhood vaccination for the prevention of varicella? A model-based study for Italy.

PubMed

Holl, Katsiaryna; Sauboin, Christophe; Amodio, Emanuele; Bonanni, Paolo; Gabutti, Giovanni

2016-10-21

Varicella is a highly infectious disease with a significant public health and economic burden, which can be prevented with childhood routine varicella vaccination. Vaccination strategies differ by country. Some factors are known to play an important role (number of doses, coverage, dosing interval, efficacy and catch-up programmes), however, their relative impact on the reduction of varicella in the population remains unclear. This paper aims to help policy makers prioritise the critical factors to achieve the most successful vaccination programme with the available budget. Scenarios assessed the impact of different vaccination strategies on reduction of varicella disease in the population. A dynamic transmission model was used and adapted to fit Italian demographics and population mixing patterns. Inputs included coverage, number of doses, dosing intervals, first-dose efficacy and availability of catch-up programmes, based on strategies currently used or likely to be used in different countries. The time horizon was 30 years. Both one- and two-dose routine varicella vaccination strategies prevented a comparable number of varicella cases with complications, but two-doses provided broader protection due to prevention of a higher number of milder varicella cases. A catch-up programme in susceptible adolescents aged 10-14 years old reduced varicella cases by 27-43 % in older children, which are often more severe than in younger children. Coverage, for all strategies, sustained at high levels achieved the largest reduction in varicella. In general, a 20 % increase in coverage resulted in a further 27-31 % reduction in varicella cases. When high coverage is reached, the impact of dosing interval and first-dose vaccine efficacy had a relatively lower impact on disease prevention in the population. Compared to the long (11 years) dosing interval, the short (5 months) and medium (5 years) interval schedules reduced varicella cases by a further 5-13 % and 2-5 %, respectively. Similarly, a 10 % increase in first-dose efficacy (from 65 to 75 % efficacy) prevented 2-5 % more varicella cases, suggesting it is the least influential factor when considering routine varicella vaccination. Vaccination strategies can be implemented differently in each country depending on their needs, infrastructure and healthcare budget. However, ensuring high coverage remains the critical success factor for significant prevention of varicella when introducing varicella vaccination in the national immunisation programme.

The web and public confidence in MMR vaccination in Italy.

PubMed

Aquino, Francesco; Donzelli, Gabriele; De Franco, Emanuela; Privitera, Gaetano; Lopalco, Pier Luigi; Carducci, Annalaura

2017-08-16

Measles, mumps and rubella (MMR) vaccination coverage in Italy has been decreasing starting from 2012 and, at the present, none of the Italian regions has achieved the goal of 95% coverage target. A decision of the Court of Justice of Rimini in March 2012 that awarded vaccine-injury compensation for a case of autism has been indicated as a probable trigger event leading to a reduction of vaccine confidence in Italy. The aim of the study was to explore the relationship between MMR vaccination coverage to online search trends and social network activity on the topic "autism and MMR vaccine", during the period 2010-2015. A significant inverse correlation was found between MMR vaccination coverage and Internet search activity, tweets and Facebook posts. New media might have played a role in spreading misinformation. Media monitoring could be useful to assess the level of vaccine hesitancy and to plan and target effective information campaigns. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expression of Proteins Involved in Epithelial-Mesenchymal Transition as Predictors of Metastasis and Survival in Breast Cancer Patients

DTIC Science & Technology

2013-11-01

Ptrend 0.78 0.62 0.75 Unconditional logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for risk of node...Ptrend 0.71 0.67 Unconditional logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for risk of high-grade tumors... logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for the associations between each of the seven SNPs and

Closed-form confidence intervals for functions of the normal mean and standard deviation.

PubMed

Donner, Allan; Zou, G Y

2012-08-01

Confidence interval methods for a normal mean and standard deviation are well known and simple to apply. However, the same cannot be said for important functions of these parameters. These functions include the normal distribution percentiles, the Bland-Altman limits of agreement, the coefficient of variation and Cohen's effect size. We present a simple approach to this problem by using variance estimates recovered from confidence limits computed for the mean and standard deviation separately. All resulting confidence intervals have closed forms. Simulation results demonstrate that this approach performs very well for limits of agreement, coefficients of variation and their differences.

Exposure to power frequency electric fields and the risk of childhood cancer in the UK

PubMed Central

Skinner, J; Mee, T J; Blackwell, R P; Maslanyj, M P; Simpson, J; Allen, S G; Day, N E

2002-01-01

The United Kingdom Childhood Cancer Study, a population-based case–control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0–14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure ⩾20 V m−1 to those in a reference category of exposure <10 V m−1, odds ratios of 1.31 (95% confidence interval 0.68–2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73–2.39) for total leukaemia, 2.12 (95% confidence interval 0.78–5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77–2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49–1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56–1.54) for total leukaemia, 1.43 (95% confidence interval 0.68–3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59–1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m−1 were close to unity for all disease categories, never differing significantly from one. British Journal of Cancer (2002) 87, 1257–1266. doi:10.1038/sj.bjc.6600602 www.bjcancer.com © 2002 Cancer Research UK PMID:12439715

A risk score for predicting coronary artery disease in women with angina pectoris and abnormal stress test finding.

PubMed

Lo, Monica Y; Bonthala, Nirupama; Holper, Elizabeth M; Banks, Kamakki; Murphy, Sabina A; McGuire, Darren K; de Lemos, James A; Khera, Amit

2013-03-15

Women with angina pectoris and abnormal stress test findings commonly have no epicardial coronary artery disease (CAD) at catheterization. The aim of the present study was to develop a risk score to predict obstructive CAD in such patients. Data were analyzed from 337 consecutive women with angina pectoris and abnormal stress test findings who underwent cardiac catheterization at our center from 2003 to 2007. Forward selection multivariate logistic regression analysis was used to identify the independent predictors of CAD, defined by ≥50% diameter stenosis in ≥1 epicardial coronary artery. The independent predictors included age ≥55 years (odds ratio 2.3, 95% confidence interval 1.3 to 4.0), body mass index <30 kg/m(2) (odds ratio 1.9, 95% confidence interval 1.1 to 3.1), smoking (odds ratio 2.6, 95% confidence interval 1.4 to 4.8), low high-density lipoprotein cholesterol (odds ratio 2.9, 95% confidence interval 1.5 to 5.5), family history of premature CAD (odds ratio 2.4, 95% confidence interval 1.0 to 5.7), lateral abnormality on stress imaging (odds ratio 2.8, 95% confidence interval 1.5 to 5.5), and exercise capacity <5 metabolic equivalents (odds ratio 2.4, 95% confidence interval 1.1 to 5.6). Assigning each variable 1 point summed to constitute a risk score, a graded association between the score and prevalent CAD (ptrend <0.001). The risk score demonstrated good discrimination with a cross-validated c-statistic of 0.745 (95% confidence interval 0.70 to 0.79), and an optimized cutpoint of a score of ≤2 included 62% of the subjects and had a negative predictive value of 80%. In conclusion, a simple clinical risk score of 7 characteristics can help differentiate those more or less likely to have CAD among women with angina pectoris and abnormal stress test findings. This tool, if validated, could help to guide testing strategies in women with angina pectoris. Copyright © 2013 Elsevier Inc. All rights reserved.

Influenza vaccination coverage and effectiveness in young children in Thailand, 2011–2013

PubMed Central

Kittikraisak, Wanitchaya; Suntarattiwong, Piyarat; Levy, Jens; Fernandez, Stefan; Dawood, Fatimah S; Olsen, Sonja J; Chotpitayasunondh, Tawee

2015-01-01

Background Since 2009, Thailand has recommended influenza vaccine for children aged 6 months through 2 years, but no estimates of influenza vaccine coverage or effectiveness are available for this target group. Methods During August 2011–May 2013, high-risk and healthy children aged ≤36 months were enrolled in a 2-year prospective cohort study. Parents were contacted weekly about acute respiratory illness (ARI) in their child. Ill children had combined nasal and throat swabs tested for influenza viruses by real-time reverse transcription–polymerase chain reaction. Influenza vaccination status was verified with vaccination cards. The Cox proportional hazards approach was used to estimate hazard ratios. Vaccine effectiveness (VE) was estimated as 100% x (1-hazard ratio). Results During 2011–2013, 968 children were enrolled (median age, 10·3 months); 948 (97·9%) had a vaccination record and were included. Of these, 394 (41·6%) had ≥1 medical conditions. Vaccination coverage for the 2011–2012 and 2012–2013 seasons was 29·3% (93/317) and 30·0% (197/656), respectively. In 2011–2012, there were 213 ARI episodes, of which 10 (4·6%) were influenza positive (2·3 per 1000 vaccinated and 3·8 per 1000 unvaccinated child-weeks). The VE was 55% (95% confidence interval [CI], −72, 88). In 2012–2013, there were 846 ARIs, of which 52 (6·2%) were influenza positive (1·8 per 1000 vaccinated and 4·5 per 1000 unvaccinated child-weeks). The VE was 64% (CI, 13%, 85%). Conclusion Influenza vaccination coverage among young children in Thailand was low, although vaccination was moderately effective. Continued efforts are needed to increase influenza vaccination coverage and evaluate VE among young children in Thailand. PMID:25557920

Influenza immunization among Canadian health care personnel: a cross-sectional study

PubMed Central

Buchan, Sarah A.; Kwong, Jeffrey C.

2016-01-01

Background: Influenza immunization coverage among Canadian health care personnel remains below national targets. Targeting this group is of particular importance given their elevated risk of influenza infection, role in transmission and influence on patients' immunization status. We examined influenza immunization coverage in health care personnel in Canada, reasons for not being immunized and the impact of "vaccinate-or-mask" influenza prevention policies. Methods: In this national cross-sectional study, we pooled data from the 2007 to 2014 cycles of the Canadian Community Health Survey and restricted it to respondents who reported a health care occupation. Using bootstrapped survey weights, we examined immunization coverage by occupation and by presence of vaccinate-or-mask policies, and reasons for not being immunized. We used modified Poisson regression to estimate the prevalence ratio (PR) of influenza immunization for health care occupations compared with the general working population. Results: For all survey cycles combined, 50% of 18 446 health care personnel reported receiving seasonal influenza immunization during the previous 12 months, although this varied by occupation type (range 4%-72%). Compared with the general working population, family physicians and general practitioners were most likely to be immunized (PR 3.15, 95% confidence interval [CI] 2.76-3.59), whereas chiropractors, midwives and practitioners of natural healing were least likely (PR 0.17, 95% CI 0.10-0.30). Among those who were not immunized, the most frequently cited reason was the belief that influenza immunization is unnecessary. Introduction of vaccinate-or-mask policies was associated with increased influenza immunization among health care personnel. Interpretation: Health care personnel are more likely to be immunized against influenza than the general working population, but coverage remains suboptimal overall, and we observed wide variation by occupation type. More efforts are needed to target specific health care occupations with low immunization coverage. PMID:27730112

Evaluation of the measles, mumps and rubella vaccination catch-up campaign in England in 2013.

PubMed

Simone, Benedetto; Balasegaram, Sooria; Gobin, Maya; Anderson, Charlotte; Charlett, André; Coole, Louise; Maguire, Helen; Nichols, Tom; Rawlings, Chas; Ramsay, Mary; Oliver, Isabel

2014-08-06

In January-March 2013 in England, confirmed measles cases increased in children aged 10-16 years. In April-September 2013, the National Health System and Public Health England launched a national measles-mumps-rubella (MMR) campaign based on data from Child Health Information Systems (CHIS) estimating that approximately 8% in this age group were unvaccinated. We estimated coverage at baseline, and, of those unvaccinated (target), the proportion vaccinated up to 20/08/2013 (mid-point) to inform further public health action. We selected a sample of 6644 children aged 10-16 years using multistage sampling from those reported unvaccinated in CHIS at baseline and validated their records against GP records. We adjusted the CHIS MMR vaccine coverage estimates correcting by the proportion of vaccinated children obtained through sample validation. We validated 5179/6644 (78%) of the sample records. Coverage at baseline was estimated as 94.7% (95% confidence intervals, CI: 93.5-96.0%), lower in London (86.9%, 95%CI: 83.0-90.9%) than outside (96.1%, 95%CI 95.5-96.8%). The campaign reached 10.8% (95%CI: 7.0-14.6%) of the target population, lower in London (7.1%, 95%CI: 4.9-9.3) than in the rest of England (11.4%, 95%CI: 7.0-15.9%). Coverage increased by 0.5% up to 95.3% (95% CI: 94.1-96.4%) but an estimated 210,000 10-16 year old children remained unvaccinated nationally. Baseline MMR coverage was higher than previously reported and was estimated to have reached the 95% campaign objective at midpoint. Eleven per cent of the target population were vaccinated during the campaign, and may be underestimated, especially in London. No further national campaigns are needed but targeted local vaccination activities should be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Household Size and the Decision to Purchase Health Insurance in Cambodia: Results of a Discrete-Choice Experiment with Scale Adjustment.

PubMed

Ozawa, Sachiko; Grewal, Simrun; Bridges, John F P

2016-04-01

Community-based health insurance (CBHI) schemes have been introduced in low- and middle-income countries to increase health service utilization and provide financial protection from high healthcare expenditures. We assess the impact of household size on decisions to enroll in CBHI and demonstrate how to correct for group disparity in scale (i.e. variance differences). A discrete choice experiment was conducted across five CBHI attributes. Preferences were elicited through forced-choice paired comparison choice tasks designed based on D-efficiency. Differences in preferences were examined between small (1-4 family members) and large (5-12 members) households using conditional logistic regression. Swait and Louviere test was used to identify and correct for differences in scale. One-hundred and sixty households were surveyed in Northwest Cambodia. Increased insurance premium was associated with disutility [odds ratio (OR) 0.61, p < 0.01], while significant increase in utility was noted for higher hospital fee coverage (OR 10.58, p < 0.01), greater coverage of travel and meal costs (OR 4.08, p < 0.01), and more frequent communication with the insurer (OR 1.33, p < 0.01). While the magnitude of preference for hospital fee coverage appeared larger for the large household group (OR 14.15) compared to the small household group (OR 8.58), differences in scale were observed (p < 0.05). After adjusting for scale (k, ratio of scale between large to small household groups = 1.227, 95 % confidence interval 1.002-1.515), preference differences by household size became negligible. Differences in stated preferences may be due to scale, or variance differences between groups, rather than true variations in preference. Coverage of hospital fees, travel and meal costs are given significant weight in CBHI enrollment decisions regardless of household size. Understanding how community members make decisions about health insurance can inform low- and middle-income countries' paths towards universal health coverage.

The Role of Short-Term Memory Capacity and Task Experience for Overconfidence in Judgment under Uncertainty

ERIC Educational Resources Information Center

Hansson, Patrik; Juslin, Peter; Winman, Anders

2008-01-01

Research with general knowledge items demonstrates extreme overconfidence when people estimate confidence intervals for unknown quantities, but close to zero overconfidence when the same intervals are assessed by probability judgment. In 3 experiments, the authors investigated if the overconfidence specific to confidence intervals derives from…

Confidence Intervals for Weighted Composite Scores under the Compound Binomial Error Model

ERIC Educational Resources Information Center

Kim, Kyung Yong; Lee, Won-Chan

2018-01-01

Reporting confidence intervals with test scores helps test users make important decisions about examinees by providing information about the precision of test scores. Although a variety of estimation procedures based on the binomial error model are available for computing intervals for test scores, these procedures assume that items are randomly…

Towards the estimation of effect measures in studies using respondent-driven sampling.

PubMed

Rotondi, Michael A

2014-06-01

Respondent-driven sampling (RDS) is an increasingly common sampling technique to recruit hidden populations. Statistical methods for RDS are not straightforward due to the correlation between individual outcomes and subject weighting; thus, analyses are typically limited to estimation of population proportions. This manuscript applies the method of variance estimates recovery (MOVER) to construct confidence intervals for effect measures such as risk difference (difference of proportions) or relative risk in studies using RDS. To illustrate the approach, MOVER is used to construct confidence intervals for differences in the prevalence of demographic characteristics between an RDS study and convenience study of injection drug users. MOVER is then applied to obtain a confidence interval for the relative risk between education levels and HIV seropositivity and current infection with syphilis, respectively. This approach provides a simple method to construct confidence intervals for effect measures in RDS studies. Since it only relies on a proportion and appropriate confidence limits, it can also be applied to previously published manuscripts.

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease: a meta-analysis.

PubMed

Tully, Phillip J; Cosh, Suzanne M

2013-12-01

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease patients remain unquantified. Systematic searching of Medline, Embase, SCOPUS and PsycINFO databases revealed 1025 unique citations. Aggregate generalized anxiety disorder prevalence (12 studies, N = 3485) was 10.94 per cent (95% confidence interval: 7.8-13.99) and 13.52 per cent (95% confidence interval: 8.39-18.66) employing Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (random effects). Lifetime generalized anxiety disorder prevalence was 25.80 per cent (95% confidence interval: 20.84-30.77). In seven studies, modest correlation was evident between generalized anxiety disorder and depression, Fisher's Z = .30 (95% confidence interval: .19-.42), suggesting that each psychiatric disorder is best conceptualized as contributing unique variance to coronary heart disease prognosis.

Autonomous motivation mediates the relation between goals for physical activity and physical activity behavior in adolescents.

PubMed

Duncan, Michael J; Eyre, Emma Lj; Bryant, Elizabeth; Seghers, Jan; Galbraith, Niall; Nevill, Alan M

2017-04-01

Overall, 544 children (mean age ± standard deviation = 14.2 ± .94 years) completed self-report measures of physical activity goal content, behavioral regulations, and physical activity behavior. Body mass index was determined from height and mass. The indirect effect of intrinsic goal content on physical activity was statistically significant via autonomous ( b = 162.27; 95% confidence interval [89.73, 244.70]), but not controlled motivation ( b = 5.30; 95% confidence interval [-39.05, 45.16]). The indirect effect of extrinsic goal content on physical activity was statistically significant via autonomous ( b = 106.25; 95% confidence interval [63.74, 159.13]) but not controlled motivation ( b = 17.28; 95% confidence interval [-31.76, 70.21]). Weight status did not alter these findings.

The impact of generic-only drug benefits on patients' use of inhaled corticosteroids in a Medicare population with asthma

PubMed Central

Fung, Vicki; Tager, Ira B; Brand, Richard; Newhouse, Joseph P; Hsu, John

2008-01-01

Background Patients face increasing insurance restrictions on prescription drugs, including generic-only coverage. There are no generic inhaled corticosteroids (ICS), which are a mainstay of asthma therapy, and patients pay the full price for these drugs under generic-only policies. We examined changes in ICS use following the introduction of generic-only coverage in a Medicare Advantage population from 2003–2004. Methods Subjects were age 65+, with asthma, prior ICS use, and no chronic obstructive pulmonary disorder (n = 1,802). In 2004, 74.0% switched from having a $30 brand-copayment plan to a generic-only coverage plan (restricted coverage); 26% had $15–25 brand copayments in 2003–2004 (unrestricted coverage). Using linear difference-in-difference models, we examined annual changes in ICS use (measured by days-of-supply dispensed). There was a lower-cost ICS available within the study setting and we also examined changes in drug choice (higher- vs. lower-cost ICS). In multivariable models we adjusted for socio-demographic, clinical, and asthma characteristics. Results In 2003 subjects had an average of 188 days of ICS supply. Restricted compared with unrestricted coverage was associated with reductions in ICS use from 2003–2004 (-15.5 days-of-supply, 95% confidence interval (CI): -25.0 to -6.0). Among patients using higher-cost ICS drugs in 2003 (n = 662), more restricted versus unrestricted coverage subjects switched to the lower-cost ICS in 2004 (39.8% vs. 10.3%). Restricted coverage was not associated with decreased ICS use (2003–2004) among patients who switched to the lower-cost ICS (18.7 days-of-supply, CI: -27.5 to 65.0), but was among patients who did not switch (-38.6 days-of-supply, CI: -57.0 to -20.3). In addition, restricted coverage was associated with decreases in ICS use among patients with both higher- and lower-risk asthma (-15.0 days-of-supply, CI: -41.4 to 11.44; and -15.6 days-of-supply, CI: -25.8 to -5.3, respectively). Conclusion In this elderly population, patients reduced their already low ICS use in response to losing drug coverage. Switching to the lower-cost ICS mitigated reductions in use among patients who previously used higher-cost drugs. Additional work is needed to assess barriers to switching ICS drugs and the clinical effects of these drug use changes. PMID:18638405

Factors influencing full immunization coverage among 12-23 months of age children in Ethiopia: evidence from the national demographic and health survey in 2011.

PubMed

Lakew, Yihunie; Bekele, Alemayhu; Biadgilign, Sibhatu

2015-07-30

Immunization remains one of the most important public health interventions to reduce child morbidity and mortality. The 2011 national demographic and health survey (DHS) indicated low full immunization coverage among children aged 12-23 months in Ethiopia. Factors contributing to the low coverage of immunization have been poorly understood. The aim of this study was to identify factors associated with full immunization coverage among children aged 12-23 months in Ethiopia. This study used the 2011 Ethiopian demographic and health survey data. The survey was cross sectional by design and used a multistage cluster sampling procedure. A total of 1,927 mothers with children of 12-23 months of age were extracted from the children's dataset. Mothers' self-reported data and observations of vaccination cards were used to determine vaccine coverage. An adjusted odds ratio (AOR) with 95% confidence intervals (CI) was used to outline the independent predictors. The prevalence of fully immunized children was 24.3%. Specific vaccination coverage for three doses of DPT, three doses of polio, measles and BCG were 36.5%, 44.3%, 55.7% and 66.3%, respectively. The multivariable analysis showed that sources of information from vaccination card [AOR 95% CI; 7.7 (5.95-10.06)], received postnatal check-up within two months after birth [AOR 95% CI; 1.8 (1.28-2.56)], women's awareness of community conversation program [AOR 95% CI; 1.9 (1.44-2.49)] and women in the rich wealth index [AOR 95% CI; 1.4 (1.06-1.94)] were the predictors of full immunization coverage. Women from Afar [AOR 95% CI; 0.07 (0.01-0.68)], Amhara [AOR 95% CI; 0.33 (0.13-0.81)], Oromiya [AOR 95% CI; 0.15 (0.06-0.37)], Somali [AOR 95% CI; 0.15 (0.04-0.55)] and Southern Nation and Nationalities People administrative regions [AOR 95% CI; 0.35 (0.14-0.87)] were less likely to fully vaccinate their children. The overall full immunization coverage in Ethiopia was considerably low as compared to the national target set (66%). Health service use and access to information on maternal and child health were found to predict full immunization coverage. Appropriate strategies should be devised to enhance health information and accessibility for full immunization coverage by addressing the variations among regions.

Assessing the Impact of Leveraging Traditional Leadership on Access to Sanitation in Rural Zambia.

PubMed

Tiwari, Amy; Russpatrick, Scott; Hoehne, Alexandra; Matimelo, Selma M; Mazimba, Sharon; Nkhata, Ilenga; Osbert, Nicolas; Soloka, Geoffrey; Winters, Anna; Winters, Benjamin; Larsen, David A

2017-11-01

Open defecation is practiced by more than one billion people throughout the world and leads to significant public health issues including infectious disease transmission and stunted growth in children. Zambia implemented community-led total sanitation (CLTS) as an intervention to eliminate open defecation in rural areas. To support CLTS and the attainment of open defecation free communities, chiefs were considered key agents of change and were empowered to drive CLTS and improve sanitation for their chiefdom. Chiefs were provided with data on access to sanitation in the chiefdom during chiefdom orientations prior to the initiation of CLTS within each community and encouraged to make goals of universal sanitation access within the community. Using a survival regression, we found that where chiefs were orientated and mobilized in CLTS, the probability that a village would achieve 100% coverage of adequate sanitation increased by 23% (hazard ratio = 1.263, 95% confidence interval = 1.080-1.478, P = 0.003). Using an interrupted time series, we found a 30% increase in the number of individuals with access to adequate sanitation following chiefdom orientations (95% confidence interval = 28.8-32.0%). The mobilization and support of chiefs greatly improved the uptake of CLTS, and empowering them with increased CLTS knowledge and authority of the program in their chiefdom allowed chiefs to closely monitor village sanitation progress and follow-up with their headmen/headwomen. These key agents of change are important facilitators of public health goals such as the elimination of open defecation in Zambia by 2020.

A multiscale Bayesian data integration approach for mapping air dose rates around the Fukushima Daiichi Nuclear Power Plant.

PubMed

Wainwright, Haruko M; Seki, Akiyuki; Chen, Jinsong; Saito, Kimiaki

2017-02-01

This paper presents a multiscale data integration method to estimate the spatial distribution of air dose rates in the regional scale around the Fukushima Daiichi Nuclear Power Plant. We integrate various types of datasets, such as ground-based walk and car surveys, and airborne surveys, all of which have different scales, resolutions, spatial coverage, and accuracy. This method is based on geostatistics to represent spatial heterogeneous structures, and also on Bayesian hierarchical models to integrate multiscale, multi-type datasets in a consistent manner. The Bayesian method allows us to quantify the uncertainty in the estimates, and to provide the confidence intervals that are critical for robust decision-making. Although this approach is primarily data-driven, it has great flexibility to include mechanistic models for representing radiation transport or other complex correlations. We demonstrate our approach using three types of datasets collected at the same time over Fukushima City in Japan: (1) coarse-resolution airborne surveys covering the entire area, (2) car surveys along major roads, and (3) walk surveys in multiple neighborhoods. Results show that the method can successfully integrate three types of datasets and create an integrated map (including the confidence intervals) of air dose rates over the domain in high resolution. Moreover, this study provides us with various insights into the characteristics of each dataset, as well as radiocaesium distribution. In particular, the urban areas show high heterogeneity in the contaminant distribution due to human activities as well as large discrepancy among different surveys due to such heterogeneity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Screening history of cervical cancers in Emilia-Romagna, Italy: defining priorities to improve cervical cancer screening.

PubMed

Rossi, Paolo Giorgi; Caroli, Stefania; Mancini, Silvia; de' Bianchi, Priscilla Sassoli; Finarelli, Alba C; Naldoni, Carlo; Bucchi, Lauro; Falcini, Fabio

2015-03-01

Most invasive cervical cancers in industrialized countries are due to the lack of Pap test coverage, very few are due to screening failures. This study aimed at quantifying the proportion of invasive cancers occurring in nonscreened or underscreened women and that in women with a previous negative screening, that is, screening failure, during the first two screening rounds (1996-2002) and in the following rounds (2003-2008) in the Emilia-Romagna region. All cases of invasive cancers registered in the regional cancer registry between 1996 and 2008 were classified according to screening history through a record linkage with the screening programme registry. The incidence significantly decreased from 11.6/100 000 to 8.7/100 000; this decrease is due to a reduction in squamous cell cancers (annual percentage change -6.2; confidence interval: -7.8, -4.6) and advanced cancers (annual percentage change -6.6; confidence interval: -8.8, -4.3), whereas adenocarcinomas and microinvasive cancers were essentially stable. The proportion of cancers among women not yet invited and among nonresponders decreased over the two periods, from 45.5 to 33.3%. In contrast, the proportion of women with a previous negative Pap test less than 5 years and 5 years or more before cancer incidence increased from 5.7 to 13.3% and from 0.3 to 5.5%, respectively. Although nonattendance of the screening programme remains the main barrier to cervical cancer control, the introduction of a more sensitive test, such as the human papillomavirus DNA test, could significantly reduce the burden of disease.

Ruling out Legionella in community-acquired pneumonia.

PubMed

Haubitz, Sebastian; Hitz, Fabienne; Graedel, Lena; Batschwaroff, Marcus; Wiemken, Timothy Lee; Peyrani, Paula; Ramirez, Julio A; Fux, Christoph Andreas; Mueller, Beat; Schuetz, Philipp

2014-10-01

Assessing the likelihood for Legionella sp. in community-acquired pneumonia is important because of differences in treatment regimens. Currently used antigen tests and culture have limited sensitivity with important time delays, making empirical broad-spectrum coverage necessary. Therefore, a score with 6 variables recently has been proposed. We sought to validate these parameters in an independent cohort. We analyzed adult patients with community-acquired pneumonia from a large multinational database (Community Acquired Pneumonia Organization) who were treated between 2001 and 2012 with more than 4 of the 6 prespecified clinical variables available. Association and discrimination were assessed using logistic regression analysis and area under the curve (AUC). Of 1939 included patients, the infectious cause was known in 594 (28.9%), including Streptococcus pneumoniae in 264 (13.6%) and Legionella sp. in 37 (1.9%). The proposed clinical predictors fever, cough, hyponatremia, lactate dehydrogenase, C-reactive protein, and platelet count were all associated or tended to be associated with Legionella cause. A logistic regression analysis including all these predictors showed excellent discrimination with an AUC of 0.91 (95% confidence interval, 0.87-0.94). The original dichotomized score showed good discrimination (AUC, 0.73; 95% confidence interval, 0.65-0.81) and a high negative predictive value of 99% for patients with less than 2 parameters present. With the use of a large independent patient sample from an international database, this analysis validates previously proposed clinical variables to accurately rule out Legionella sp., which may help to optimize initial empiric therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

The educational gradient of obesity increases among Swedish pregnant women: a register-based study.

PubMed

Bjermo, Helena; Lind, Simon; Rasmussen, Finn

2015-04-01

Overweight or obesity is detrimental during pregnancy. We studied time trends in the educational gradient of overweight and obesity among pregnant women. Differences in overweight and obesity by area of residence and country of birth were also examined. The study was based on the Swedish Medical Birth Register between 1992 and 2010 and included 1,569,173 singleton pregnancies. Weight and height were registered during the first visit at the antenatal-care clinic. Data on education, country of birth, and area of residence were derived from registers with national coverage. In 2008-2010, 32% of Swedish nulliparous pregnant women were overweight or obese. The relative risk of obesity among lower educated women compared to women with higher education increased from 1.91 (95% confidence interval: 1.85-1.97) in 1992-1995 to 2.09 (95% confidence interval: 2.05-2.14) in 2008-2010. There was an inverse linear relationship between risks of overweight or obesity, and population density and type of residence municipality. An excessive gestational weight gain according to the American Institute of Medicine was observed among 57-63% of the overweight or obese women, but there were small differences by education. Pregnant women born in Africa, Middle East or Latin America had higher risks of being overweight or obese compared to women born in Sweden. The prevalence of obesity as well as the social inequalities in obesity during pregnancy increased in Sweden between 1992 and 2010. Further understanding of social inequalities and geographical differentials in health behaviours of pregnant women is needed when planning public health interventions.

Parents' willingness to pay for biologic treatments in juvenile idiopathic arthritis.

PubMed

Burnett, Heather F; Ungar, Wendy J; Regier, Dean A; Feldman, Brian M; Miller, Fiona A

2014-12-01

Biologic therapies are considered the standard of care for children with the most severe forms of juvenile idiopathic arthritis (JIA). Inconsistent and inadequate drug coverage, however, prevents many children from receiving timely and equitable access to the best treatment. The objective of this study was to evaluate parents' willingness to pay (WTP) for biologic and nonbiologic disease-modifying antirheumatic drugs (DMARDs) used to treat JIA. Utility weights from a discrete choice experiment were used to estimate the WTP for treatment characteristics including child-reported pain, participation in daily activities, side effects, days missed from school, drug treatment, and cost. Conditional logit regression was used to estimate utilities for each attribute level, and expected compensating variation was used to estimate the WTP. Bootstrapping was used to generate 95% confidence intervals for all WTP estimates. Parents had the highest marginal WTP for improved participation in daily activities and pain relief followed by the elimination of side effects of treatment. Parents were willing to pay $2080 (95% confidence interval $698-$4065) more for biologic DMARDs than for nonbiologic DMARDs if the biologic DMARD was more effective. Parents' WTP indicates their preference for treatments that reduce pain and improve daily functioning without side effects by estimating the monetary equivalent of utility for drug treatments in JIA. In addition to evidence of safety and efficacy, assessments of parents' preferences provide a broader perspective to decision makers by helping them understand the aspects of drug treatments in JIA that are most valued by families. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Cost and lack of insurance coverage are prohibitive to having dental implants after resections for benign mandibular neoplasms.

PubMed

Peacock, Zachary S; Ji, Yisi D

2017-06-01

To assess how often patients receive dental implants after mandibular resection for benign neoplasms and to determine barriers to completion of functional reconstruction. This was a retrospective cohort study of patients who underwent resection for benign mandibular neoplasms between 2005 and 2014. Demographic variables included age, sex, and race. Outcome variables include rates of implant placement, implant restoration, and reasons for not having implants. Fisher's exact test and odds ratios were calculated. In all, 52 subjects (age 47.1 ± 19.2 years) were included. Twenty (38.6%) received dental implants. Race was associated with the likelihood of receiving implants (P = .0302). African Americans (1/11, 9.1%) were least likely compared to all other racial groups to have implants (odds ratio = 0.1158; P = .035; 95% confidence interval 0.013-0.989). Caucasians (17/35, 48.6%) were 4.41 times more likely to receive implants compared to all other races (odds ratio = 4.41; 95% confidence interval 1.073-18.093; P = .038). Of the 20 patients who received implants, 10 went on to have dental prostheses. The most common reason for not having implants was cost (37.5% overall), cited by 50% of black and 16.7% of white patients. Patients do not typically go on to dental reconstruction after mandibular resection, with cost as a major barrier. African Americans were least likely to complete full reconstruction. Copyright © 2016 Elsevier Inc. All rights reserved.

Guillain-Barré Syndrome During the 2009–2010 H1N1 Influenza Vaccination Campaign: Population-based Surveillance Among 45 Million Americans

PubMed Central

Wise, Matthew E.; Viray, Melissa; Sejvar, James J.; Lewis, Paige; Baughman, Andrew L.; Connor, Walter; Danila, Richard; Giambrone, Greg P.; Hale, Christa; Hogan, Brenna C.; Meek, James I.; Murphree, Rendi; Oh, John Y.; Reingold, Arthur; Tellman, Norisse; Conner, Susan M.; Singleton, James A.; Lu, Peng-Jun; DeStefano, Frank; Fridkin, Scott K.; Vellozzi, Claudia; Morgan, Oliver W.

2012-01-01

Because of widespread distribution of the influenza A (H1N1) 2009 monovalent vaccine (pH1N1 vaccine) and the prior association between Guillain-Barré syndrome (GBS) and the 1976 H1N1 influenza vaccine, enhanced surveillance was implemented to estimate the magnitude of any increased GBS risk following administration of pH1N1 vaccine. The authors conducted active, population-based surveillance for incident cases of GBS among 45 million persons residing at 10 Emerging Infections Program sites during October 2009–May 2010; GBS was defined according to published criteria. The authors determined medical and vaccine history for GBS cases through medical record review and patient interviews. The authors used vaccine coverage data to estimate person-time exposed and unexposed to pH1N1 vaccine and calculated age- and sex-adjusted rate ratios comparing GBS incidence in these groups, as well as age- and sex-adjusted numbers of excess GBS cases. The authors received 411 reports of confirmed or probable GBS. The rate of GBS immediately following pH1N1 vaccination was 57% higher than in person-time unexposed to vaccine (adjusted rate ratio = 1.57, 95% confidence interval: 1.02, 2.21), corresponding to 0.74 excess GBS cases per million pH1N1 vaccine doses (95% confidence interval: 0.04, 1.56). This excess risk was much smaller than that observed during the 1976 vaccine campaign and was comparable to some previous seasonal influenza vaccine risk assessments. PMID:22582209

Prolonged corrected QT interval is predictive of future stroke events even in subjects without ECG-diagnosed left ventricular hypertrophy.

PubMed

Ishikawa, Joji; Ishikawa, Shizukiyo; Kario, Kazuomi

2015-03-01

We attempted to evaluate whether subjects who exhibit prolonged corrected QT (QTc) interval (≥440 ms in men and ≥460 ms in women) on ECG, with and without ECG-diagnosed left ventricular hypertrophy (ECG-LVH; Cornell product, ≥244 mV×ms), are at increased risk of stroke. Among the 10 643 subjects, there were a total of 375 stroke events during the follow-up period (128.7±28.1 months; 114 142 person-years). The subjects with prolonged QTc interval (hazard ratio, 2.13; 95% confidence interval, 1.22-3.73) had an increased risk of stroke even after adjustment for ECG-LVH (hazard ratio, 1.71; 95% confidence interval, 1.22-2.40). When we stratified the subjects into those with neither a prolonged QTc interval nor ECG-LVH, those with a prolonged QTc interval but without ECG-LVH, and those with ECG-LVH, multivariate-adjusted Cox proportional hazards analysis demonstrated that the subjects with prolonged QTc intervals but not ECG-LVH (1.2% of all subjects; incidence, 10.7%; hazard ratio, 2.70, 95% confidence interval, 1.48-4.94) and those with ECG-LVH (incidence, 7.9%; hazard ratio, 1.83; 95% confidence interval, 1.31-2.57) had an increased risk of stroke events, compared with those with neither a prolonged QTc interval nor ECG-LVH. In conclusion, prolonged QTc interval was associated with stroke risk even among patients without ECG-LVH in the general population. © 2014 American Heart Association, Inc.

Calculating Confidence Intervals for Regional Economic Impacts of Recreastion by Bootstrapping Visitor Expenditures

Treesearch

Donald B.K. English

2000-01-01

In this paper I use bootstrap procedures to develop confidence intervals for estimates of total industrial output generated per thousand tourist visits. Mean expenditures from replicated visitor expenditure data included weights to correct for response bias. Impacts were estimated with IMPLAN. Ninety percent interval endpoints were 6 to 16 percent above or below the...

Cost-effectiveness of increasing cervical cancer screening coverage in the Middle East: An example from Lebanon.

PubMed

Sharma, Monisha; Seoud, Muhieddine; Kim, Jane J

2017-01-23

Most cervical cancer (CC) cases in Lebanon are detected at later stages and associated with high mortality. There is no national organized CC screening program so screening is opportunistic and limited to women who can pay out-of-pocket. Therefore, a small percentage of women receive repeated screenings while most are under-or never screened. We evaluated the cost-effectiveness of increasing screening coverage and extending intervals. We used an individual-based Monte Carlo model simulating HPV and CC natural history and screening. We calibrated the model to epidemiological data from Lebanon, including CC incidence and HPV type distribution. We evaluated cytology and HPV DNA screening for women aged 25-65years, varying coverage from 20 to 70% and frequency from 1 to 5years. At 20% coverage, annual cytologic screening reduced lifetime CC risk by 14% and had an incremental cost-effectiveness ratio of I$80,670/year of life saved (YLS), far exceeding Lebanon's gross domestic product (GDP) per capita (I$17,460), a commonly cited cost-effectiveness threshold. By comparison, increasing cytologic screening coverage to 50% and extending screening intervals to 3 and 5years provided greater CC reduction (26.1% and 21.4, respectively) at lower costs compared to 20% coverage with annual screening. Screening every 5years with HPV DNA testing at 50% coverage provided greater CC reductions than cytology at the same frequency (23.4%) and was cost-effective assuming a cost of I$18 per HPV test administered (I$12,210/YLS); HPV DNA testing every 4years at 50% coverage was also cost-effective at the same cost per test (I$16,340). Increasing coverage of annual cytology was not found to be cost-effective. Current practice of repeated cytology in a small percentage of women is inefficient. Increasing coverage to 50% with extended screening intervals provides greater health benefits at a reasonable cost and can more equitably distribute health gains. Novel HPV DNA strategies offer greater CC reductions and may be more cost-effective than cytology. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Study on the coverage of cervical and breast cancer screening among women aged 35-69 years and related impact of socioeconomic factors in China, 2013].

PubMed

Bao, H L; Wang, L H; Wang, L M; Fang, L W; Zhang, M; Zhao, Z P; Cong, S

2018-02-10

Objective: To estimate the cervical and breast cancer screening coverage and related factors among women aged 35-69 years who were in the National Cervical and Breast Screening Program, to provide evidence for improving cervical and breast cancer control and prevention strategy. Methods: Data used in this study were abstracted from the 2013 Chinese Chronic Diseases and Risk Factors Surveillance Program. A total of 66 130 women aged 35-64 years and 72 511 women aged 35-69 years were included for this study. Weighted prevalence, (with 95% confidence interval, CI ) was calculated for complex sampling design. Rao-Scott χ (2) method was used to compare the screening coverage among subgroups. A random intercept equation which involved the logit-link function, was fitted under the following five levels: provincial, county, township, village and individual. Fix effects of all explanatory variables were converted into OR with 95% CI . Results: In 2013, 26.7% (95% CI : 24.6%-28.9%) of the 35-64 year-old women reported that they ever had been screened for cervical cancer and 22.5% (95% CI : 20.4%-24.6%) of the 35-69 year-olds had ever undergone breast cancer screening. Lower coverage was observed among women residing in rural and central or western China than those in urban or eastern China ( P <0.000 1). The coverage among women aged 50 years or older was substantially lower than those aged 35-49 years. Those who were with low education level, unemployed, low household income and not covered by insurance, appeared fewer number on this cervical or breast cancer screening program ( P <0.000 1). Women living in rural and western China were having less chance of receiving the breast cancer screening ( P <0.05), but the difference was not statistically significant. Conclusion: It is essential to strengthen the community-based cervical and breast cancer screening programs, in order to increase the coverage. More attention should be paid to women aged 50 years or older, especially those socioeconomically disadvantaged ones.

Income-related inequality in health insurance coverage: analysis of China Health and Nutrition Survey of 2006 and 2009

PubMed Central

2012-01-01

Introduction China introduced the urban resident basic medical insurance (URBMI) in 2007 to cover children and urban unemployed adults, in addition to the new cooperative medical scheme (NCMS) for rural residents in 2003 and the basic health insurance scheme (BHIS) for urban employees in 1998. This study examined whether the overall income-related inequality in health insurance coverage improved during 2006 and 2009 in China. Methods The China Health and Nutrition Survey (CHNS) data of 2006 and 2009 were used to create the concentration curve and the concentration index. GEE logistic regression was used to model the health insurance coverage as dependent variable and household income per capita as independent variable, controlling for individuals' age, gender, marital status, educational attainment, employment status, year 2009 (Y2009), household size, retirement status, and geographic variations. The change in the income-related inequality in 2009 was estimated using the interaction term of income*Y2009. Results In 2006, 49.7% (4,712/9,476) respondents had health insurance: 13.4% with BHIS and 28.4% with NCMS. In 2009, 90.8% (8,964/9,863) had health insurance: 10.1% with URBMI, 18.3% with BHIS, and 57.6% with NCMS. The BHIS, URBMI, and NCMS programs had different patterns of population coverage over 10 income deciles. The concentration index was 0.15 in 2006 and 0.04 in 2009. The dominance test showed that the concentration curves were significantly different between 2006 and 2009 (p < 0.05). An income increase per capita by 10,000 RMB was associated with 25.5% more likely to have health insurance coverage (odds ratio = 1.255, 95% confidence interval: [1.130-1.393]). In 2009, there was significant improvement in the income-related inequality (p < 0.001). Discussions Comparing 2009 to 2006, the income inequality in health insurance coverage was largely corrected in China through rapid expansion of CHNS in rural areas and initiation of URBMI in urban areas. PMID:22891984

Changes in drug utilization during a gap in insurance coverage: an examination of the medicare Part D coverage gap.

PubMed

Polinski, Jennifer M; Shrank, William H; Huskamp, Haiden A; Glynn, Robert J; Liberman, Joshua N; Schneeweiss, Sebastian

2011-08-01

Nations are struggling to expand access to essential medications while curbing rising health and drug spending. While the US government's Medicare Part D drug insurance benefit expanded elderly citizens' access to drugs, it also includes a controversial period called the "coverage gap" during which beneficiaries are fully responsible for drug costs. We examined the impact of entering the coverage gap on drug discontinuation, switching to another drug for the same indication, and drug adherence. While increased discontinuation of and adherence to essential medications is a regrettable response, increased switching to less expensive but therapeutically interchangeable medications is a positive response to minimize costs. We followed 663,850 Medicare beneficiaries enrolled in Part D or retiree drug plans with prescription and health claims in 2006 and/or 2007 to determine who reached the gap spending threshold, n = 217,131 (33%). In multivariate Cox proportional hazards models, we compared drug discontinuation and switching rates in selected drug classes after reaching the threshold between all 1,993 who had no financial assistance during the coverage gap (exposed) versus 9,965 multivariate propensity score-matched comparators with financial assistance (unexposed). Multivariate logistic regressions compared drug adherence (≤ 80% versus >80% of days covered). Beneficiaries reached the gap spending threshold on average 222 d ±79. At the drug level, exposed beneficiaries were twice as likely to discontinue (hazard ratio [HR]  = 2.00, 95% confidence interval [CI] 1.64-2.43) but less likely to switch a drug (HR  = 0.60, 0.46-0.78) after reaching the threshold. Gap-exposed beneficiaries were slightly more likely to have reduced adherence (OR  = 1.07, 0.98-1.18). A lack of financial assistance after reaching the gap spending threshold was associated with a doubling in discontinuing essential medications but not switching drugs in 2006 and 2007. Blunt cost-containment features such as the coverage gap have an adverse impact on drug utilization that may conceivably affect health outcomes.

Impact of statin related media coverage on use of statins: interrupted time series analysis with UK primary care data.

PubMed

Matthews, Anthony; Herrett, Emily; Gasparrini, Antonio; Van Staa, Tjeerd; Goldacre, Ben; Smeeth, Liam; Bhaskaran, Krishnan

2016-06-28

 To quantify how a period of intense media coverage of controversy over the risk:benefit balance of statins affected their use.  Interrupted time series analysis of prospectively collected electronic data from primary care.  Clinical Practice Research Datalink (CPRD) in the United Kingdom.  Patients newly eligible for or currently taking statins for primary and secondary cardiovascular disease prevention in each month in January 2011-March 2015.  Adjusted odds ratios for starting/stopping taking statins after the media coverage (October 2013-March 2014).  There was no evidence that the period of high media coverage was associated with changes in statin initiation among patients with a high recorded risk score for cardiovascular disease (primary prevention) or a recent cardiovascular event (secondary prevention) (odds ratio 0.99 (95% confidence interval 0.87 to 1.13; P=0.92) and 1.04 (0.92 to 1.18; P=0.54), respectively), though there was a decrease in the overall proportion of patients with a recorded risk score. Patients already taking statins were more likely to stop taking them for both primary and secondary prevention after the high media coverage period (1.11 (1.05 to 1.18; P<0.001) and 1.12 (1.04 to 1.21; P=0.003), respectively). Stratified analyses showed that older patients and those with a longer continuous prescription were more likely to stop taking statins after the media coverage. In post hoc analyses, the increased rates of cessation were no longer observed after six months.  A period of intense public discussion over the risks:benefit balance of statins, covered widely in the media, was followed by a transient rise in the proportion of people who stopped taking statins. This research highlights the potential for widely covered health stories in the lay media to impact on healthcare related behaviour. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Does blood transfusion affect intermediate survival after coronary artery bypass surgery?

PubMed

Mikkola, R; Heikkinen, J; Lahtinen, J; Paone, R; Juvonen, T; Biancari, F

2013-01-01

The aim of this study was to investigate the impact of transfusion of blood products on intermediate outcome after coronary artery bypass surgery. Complete data on perioperative blood transfusion in patients undergoing coronary artery bypass surgery were available from 2001 patients who were operated at our institution. Transfusion of any blood product (relative risk = 1.678, 95% confidence interval = 1.087-2.590) was an independent predictor of all-cause mortality. The additive effect of each blood product on all-cause mortality (relative risk = 1.401, 95% confidence interval = 1.203-1.630) and cardiac mortality (relative risk = 1.553, 95% confidence interval = 1.273-1.895) was evident when the sum of each blood product was included in the regression models. However, when single blood products were included in the regression model, transfusion of fresh frozen plasma/Octaplas® was the only blood product associated with increased risk of all-cause mortality (relative risk = 1.692, 95% confidence interval = 1.222-2.344) and cardiac mortality (relative risk = 2.125, 95% confidence interval = 1.414-3.194). The effect of blood product transfusion was particularly evident during the first three postoperative months. Since follow-up was truncated at 3 months, transfusion of any blood product was a significant predictor of all-cause mortality (relative risk = 2.998, 95% confidence interval = 1.053-0.537). Analysis of patients who survived or had at least 3 months of potential follow-up showed that transfusion of any blood product was not associated with a significantly increased risk of intermediate all-cause mortality (relative risk = 1.430, 95% confidence interval = 0.880-2.323). Transfusion of any blood product is associated with a significant risk of all-cause and cardiac mortality after coronary artery bypass surgery. Such a risk seems to be limited to the early postoperative period and diminishes later on. Among blood products, perioperative use of fresh frozen plasma or Octaplas seems to be the main determinant of mortality.

Rapid Contour-based Segmentation for 18F-FDG PET Imaging of Lung Tumors by Using ITK-SNAP: Comparison to Expert-based Segmentation.

PubMed

Besson, Florent L; Henry, Théophraste; Meyer, Céline; Chevance, Virgile; Roblot, Victoire; Blanchet, Elise; Arnould, Victor; Grimon, Gilles; Chekroun, Malika; Mabille, Laurence; Parent, Florence; Seferian, Andrei; Bulifon, Sophie; Montani, David; Humbert, Marc; Chaumet-Riffaud, Philippe; Lebon, Vincent; Durand, Emmanuel

2018-04-03

Purpose To assess the performance of the ITK-SNAP software for fluorodeoxyglucose (FDG) positron emission tomography (PET) segmentation of complex-shaped lung tumors compared with an optimized, expert-based manual reference standard. Materials and Methods Seventy-six FDG PET images of thoracic lesions were retrospectively segmented by using ITK-SNAP software. Each tumor was manually segmented by six raters to generate an optimized reference standard by using the simultaneous truth and performance level estimate algorithm. Four raters segmented 76 FDG PET images of lung tumors twice by using ITK-SNAP active contour algorithm. Accuracy of ITK-SNAP procedure was assessed by using Dice coefficient and Hausdorff metric. Interrater and intrarater reliability were estimated by using intraclass correlation coefficients of output volumes. Finally, the ITK-SNAP procedure was compared with currently recommended PET tumor delineation methods on the basis of thresholding at 41% volume of interest (VOI; VOI 41 ) and 50% VOI (VOI 50 ) of the tumor's maximal metabolism intensity. Results Accuracy estimates for the ITK-SNAP procedure indicated a Dice coefficient of 0.83 (95% confidence interval: 0.77, 0.89) and a Hausdorff distance of 12.6 mm (95% confidence interval: 9.82, 15.32). Interrater reliability was an intraclass correlation coefficient of 0.94 (95% confidence interval: 0.91, 0.96). The intrarater reliabilities were intraclass correlation coefficients above 0.97. Finally, VOI 41 and VOI 50 accuracy metrics were as follows: Dice coefficient, 0.48 (95% confidence interval: 0.44, 0.51) and 0.34 (95% confidence interval: 0.30, 0.38), respectively, and Hausdorff distance, 25.6 mm (95% confidence interval: 21.7, 31.4) and 31.3 mm (95% confidence interval: 26.8, 38.4), respectively. Conclusion ITK-SNAP is accurate and reliable for active-contour-based segmentation of heterogeneous thoracic PET tumors. ITK-SNAP surpassed the recommended PET methods compared with ground truth manual segmentation. © RSNA, 2018.

Amnioinfusion for meconium-stained liquor in labour.

PubMed

Hofmeyr, G J

2000-01-01

Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. Eligibility and trial quality were assessed by one reviewer. Ten studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.47, 95% confidence interval 0.24 to 0. 90); and a trend to reduced caesarean section overall (relative risk 0.83, 95% confidence interval 0.69 to 1.00). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0. 12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Amnioinfusion for meconium-stained liquor in labour.

PubMed

Hofmeyr, G J

2002-01-01

Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However, it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. The Cochrane Pregnancy and Childbirth Group trials register (October 2001) and the Cochrane Controlled Trials Register (Issue 3, 2001) were searched. Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. Eligibility and trial quality were assessed by one reviewer. Twelve studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.65, 95% confidence interval 0.49 to 0.88); and reduced caesarean section overall (relative risk 0.82, 95% confidence interval 0.69 to 1.97). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0.12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Association between GFR Estimated by Multiple Methods at Dialysis Commencement and Patient Survival

PubMed Central

Wong, Muh Geot; Pollock, Carol A.; Cooper, Bruce A.; Branley, Pauline; Collins, John F.; Craig, Jonathan C.; Kesselhut, Joan; Luxton, Grant; Pilmore, Andrew; Harris, David C.

2014-01-01

Summary Background and objectives The Initiating Dialysis Early and Late study showed that planned early or late initiation of dialysis, based on the Cockcroft and Gault estimation of GFR, was associated with identical clinical outcomes. This study examined the association of all-cause mortality with estimated GFR at dialysis commencement, which was determined using multiple formulas. Design, setting, participants, & measurements Initiating Dialysis Early and Late trial participants were stratified into tertiles according to the estimated GFR measured by Cockcroft and Gault, Modification of Diet in Renal Disease, or Chronic Kidney Disease-Epidemiology Collaboration formula at dialysis commencement. Patient survival was determined using multivariable Cox proportional hazards model regression. Results Only Initiating Dialysis Early and Late trial participants who commenced on dialysis were included in this study (n=768). A total of 275 patients died during the study. After adjustment for age, sex, racial origin, body mass index, diabetes, and cardiovascular disease, no significant differences in survival were observed between estimated GFR tertiles determined by Cockcroft and Gault (lowest tertile adjusted hazard ratio, 1.11; 95% confidence interval, 0.82 to 1.49; middle tertile hazard ratio, 1.29; 95% confidence interval, 0.96 to 1.74; highest tertile reference), Modification of Diet in Renal Disease (lowest tertile hazard ratio, 0.88; 95% confidence interval, 0.63 to 1.24; middle tertile hazard ratio, 1.20; 95% confidence interval, 0.90 to 1.61; highest tertile reference), and Chronic Kidney Disease-Epidemiology Collaboration equations (lowest tertile hazard ratio, 0.93; 95% confidence interval, 0.67 to 1.27; middle tertile hazard ratio, 1.15; 95% confidence interval, 0.86 to 1.54; highest tertile reference). Conclusion Estimated GFR at dialysis commencement was not significantly associated with patient survival, regardless of the formula used. However, a clinically important association cannot be excluded, because observed confidence intervals were wide. PMID:24178976

A Two-Step Bayesian Approach for Propensity Score Analysis: Simulations and Case Study.

PubMed

Kaplan, David; Chen, Jianshen

2012-07-01

A two-step Bayesian propensity score approach is introduced that incorporates prior information in the propensity score equation and outcome equation without the problems associated with simultaneous Bayesian propensity score approaches. The corresponding variance estimators are also provided. The two-step Bayesian propensity score is provided for three methods of implementation: propensity score stratification, weighting, and optimal full matching. Three simulation studies and one case study are presented to elaborate the proposed two-step Bayesian propensity score approach. Results of the simulation studies reveal that greater precision in the propensity score equation yields better recovery of the frequentist-based treatment effect. A slight advantage is shown for the Bayesian approach in small samples. Results also reveal that greater precision around the wrong treatment effect can lead to seriously distorted results. However, greater precision around the correct treatment effect parameter yields quite good results, with slight improvement seen with greater precision in the propensity score equation. A comparison of coverage rates for the conventional frequentist approach and proposed Bayesian approach is also provided. The case study reveals that credible intervals are wider than frequentist confidence intervals when priors are non-informative.

VizieR Online Data Catalog: Fermi/GBM GRB time-resolved spectral catalog (Yu+, 2016)

NASA Astrophysics Data System (ADS)

Yu, H.-F.; Preece, R. D.; Greiner, J.; Bhat, P. N.; Bissaldi, E.; Briggs, M. S.; Cleveland, W. H.; Connaughton, V.; Goldstein, A.; von Kienlin; A.; Kouveliotou, C.; Mailyan, B.; Meegan, C. A.; Paciesas, W. S.; Rau, A.; Roberts, O. J.; Veres, P.; Wilson-Hodge, C.; Zhang, B.-B.; van Eerten, H. J.

2016-01-01

Time-resolved spectral analysis results of BEST models: for each spectrum GRB name using the Fermi GBM trigger designation, spectrum number within individual burst, start time Tstart and end time Tstop for the time bin, BEST model, best-fit parameters of the BEST model, value of CSTAT per degrees of freedom, 10keV-1MeV photon and energy flux are given. Ep evolutionary trends: for each burst GRB name, number of spectra with Ep, Spearman's Rank Correlation Coefficients between Ep_ and photon flux and 90%, 95%, and 99% confidence intervals, Spearman's Rank Correlation Coefficients between Ep and energy flux and 90%, 95%, and 99% confidence intervals, Spearman's Rank Correlation Coefficient between Ep and time and 90%, 95%, and 99% confidence intervals, trends as determined by computer for 90%, 95%, and 99% confidence intervals, trends as determined by human eyes are given. (2 data files).

Primary care practice and health professional determinants of immunisation coverage.

PubMed

Grant, Cameron C; Petousis-Harris, Helen; Turner, Nikki; Goodyear-Smith, Felicity; Kerse, Ngaire; Jones, Rhys; York, Deon; Desmond, Natalie; Stewart, Joanna

2011-08-01

To identify primary care factors associated with immunisation coverage. A survey during 2005-2006 of a random sample of New Zealand primary care practices, with over-sampling of practices serving indigenous children. An immunisation audit was conducted for children registered at each practice. Practice characteristics and the knowledge and attitudes of doctors, nurses and caregivers were measured. Practice immunisation coverage was defined as the percentage of registered children from 6 weeks to 23 months old at each practice who were fully immunised for age. Associations of practice, doctor, nurse and caregiver factors with practice immunisation coverage were determined using multiple regression analyses. One hundred and twenty-four (61%) of 205 eligible practices were recruited. A median (25th-75th centile) of 71% (57-77%) of registered children at each practice was fully immunised. In multivariate analyses, immunisation coverage was higher at practices with no staff shortages (median practice coverage 76% vs 67%, P = 0.004) and where doctors were confident in their immunisation knowledge (72% vs 67%, P= 0.005). Coverage was lower if the children's parents had received information antenatally, which discouraged immunisation (67% vs 73%, P = 0.008). Coverage decreased as socio-economic deprivation of the registered population increased (P < 0.001) and as the children's age (P = 0.001) and registration age (P = 0.02) increased. CONCLUSIONS Higher immunisation coverage is achieved by practices that establish an early relationship with the family and that are adequately resourced with stable and confident staff. Immunisation promotion should begin antenatally. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Family environment, hobbies and habits as psychosocial predictors of survival for surgically treated patients with breast cancer.

PubMed

Tominaga, K; Andow, J; Koyama, Y; Numao, S; Kurokawa, E; Ojima, M; Nagai, M

1998-01-01

Many psychosocial factors have been reported to influence the duration of survival of breast cancer patients. We have studied how family members, hobbies and habits of the patients may alter their psychosocial status. Female patients with surgically treated breast cancer diagnosed between 1986 and 1995 at the Tochigi Cancer Center Hospital, who provided information on the above-mentioned factors, were used. Their subsequent physical status was followed up in the outpatients clinic. The Cox regression model was used to evaluate the relationship between the results of the factors examined and the duration of the patients' survival, adjusting for the patients' age, stage of disease at diagnosis and curability, as judged by the physician in charge after the treatment. The following factors were revealed to be significant with regard to the survival of surgically treated breast cancer patients: being a widow (hazard ratio 3.29; 95% confidence interval 1.32-8.20), having a hobby (hazard ratio 0.43; 95% confidence interval 0.23-0.82), number of hobbies (hazard ratio 0.64; 95% confidence interval 0.41-1.00), number of female children (hazard ratio 0.64; 95% confidence interval 0.42-0.98), smoker (hazard ratio 2.08; 95% confidence interval 1.02-4.26) and alcohol consumption (hazard ratio 0.10; 95% confidence interval 0.01-0.72). These results suggest that psychosocial factors, including the family environment, where patients receive emotional support from their spouse and children, hobbies and the patients' habits, may influence the duration of survival in surgically treated breast cancer patients.

A new mathematical approach for the estimation of the AUC and its variability under different experimental designs in preclinical studies.

PubMed

Navarro-Fontestad, Carmen; González-Álvarez, Isabel; Fernández-Teruel, Carlos; Bermejo, Marival; Casabó, Vicente Germán

2012-01-01

The aim of the present work was to develop a new mathematical method for estimating the area under the curve (AUC) and its variability that could be applied in different preclinical experimental designs and amenable to be implemented in standard calculation worksheets. In order to assess the usefulness of the new approach, different experimental scenarios were studied and the results were compared with those obtained with commonly used software: WinNonlin® and Phoenix WinNonlin®. The results do not show statistical differences among the AUC values obtained by both procedures, but the new method appears to be a better estimator of the AUC standard error, measured as the coverage of 95% confidence interval. In this way, the new proposed method demonstrates to be as useful as WinNonlin® software when it was applicable. Copyright © 2011 John Wiley & Sons, Ltd.

Model selection bias and Freedman's paradox

USGS Publications Warehouse

Lukacs, P.M.; Burnham, K.P.; Anderson, D.R.

2010-01-01

In situations where limited knowledge of a system exists and the ratio of data points to variables is small, variable selection methods can often be misleading. Freedman (Am Stat 37:152-155, 1983) demonstrated how common it is to select completely unrelated variables as highly "significant" when the number of data points is similar in magnitude to the number of variables. A new type of model averaging estimator based on model selection with Akaike's AIC is used with linear regression to investigate the problems of likely inclusion of spurious effects and model selection bias, the bias introduced while using the data to select a single seemingly "best" model from a (often large) set of models employing many predictor variables. The new model averaging estimator helps reduce these problems and provides confidence interval coverage at the nominal level while traditional stepwise selection has poor inferential properties. ?? The Institute of Statistical Mathematics, Tokyo 2009.

Two proposed convergence criteria for Monte Carlo solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forster, R.A.; Pederson, S.P.; Booth, T.E.

1992-01-01

The central limit theorem (CLT) can be applied to a Monte Carlo solution if two requirements are satisfied: (1) The random variable has a finite mean and a finite variance; and (2) the number N of independent observations grows large. When these two conditions are satisfied, a confidence interval (CI) based on the normal distribution with a specified coverage probability can be formed. The first requirement is generally satisfied by the knowledge of the Monte Carlo tally being used. The Monte Carlo practitioner has a limited number of marginal methods to assess the fulfillment of the second requirement, such asmore » statistical error reduction proportional to 1/[radical]N with error magnitude guidelines. Two proposed methods are discussed in this paper to assist in deciding if N is large enough: estimating the relative variance of the variance (VOV) and examining the empirical history score probability density function (pdf).« less

Brief Report: Investigating Uncertainty in the Minimum Mortality Temperature: Methods and Application to 52 Spanish Cities.

PubMed

Tobías, Aurelio; Armstrong, Ben; Gasparrini, Antonio

2017-01-01

The minimum mortality temperature from J- or U-shaped curves varies across cities with different climates. This variation conveys information on adaptation, but ability to characterize is limited by the absence of a method to describe uncertainty in estimated minimum mortality temperatures. We propose an approximate parametric bootstrap estimator of confidence interval (CI) and standard error (SE) for the minimum mortality temperature from a temperature-mortality shape estimated by splines. The coverage of the estimated CIs was close to nominal value (95%) in the datasets simulated, although SEs were slightly high. Applying the method to 52 Spanish provincial capital cities showed larger minimum mortality temperatures in hotter cities, rising almost exactly at the same rate as annual mean temperature. The method proposed for computing CIs and SEs for minimums from spline curves allows comparing minimum mortality temperatures in different cities and investigating their associations with climate properly, allowing for estimation uncertainty.

Breast cancer survival in Canada and the USA: meta-analytic evidence of a Canadian advantage in low-income areas.

PubMed

Gorey, Kevin M

2009-12-01

This study tested the hypothesis that relatively poor Canadian women with breast cancer have a survival advantage over their counterparts in the USA. Seventy-eight independent retrospective cohort (incidence between 1984 and 2000, followed until 2006) outcomes were synthesized. Fixed effects meta-regression models compared women with breast cancer in low-income areas of Canada and the USA. Low-income Canadian women were advantaged on survival [rate ratio (RR) = 1.14; 95% confidence interval (CI) 1.13-1.15] and their advantage was even larger among women <65 years of age who are not yet eligible for Medicare coverage in the USA (RR = 1.21, 95% CI 1.18-1.24). Canadian advantages were also larger for node positive breast cancer, which may present with greater clinical and managerial discretion (RR = 1.40, 95% CI 1.30-1.50), and smaller when Hawaii, the state providing the most Canadian-like access, was the US comparator (RR = 1.12, 95% CI 1.01-1.20). More inclusive health care insurance coverage in Canada vs the USA, particularly among each country's relatively poor people, seems the most plausible explanation for such Canadian advantages. Provision of health care for all Americans would likely prevent countless early deaths, particularly among the relatively poor.

The Affordable Care Act, Insurance Coverage, and Health Care Utilization of Previously Incarcerated Young Men: 2008-2015.

PubMed

Winkelman, Tyler N A; Choi, HwaJung; Davis, Matthew M

2017-05-01

To estimate health insurance and health care utilization patterns among previously incarcerated men following implementation of the Affordable Care Act's (ACA's) Medicaid expansion and Marketplace plans in 2014. We performed serial cross-sectional analyses using data from the National Survey of Family Growth between 2008 and 2015. Our sample included men aged 18 to 44 years with (n = 3476) and without (n = 8702) a history of incarceration. Uninsurance declined significantly among previously incarcerated men after ACA implementation (-5.9 percentage points; 95% confidence interval [CI] = -11.5, -0.4), primarily because of an increase in private insurance (6.8 percentage points; 95% CI = 0.1, 13.3). Previously incarcerated men accounted for a large proportion of the remaining uninsured (38.6%) in 2014 to 2015. Following ACA implementation, previously incarcerated men continued to be significantly less likely to report a regular source of primary care and more likely to report emergency department use than were never-incarcerated peers. Health insurance coverage improved among previously incarcerated men following ACA implementation. However, these men account for a substantial proportion of the remaining uninsured. Previously incarcerated men continue to lack primary care and frequently utilize acute care services.

Adaptive pre-specification in randomized trials with and without pair-matching.

PubMed

Balzer, Laura B; van der Laan, Mark J; Petersen, Maya L

2016-11-10

In randomized trials, adjustment for measured covariates during the analysis can reduce variance and increase power. To avoid misleading inference, the analysis plan must be pre-specified. However, it is often unclear a priori which baseline covariates (if any) should be adjusted for in the analysis. Consider, for example, the Sustainable East Africa Research in Community Health (SEARCH) trial for HIV prevention and treatment. There are 16 matched pairs of communities and many potential adjustment variables, including region, HIV prevalence, male circumcision coverage, and measures of community-level viral load. In this paper, we propose a rigorous procedure to data-adaptively select the adjustment set, which maximizes the efficiency of the analysis. Specifically, we use cross-validation to select from a pre-specified library the candidate targeted maximum likelihood estimator (TMLE) that minimizes the estimated variance. For further gains in precision, we also propose a collaborative procedure for estimating the known exposure mechanism. Our small sample simulations demonstrate the promise of the methodology to maximize study power, while maintaining nominal confidence interval coverage. We show how our procedure can be tailored to the scientific question (intervention effect for the study sample vs. for the target population) and study design (pair-matched or not). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Joint modelling compared with two stage methods for analysing longitudinal data and prospective outcomes: A simulation study of childhood growth and BP.

PubMed

Sayers, A; Heron, J; Smith, Adac; Macdonald-Wallis, C; Gilthorpe, M S; Steele, F; Tilling, K

2017-02-01

There is a growing debate with regards to the appropriate methods of analysis of growth trajectories and their association with prospective dependent outcomes. Using the example of childhood growth and adult BP, we conducted an extensive simulation study to explore four two-stage and two joint modelling methods, and compared their bias and coverage in estimation of the (unconditional) association between birth length and later BP, and the association between growth rate and later BP (conditional on birth length). We show that the two-stage method of using multilevel models to estimate growth parameters and relating these to outcome gives unbiased estimates of the conditional associations between growth and outcome. Using simulations, we demonstrate that the simple methods resulted in bias in the presence of measurement error, as did the two-stage multilevel method when looking at the total (unconditional) association of birth length with outcome. The two joint modelling methods gave unbiased results, but using the re-inflated residuals led to undercoverage of the confidence intervals. We conclude that either joint modelling or the simpler two-stage multilevel approach can be used to estimate conditional associations between growth and later outcomes, but that only joint modelling is unbiased with nominal coverage for unconditional associations.

Taichi exercise for self-rated sleep quality in older people: a systematic review and meta-analysis.

PubMed

Du, Shizheng; Dong, Jianshu; Zhang, Heng; Jin, Shengji; Xu, Guihua; Liu, Zengxia; Chen, Lixia; Yin, Haiyan; Sun, Zhiling

2015-01-01

Self-reported sleep disorders are common in older adults, resulting in serious consequences. Non-pharmacological measures are important complementary interventions, among which Taichi exercise is a popular alternative. Some experiments have been performed; however, the effect of Taichi exercise in improving sleep quality in older people has yet to be validated by systematic review. Using systematic review and meta-analysis, this study aimed to examine the efficacy of Taichi exercise in promoting self-reported sleep quality in older adults. Systematic review and meta-analysis of randomized controlled studies. 4 English databases: Pubmed, Cochrane Library, Web of Science and CINAHL, and 4 Chinese databases: CBMdisc, CNKI, VIP, and Wanfang database were searched through December 2013. Two reviewers independently selected eligible trials, conducted critical appraisal of the methodological quality by using the quality appraisal criteria for randomized controlled studies recommended by Cochrane Handbook. A standardized data form was used to extract information. Meta-analysis was performed. Five randomized controlled studies met inclusion criteria. All suffered from some methodological flaws. The results of this study showed that Taichi has large beneficial effect on sleep quality in older people, as indicated by decreases in the global Pittsburgh Sleep Quality Index score [standardized mean difference=-0.87, 95% confidence intervals (95% confidence interval) (-1.25, -0.49)], as well as its sub-domains of subjective sleep quality [standardized mean difference=-0.83, 95% confidence interval (-1.08, -0.57)], sleep latency [standardized mean difference=-0.75, 95% confidence interval (-1.42, -0.07)], sleep duration [standardized mean difference=-0.55, 95% confidence interval (-0.90, -0.21)], habitual sleep efficiency [standardized mean difference=-0.49, 95% confidence interval (-0.74, -0.23)], sleep disturbance [standardized mean difference=-0.44, 95% confidence interval (-0.69, -0.19)], and daytime dysfunction [standardized mean difference=-0.34, 95% confidence interval (-0.59, -0.09)]. Daytime sleepiness improvement was also observed. Weak evidence shows that Taichi exercise has a beneficial effect in improving self-rated sleep quality for older adults, suggesting that Taichi could be an effective alternative and complementary approach to existing therapies for older people with sleep problems. More rigorous experimental studies are required. Copyright © 2014 Elsevier Ltd. All rights reserved.

Previous treatment, sputum-smear nonconversion, and suburban living: The risk factors of multidrug-resistant tuberculosis among Malaysians.

PubMed

Mohd Shariff, Noorsuzana; Shah, Shamsul Azhar; Kamaludin, Fadzilah

2016-03-01

The number of multidrug-resistant tuberculosis patients is increasing each year in many countries all around the globe. Malaysia has no exception in facing this burdensome health problem. We aimed to investigate the factors that contribute to the occurrence of multidrug-resistant tuberculosis among Malaysian tuberculosis patients. An unmatched case-control study was conducted among tuberculosis patients who received antituberculosis treatments from April 2013 until April 2014. Cases are those diagnosed as pulmonary tuberculosis patients clinically, radiologically, and/or bacteriologically, and who were confirmed to be resistant to both isoniazid and rifampicin through drug-sensitivity testing. On the other hand, pulmonary tuberculosis patients who were sensitive to all first-line antituberculosis drugs and were treated during the same time period served as controls. A total of 150 tuberculosis patients were studied, of which the susceptible cases were 120. Factors found to be significantly associated with the occurrence of multidrug-resistant tuberculosis are being Indian or Chinese (odds ratio 3.17, 95% confidence interval 1.04-9.68; and odds ratio 6.23, 95% confidence interval 2.24-17.35, respectively), unmarried (odds ratio 2.58, 95% confidence interval 1.09-6.09), living in suburban areas (odds ratio 2.58, 95% confidence interval 1.08-6.19), are noncompliant (odds ratio 4.50, 95% confidence interval 1.71-11.82), were treated previously (odds ratio 8.91, 95% confidence interval 3.66-21.67), and showed positive sputum smears at the 2nd (odds ratio 7.00, 95% confidence interval 2.46-19.89) and 6th months of treatment (odds ratio 17.96, 95% confidence interval 3.51-91.99). Living in suburban areas, positive sputum smears in the 2nd month of treatment, and was treated previously are factors that independently contribute to the occurrence of multidrug-resistant tuberculosis. Those with positive smears in the second month of treatment, have a history of previous treatment, and live in suburban areas are found to have a higher probability of becoming multidrug resistant. The results presented here may facilitate improvements in the screening and detection process of drug-resistant patients in Malaysia in the future. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Stapled versus handsewn methods for colorectal anastomosis surgery.

PubMed

Lustosa, S A; Matos, D; Atallah, A N; Castro, A A

2001-01-01

Randomized controlled trials comparing stapled with handsewn colorectal anastomosis have not shown either technique to be superior, perhaps because individual studies lacked statistical power. A systematic review, with pooled analysis of results, might provide a more definitive answer. To compare the safety and effectiveness of stapled and handsewn colorectal anastomosis. The following primary hypothesis was tested: the stapled technique is more effective because it decreases the level of complications. The RCT register of the Cochrane Review Group was searched for any trial or reference to a relevant trial (published, in-press, or in progress). All publications were sought through computerised searches of EMBASE, LILACS, MEDLINE, the Cochrane Controlled Clinical Trials Database, and through letters to industrial companies and authors. There were no limits upon language, date, or other criteria. All randomized clinical trials (RCTs) in which stapled and handsewn colorectal anastomosis were compared. Adult patients submitted electively to colorectal anastomosis. Endoluminal circular stapler and handsewn colorectal anastomosis. a) Mortality b) Overall Anastomotic Dehiscence c) Clinical Anastomotic Dehiscence d) Radiological Anastomotic Dehiscence e) Stricture f) Anastomotic Haemorrhage g) Reoperation h) Wound Infection i) Anastomosis Duration j) Hospital Stay. Data were independently extracted by the two reviewers (SASL, DM) and cross-checked. The methodological quality of each trial was assessed by the same two reviewers. Details of the randomization (generation and concealment), blinding, whether an intention-to-treat analysis was done, and the number of patients lost to follow-up were recorded. The results of each RCT were summarised on an intention-to-treat basis in 2 x 2 tables for each outcome. External validity was defined by characteristics of the participants, the interventions and the outcomes. The RCTs were stratified according to the level of colorectal anastomosis. The Risk Difference method (random effects model) and NNT for dichotomous outcomes measures and weighted mean difference for continuous outcomes measures, with the corresponding 95% confidence interval, were presented in this review. Statistical heterogeneity was evaluated by using funnel plot and chi-square testing. Of the 1233 patients enrolled ( in 9 trials), 622 were treated with stapled, and 611 with manual, suture. The following main results were obtained: a) Mortality: result based on 901 patients; Risk Difference - 0.6% Confidence Interval -2.8% to +1.6%. b) Overall Dehiscence: result based on 1233 patients; Risk Difference 0.2%, 95% Confidence Interval -5.0% to +5.3%. c) Clinical Anastomotic Dehiscence : result based on 1233 patients; Risk Difference -1.4%, 95% Confidence Interval -5.2 to +2.3%. d) Radiological Anastomotic Dehiscence : result based on 825 patients; Risk Difference 1.2%, 95% Confidence Interval -4.8% to +7.3%. e) Stricture: result based on 1042 patients; Risk Difference 4.6%, 95% Confidence Interval 1.2% to 8.1%. Number needed to treat 17, 95% confidence interval 12 to 31. f) Anastomotic Hemorrhage: result based on 662 patients; Risk Difference 2.7%, 95% Confidence Interval - 0.1% to +5.5%. g) Reoperation: result based on 544 patients; Risk Difference 3.9%, 95% Confidence Interval 0.3% to 7.4%. h) Wound Infection: result based on 567 patients; Risk Difference 1.0%, 95% Confidence Interval -2.2% to +4.3%. i) Anastomosis duration: result based on one study (159 patients); Weighted Mean Difference -7.6 minutes, 95% Confidence Interval -12.9 to -2.2 minutes. j) Hospital Stay: result based on one study (159 patients), Weighted Mean Difference 2.0 days, 95% Confidence Interval -3.27 to +7.2 days. The evidence found was insufficient to demonstrate any superiority of stapled over handsewn techniques in colorectal anastomosis, regardless of the level of anastomosis.

Etiological classifications of transient ischemic attacks: subtype classification by TOAST, CCS and ASCO--a pilot study.

PubMed

Amort, Margareth; Fluri, Felix; Weisskopf, Florian; Gensicke, Henrik; Bonati, Leo H; Lyrer, Philippe A; Engelter, Stefan T

2012-01-01

In patients with transient ischemic attacks (TIA), etiological classification systems are not well studied. The Trial of ORG 10172 in Acute Stroke Treatment (TOAST), the Causative Classification System (CCS), and the Atherosclerosis Small Vessel Disease Cardiac Source Other Cause (ASCO) classification may be useful to determine the underlying etiology. We aimed at testing the feasibility of each of the 3 systems. Furthermore, we studied and compared their prognostic usefulness. In a single-center TIA registry prospectively ascertained over 2 years, we applied 3 etiological classification systems. We compared the distribution of underlying etiologies, the rates of patients with determined versus undetermined etiology, and studied whether etiological subtyping distinguished TIA patients with versus without subsequent stroke or TIA within 3 months. The 3 systems were applicable in all 248 patients. A determined etiology with the highest level of causality was assigned similarly often with TOAST (35.9%), CCS (34.3%), and ASCO (38.7%). However, the frequency of undetermined causes differed significantly between the classification systems and was lowest for ASCO (TOAST: 46.4%; CCS: 37.5%; ASCO: 18.5%; p < 0.001). In TOAST, CCS, and ASCO, cardioembolism (19.4/14.5/18.5%) was the most common etiology, followed by atherosclerosis (11.7/12.9/14.5%). At 3 months, 33 patients (13.3%, 95% confidence interval 9.3-18.2%) had recurrent cerebral ischemic events. These were strokes in 13 patients (5.2%; 95% confidence interval 2.8-8.8%) and TIAs in 20 patients (8.1%, 95% confidence interval 5.0-12.2%). Patients with a determined etiology (high level of causality) had higher rates of subsequent strokes than those without a determined etiology [TOAST: 6.7% (95% confidence interval 2.5-14.1%) vs. 4.4% (95% confidence interval 1.8-8.9%); CSS: 9.3% (95% confidence interval 4.1-17.5%) vs. 3.1% (95% confidence interval 1.0-7.1%); ASCO: 9.4% (95% confidence interval 4.4-17.1%) vs. 2.6% (95% confidence interval 0.7-6.6%)]. However, this difference was only significant in the ASCO classification (p = 0.036). Using ASCO, there was neither an increase in risk of subsequent stroke among patients with incomplete diagnostic workup (at least one subtype scored 9) compared with patients with adequate workup (no subtype scored 9), nor among patients with multiple causes compared with patients with a single cause. In TIA patients, all etiological classification systems provided a similar distribution of underlying etiologies. The increase in stroke risk in TIA patients with determined versus undetermined etiology was most evident using the ASCO classification. Copyright © 2012 S. Karger AG, Basel.

Health service use in a population covered by the Estratégia de Saúde da Família (Family Health Strategy).

PubMed

Fernandes, Léia Cristiane L; Bertoldi, Andréa D; Barros, Aluísio J D

2009-08-01

To analyze health service use patterns in communities covered by the Estratégia de Saúde da Família (Family Health Strategy). Population-based cross-sectional study with a sample of 2,988 individuals, of all ages, living in areas covered by the Estratégia de Saúde da Família, in the city of Porto Alegre, Southern Brazil, between July and September 2003. Pre-coded questionnaires about demographic, socioeconomic and health information were applied to all residents of selected households. Prevalence ratios and 95% confidence intervals were calculated and chi-square tests were applied in the analyses. Poisson regression was used in the multivariable analysis to control for potential confounding factors. Females, persons aged 60 years or older, white, with better socioeconomic level, without health care plan coverage and with poor health self-perception were more likely to use the local family health unit. Regarding users of other health services, a similar pattern for sex, age and health self-perception was observed. However, greater use was found among people with better socioeconomic level and with health care plan coverage. Use of a local family health unit was greater among people from a lower socioeconomic level and without health care plan coverage, revealing the poorer individuals to be the priority of governmental actions. Model changes made to health care with the implementation of the Estratégia Saúde da Família tend to progressively improve the health conditions of the poorer population, with consequent reduction of health inequalities.

A Novel Evaluation of World No Tobacco Day in Latin America

PubMed Central

Althouse, Benjamin M; Allem, Jon-Patrick; Ford, Daniel E; Ribisl, Kurt M; Cohen, Joanna E

2012-01-01

Background World No Tobacco Day (WNTD), commemorated annually on May 31, aims to inform the public about tobacco harms. Because tobacco control surveillance is usually annualized, the effectiveness of WNTD remains unexplored into its 25th year. Objective To explore the potential of digital surveillance (infoveillance) to evaluate the impacts of WNTD on population awareness of and interest in cessation. Methods Health-related news stories and Internet search queries were aggregated to form a continuous and real-time data stream. We monitored daily news coverage of and Internet search queries for cessation in seven Latin American nations from 2006 to 2011. Results Cessation news coverage peaked around WNTD, typically increasing 71% (95% confidence interval [CI] 61–81), ranging from 61% in Mexico to 83% in Venezuela. Queries indicative of cessation interest peaked on WNTD, increasing 40% (95% CI 32–48), ranging from 24% in Colombia to 84% in Venezuela. A doubling in cessation news coverage was associated with approximately a 50% increase in cessation queries. To gain a practical perspective, we compared WNTD-related activity with New Year’s Day and several cigarette excise tax increases in Mexico. Cessation queries around WNTD were typically greater than New Year’s Day and approximated a 2.8% (95% CI –0.8 to 6.3) increase in cigarette excise taxes. Conclusions This novel evaluation suggests WNTD had a significant impact on popular awareness (media trends) and individual interest (query trends) in smoking cessation. Because WNTD is constantly evolving, our work is also a model for real-time surveillance and potential improvement in WNTD and similar initiatives. PMID:22634568

The high burden of cervical cancer in Fiji, 2004-07.

PubMed

Law, Irwin; Fong, James J; Buadromo, Eka M; Samuela, Josaia; Patel, Mahomed S; Garland, Suzanne M; Mulholland, E Kim; Russell, Fiona M

2013-05-01

There are few population-based data on the disease burden of cervical cancer from developing countries, especially South Pacific islands. This study aimed to determine the incidence and mortality associated with cervical cancer and the coverage of Papanicolaou (Pap) cervical cytology in 20- to 69-year-old women in Fiji from 2004 to 2007. National data on the incident cases of histologically confirmed cervical cancer and the associated deaths, and on Pap smear results were collected from all pathology laboratories, and cancer and death registries in Fiji from 2004 to 2007. There were 413 incident cases of cervical cancer and 215 related deaths during the study timeframe. The annualised incidence and mortality rates in 20- to 69-year-old Melanesian Fijian women, at 49.7 per 100?000 (95% confidence interval (CI): 43.7-56.4) and 32.3 per 100?000 (95% CI: 26.9-38.4) respectively, were significantly higher than among 20- to 69-year-old Indo-Fijian women at 35.2 per 100?000 (P<0.001, 95% CI: 29.5-41.7) and 19.8 per 100?000 (P=0.002, 95% CI: 15.1-25.5) respectively. Of 330 cases diagnosed between 2004 and 2006, 186 (56%) had died by 31 December 2006. Pap smear coverage for this period was 8.0% (95% CI: 7.9-8.1) of the target population. The incidence and mortality related to cervical cancer in Fiji is high, whereas Pap smear coverage is very low. Greater investment in alternative screening strategies and preventive measures should be integrated into a comprehensive, strategic cervical cancer control program in Fiji.

State Insurance Mandates and Multiple Birth Rates After In Vitro Fertilization.

PubMed

Provost, Meredith P; Thomas, Samantha M; Yeh, Jason S; Hurd, William W; Eaton, Jennifer L

2016-12-01

To examine the association between state-mandated insurance coverage for in vitro fertilization (IVF) and the incidence of multiple birth while controlling for differences in baseline patient characteristics. We conducted a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System from 2007 to 2011 to examine the association between state-mandated insurance coverage for IVF and the incidence of multiple birth while controlling for differences in baseline patient characteristics. Analyses were stratified according to patient age and day of embryo transfer (3 or 5). Of the 173,968 cycles included in the analysis, 45,011 (25.9%) were performed in mandated states and 128,957 (74.1%) in nonmandated states. The multiple birth rate was significantly lower in mandated states (29.0% compared with 32.8%, adjusted odds ratio [OR] 0.87, 99.95% confidence interval [CI] 0.80-0.94). After stratification, this association remained statistically significant only in women younger than 35 years old who underwent transfer on day 5 (33.1% compared with 38.6%, adjusted OR 0.81, 99.95% CI 0.71-0.92). Among women younger than 35 years with day 5 transfer, the elective single embryo transfer rate was significantly higher in mandated states (21.8% compared with 13.1%, adjusted OR 2.36, 99.95% CI 2.09-2.67). State-mandated insurance coverage for IVF is associated with decreased odds of multiple birth. This relationship is driven by increased use of elective single embryo transfer among young women undergoing day 5 transfer.

Improving equity in health care financing in China during the progression towards Universal Health Coverage.

PubMed

Chen, Mingsheng; Palmer, Andrew J; Si, Lei

2017-12-29

China is reforming the way it finances health care as it moves towards Universal Health Coverage (UHC) after the failure of market-oriented mechanisms for health care. Improving financing equity is a major policy goal of health care system during the progression towards universal coverage. We used progressivity analysis and dominance test to evaluate the financing channels of general taxation, pubic health insurance, and out-of-pocket (OOP) payments. In 2012 a survey of 8854 individuals in 3008 households recorded the socioeconomic and demographic status, and health care payments of those households. The overall Kakwani index (KI) of China's health care financing system is 0.0444. For general tax KI was -0.0241 (95% confidence interval (CI): -0.0315 to -0.0166). The indices for public health schemes (Urban Employee Basic Medical Insurance, Urban Resident's Basic Medical Insurance, New Rural Cooperative Medical Scheme) were respectively 0.1301 (95% CI: 0.1008 to 0.1594), -0.1737 (95% CI: -0.2166 to -0.1308), and -0.5598 (95% CI: -0.5830 to -0.5365); and for OOP payments KI was 0.0896 (95%CI: 0.0345 to 0.1447). OOP payments are still the dominant part of China's health care finance system. China's health care financing system is not really equitable. Reducing the proportion of indirect taxes would considerably improve health care financing equity. The flat-rate contribution mechanism is not recommended for use in public health insurance schemes, and more attention should be given to optimizing benefit packages during China's progression towards UHC.

Likelihood-based confidence intervals for estimating floods with given return periods

NASA Astrophysics Data System (ADS)

Martins, Eduardo Sávio P. R.; Clarke, Robin T.

1993-06-01

This paper discusses aspects of the calculation of likelihood-based confidence intervals for T-year floods, with particular reference to (1) the two-parameter gamma distribution; (2) the Gumbel distribution; (3) the two-parameter log-normal distribution, and other distributions related to the normal by Box-Cox transformations. Calculation of the confidence limits is straightforward using the Nelder-Mead algorithm with a constraint incorporated, although care is necessary to ensure convergence either of the Nelder-Mead algorithm, or of the Newton-Raphson calculation of maximum-likelihood estimates. Methods are illustrated using records from 18 gauging stations in the basin of the River Itajai-Acu, State of Santa Catarina, southern Brazil. A small and restricted simulation compared likelihood-based confidence limits with those given by use of the central limit theorem; for the same confidence probability, the confidence limits of the simulation were wider than those of the central limit theorem, which failed more frequently to contain the true quantile being estimated. The paper discusses possible applications of likelihood-based confidence intervals in other areas of hydrological analysis.

Performance of an Automated Versus a Manual Whole-Body Magnetic Resonance Imaging Workflow.

PubMed

Stocker, Daniel; Finkenstaedt, Tim; Kuehn, Bernd; Nanz, Daniel; Klarhoefer, Markus; Guggenberger, Roman; Andreisek, Gustav; Kiefer, Berthold; Reiner, Caecilia S

2018-04-24

The aim of this study was to evaluate the performance of an automated workflow for whole-body magnetic resonance imaging (WB-MRI), which reduces user interaction compared with the manual WB-MRI workflow. This prospective study was approved by the local ethics committee. Twenty patients underwent WB-MRI for myopathy evaluation on a 3 T MRI scanner. Ten patients (7 women; age, 52 ± 13 years; body weight, 69.9 ± 13.3 kg; height, 173 ± 9.3 cm; body mass index, 23.2 ± 3.0) were examined with a prototypical automated WB-MRI workflow, which automatically segments the whole body, and 10 patients (6 women; age, 35.9 ± 12.4 years; body weight, 72 ± 21 kg; height, 169.2 ± 10.4 cm; body mass index, 24.9 ± 5.6) with a manual scan. Overall image quality (IQ; 5-point scale: 5, excellent; 1, poor) and coverage of the study volume were assessed by 2 readers for each sequence (coronal T2-weighted turbo inversion recovery magnitude [TIRM] and axial contrast-enhanced T1-weighted [ce-T1w] gradient dual-echo sequence). Interreader agreement was evaluated with intraclass correlation coefficients. Examination time, number of user interactions, and MR technicians' acceptance rating (1, highest; 10, lowest) was compared between both groups. Total examination time was significantly shorter for automated WB-MRI workflow versus manual WB-MRI workflow (30.0 ± 4.2 vs 41.5 ± 3.4 minutes, P < 0.0001) with significantly shorter planning time (2.5 ± 0.8 vs 14.0 ± 7.0 minutes, P < 0.0001). Planning took 8% of the total examination time with automated versus 34% with manual WB-MRI workflow (P < 0.0001). The number of user interactions with automated WB-MRI workflow was significantly lower compared with manual WB-MRI workflow (10.2 ± 4.4 vs 48.2 ± 17.2, P < 0.0001). Planning efforts were rated significantly lower by the MR technicians for the automated WB-MRI workflow than for the manual WB-MRI workflow (2.20 ± 0.92 vs 4.80 ± 2.39, respectively; P = 0.005). Overall IQ was similar between automated and manual WB-MRI workflow (TIRM: 4.00 ± 0.94 vs 3.45 ± 1.19, P = 0.264; ce-T1w: 4.20 ± 0.88 vs 4.55 ± .55, P = 0.423). Interreader agreement for overall IQ was excellent for TIRM and ce-T1w with an intraclass correlation coefficient of 0.95 (95% confidence interval, 0.86-0.98) and 0.88 (95% confidence interval, 0.70-0.95). Incomplete coverage of the thoracic compartment in the ce-T1w sequence occurred more often in the automated WB-MRI workflow (P = 0.008) for reader 2. No other significant differences in the study volume coverage were found. In conclusion, the automated WB-MRI scanner workflow showed a significant reduction of the examination time and the user interaction compared with the manual WB-MRI workflow. Image quality and the coverage of the study volume were comparable in both groups.

Estimating equivalence with quantile regression

USGS Publications Warehouse

Cade, B.S.

2011-01-01

Equivalence testing and corresponding confidence interval estimates are used to provide more enlightened statistical statements about parameter estimates by relating them to intervals of effect sizes deemed to be of scientific or practical importance rather than just to an effect size of zero. Equivalence tests and confidence interval estimates are based on a null hypothesis that a parameter estimate is either outside (inequivalence hypothesis) or inside (equivalence hypothesis) an equivalence region, depending on the question of interest and assignment of risk. The former approach, often referred to as bioequivalence testing, is often used in regulatory settings because it reverses the burden of proof compared to a standard test of significance, following a precautionary principle for environmental protection. Unfortunately, many applications of equivalence testing focus on establishing average equivalence by estimating differences in means of distributions that do not have homogeneous variances. I discuss how to compare equivalence across quantiles of distributions using confidence intervals on quantile regression estimates that detect differences in heterogeneous distributions missed by focusing on means. I used one-tailed confidence intervals based on inequivalence hypotheses in a two-group treatment-control design for estimating bioequivalence of arsenic concentrations in soils at an old ammunition testing site and bioequivalence of vegetation biomass at a reclaimed mining site. Two-tailed confidence intervals based both on inequivalence and equivalence hypotheses were used to examine quantile equivalence for negligible trends over time for a continuous exponential model of amphibian abundance. ?? 2011 by the Ecological Society of America.

Broad- versus Narrow-Spectrum Oral Antibiotic Transition and Outcomes in Health Care-associated Pneumonia.

PubMed

Buckel, Whitney R; Stenehjem, Edward; Sorensen, Jeff; Dean, Nathan; Webb, Brandon

2017-02-01

Guidelines recommend a switch from intravenous to oral antibiotics once patients who are hospitalized with pneumonia achieve clinical stability. However, little evidence guides the selection of an oral antibiotic for patients with health care-associated pneumonia, especially where no microbiological diagnosis is made. To compare outcomes between patients who were transitioned to broad- versus narrow-spectrum oral antibiotics after initially receiving broad-spectrum intravenous antibiotic coverage. We performed a secondary analysis of an existing database of adults with community-onset pneumonia admitted to seven Utah hospitals. We identified 220 inpatients with microbiology-negative health care-associated pneumonia from 2010 to 2012. After excluding inpatient deaths and treatment failures, 173 patients remained in which broad-spectrum intravenous antibiotics were transitioned to an oral regimen. We classified oral regimens as broad-spectrum (fluoroquinolone) versus narrow-spectrum (usually a β-lactam). We compared demographic and clinical characteristics between groups. Using a multivariable regression model, we adjusted outcomes by severity (electronically calculated CURB-65), comorbidity (Charlson Index), time to clinical stability, and length of intravenous therapy. Age, severity, comorbidity, length of intravenous therapy, and clinical response were similar between the two groups. Observed 30-day readmission (11.9 vs. 21.4%; P = 0.26) and 30-day all-cause mortality (2.3 vs. 5.3%; P = 0.68) were also similar between the narrow and broad oral antibiotic groups. In multivariable analysis, we found no statistically significant differences for adjusted odds of 30-day readmission (adjusted odds ratio, 0.56; 95% confidence interval, 0.06-5.2; P = 0.61) or 30-day all-cause mortality (adjusted odds ratio, 0.55; 95% confidence interval, 0.19-1.6; P = 0.26) between narrow and broad oral antibiotic groups. On the basis of analysis of a limited number of patients observed retrospectively, our findings suggest that it may be safe to switch from broad-spectrum intravenous antibiotic coverage to a narrow-spectrum oral antibiotic once clinical stability is achieved for hospitalized patients with health care-associated pneumonia when no microbiological diagnosis is made. A larger retrospective study with propensity matching or regression-adjusted test of equivalence or ideally a prospective comparative effectiveness study will be necessary to confirm our observations.

Fasting glucose levels, incident diabetes, subclinical atherosclerosis and cardiovascular events in apparently healthy adults: A 12-year longitudinal study.

PubMed

Sitnik, Debora; Santos, Itamar S; Goulart, Alessandra C; Staniak, Henrique L; Manson, JoAnn E; Lotufo, Paulo A; Bensenor, Isabela M

2016-11-01

We aimed to study the association between fasting plasma glucose, diabetes incidence and cardiovascular burden after 10-12 years. We evaluated diabetes and cardiovascular events incidences, carotid intima-media thickness and coronary artery calcium scores in ELSA-Brasil (the Brazilian Longitudinal Study of Adult Health) baseline (2008-2010) of 1536 adults without diabetes in 1998. We used regression models to estimate association with carotid intima-media thickness (in mm), coronary artery calcium scores (in Agatston points) and cardiovascular events according to fasting plasma glucose in 1998. Adjusted diabetes incidence rate was 9.8/1000 person-years (95% confidence interval: 7.7-13.6/1000 person-years). Incident diabetes was positively associated with higher fasting plasma glucose. Fasting plasma glucose levels 110-125 mg/dL were associated with higher carotid intima-media thickness (β = 0.028; 95% confidence interval: 0.003-0.053). Excluding those with incident diabetes, there was a borderline association between higher carotid intima-media thickness and fasting plasma glucose 110-125 mg/dL (β = 0.030; 95% confidence interval: -0.005 to 0.065). Incident diabetes was associated with higher carotid intima-media thickness (β = 0.034; 95% confidence interval: 0.015-0.053), coronary artery calcium scores ⩾400 (odds ratio = 2.84; 95% confidence interval: 1.17-6.91) and the combined outcome of a coronary artery calcium scores ⩾400 or incident cardiovascular event (odds ratio = 3.50; 95% confidence interval: 1.60-7.65). In conclusion, fasting plasma glucose in 1998 and incident diabetes were associated with higher cardiovascular burden. © The Author(s) 2016.

Prevalence of infections among residents of Residential Care Homes for the Elderly in Hong Kong.

PubMed

Choy, C Sm; Chen, H; Yau, C Sw; Hsu, E K; Chik, N Y; Wong, A Ty

2016-08-01

A point prevalence study was conducted to study the epidemiology of common infections among residents in Residential Care Homes for the Elderly in Hong Kong and their associated factors. Residential Care Homes for the Elderly in Hong Kong were selected by stratified single-stage cluster random sampling. All residents aged 65 years or above from the recruited homes were surveyed. Infections were identified using standardised definitions. Demographic and health information-including medical history, immunisation record, antibiotic use, and activities of daily living (as measured by Barthel Index)-was collected by a survey team to determine any associated factors. Data were collected from 3857 residents in 46 Residential Care Homes for the Elderly from February to May 2014. A total of 105 residents had at least one type of infection based on the survey definition. The overall prevalence of all infections was 2.7% (95% confidence interval, 2.2%-3.4%). The three most common infections were of the respiratory tract (1.3%; 95% confidence interval, 0.9%-1.9%), skin and soft tissue (0.7%; 95% confidence interval, 0.5%-1.0%), and urinary tract (0.5%; 95% confidence interval, 0.3%-0.9%). Total dependence in activities of daily living, as indicated by low Barthel Index score of 0 to 20 (odds ratio=3.0; 95% confidence interval, 1.4-6.2), and presence of a wound or stoma (odds ratio=2.7; 95% confidence interval, 1.4-4.9) were significantly associated with presence of infection. This survey provides information about infections among residents in Residential Care Homes for the Elderly in the territory. Local data enable us to understand the burden of infections and formulate targeted measures for prevention.

Influence of Objective Three-Dimensional Measures and Movement Images on Surgeon Treatment Planning for Lip Revision Surgery

PubMed Central

Trotman, Carroll-Ann; Phillips, Ceib; Faraway, Julian J.; Hartman, Terry; van Aalst, John A.

2013-01-01

Objective To determine whether a systematic evaluation of facial soft tissues of patients with cleft lip and palate, using facial video images and objective three-dimensional measurements of movement, change surgeons’ treatment plans for lip revision surgery. Design Prospective longitudinal study. Setting The University of North Carolina School of Dentistry. Patients, Participants A group of patients with repaired cleft lip and palate (n = 21), a noncleft control group (n = 37), and surgeons experienced in cleft care. Interventions Lip revision. Main Outcome Measures (1) facial photographic images; (2) facial video images during animations; (3) objective three-dimensional measurements of upper lip movement based on z scores; and (4) objective dynamic and visual three-dimensional measurement of facial soft tissue movement. Results With the use of the video images plus objective three-dimensional measures, changes were made to the problem list of the surgical treatment plan for 86% of the patients (95% confidence interval, 0.64 to 0.97) and the surgical goals for 71% of the patients (95% confidence interval, 0.48 to 0.89). The surgeon group varied in the percentage of patients for whom the problem list was modified, ranging from 24% (95% confidence interval, 8% to 47%) to 48% (95% confidence interval, 26% to 70%) of patients, and the percentage for whom the surgical goals were modified, ranging from 14% (94% confidence interval, 3% to 36%) to 48% (95% confidence interval, 26% to 70%) of patients. Conclusions For all surgeons, the additional assessment components of the systematic valuation resulted in a change in clinical decision making for some patients. PMID:23855676

Lower hospital mortality and complications after pediatric hematopoietic stem cell transplantation.

PubMed

Bratton, Susan L; Van Duker, Heather; Statler, Kimberly D; Pulsipher, Michael A; McArthur, Jennifer; Keenan, Heather T

2008-03-01

To assess protective and risk factors for mortality among pediatric patients during initial care after hematopoietic stem cell transplantation (HSCT) and to evaluate changes in hospital mortality. Retrospective cohort using the 1997, 2000, and 2003 Kids Inpatient Database, a probabilistic sample of children hospitalized in the United States with a procedure code for HSCT. Hospitalized patients in the United States submitted to the database. Age, <19 yrs. None. Hospital mortality significantly decreased from 12% in 1997 to 6% in 2003. Source of stem cells changed with increased use of cord blood. Rates of sepsis, graft versus host disease, and mechanical ventilation significantly decreased. Compared with autologous HSCT, patients who received an allogenic HSCT without T-cell depletion were more likely to die (adjusted odds ratio, 2.4; 95% confidence interval, 1.5, 3.9), while children who received cord blood HSCT were at the greatest risk of hospital death (adjusted odds ratio, 4.8; 95% confidence interval, 2.6, 9.1). Mechanical ventilation (adjusted odds ratio, 26.32; 95% confidence interval, 16.3-42.2), dialysis (adjusted odds ratio, 12.9; 95% confidence interval, 4.7-35.4), and sepsis (adjusted odds ratio, 3.9; 95% confidence interval, 2.5-6.1) were all independently associated with death, while care in 2003 was associated with decreased risk (adjusted odds ratio, 0.4; 95% confidence interval, 0.2-0.7) of death. Hospital mortality after HSCT in children decreased over time as did complications including need for mechanical ventilation, graft versus host disease, and sepsis. Prevention of complications is essential as the need for invasive support continues to be associated with high mortality risk.

High prevalence of refractive errors in a rural population: 'Nooravaran Salamat' Mobile Eye Clinic experience.

PubMed

Hashemi, Hassan; Rezvan, Farhad; Ostadimoghaddam, Hadi; Abdollahi, Majid; Hashemi, Maryam; Khabazkhoob, Mehdi

2013-01-01

The prevalence of myopia and hyperopia and determinants were determined in a rural population of Iran. Population-based cross-sectional study. Using random cluster sampling, 13 of the 83 villages of Khaf County in the north east of Iran were selected. Data from 2001 people over the age of 15 years were analysed. Visual acuity measurement, non-cycloplegic refraction and eye examinations were done at the Mobile Eye Clinic. The prevalence of myopia and hyperopia based on spherical equivalent worse than -0.5 dioptre and +0.5 dioptre, respectively. The prevalence of myopia, hyperopia and anisometropia in the total study sample was 28% (95% confidence interval: 25.9-30.2), 19.2% (95% confidence interval: 17.3-21.1), and 11.5% (95% confidence interval: 10.0-13.1), respectively. In the over 40 population, the prevalence of myopia and hyperopia was 32.5% (95% confidence interval: 28.9-36.1) and 27.9% (95% confidence interval: 24.5-31.3), respectively. In the multiple regression model for this group, myopia strongly correlated with cataract (odds ratio = 1.98 and 95% confidence interval: 1.33-2.93), and hyperopia only correlated with age (P < 0.001). The prevalence of high myopia and high hyperopia was 1.5% and 4.6%. In the multiple regression model, anisometropia significantly correlated with age (odds ratio = 1.04) and cataract (odds ratio = 5.2) (P < 0.001). The prevalence of myopia and anisometropia was higher than that in previous studies in urban population of Iran, especially in the elderly. Cataract was the only variable that correlated with myopia and anisometropia. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.

The Association Between Maternal Age and Cerebral Palsy Risk Factors.

PubMed

Schneider, Rilla E; Ng, Pamela; Zhang, Xun; Andersen, John; Buckley, David; Fehlings, Darcy; Kirton, Adam; Wood, Ellen; van Rensburg, Esias; Shevell, Michael I; Oskoui, Maryam

2018-05-01

Advanced maternal age is associated with higher frequencies of antenatal and perinatal conditions, as well as a higher risk of cerebral palsy in offspring. We explore the association between maternal age and specific cerebral palsy risk factors. Data were extracted from the Canadian Cerebral Palsy Registry. Maternal age was categorized as ≥35 years of age and less than 20 years of age at the time of birth. Chi-square and multivariate logistic regressions were performed to calculate odds ratios and their 95% confidence intervals. The final sample consisted of 1391 children with cerebral palsy, with 19% of children having mothers aged 35 or older and 4% of children having mothers below the age of 20. Univariate analyses showed that mothers aged 35 or older were more likely to have gestational diabetes (odds ratio 1.9, 95% confidence interval 1.3 to 2.8), to have a history of miscarriage (odds ratio 1.8, 95% confidence interval 1.3 to 2.4), to have undergone fertility treatments (odds ratio 2.4, 95% confidence interval 1.5 to 3.9), and to have delivered by Caesarean section (odds ratio 1.6, 95% confidence interval 1.2 to 2.2). These findings were supported by multivariate analyses. Children with mothers below the age of 20 were more likely to have a congenital malformation (odds ratio 2.4, 95% confidence interval 1.4 to 4.2), which is also supported by multivariate analysis. The risk factor profiles of children with cerebral palsy vary by maternal age. Future studies are warranted to further our understanding of the compound causal pathways leading to cerebral palsy and the observed greater prevalence of cerebral palsy with increasing maternal age. Copyright © 2018 Elsevier Inc. All rights reserved.

Priorities for treatment, care and information if faced with serious illness: a comparative population-based survey in seven European countries.

PubMed

Higginson, Irene J; Gomes, Barbara; Calanzani, Natalia; Gao, Wei; Bausewein, Claudia; Daveson, Barbara A; Deliens, Luc; Ferreira, Pedro L; Toscani, Franco; Gysels, Marjolein; Ceulemans, Lucas; Simon, Steffen T; Cohen, Joachim; Harding, Richard

2014-02-01

Health-care costs are growing, with little population-based data about people's priorities for end-of-life care, to guide service development and aid discussions. We examined variations in people's priorities for treatment, care and information across seven European countries. Telephone survey of a random sample of households; we asked respondents their priorities if 'faced with a serious illness, like cancer, with limited time to live' and used multivariable logistic regressions to identify associated factors. Members of the general public aged ≥ 16 years residing in England, Flanders, Germany, Italy, the Netherlands, Portugal and Spain. In total, 9344 individuals were interviewed. Most people chose 'improve quality of life for the time they had left', ranging from 57% (95% confidence interval: 55%-60%, Italy) to 81% (95% confidence interval: 79%-83%, Spain). Only 2% (95% confidence interval: 1%-3%, England) to 6% (95% confidence interval: 4%-7%, Flanders) said extending life was most important, and 15% (95% confidence interval: 13%-17%, Spain) to 40% (95% confidence interval: 37%-43%, Italy) said quality and extension were equally important. Prioritising quality of life was associated with higher education in all countries (odds ratio = 1.3 (Flanders) to 7.9 (Italy)), experience of caregiving or bereavement (England, Germany, Portugal), prioritising pain/symptom control over having a positive attitude and preferring death in a hospice/palliative care unit. Those prioritising extending life had the highest home death preference of all groups. Health status did not affect priorities. Across all countries, extending life was prioritised by a minority, regardless of health status. Treatment and care needs to be reoriented with patient education and palliative care becoming mainstream for serious conditions such as cancer.

Air pollution attributable postneonatal infant mortality in U.S. metropolitan areas: a risk assessment study

PubMed Central

Kaiser, Reinhard; Romieu, Isabelle; Medina, Sylvia; Schwartz, Joel; Krzyzanowski, Michal; Künzli, Nino

2004-01-01

Background The impact of outdoor air pollution on infant mortality has not been quantified. Methods Based on exposure-response functions from a U.S. cohort study, we assessed the attributable risk of postneonatal infant mortality in 23 U.S. metropolitan areas related to particulate matter <10 μm in diameter (PM10) as a surrogate of total air pollution. Results The estimated proportion of all cause mortality, sudden infant death syndrome (normal birth weight infants only) and respiratory disease mortality (normal birth weight) attributable to PM10 above a chosen reference value of 12.0 μg/m3 PM10 was 6% (95% confidence interval 3–11%), 16% (95% confidence interval 9–23%) and 24% (95% confidence interval 7–44%), respectively. The expected number of infant deaths per year in the selected areas was 106 (95% confidence interval 53–185), 79 (95% confidence interval 46–111) and 15 (95% confidence interval 5–27), respectively. Approximately 75% of cases were from areas where the current levels are at or below the new U.S. PM2.5 standard of 15 μg/m3 (equivalent to 25 μg/m3 PM10). In a country where infant mortality rates and air pollution levels are relatively low, ambient air pollution as measured by particulate matter contributes to a substantial fraction of infant death, especially for those due to sudden infant death syndrome and respiratory disease. Even if all counties would comply to the new PM2.5 standard, the majority of the estimated burden would remain. Conclusion Given the inherent limitations of risk assessments, further studies are needed to support and quantify the relationship between infant mortality and air pollution. PMID:15128459

Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

PubMed

Fung, Tak; Keenan, Kevin

2014-01-01

The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

Coefficient Alpha Bootstrap Confidence Interval under Nonnormality

ERIC Educational Resources Information Center

Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew

2012-01-01

Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…

Four Bootstrap Confidence Intervals for the Binomial-Error Model.

ERIC Educational Resources Information Center

Lin, Miao-Hsiang; Hsiung, Chao A.

1992-01-01

Four bootstrap methods are identified for constructing confidence intervals for the binomial-error model. The extent to which similar results are obtained and the theoretical foundation of each method and its relevance and ranges of modeling the true score uncertainty are discussed. (SLD)

Teach a Confidence Interval for the Median in the First Statistics Course

ERIC Educational Resources Information Center

Howington, Eric B.

2017-01-01

Few introductory statistics courses consider statistical inference for the median. This article argues in favour of adding a confidence interval for the median to the first statistics course. Several methods suitable for introductory statistics students are identified and briefly reviewed.

Increased calcium supplementation is associated with morbidity and mortality in the infant postoperative cardiac patient.

PubMed

Dyke, Peter C; Yates, Andrew R; Cua, Clifford L; Hoffman, Timothy M; Hayes, John; Feltes, Timothy F; Springer, Michelle A; Taeed, Roozbeh

2007-05-01

The purpose of this study was to assess the association of calcium replacement therapy with morbidity and mortality in infants after cardiac surgery involving cardiopulmonary bypass. Retrospective chart review. The cardiac intensive care unit at a tertiary care children's hospital. Infants undergoing cardiac surgery involving cardiopulmonary bypass between October 2002 and August 2004. None. Total calcium replacement (mg/kg calcium chloride given) for the first 72 postoperative hours was measured. Morbidity and mortality data were collected. The total volume of blood products given during the first 72 hrs was recorded. Infants with confirmed chromosomal deletions at the 22q11 locus were noted. Correlation and logistic regression analyses were used to generate odds ratios and 95% confidence intervals, with p < .05 being significant. One hundred seventy-one infants met inclusion criteria. Age was 4 +/- 3 months and weight was 4.9 +/- 1.7 kg at surgery. Six infants had deletions of chromosome 22q11. Infants who weighed less required more calcium replacement (r = -.28, p < .001). Greater calcium replacement correlated with a longer intensive care unit length of stay (r = .27, p < .001) and a longer total hospital length of stay (r = .23, p = .002). Greater calcium replacement was significantly associated with morbidity (liver dysfunction [odds ratio, 3.9; confidence interval, 2.1-7.3; p < .001], central nervous system complication [odds ratio, 1.8; confidence interval, 1.1-3.0; p = .02], infection [odds ratio, 1.5; confidence interval, 1.0-2.2; p < .04], extracorporeal membrane oxygenation [odds ratio, 5.0; confidence interval, 2.3-10.6; p < .001]) and mortality (odds ratio, 5.8; confidence interval, 5.8-5.9; p < .001). Greater calcium replacement was not associated with renal insufficiency (odds ratio, 1.5; confidence interval, 0.9-2.3; p = .07). Infants with >1 sd above the mean of total calcium replacement received on average fewer blood products than the total study population. Greater calcium replacement is associated with increasing morbidity and mortality. Further investigation of the etiology and therapy of hypocalcemia in this population is warranted.

WITHDRAWN: Amnioinfusion for meconium-stained liquor in labour.

PubMed

Hofmeyr, G Justus

2009-01-21

Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However, it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. The Cochrane Pregnancy and Childbirth Group trials register (October 2001) and the Cochrane Controlled Trials Register (Issue 3, 2001) were searched. Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. Eligibility and trial quality were assessed by one reviewer. Twelve studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.65, 95% confidence interval 0.49 to 0.88); and reduced caesarean section overall (relative risk 0.82, 95% confidence interval 0.69 to 1.97). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0.12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Reliability of clinical findings and magnetic resonance imaging for the diagnosis of chondromalacia patellae.

PubMed

Pihlajamäki, Harri K; Kuikka, Paavo-Ilari; Leppänen, Vesa-Veikko; Kiuru, Martti J; Mattila, Ville M

2010-04-01

This diagnostic study was performed to determine the correlation between anterior knee pain and chondromalacia patellae and to define the reliability of magnetic resonance imaging for the diagnosis of chondromalacia patellae. Fifty-six young adults (median age, 19.5 years) with anterior knee pain had magnetic resonance imaging of the knee followed by arthroscopy. The patellar chondral lesions identified by magnetic resonance imaging were compared with the arthroscopic findings. Arthroscopy confirmed the presence of chondromalacia patellae in twenty-five (45%) of the fifty-six knees, a synovial plica in twenty-five knees, a meniscal tear in four knees, and a femorotibial chondral lesion in four knees; normal anatomy was seen in six knees. No association was found between the severity of the chondromalacia patellae seen at arthroscopy and the clinical symptoms of anterior knee pain syndrome (p = 0.83). The positive predictive value for the ability of 1.0-T magnetic resonance imaging to detect chondromalacia patellae was 75% (95% confidence interval, 53% to 89%), the negative predictive value was 72% (95% confidence interval, 56% to 84%), the sensitivity was 60% (95% confidence interval, 41% to 77%), the specificity was 84% (95% confidence interval, 67% to 93%), and the diagnostic accuracy was 73% (95% confidence interval, 60% to 83%). The sensitivity was 13% (95% confidence interval, 2% to 49%) for grade-I lesions and 83% (95% confidence interval, 59% to 94%) for grade-II, III, or IV lesions. Chondromalacia patellae cannot be diagnosed on the basis of symptoms or with current physical examination methods. The present study demonstrated no correlation between the severity of chondromalacia patellae and the clinical symptoms of anterior knee pain syndrome. Thus, symptoms of anterior knee pain syndrome should not be used as an indication for knee arthroscopy. The sensitivity of 1.0-T magnetic resonance imaging was low for grade-I lesions but considerably higher for more severe (grade-II, III, or IV) lesions. Magnetic resonance imaging may be considered an accurate diagnostic tool for identification of more severe cases of chondromalacia patellae.

Asymptomatic Intradialytic Supraventricular Arrhythmias and Adverse Outcomes in Patients on Hemodialysis

PubMed Central

Pérez de Prado, Armando; López-Gómez, Juan M.; Quiroga, Borja; Goicoechea, Marian; García-Prieto, Ana; Torres, Esther; Reque, Javier; Luño, José

2016-01-01

Background and objectives Supraventricular arrhythmias are associated with high morbidity and mortality. Nevertheless, this condition has received little attention in patients on hemodialysis. The objective of this study was to analyze the incidence of intradialysis supraventricular arrhythmia and its long–term prognostic value. Design, setting, participants, & measurements We designed an observational and prospective study in a cohort of patients on hemodialysis with a 10-year follow-up period. All patients were recruited for study participation and were not recruited for clinical indications. The study population comprised 77 patients (42 men and 35 women; mean age =58±15 years old) with sinus rhythm monitored using a Holter electrocardiogram over six consecutive hemodialysis sessions at recruitment. Results Hypertension was present in 68.8% of patients, and diabetes was present in 29.9% of patients. Supraventricular arrhythmias were recorded in 38 patients (49.3%); all of these were short, asymptomatic, and self-limiting. Age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08) and right atrial enlargement (hazard ratio, 4.29; 95% confidence interval, 1.30 to 14.09) were associated with supraventricular arrhythmia in the multivariate analysis. During a median follow-up of 40 months, 57 patients died, and cardiovascular disease was the main cause of death (52.6%). The variables associated with all-cause mortality in the Cox model were age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08), C-reactive protein (hazard ratio, 1.04 per 1 mg/L; 95% confidence interval, 1.00 to 1.08), and supraventricular arrhythmia (hazard ratio, 3.21; 95% confidence interval, 1.29 to 7.96). Patients with supraventricular arrhythmia also had a higher risk of nonfatal cardiovascular events (hazard ratio, 4.32; 95% confidence interval, 2.11 to 8.83) and symptomatic atrial fibrillation during follow-up (hazard ratio, 17.19; 95% confidence interval, 2.03 to 145.15). Conclusions The incidence of intradialysis supraventricular arrhythmia was high in our hemodialysis study population. Supraventricular arrhythmias were short, asymptomatic, and self-limiting, and although silent, these arrhythmias were independently associated with mortality and cardiovascular events. PMID:27697781

Asymptomatic Intradialytic Supraventricular Arrhythmias and Adverse Outcomes in Patients on Hemodialysis.

PubMed

Verde, Eduardo; Pérez de Prado, Armando; López-Gómez, Juan M; Quiroga, Borja; Goicoechea, Marian; García-Prieto, Ana; Torres, Esther; Reque, Javier; Luño, José

2016-12-07

Supraventricular arrhythmias are associated with high morbidity and mortality. Nevertheless, this condition has received little attention in patients on hemodialysis. The objective of this study was to analyze the incidence of intradialysis supraventricular arrhythmia and its long-term prognostic value. We designed an observational and prospective study in a cohort of patients on hemodialysis with a 10-year follow-up period. All patients were recruited for study participation and were not recruited for clinical indications. The study population comprised 77 patients (42 men and 35 women; mean age =58±15 years old) with sinus rhythm monitored using a Holter electrocardiogram over six consecutive hemodialysis sessions at recruitment. Hypertension was present in 68.8% of patients, and diabetes was present in 29.9% of patients. Supraventricular arrhythmias were recorded in 38 patients (49.3%); all of these were short, asymptomatic, and self-limiting. Age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08) and right atrial enlargement (hazard ratio, 4.29; 95% confidence interval, 1.30 to 14.09) were associated with supraventricular arrhythmia in the multivariate analysis. During a median follow-up of 40 months, 57 patients died, and cardiovascular disease was the main cause of death (52.6%). The variables associated with all-cause mortality in the Cox model were age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08), C-reactive protein (hazard ratio, 1.04 per 1 mg/L; 95% confidence interval, 1.00 to 1.08), and supraventricular arrhythmia (hazard ratio, 3.21; 95% confidence interval, 1.29 to 7.96). Patients with supraventricular arrhythmia also had a higher risk of nonfatal cardiovascular events (hazard ratio, 4.32; 95% confidence interval, 2.11 to 8.83) and symptomatic atrial fibrillation during follow-up (hazard ratio, 17.19; 95% confidence interval, 2.03 to 145.15). The incidence of intradialysis supraventricular arrhythmia was high in our hemodialysis study population. Supraventricular arrhythmias were short, asymptomatic, and self-limiting, and although silent, these arrhythmias were independently associated with mortality and cardiovascular events. Copyright © 2016 by the American Society of Nephrology.

Long-term Results of an Obesity Program in an Ethnically Diverse Pediatric Population

PubMed Central

Nowicka, Paulina; Shaw, Melissa; Yu, Sunkyung; Dziura, James; Chavent, Georgia; O'Malley, Grace; Serrecchia, John B.; Tamborlane, William V.; Caprio, Sonia

2011-01-01

OBJECTIVE: To determine if beneficial effects of a weight-management program could be sustained for up to 24 months in a randomized trial in an ethnically diverse obese population. PATIENTS AND METHODS: There were 209 obese children (BMI > 95th percentile), ages 8 to 16 of mixed ethnic backgrounds randomly assigned to the intensive lifestyle intervention or clinic control group. The control group received counseling every 6 months, and the intervention group received a family-based program, which included exercise, nutrition, and behavior modification. Lifestyle intervention sessions occurred twice weekly for the first 6 months, then twice monthly for the second 6 months; for the last 12 months there was no active intervention. There were 174 children who completed the 12 months of the randomized trial. Follow-up data were available for 76 of these children at 24 months. There were no statistical differences in dropout rates among ethnic groups or in any other aspects. RESULTS: Treatment effect was sustained at 24 months in the intervention versus control group for BMI z score (−0.16 [95% confidence interval: −0.23 to −0.09]), BMI (−2.8 kg/m2 [95% confidence interval: −4.0–1.6 kg/m2]), percent body fat (−4.2% [95% confidence interval: −6.4% to −2.0%]), total body fat mass (−5.8 kg [95% confidence interval: −9.1 kg to −2.6 kg]), total cholesterol (−13.0 mg/dL [95% confidence interval: −21.7 mg/dL to −4.2 mg/dL]), low-density lipoprotein cholesterol (−10.4 mg/dL [95% confidence interval: −18.3 mg/dL to −2.4 mg/dL]), and homeostasis model assessment of insulin resistance (−2.05 [95% confidence interval: −2.48 to −1.75]). CONCLUSIONS: This study, unprecedented because of the high degree of obesity and ethnically diverse backgrounds of children, reveals that benefits of an intensive lifestyle program can be sustained 12 months after completing the active intervention phase. PMID:21300674

Trends in contraceptive use according to HIV status among privately insured women in the United States.

PubMed

Haddad, Lisa B; Monsour, Michael; Tepper, Naomi K; Whiteman, Maura K; Kourtis, Athena P; Jamieson, Denise J

2017-12-01

There is limited information on the patterns and trends of contraceptive use among women living with HIV, compared with noninfected women in the United States. Further, little is known about whether antiretroviral therapy correlates with contraceptive use. Such information is needed to help identify potential gaps in care and to enhance unintended pregnancy prevention efforts. We sought to compare contraceptive method use among HIV-infected and noninfected privately insured women in the United States, and to evaluate the association between antiretroviral therapy use and contraceptive method use. We used a large US nationwide health care claims database to identify girls and women ages 15-44 years with prescription drug coverage. We used diagnosis, procedure, and National Drug Codes to assess female sterilization and reversible prescription contraception use in 2008 and 2014 among women continuously enrolled in the database during 2003 through 2008 or 2009 through 2014, respectively. Women with no codes were classified as using no method; these may have included women using nonprescription methods, such as condoms. We calculated prevalence of contraceptive use by HIV infection status, and by use of antiretroviral therapy among those with HIV. We used multivariable polytomous logistic regression to calculate unadjusted and adjusted odds ratios and 95% confidence intervals for female sterilization, long-acting reversible contraception, and short-acting hormonal contraception compared to no method. While contraceptive use increased among HIV-infected and noninfected women from 2008 through 2014, in both years, a lower proportion of HIV-infected women used prescription contraceptive methods (2008: 17.5%; 2014: 28.9%, compared with noninfected women (2008: 28.8%; 2014: 39.8%, P < .001 for both). Controlling for demographics, chronic medical conditions, pregnancy history, and cohort year, HIV-infected women compared to HIV-noninfected women had lower odds of using long-acting reversible contraception (adjusted odds ratio, 0.67; 95% confidence interval, 0.52-0.86 compared to no method) or short-acting hormonal contraception method (adjusted odds ratio, 0.59; 95% confidence interval, 0.50-0.70 compared to no method). In 2014, HIV-infected women using antiretroviral therapy were significantly more likely to use no method (76.8% vs 64.1%), and significantly less likely to use short-acting hormonal contraception (11.0% vs 22.7%) compared to HIV-infected women not using antiretroviral therapy. Those receiving antiretroviral therapy had lower odds of using short-acting hormonal contraception compared to no method (adjusted odds ratio, 0.45; 95% confidence interval, 0.32-0.63). There was no significant difference in female sterilization by HIV status or antiretroviral therapy use. Despite the safety of reversible contraceptives for women with HIV, use of prescription contraception continues to be lower among privately insured HIV-infected women compared to noninfected women, particularly among those receiving antiretroviral therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Psychosocial and nonclinical factors predicting hospital utilization in patients of a chronic disease management program: a prospective observational study.

PubMed

Tran, Mark W; Weiland, Tracey J; Phillips, Georgina A

2015-01-01

Psychosocial factors such as marital status (odds ratio, 3.52; 95% confidence interval, 1.43-8.69; P = .006) and nonclinical factors such as outpatient nonattendances (odds ratio, 2.52; 95% confidence interval, 1.22-5.23; P = .013) and referrals made (odds ratio, 1.20; 95% confidence interval, 1.06-1.35; P = .003) predict hospital utilization for patients in a chronic disease management program. Along with optimizing patients' clinical condition by prescribed medical guidelines and supporting patient self-management, addressing psychosocial and nonclinical issues are important in attempting to avoid hospital utilization for people with chronic illnesses.

Bias and inference from misspecified mixed-effect models in stepped wedge trial analysis.

PubMed

Thompson, Jennifer A; Fielding, Katherine L; Davey, Calum; Aiken, Alexander M; Hargreaves, James R; Hayes, Richard J

2017-10-15

Many stepped wedge trials (SWTs) are analysed by using a mixed-effect model with a random intercept and fixed effects for the intervention and time periods (referred to here as the standard model). However, it is not known whether this model is robust to misspecification. We simulated SWTs with three groups of clusters and two time periods; one group received the intervention during the first period and two groups in the second period. We simulated period and intervention effects that were either common-to-all or varied-between clusters. Data were analysed with the standard model or with additional random effects for period effect or intervention effect. In a second simulation study, we explored the weight given to within-cluster comparisons by simulating a larger intervention effect in the group of the trial that experienced both the control and intervention conditions and applying the three analysis models described previously. Across 500 simulations, we computed bias and confidence interval coverage of the estimated intervention effect. We found up to 50% bias in intervention effect estimates when period or intervention effects varied between clusters and were treated as fixed effects in the analysis. All misspecified models showed undercoverage of 95% confidence intervals, particularly the standard model. A large weight was given to within-cluster comparisons in the standard model. In the SWTs simulated here, mixed-effect models were highly sensitive to departures from the model assumptions, which can be explained by the high dependence on within-cluster comparisons. Trialists should consider including a random effect for time period in their SWT analysis model. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

New diagnosis of cancer and the risk of subsequent cerebrovascular events.

PubMed

Navi, Babak B; Howard, George; Howard, Virginia J; Zhao, Hong; Judd, Suzanne E; Elkind, Mitchell S V; Iadecola, Costantino; DeAngelis, Lisa M; Kamel, Hooman; Okin, Peter M; Gilchrist, Susan; Soliman, Elsayed Z; Cushman, Mary; Muntner, Paul

2018-06-05

We aimed to evaluate the association between cancer and cerebrovascular disease in a prospective cohort study with adjudicated cerebrovascular diagnoses. We analyzed participants from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who were 45 years and older and had Medicare coverage for 365 days before their baseline study visit. Participants with a history of cancer or cerebrovascular events were excluded. The time-dependent exposure was a new diagnosis of malignant cancer identified through Medicare claims algorithms. Participants were prospectively followed from their baseline study visit (2003-2007) through 2014 for the outcome of a neurologist-adjudicated cerebrovascular event defined as a composite of stroke (ischemic or hemorrhagic) or TIA. Cox regression was used to evaluate the association between a new cancer diagnosis and subsequent cerebrovascular events. Follow-up time was modeled in discrete time periods to fulfill the proportional hazard assumption. Among 6,602 REGARDS participants who met eligibility criteria, 1,149 were diagnosed with cancer during follow-up. Compared to no cancer, a new cancer diagnosis was associated with subsequent cerebrovascular events in the first 30 days after diagnosis (hazard ratio 6.1, 95% confidence interval 2.7-13.7). This association persisted after adjustment for demographics, region of residence, and vascular risk factors (hazard ratio 6.6, 95% confidence interval 2.7-16.0). There was no association between cancer diagnosis and incident cerebrovascular events beyond 30 days. Cancers considered high risk for venous thromboembolism demonstrated the strongest associations with cerebrovascular event risk. A new diagnosis of cancer is associated with a substantially increased short-term risk of cerebrovascular events. © 2018 American Academy of Neurology.

Bias and inference from misspecified mixed‐effect models in stepped wedge trial analysis

PubMed Central

Fielding, Katherine L.; Davey, Calum; Aiken, Alexander M.; Hargreaves, James R.; Hayes, Richard J.

2017-01-01

Many stepped wedge trials (SWTs) are analysed by using a mixed‐effect model with a random intercept and fixed effects for the intervention and time periods (referred to here as the standard model). However, it is not known whether this model is robust to misspecification. We simulated SWTs with three groups of clusters and two time periods; one group received the intervention during the first period and two groups in the second period. We simulated period and intervention effects that were either common‐to‐all or varied‐between clusters. Data were analysed with the standard model or with additional random effects for period effect or intervention effect. In a second simulation study, we explored the weight given to within‐cluster comparisons by simulating a larger intervention effect in the group of the trial that experienced both the control and intervention conditions and applying the three analysis models described previously. Across 500 simulations, we computed bias and confidence interval coverage of the estimated intervention effect. We found up to 50% bias in intervention effect estimates when period or intervention effects varied between clusters and were treated as fixed effects in the analysis. All misspecified models showed undercoverage of 95% confidence intervals, particularly the standard model. A large weight was given to within‐cluster comparisons in the standard model. In the SWTs simulated here, mixed‐effect models were highly sensitive to departures from the model assumptions, which can be explained by the high dependence on within‐cluster comparisons. Trialists should consider including a random effect for time period in their SWT analysis model. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:28556355

Effectiveness of fecal immunochemical testing in reducing colorectal cancer mortality from the One Million Taiwanese Screening Program.

PubMed

Chiu, Han-Mo; Chen, Sam Li-Sheng; Yen, Amy Ming-Fang; Chiu, Sherry Yueh-Hsia; Fann, Jean Ching-Yuan; Lee, Yi-Chia; Pan, Shin-Liang; Wu, Ming-Shiang; Liao, Chao-Sheng; Chen, Hsiu-Hsi; Koong, Shin-Lan; Chiou, Shu-Ti

2015-09-15

The effectiveness of fecal immunochemical testing (FIT) in reducing colorectal cancer (CRC) mortality has not yet been fully assessed in a large, population-based service screening program. A prospective cohort study of the follow-up of approximately 5 million Taiwanese from 2004 to 2009 was conducted to compare CRC mortality for an exposed (screened) group and an unexposed (unscreened) group in a population-based CRC screening service targeting community residents of Taiwan who were 50 to 69 years old. Given clinical capacity, this nationwide screening program was first rolled out in 2004. In all, 1,160,895 eligible subjects who were 50 to 69 years old (ie, 21.4% of the 5,417,699 subjects of the underlying population) participated in the biennial nationwide screening program by 2009. The actual effectiveness in reducing CRC mortality attributed to the FIT screening was 62% (relative rate for the screened group vs the unscreened group, 0.38; 95% confidence interval, 0.35-0.42) with a maximum follow-up of 6 years. The 21.4% coverage of the population receiving FIT led to a significant 10% reduction in CRC mortality (relative rate, 0.90; 95% confidence interval, 0.84-0.95) after adjustments for a self-selection bias. This large, prospective Taiwanese cohort undergoing population-based FIT screening for CRC had the statistical power to demonstrate a significant CRC mortality reduction, although the follow-up time was short. Although such findings are informative for health decision makers, continued follow-up of this large cohort will be required to estimate the long-term impact of FIT screening if the covered population is expanded. © 2015 American Cancer Society.

Spillover Effects of Adult Medicaid Expansions on Children's Use of Preventive Services.

PubMed

Venkataramani, Maya; Pollack, Craig Evan; Roberts, Eric T

2017-12-01

Since the passage of the Affordable Care Act, Medicaid enrollment has increased by ∼17 million adults, including many low-income parents. One potentially important, but little studied, consequence of expanding health insurance for parents is its effect on children's receipt of preventive services. By using state Medicaid eligibility thresholds linked to the 2001-2013 Medical Expenditure Panel Surveys, we assessed the relationship between changes in adult Medicaid eligibility and children's likelihood of receiving annual well-child visits (WCVs). In instrumental variable analyses, we used these changes in Medicaid eligibility to estimate the relationship between parental enrollment in Medicaid and children's receipt of WCVs. Our analytic sample consisted of 50 622 parent-child dyads in families with incomes <200% of the federal poverty level, surveyed from 2001 to 2013. On average, a 10-point increase in a state's parental Medicaid eligibility (measured relative to the federal poverty level) was associated with a 0.27 percentage point higher probability that a child received an annual WCV (95% confidence interval: 0.058 to 0.48 percentage points, P = .012). Instrumental variable analyses revealed that parental enrollment in Medicaid was associated with a 29 percentage point higher probability that their child received an annual WCV (95% confidence interval: 11 to 47 percentage points, P = .002). In our study, we demonstrate that Medicaid expansions targeted at low-income adults are associated with increased receipt of recommended pediatric preventive care for their children. This finding reveals an important spillover effect of parental insurance coverage that should be considered in future policy decisions surrounding adult Medicaid eligibility. Copyright © 2017 by the American Academy of Pediatrics.

A prospective multicenter study of microbiologically defined infections in pediatric cancer patients with fever and neutropenia: Swiss Pediatric Oncology Group 2003 fever and neutropenia study.

PubMed

Agyeman, Philipp; Kontny, Udo; Nadal, David; Leibundgut, Kurt; Niggli, Felix; Simon, Arne; Kronenberg, Andreas; Frei, Reno; Escobar, Hugo; Kühne, Thomas; Beck-Popovic, Maja; Bodmer, Nicole; Ammann, Roland A

2014-09-01

Fever and neutropenia (FN) often complicate anticancer treatment and can be caused by potentially fatal infections. Knowledge of pathogen distribution is paramount for optimal patient management. Microbiologically defined infections (MDI) in pediatric cancer patients presenting with FN by nonmyeloablative chemotherapy enrolled in a prospective multicenter study were analyzed. Effectiveness of empiric antibiotic therapy in FN episodes with bacteremia was assessed taking into consideration recently published treatment guidelines for pediatric patients with FN. MDI were identified in a minority (22%) of pediatric cancer patients with FN. In patients with, compared with patients without MDI, fever [median, 5 (interquartile range: 3-8) vs. 2 (interquartile range: 1-3) days, P < 0.001] and hospitalization [10 (6-14) vs. 5 (3-8) days, P < 0.001] lasted longer, transfer to the intensive care unit was more likely [13 of 95 (14%) vs. 7 of 346 (2.0%), P < 0.001], and antibiotics were given longer [10 (7-14) vs. 5 (4-7) days, P < 0.001]. Empiric antibiotic therapy in FN episodes with bacteremia was highly effective if not only intrinsic and reported antimicrobial susceptibilities were considered but also the purposeful omission of coverage for coagulase-negative staphylococci and enterococci was taken into account [81% (95% confidence interval: 68-90) vs. 96.6% (95% confidence interval: 87-99.4), P = 0.004]. MDI were identified in a minority of FN episodes but they significantly affected management and the clinical course of pediatric cancer patients. Compliance with published guidelines was associated with effectiveness of empiric antibiotic therapy in FN episodes with bacteremia.

Gaps in referral to cardiac rehabilitation of patients undergoing percutaneous coronary intervention in the United States.

PubMed

Aragam, Krishna G; Dai, Dadi; Neely, Megan L; Bhatt, Deepak L; Roe, Matthew T; Rumsfeld, John S; Gurm, Hitinder S

2015-05-19

Rates of referral to cardiac rehabilitation after percutaneous coronary intervention (PCI) have been historically low despite the evidence that rehabilitation is associated with lower mortality in PCI patients. This study sought to determine the prevalence of and factors associated with referral to cardiac rehabilitation in a national PCI cohort, and to assess the association between insurance status and referral patterns. Consecutive patients who underwent PCI and survived to hospital discharge in the National Cardiovascular Data Registry between July 1, 2009 and March 31, 2012 were analyzed. Cardiac rehabilitation referral rates, and patient and institutional factors associated with referral were evaluated for the total study population and for a subset of Medicare patients presenting with acute myocardial infarction. Patients who underwent PCI (n = 1,432,399) at 1,310 participating hospitals were assessed. Cardiac rehabilitation referral rates were 59.2% and 66.0% for the overall population and the AMI/Medicare subgroup, respectively. In multivariable analyses, presentation with ST-segment elevation myocardial infarction (odds ratio 2.99; 95% confidence interval: 2.92 to 3.06) and non-ST-segment elevation myocardial infarction (odds ratio: 1.99; 95% confidence interval: 1.94 to 2.03) were associated with increased odds of referral to cardiac rehabilitation. Models adjusted for insurance status showed significant site-specific variability in referral rates, with more than one-quarter of all hospitals referring <20% of patients. Approximately 60% of patients undergoing PCI in the United States are referred for cardiac rehabilitation. Site-specific variation in referral rates is significant and is unexplained by insurance coverage. These findings highlight the potential need for hospital-level interventions to improve cardiac rehabilitation referral rates after PCI. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Guillain-Barré syndrome and adjuvanted pandemic influenza A (H1N1) 2009 vaccine: multinational case-control study in Europe

PubMed Central

Dieleman, Jeanne; Romio, Silvana; Johansen, Kari; Weibel, Daniel; Bonhoeffer, Jan

2011-01-01

Objective To assess the association between pandemic influenza A (H1N1) 2009 vaccine and Guillain-Barré syndrome. Design Case-control study. Setting Five European countries. Participants 104 patients with Guillain-Barré syndrome and its variant Miller-Fisher syndrome matched to one or more controls. Case status was classified according to the Brighton Collaboration definition. Controls were matched to cases on age, sex, index date, and country. Main outcome measures Relative risk estimate for Guillain-Barré syndrome after pandemic influenza vaccine. Results Case recruitment and vaccine coverage varied considerably between countries; the most common vaccines used were adjuvanted (Pandemrix and Focetria). The unadjusted pooled risk estimate for all countries was 2.8 (95% confidence interval 1.3 to 6.0). After adjustment for influenza-like illness/upper respiratory tract infection and seasonal influenza vaccination, receipt of pandemic influenza vaccine was not associated with an increased risk of Guillain-Barré syndrome (adjusted odds ratio 1.0, 0.3 to 2.7). The 95% confidence interval shows that the absolute effect of vaccination could range from one avoided case of Guillain-Barré syndrome up to three excess cases within six weeks after vaccination in one million people. Conclusions The risk of occurrence of Guillain-Barré syndrome is not increased after pandemic influenza vaccine, although the upper limit does not exclude a potential increase in risk up to 2.7-fold or three excess cases per one million vaccinated people. When assessing the association between pandemic influenza vaccines and Guillain-Barré syndrome it is important to account for the effects of influenza-like illness/upper respiratory tract infection, seasonal influenza vaccination, and calendar time. PMID:21750072

Methods for calculating confidence and credible intervals for the residual between-study variance in random effects meta-regression models

PubMed Central

2014-01-01

Background Meta-regression is becoming increasingly used to model study level covariate effects. However this type of statistical analysis presents many difficulties and challenges. Here two methods for calculating confidence intervals for the magnitude of the residual between-study variance in random effects meta-regression models are developed. A further suggestion for calculating credible intervals using informative prior distributions for the residual between-study variance is presented. Methods Two recently proposed and, under the assumptions of the random effects model, exact methods for constructing confidence intervals for the between-study variance in random effects meta-analyses are extended to the meta-regression setting. The use of Generalised Cochran heterogeneity statistics is extended to the meta-regression setting and a Newton-Raphson procedure is developed to implement the Q profile method for meta-analysis and meta-regression. WinBUGS is used to implement informative priors for the residual between-study variance in the context of Bayesian meta-regressions. Results Results are obtained for two contrasting examples, where the first example involves a binary covariate and the second involves a continuous covariate. Intervals for the residual between-study variance are wide for both examples. Conclusions Statistical methods, and R computer software, are available to compute exact confidence intervals for the residual between-study variance under the random effects model for meta-regression. These frequentist methods are almost as easily implemented as their established counterparts for meta-analysis. Bayesian meta-regressions are also easily performed by analysts who are comfortable using WinBUGS. Estimates of the residual between-study variance in random effects meta-regressions should be routinely reported and accompanied by some measure of their uncertainty. Confidence and/or credible intervals are well-suited to this purpose. PMID:25196829

Persistent opioid use following Cesarean delivery: patterns and predictors among opioid naïve women

PubMed Central

Bateman, Brian T.; Franklin, Jessica M.; Bykov, Katsiaryna; Avorn, Jerry; Shrank, William H.; Brennan, Troyen A.; Landon, Joan E.; Rathmell, James P.; Huybrechts, Krista F.; Fischer, Michael A.; Choudhry, Niteesh K.

2016-01-01

Background The incidence of opioid-related death in women has increased five-fold over the past decade. For many women, their initial opioid exposure will occur in the setting of routine medical care. Approximately 1 in 3 deliveries in the U.S. is by Cesarean and opioids are commonly prescribed for post-surgical pain management. Objective The objective of this study was to determine the risk that opioid naïve women prescribed opioids after Cesarean delivery will subsequently become consistent prescription opioid users in the year following delivery, and to identify predictors for this behavior. Study Design We identified women in a database of commercial insurance beneficiaries who underwent Cesarean delivery and who were opioid-naïve in the year prior to delivery. To identify persistent users of opioids, we used trajectory models, which group together patients with similar patterns of medication filling during follow-up, based on patterns of opioid dispensing in the year following Cesarean delivery. We then constructed a multivariable logistic regression model to identify independent risk factors for membership in the persistent user group. Results 285 of 80,127 (0.36%, 95% confidence interval 0.32 to 0.40), opioid-naïve women became persistent opioid users (identified using trajectory models based on monthly patterns of opioid dispensing) following Cesarean delivery. Demographics and baseline comorbidity predicted such use with moderate discrimination (c statistic = 0.73). Significant predictors included a history of cocaine abuse (risk 7.41%; adjusted odds ratio 6.11, 95% confidence interval 1.03 to 36.31) and other illicit substance abuse (2.36%; adjusted odds ratio 2.78, 95% confidence interval 1.12 to 6.91), tobacco use (1.45%; adjusted odds ratio 3.04, 95% confidence interval 2.03 to 4.55), back pain (0.69%; adjusted odds ratio 1.74, 95% confidence interval 1.33 to 2.29), migraines (0.91%; adjusted odds ratio 2.14, 95% confidence interval 1.58 to 2.90), antidepressant use (1.34%; adjusted odds ratio 3.19, 95% confidence interval 2.41 to 4.23) and benzodiazepine use (1.99%; adjusted odds ratio 3.72, 95% confidence interval 2.64 to 5.26) in the year prior to Cesarean delivery. Conclusions A very small proportion of opioid-naïve women (approximately 1 in 300) become persistent prescription opioid users following Cesarean delivery. Pre-existing psychiatric comorbidity, certain pain conditions, and substance use/abuse conditions identifiable at the time of initial opioid prescribing were predictors of persistent use. PMID:26996986

Emergency department patient satisfaction survey in Imam Reza Hospital, Tabriz, Iran

PubMed Central

2011-01-01

Introduction Patient satisfaction is an important indicator of the quality of care and service delivery in the emergency department (ED). The objective of this study was to evaluate patient satisfaction with the Emergency Department of Imam Reza Hospital in Tabriz, Iran. Methods This study was carried out for 1 week during all shifts. Trained researchers used the standard Press Ganey questionnaire. Patients were asked to complete the questionnaire prior to discharge. The study questionnaire included 30 questions based on a Likert scale. Descriptive and analytical statistics were used throughout data analysis in a number of ways using SPSS version 13. Results Five hundred patients who attended our ED were included in this study. The highest satisfaction rates were observed in the terms of physicians' communication with patients (82.5%), security guards' courtesy (78.3%) and nurses' communication with patients (78%). The average waiting time for the first visit to a physician was 24 min 15 s. The overall satisfaction rate was dependent on the mean waiting time. The mean waiting time for a low rate of satisfaction was 47 min 11 s with a confidence interval of (19.31, 74.51), and for very good level of satisfaction it was 14 min 57 s with a (10.58, 18.57) confidence interval. Approximately 63% of the patients rated their general satisfaction with the emergency setting as good or very good. On the whole, the patient satisfaction rate at the lowest level was 7.7 with a confidence interval of (5.1, 10.4), and at the low level it was 5.8% with a confidence interval of (3.7, 7.9). The rate of satisfaction for the mediocre level was 23.3 with a confidence interval of (19.1, 27.5); for the high level of satisfaction it was 28.3 with a confidence interval of (22.9, 32.8), and for the very high level of satisfaction, this rate was 32.9% with a confidence interval of (28.4, 37.4). Conclusion The study findings indicated the need for evidence-based interventions in emergency care services in areas such as medical care, nursing care, courtesy of staff, physical comfort and waiting time. Efforts should focus on shortening waiting intervals and improving patients' perceptions about waiting in the ED, and also improving the overall cleanliness of the emergency room. PMID:21407998

Comparison of WBRT alone, SRS alone, and their combination in the treatment of one or more brain metastases: Review and meta-analysis.

PubMed

Khan, Muhammad; Lin, Jie; Liao, Guixiang; Li, Rong; Wang, Baiyao; Xie, Guozhu; Zheng, Jieling; Yuan, Yawei

2017-07-01

Whole brain radiotherapy has been a standard treatment of brain metastases. Stereotactic radiosurgery provides more focal and aggressive radiation and normal tissue sparing but worse local and distant control. This meta-analysis was performed to assess and compare the effectiveness of whole brain radiotherapy alone, stereotactic radiosurgery alone, and their combination in the treatment of brain metastases based on randomized controlled trial studies. Electronic databases (PubMed, MEDLINE, Embase, and Cochrane Library) were searched to identify randomized controlled trial studies that compared treatment outcome of whole brain radiotherapy and stereotactic radiosurgery. This meta-analysis was performed using the Review Manager (RevMan) software (version 5.2) that is provided by the Cochrane Collaboration. The data used were hazard ratios with 95% confidence intervals calculated for time-to-event data extracted from survival curves and local tumor control rate curves. Odds ratio with 95% confidence intervals were calculated for dichotomous data, while mean differences with 95% confidence intervals were calculated for continuous data. Fixed-effects or random-effects models were adopted according to heterogeneity. Five studies (n = 763) were included in this meta-analysis meeting the inclusion criteria. All the included studies were randomized controlled trials. The sample size ranged from 27 to 331. In total 202 (26%) patients with whole brain radiotherapy alone, 196 (26%) patients receiving stereotactic radiosurgery alone, and 365 (48%) patients were in whole brain radiotherapy plus stereotactic radiosurgery group. No significant survival benefit was observed for any treatment approach; hazard ratio was 1.19 (95% confidence interval: 0.96-1.43, p = 0.12) based on three randomized controlled trials for whole brain radiotherapy only compared to whole brain radiotherapy plus stereotactic radiosurgery and hazard ratio was 1.03 (95% confidence interval: 0.82-1.29, p = 0.81) for stereotactic radiosurgery only compared to combined approach. Local control was best achieved when whole brain radiotherapy was combined with stereotactic radiosurgery. Hazard ratio 2.05 (95% confidence interval: 1.36-3.09, p = 0.0006) and hazard ratio 1.84 (95% confidence interval: 1.26-2.70, p = 0.002) were obtained from comparing whole brain radiotherapy only and stereotactic radiosurgery only to whole brain radiotherapy + stereotactic radiosurgery, respectively. No difference in adverse events for treatment difference; odds ratio 1.16 (95% confidence interval: 0.77-1.76, p = 0.48) and odds ratio 0.92 (95% confidence interval: 0.59-1.42, p = 71) for whole brain radiotherapy + stereotactic radiosurgery versus whole brain radiotherapy only and whole brain radiotherapy + stereotactic radiosurgery versus stereotactic radiosurgery only, respectively. Adding stereotactic radiosurgery to whole brain radiotherapy provides better local control as compared to whole brain radiotherapy only and stereotactic radiosurgery only with no difference in radiation related toxicities.

Maternal and neonatal outcomes after bariatric surgery; a systematic review and meta-analysis: do the benefits outweigh the risks?

PubMed

Kwong, Wilson; Tomlinson, George; Feig, Denice S

2018-02-15

Obesity during pregnancy is associated with a number of adverse obstetric outcomes that include gestational diabetes mellitus, macrosomia, and preeclampsia. Increasing evidence shows that bariatric surgery may decrease the risk of these outcomes. Our aim was to evaluate the benefits and risks of bariatric surgery in obese women according to obstetric outcomes. We performed a systematic literature search using MEDLINE, Embase, Cochrane, Web of Science, and PubMed from inception up to December 12, 2016. Studies were included if they evaluated patients who underwent bariatric surgery, reported subsequent pregnancy outcomes, and compared these outcomes with a control group. Two reviewers extracted study outcomes independently, and risk of bias was assessed with the use of the Newcastle-Ottawa Quality Assessment Scale. Pooled odds ratios for each outcome were estimated with the Dersimonian and Laird random effects model. After a review of 2616 abstracts, 20 cohort studies and approximately 2.8 million subjects (8364 of whom had bariatric surgery) were included in the metaanalysis. In our primary analysis, patients who underwent bariatric surgery showed reduced rates of gestational diabetes mellitus (odds ratio, 0.20; 95% confidence interval, 0.11-0.37, number needed to benefit, 5), large-for-gestational-age infants (odds ratio, 0.31; 95% confidence interval, 0.17-0.59; number needed to benefit, 6), gestational hypertension (odds ratio, 0.38; 95% confidence interval, 0.19-0.76; number needed to benefit, 11), all hypertensive disorders (odds ratio, 0.38; 95% confidence interval, 0.27-0.53; number needed to benefit, 8), postpartum hemorrhage (odds ratio, 0.32; 95% confidence interval, 0.08-1.37; number needed to benefit, 21), and caesarean delivery rates (odds ratio, 0.50; 95% confidence interval, 0.38-0.67; number needed to benefit, 9); however, group of patients showed an increase in small-for-gestational-age infants (odds ratio, 2.16; 95% confidence interval, 1.34-3.48; number needed to harm, 21), intrauterine growth restriction (odds ratio, 2.16; 95% confidence interval, 1.34-3.48; number needed to harm, 66), and preterm deliveries (odds ratio, 1.35; 95% confidence interval, 1.02-1.79; number needed to harm, 35) when compared with control subjects who were matched for presurgery body mass index. There were no differences in rates of preeclampsia, neonatal intensive care unit admissions, stillbirths, malformations, and neonatal death. Malabsorptive surgeries resulted in a greater increase in small-for-gestational-age infants (P=.0466) and a greater decrease in large-for-gestational-age infants (P=<.0001) compared with restrictive surgeries. There were no differences in outcomes when we used administrative databases vs clinical charts. Although bariatric surgery is associated with a reduction in the risk of several adverse obstetric outcomes, there is a potential for an increased risk of other important outcomes that should be considered when bariatric surgery is discussed with reproductive-age women. Copyright © 2018 Elsevier Inc. All rights reserved.

Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

ERIC Educational Resources Information Center

Padilla, Miguel A.; Divers, Jasmin

2013-01-01

The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

WASP (Write a Scientific Paper) using Excel - 6: Standard error and confidence interval.

PubMed

Grech, Victor

2018-03-01

The calculation of descriptive statistics includes the calculation of standard error and confidence interval, an inevitable component of data analysis in inferential statistics. This paper provides pointers as to how to do this in Microsoft Excel™. Copyright © 2018 Elsevier B.V. All rights reserved.

Robust Confidence Interval for a Ratio of Standard Deviations

ERIC Educational Resources Information Center

Bonett, Douglas G.

2006-01-01

Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

The microcomputer scientific software series 2: general linear model--regression.

Treesearch

Harold M. Rauscher

1983-01-01

The general linear model regression (GLMR) program provides the microcomputer user with a sophisticated regression analysis capability. The output provides a regression ANOVA table, estimators of the regression model coefficients, their confidence intervals, confidence intervals around the predicted Y-values, residuals for plotting, a check for multicollinearity, a...

Toward Using Confidence Intervals to Compare Correlations

ERIC Educational Resources Information Center

Zou, Guang Yong

2007-01-01

Confidence intervals are widely accepted as a preferred way to present study results. They encompass significance tests and provide an estimate of the magnitude of the effect. However, comparisons of correlations still rely heavily on significance testing. The persistence of this practice is caused primarily by the lack of simple yet accurate…

Women seeking treatment for advanced pelvic organ prolapse have decreased body image and quality of life.

PubMed

Jelovsek, J Eric; Barber, Matthew D

2006-05-01

Women who seek treatment for pelvic organ prolapse strive for an improvement in quality of life. Body image has been shown to be an important component of differences in quality of life. To date, there are no data on body image in patients with advanced pelvic organ prolapse. Our objective was to compare body image and quality of life in women with advanced pelvic organ prolapse with normal controls. We used a case-control study design. Cases were defined as subjects who presented to a tertiary urogynecology clinic with advanced pelvic organ prolapse (stage 3 or 4). Controls were defined as subjects who presented to a tertiary care gynecology or women's health clinic for an annual visit with normal pelvic floor support (stage 0 or 1) and without urinary incontinence. All patients completed a valid and reliable body image scale and a generalized (Short Form Health Survey) and condition-specific (Pelvic Floor Distress Inventory-20) quality-of-life scale. Linear and logistic regression analyses were performed to adjust for possible confounding variables. Forty-seven case and 51 control subjects were enrolled. After controlling for age, race, parity, previous hysterectomy, and medical comorbidities, subjects with advanced pelvic organ prolapse were more likely to feel self-conscious (adjusted odds ratio 4.7; 95% confidence interval 1.4 to 18, P = .02), less likely to feel physically attractive (adjusted odds ratio 11; 95% confidence interval 2.9 to 51, P < .001), less likely to feel feminine (adjusted odds ratio 4.0; 95% confidence interval 1.2 to 15, P = .03), and less likely to feel sexually attractive (adjusted odds ratio 4.6; 95% confidence interval 1.4 to 17, P = .02) than normal controls. The groups were similar in their feeling of dissatisfaction with appearance when dressed, difficulty looking at themselves naked, avoiding people because of appearance, and overall dissatisfaction with their body. Subjects with advanced pelvic organ prolapse suffered significantly lower quality of life on the physical scale of the SF-12 (mean 42; 95% confidence interval 39 to 45 versus mean 50; 95% confidence interval 47 to 53, P < .009). However, no differences between groups were noted on the mental scale of the SF-12 (mean 51; 95% confidence interval 50 to 54 versus mean 50; 95% confidence interval 47 to 52, P = .56). Additionally, subjects with advanced pelvic organ prolapse scored significantly worse on the prolapse, urinary, and colorectal scales and overall summary score of Pelvic Floor Distress Inventory-20 than normal controls (mean summary score 104; 95% confidence interval 90 to 118 versus mean 29; 95% confidence interval 16 to 43, P < .0001), indicating a decrease in condition-specific quality of life. Worsening body image correlated with lower quality of life on both the physical and mental scales of the SF-12 as well as the prolapse, urinary, and colorectal scales and overall summary score of Pelvic Floor Distress Inventory-20 in subjects with advanced pelvic organ prolapse. Women seeking treatment for advanced pelvic organ prolapse have decreased body image and overall quality of life. Body image may be a key determinant for quality of life in patients with advanced prolapse and may be an important outcome measure for treatment evaluation in clinical trials.

Exercise during pregnancy in normal-weight women and risk of preterm birth: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Di Mascio, Daniele; Magro-Malosso, Elena Rita; Saccone, Gabriele; Marhefka, Gregary D; Berghella, Vincenzo

2016-11-01

Preterm birth is the major cause of perinatal mortality in the United States. In the past, pregnant women have been recommended to not exercise because of presumed risks of preterm birth. Physical activity has been theoretically related to preterm birth because it increases the release of catecholamines, especially norepinephrine, which might stimulate myometrial activity. Conversely, exercise may reduce the risk of preterm birth by other mechanisms such as decreased oxidative stress or improved placenta vascularization. Therefore, the safety of exercise regarding preterm birth and its effects on gestational age at delivery remain controversial. The objective of the study was to evaluate the effects of exercise during pregnancy on the risk of preterm birth. MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and Cochrane Library were searched from the inception of each database to April 2016. Selection criteria included only randomized clinical trials of pregnant women randomized before 23 weeks to an aerobic exercise regimen or not. Types of participants included women of normal weight with uncomplicated, singleton pregnancies without any obstetric contraindication to physical activity. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals. The primary outcome was the incidence of preterm birth <37 weeks. Of the 2059 women included in the meta-analysis, 1022 (49.6%) were randomized to the exercise group and 1037 (50.4%) to the control group. Aerobic exercise lasted about 35-90 minutes 3-4 times per week. Women who were randomized to aerobic exercise had a similar incidence of preterm birth of <37 weeks (4.5% vs 4.4%; relative risk, 1.01, 95% confidence interval, 0.68-1.50) and a similar mean gestational age at delivery (mean difference, 0.05 week, 95% confidence interval, -0.07 to 0.17) compared with controls. Women in the exercise group had a significantly higher incidence of vaginal delivery (73.6% vs 67.5%; relative risk, 1.09, 95% confidence interval, 1.04-1.15) and a significantly lower incidence of cesarean delivery (17.9% vs 22%; relative risk, 0.82, 95% confidence interval, 0.69-0.97) compared with controls. The incidence of operative vaginal delivery (12.9% vs 16.5%; relative risk, 0.78, 95% confidence interval, 0.61-1.01) was similar in both groups. Women in the exercise group had a significantly lower incidence of gestational diabetes mellitus (2.9% vs 5.6%; relative risk, 0.51, 95% confidence interval, 0.31-0.82) and a significantly lower incidence of hypertensive disorders (1.0% vs 5.6%; relative risk, 0.21, 95% confidence interval, 0.09-0.45) compared with controls. No differences in low birthweight (5.2% vs 4.7%; relative risk, 1.11, 95% confidence interval, 0.72-1.73) and mean birthweight (mean difference, -10.46 g, 95% confidence interval, -47.10 to 26.21) between the exercise group and controls were found. Aerobic exercise for 35-90 minutes 3-4 times per week during pregnancy can be safely performed by normal-weight women with singleton, uncomplicated gestations because this is not associated with an increased risk of preterm birth or with a reduction in mean gestational age at delivery. Exercise was associated with a significantly higher incidence of vaginal delivery and a significantly lower incidence of cesarean delivery, with a significantly lower incidence of gestational diabetes mellitus and hypertensive disorders and therefore should be encouraged. Copyright © 2016. Published by Elsevier Inc.

Combination HIV prevention among MSM in South Africa: results from agent-based modeling.

PubMed

Brookmeyer, Ron; Boren, David; Baral, Stefan D; Bekker, Linda-Gail; Phaswana-Mafuya, Nancy; Beyrer, Chris; Sullivan, Patrick S

2014-01-01

HIV prevention trials have demonstrated the effectiveness of a number of behavioral and biomedical interventions. HIV prevention packages are combinations of interventions and offer potential to significantly increase the effectiveness of any single intervention. Estimates of the effectiveness of prevention packages are important for guiding the development of prevention strategies and for characterizing effect sizes before embarking on large scale trials. Unfortunately, most research to date has focused on testing single interventions rather than HIV prevention packages. Here we report the results from agent-based modeling of the effectiveness of HIV prevention packages for men who have sex with men (MSM) in South Africa. We consider packages consisting of four components: antiretroviral therapy for HIV infected persons with CD4 count <350; PrEP for high risk uninfected persons; behavioral interventions to reduce rates of unprotected anal intercourse (UAI); and campaigns to increase HIV testing. We considered 163 HIV prevention packages corresponding to different intensity levels of the four components. We performed 2252 simulation runs of our agent-based model to evaluate those packages. We found that a four component package consisting of a 15% reduction in the rate of UAI, 50% PrEP coverage of high risk uninfected persons, 50% reduction in persons who never test for HIV, and 50% ART coverage over and above persons already receiving ART at baseline, could prevent 33.9% of infections over 5 years (95% confidence interval, 31.5, 36.3). The package components with the largest incremental prevention effects were UAI reduction and PrEP coverage. The impact of increased HIV testing was magnified in the presence of PrEP. We find that HIV prevention packages that include both behavioral and biomedical components can in combination prevent significant numbers of infections with levels of coverage, acceptance and adherence that are potentially achievable among MSM in South Africa.

Stent coverage and neointimal proliferation in bare metal stents postdilated with a Paclitaxel-eluting balloon versus everolimus-eluting stents: prospective randomized study using optical coherence tomography at 6-month follow-up.

PubMed

Poerner, Tudor C; Otto, Sylvia; Gassdorf, Johannes; Nitsche, Kristina; Janiak, Florian; Scheller, Bruno; Goebel, Björn; Jung, Christian; Figulla, Hans R

2014-12-01

In this randomized trial, strut coverage and neointimal proliferation of a therapy of bare metal stents (BMSs) postdilated with the paclitaxel drug-eluting balloon (DEB) was compared with everolimus drug-eluting stents (DESs) at 6-month follow-up using optical coherence tomography. We hypothesized sufficient stent coverage at follow-up. A total of 105 lesions in 90 patients were treated with either XIENCE V DES (n=51) or BMS postdilated with the SeQuent Please DEB (n=54). At follow-up, comparable results on the primary optical coherence tomography end point (percentage uncovered struts 5.64±9.65% in BMS+DEB versus 4.93±9.29% in DES; P=0.366) were found. Thus, BMS+DEB achieved the prespecified noninferiority margin of 5% uncovered struts versus DES (difference between treatment means, 0.71%; one-sided upper 95% confidence interval, 4.14%; noninferiority P=0.04). Optical coherence tomography analysis showed significantly more global neointimal proliferation in the BMS+DEB group (15.7±7.8 versus 11.0±5.2 mm(3) proliferation volume/cm stent length; P=0.002). No significant focal in-stent stenosis analyzed with angiography (percentage diameter stenosis at follow-up, 22.8±11.9 versus 16.9±10.4; P=0.014) and optical coherence tomography (peak local area stenosis, 39.5±13.8% versus 36.8±15.6%; P=0.409) was found. Good stent strut coverage of >94% was found in both therapy groups. Despite greater suppression of global neointimal growth in DES, both DES and BMS+DEB effectively prevented clinically relevant focal restenosis at 6-month follow-up. http://www.clinicaltrials.gov. Unique identifier: NCT01056744. © 2014 American Heart Association, Inc.

Reporting of HIV-infected pregnant women: estimates from a Brazilian study.

PubMed

Domingues, Rosa Maria Soares Madeira; Saraceni, Valéria; Leal, Maria do Carmo

2018-01-01

To estimate the coverage of the reporting of cases of HIV-infected pregnant women, to estimate the increase in the coverage of the reporting with the routine search of data in other Brazilian health information systems, and to identify missed opportunities for identification of HIV-infected pregnant women in Brazilian maternity hospitals. This is a descriptive study on the linkage of Brazilian databases with primary data from the "Nascer no Brasil" study and secondary database collection from national health information systems. The "Nascer no Brasil" is a national-based study carried out in 2011-2012 with 23,894 pregnant women, which identified HIV-infected pregnant women using prenatal and medical records. We searched for cases of HIV-infected pregnant women identified in the "Nascer no Brasil" study in the Information System of Notifiable Diseases, the Control System for Laboratory Tests of the National CD4+/CD8+ Lymphocyte Count and HIV Viral Load Network, and the Logistics Control System for Medications. We used the OpenRecLink software for the linkage of databases. We estimated the notification coverage, with the respective confidence interval, of the evaluated Brazilian health information systems. We estimated the coverage of the reporting of HIV-infected pregnant women in the Information System of Notifiable Diseases as 57.1% (95%CI 42.9-70.2), and we located 89.3% of the HIV-infected pregnant women (95%CI 81.2-94.2) in some of the Brazilian health information systems researched. The search in other national health information systems would result in an increase of 57.1% of the reported cases. We identified no missed opportunities for the diagnosis of HIV+ in pregnant women in the maternity hospitals evaluated by the "Nascer no Brasil" study. The routine search for information in other Brazilian health information systems, a procedure carried out by the Ministry of Health for cases of AIDS in adults and children, should be adopted for cases of HIV in pregnancy.

Estimating chlamydia screening coverage: a comparison of self-report and health care effectiveness data and information set measures.

PubMed

Khosropour, Christine M; Broad, Jennifer M; Scholes, Delia; Saint-Johnson, Jacquelyn; Manhart, Lisa E; Golden, Matthew R

2014-11-01

Population-based surveys (self-report) and health insurance administrative data (Healthcare Effectiveness Data and Information Set [HEDIS]) are used to estimate chlamydia screening coverage in the United States. Estimates from these methods differ, but few studies have compared these 2 indices in the same population. In 2010, we surveyed a random sample of women aged 18 to 25 years enrolled in a Washington State-managed care organization. Respondents were asked if they were sexually active in last year and if they tested for chlamydia in that time. We linked survey responses to administrative records of chlamydia testing and reproductive/testing services used, which comprise the HEDIS definition of the screened population and the sexually active population, respectively. We compared self-report and HEDIS using 3 outcomes: (1) sexual activity (gold standard = self-report), (2) any chlamydia screening (no gold standard), and (3) within-plan chlamydia screening (gold standard = HEDIS). Of 954 eligible respondents, 377 (40%) completed the survey and consented to administrative record linkage. Chlamydia screening estimates for HEDIS and self-report were 47% and 53%, respectively. The sensitivity and specificity of HEDIS to define sexually active women were 84.8% (95% confidence interval [CI], 79.6%-89.1%) and 63.5% (95% CI, 52.4%-73.7%), respectively. Forty percent of women had a chlamydia test in their administrative record, but 53% self-reported being tested for chlamydia (κ = 0.35); 19% reported out-of-plan chlamydia testing. The sensitivity of self-reported within-plan chlamydia testing was 71.3% (95% CI, 61.0%-80.1%); the specificity was 80.6% (95% CI, 72.6%-87.2%). The Healthcare Effectiveness Data and Information Set does not accurately identify sexually active women and may underestimate chlamydia testing coverage. Self-reported testing may not be an accurate measure of true chlamydial testing coverage.

Malaria Control Interventions Contributed to Declines in Malaria Parasitemia, Severe Anemia, and All-Cause Mortality in Children Less Than 5 Years of Age in Malawi, 2000-2010.

PubMed

Hershey, Christine L; Florey, Lia S; Ali, Doreen; Bennett, Adam; Luhanga, Misheck; Mathanga, Don P; Salgado, S René; Nielsen, Carrie F; Troell, Peter; Jenda, Gomezgani; Yé, Yazoume; Bhattarai, Achuyt

2017-09-01

Malaria control intervention coverage increased nationwide in Malawi during 2000-2010. Trends in intervention coverage were assessed against trends in malaria parasite prevalence, severe anemia (hemoglobin < 8 g/dL), and all-cause mortality in children under 5 years of age (ACCM) using nationally representative household surveys. Associations between insecticide-treated net (ITN) ownership, malaria morbidity, and ACCM were also assessed. Household ITN ownership increased from 27.4% (95% confidence interval [CI] = 25.9-29.0) in 2004 to 56.8% (95% CI = 55.6-58.1) in 2010. Similarly intermittent preventive treatment during pregnancy coverage increased from 28.2% (95% CI = 26.7-29.8) in 2000 to 55.0% (95% CI = 53.4-56.6) in 2010. Malaria parasite prevalence decreased significantly from 60.5% (95% CI = 53.0-68.0) in 2001 to 20.4% (95% CI = 15.7-25.1) in 2009 in children aged 6-35 months. Severe anemia prevalence decreased from 20.4% (95% CI: 17.3-24.0) in 2004 to 13.1% (95% CI = 11.0-15.4) in 2010 in children aged 6-23 months. ACCM decreased 41%, from 188.6 deaths per 1,000 live births (95% CI = 179.1-198.0) during 1996-2000, to 112.1 deaths per 1,000 live births (95% CI = 105.8-118.5) during 2006-2010. When controlling for other covariates in random effects logistic regression models, household ITN ownership was protective against malaria parasitemia in children (odds ratio [OR] = 0.81, 95% CI = 0.72-0.92) and severe anemia (OR = 0.82, 95% CI = 0.72-0.94). After considering the magnitude of changes in malaria intervention coverage and nonmalaria factors, and given the contribution of malaria to all-cause mortality in malaria-endemic countries, the substantial increase in malaria control interventions likely improved child survival in Malawi during 2000-2010.

Neighborhood-targeted and case-triggered use of a single dose of oral cholera vaccine in an urban setting: Feasibility and vaccine coverage.

PubMed

Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Muller, Vincent; Llosa, Augusto E; Uzzeni, Florent; Luquero, Francisco J; Ciglenecki, Iza; Azman, Andrew S

2017-06-01

In June 2015, a cholera outbreak was declared in Juba, South Sudan. In addition to standard outbreak control measures, oral cholera vaccine (OCV) was proposed. As sufficient doses to cover the at-risk population were unavailable, a campaign using half the standard dosing regimen (one-dose) targeted high-risk neighborhoods and groups including neighbors of suspected cases. Here we report the operational details of this first public health use of a single-dose regimen of OCV and illustrate the feasibility of conducting highly targeted vaccination campaigns in an urban area. Neighborhoods of the city were prioritized for vaccination based on cumulative attack rates, active transmission and local knowledge of known cholera risk factors. OCV was offered to all persons older than 12 months at 20 fixed sites and to select groups, including neighbors of cholera cases after the main campaign ('case-triggered' interventions), through mobile teams. Vaccination coverage was estimated by multi-stage surveys using spatial sampling techniques. 162,377 individuals received a single-dose of OCV in the targeted neighborhoods. In these neighborhoods vaccine coverage was 68.8% (95% Confidence Interval (CI), 64.0-73.7) and was highest among children ages 5-14 years (90.0%, 95% CI 85.7-94.3), with adult men being less likely to be vaccinated than adult women (Relative Risk 0.81, 95% CI: 0.68-0.96). In the case-triggered interventions, each lasting 1-2 days, coverage varied (range: 30-87%) with an average of 51.0% (95% CI 41.7-60.3). Vaccine supply constraints and the complex realities where cholera outbreaks occur may warrant the use of flexible alternative vaccination strategies, including highly-targeted vaccination campaigns and single-dose regimens. We showed that such campaigns are feasible. Additional work is needed to understand how and when to use different strategies to best protect populations against epidemic cholera.

Theoretical Benefits of Dynamic Collimation in Pencil Beam Scanning Proton Therapy for Brain Tumors: Dosimetric and Radiobiological Metrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moignier, Alexandra, E-mail: alexandra-moignier@uiowa.edu; Gelover, Edgar; Wang, Dongxu

Purpose: To quantify the dosimetric benefit of using a dynamic collimation system (DCS) for penumbra reduction during the treatment of brain tumors by pencil beam scanning proton therapy (PBS PT). Methods and Materials: Collimated and uncollimated brain treatment plans were created for 5 patients previously treated with PBS PT and retrospectively enrolled in an institutional review board–approved study. The in-house treatment planning system, RDX, was used to generate the plans because it is capable of modeling both collimated and uncollimated beamlets. The clinically delivered plans were reproduced with uncollimated plans in terms of target coverage and organ at risk (OAR) sparingmore » to ensure a clinically relevant starting point, and collimated plans were generated to improve the OAR sparing while maintaining target coverage. Physical and biological comparison metrics, such as dose distribution conformity, mean and maximum doses, normal tissue complication probability, and risk of secondary brain cancer, were used to evaluate the plans. Results: The DCS systematically improved the dose distribution conformity while preserving the target coverage. The average reduction of the mean dose to the 10-mm ring surrounding the target and the healthy brain were 13.7% (95% confidence interval [CI] 11.6%-15.7%; P<.0001) and 25.1% (95% CI 16.8%-33.4%; P<.001), respectively. This yielded an average reduction of 24.8% (95% CI 0.8%-48.8%; P<.05) for the brain necrosis normal tissue complication probability using the Flickinger model, and 25.1% (95% CI 16.8%-33.4%; P<.001) for the risk of secondary brain cancer. A general improvement of the OAR sparing was also observed. Conclusion: The lateral penumbra reduction afforded by the DCS increases the normal tissue sparing capabilities of PBS PT for brain cancer treatment while preserving target coverage.« less

HIV Prevalence among Pregnant Women in Brazil: A National Survey.

PubMed

Pereira, Gerson Fernando Mendes; Sabidó, Meritxell; Caruso, Alessandro; Oliveira, Silvano Barbosa de; Mesquita, Fábio; Benzaken, Adele Schwartz

2016-08-01

Background This study was conducted to determine the seroprevalence of HIV among pregnant women in Brazil and to describe HIV testing coverage and the uptake of antenatal care (ANC). Methods Between October 2010 and January 2012, a probability sample survey of parturient women aged 15-49 years who visited public hospital delivery services in Brazil was conducted. Data were collected from prenatal reports and hospital records. Dried blood spot (DNS) samples were collected and tested for HIV. We describe the age-specific prevalence of HIV infection and ANC uptake with respect to sociodemographic factors. Results Of the 36,713 included women, 35,444 (96.6%) were tested for HIV during delivery admission. The overall HIV prevalence was of 0.38% (95% confidence interval [CI]: 0.31-0.48), and it was highest in: the 30 to 39 year-old age group (0.60% [0.40-0.88]), in the Southern region of Brazil (0.79% [0.59-1.04]), among women who had not completed primary (0.63% [0.30-1.31]) or secondary (0.67% [0.49-0.97]) school education, and among women who self-reported as Asian (0.94% [0.28-3.10]). The HIV testing coverage during prenatal care was of 86.6% for one test and of 38.2% for two tests. Overall, 98.5% of women attended at least 1 ANC visit, 90.4% attended at least 4 visits, 71% attended at least 6 visits, and 51.7% received ANC during the 1st trimester. HIV testing coverage and ANC uptake indicators increased with increasing age and education level of education, and were highest in the Southern region. Conclusions Brazil presents an HIV prevalence of less than 1% and almost universal coverage of ANC. However, gaps in HIV testing and ANC during the first trimester challenge the prevention of the vertical transmission of HIV. More efforts are needed to address regional and social disparities. Thieme Publicações Ltda Rio de Janeiro, Brazil.

Emergency Department Coverage by Primary Care Physicians in a Rural Practice-Based Research Network: Incentives, Confidence, and Training

ERIC Educational Resources Information Center

Lew, Edward; Fagnan, Lyle J.; Mattek, Nora; Mahler, Jo; Lowe, Robert A.

2009-01-01

Context: In rural areas of the United States, emergency departments (EDs) are often staffed by primary care physicians, as contrasted to urban and suburban hospitals where ED coverage is usually provided by physicians who are residency-trained in emergency medicine. Purpose: This study examines the reasons and incentives for rural Oregon primary…

A simple method for assessing occupational exposure via the one-way random effects model.

PubMed

Krishnamoorthy, K; Mathew, Thomas; Peng, Jie

2016-11-01

A one-way random effects model is postulated for the log-transformed shift-long personal exposure measurements, where the random effect in the model represents an effect due to the worker. Simple closed-form confidence intervals are proposed for the relevant parameters of interest using the method of variance estimates recovery (MOVER). The performance of the confidence bounds is evaluated and compared with those based on the generalized confidence interval approach. Comparison studies indicate that the proposed MOVER confidence bounds are better than the generalized confidence bounds for the overall mean exposure and an upper percentile of the exposure distribution. The proposed methods are illustrated using a few examples involving industrial hygiene data.

Vaccination Week in the Americas, 2011: an opportunity to assess the routine vaccination program in the Bolivarian Republic of Venezuela.

PubMed

Sánchez, Daniel; Sodha, Samir V; Kurtis, Hannah J; Ghisays, Gladys; Wannemuehler, Kathleen A; Danovaro-Holliday, M Carolina; Ropero-Álvarez, Alba María

2015-04-17

Vaccination Week in the Americas (VWA) is an annual initiative in countries and territories of the Americas every April to highlight the work of national expanded programs on immunization (EPI) and increase access to vaccination services for high-risk population groups. In 2011, as part of VWA, Venezuela targeted children aged less than 6 years in 25 priority border municipalities using social mobilization to increase institution-based vaccination. Implementation of social communication activities was decentralized to the local level. We conducted a survey in one border municipality of Venezuela to evaluate the outcome of VWA 2011 and provide a snapshot of the overall performance of the routine EPI at that level. We conducted a coverage survey, using stratified cluster sampling, in the Venezuelan municipality of Bolivar (bordering Colombia) in August 2011. We collected information for children aged <6 years through caregiver interviews and transcription of vaccination card data. We estimated each child's eligibility to receive a specific vaccine dose during VWA 2011 and whether or not they were actually vaccinated during VWA activities. We also estimated baseline vaccination coverage, timeliness and 95% confidence intervals (CI), and used chi-square tests to compare coverage across age cohorts, taking into account the sampling design. We surveyed 839 children from 698 households; 93% of children had a vaccination card. Among households surveyed, 216 (31%) caregivers reported having heard about a vaccination activity during April or May 2011. Of the 528 children eligible to receive a vaccine during VWA, 24% received at least one dose, while 13% received all doses due. Overall, baseline coverage with routine vaccines, as measured by the survey, was >85%, with a few exceptions. Low levels of VWA awareness among caregivers probably contributed to the limited vaccination of eligible children during the VWA activities in Bolivar in 2011. However, vaccine coverage for most EPI vaccines was high. Additionally, high vaccination card availability and high participation in VWA among those caregivers aware of it in 2011 suggest public trust in the EPI program in the municipality. Health authorities have used survey findings to inform changes to the routine EPI and better VWA implementation in subsequent years.

Exploring the use of routinely-available, retrospective data to study the association between malaria control scale-up and micro-economic outcomes in Zambia.

PubMed

Comfort, Alison; Leegwater, Anthony; Nakhimovsky, Sharon; Kansembe, Henry; Hamainza, Busiku; Bwalya, Benson; Alilio, Martin; Johns, Ben; Olsho, Lauren

2017-01-04

Country-level evidence on the impact of malaria control on micro-economic outcomes is vital for mobilizing domestic and donor resources for malaria control. Using routinely available survey data could facilitate this investigation in a cost-efficient way. The authors used Malaria Indicator Surveys (MIS) and Living Conditions Monitoring Survey (LCMS) data from 2006 to 2010 for all 72 districts in Zambia to relate malaria control scale-up with household food spending (proxy for household well-being), educational attainment and agricultural production. The authors used two quasi-experimental designs: (1) a generalized propensity score for a continuous treatment variable (defined as coverage from owning insecticide-treated bed nets and/or receipt of indoor residual spraying); and, (2) a district fixed effects model to assess changes in the outcome relative to changes in treatment pre-post scale-up. The unit of analysis was at district level. The authors also conducted simulations post-analysis to assess statistical power. Micro-economic outcomes increased (33% increase in food spending) concurrently with malaria control coverage (62% increase) from 2006 to 2010. Despite using data from all 72 districts, both analytic methods yielded wide confidence intervals that do not conclusively link outcomes and malaria control coverage increases. The authors cannot rule out positive, null or negative effects. The upper bound estimates of the results show that if malaria control coverage increases from 60 to 70%, food spending could increase up to 14%, maize production could increase up to 57%, and years of schooling could increase up to 0.5 years. Simulations indicated that the generalized propensity score model did not have good statistical power. While it is technically possible to use routinely available survey data to relate malaria control scale-up and micro-economic outcomes, it is not clear from this analysis that meaningful results can be obtained when survey data are highly aggregated. Researchers in similar settings should assess the feasibility of disaggregating existing survey data. Additionally, large surveys, such as LCMS and MIS, could incorporate data on both malaria coverage and household expenditures, respectively.

Rotavirus vaccine coverage and factors associated with uptake using linked data: Ontario, Canada

PubMed Central

Chung, Hannah; Schwartz, Kevin L.; Guttmann, Astrid; Deeks, Shelley L.; Kwong, Jeffrey C.; Crowcroft, Natasha S.; Wing, Laura; Tu, Karen

2018-01-01

Background In August 2011, Ontario, Canada introduced a rotavirus immunization program using Rotarix™ vaccine. No assessments of rotavirus vaccine coverage have been previously conducted in Ontario. Methods We assessed vaccine coverage (series initiation and completion) and factors associated with uptake using the Electronic Medical Record Administrative data Linked Database (EMRALD), a collection of family physician electronic medical records (EMR) linked to health administrative data. Series initiation (1 dose) and series completion (2 doses) before and after the program’s introduction were calculated. To identify factors associated with series initiation and completion, adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) were calculated using logistic regression. Results A total of 12,525 children were included. Series completion increased each year of the program (73%, 79% and 84%, respectively). Factors associated with series initiation included high continuity of care (aOR = 2.15; 95%CI, 1.61–2.87), maternal influenza vaccination (aOR = 1.55; 95%CI,1.24–1.93), maternal immmigration to Canada in the last five years (aOR = 1.47; 95% CI, 1.05–2.04), and having no siblings (aOR = 1.62; 95%CI,1.30–2.03). Relative to the first program year, infants were more likely to initiate the series in the second year (aOR = 1.71; 95% CI 1.39–2.10) and third year (aOR = 2.02; 95% CI 1.56–2.61) of the program. Infants receiving care from physicians with large practices were less likely to initiate the series (aOR 0.91; 95%CI, 0.88–0.94, per 100 patients rostered) and less likely to complete the series (aOR 0.94; 95%CI, 0.91–0.97, per 100 patients rostered). Additional associations were identified for series completion. Conclusions Family physician delivery achieved moderately high coverage in the program’s first three years. This assessment demonstrates the usefulness of EMR data for evaluating vaccine coverage. Important insights into factors associated with initiation or completion (i.e. high continuity of care, smaller roster sizes, rural practice location) suggest areas for research and potential program supports. PMID:29444167

Red blood cell transfusion, hyperkalemia, and heart failure in advanced chronic kidney disease.

PubMed

Gill, Karminder; Fink, Jeffrey C; Gilbertson, David T; Monda, Keri L; Muntner, Paul; Lafayette, Richard A; Petersen, Jeffrey; Chertow, Glenn M; Bradbury, Brian D

2015-06-01

In recent years, the use of red blood cell (RBC) transfusion for the treatment of chronic kidney disease (CKD)-related anemia has increased. We used the OptumInsight medical claims database to study the association between receiving a transfusion and hyperkalemia and heart failure events. Persons 18-64 years of age with diagnosed stage 4 or 5 CKD (not requiring dialysis) between 2006 and 2010 were followed until their first hospitalization or emergency room visit with a diagnosis of hyperkalemia or heart failure, termination of insurance coverage, or death. We used a case-only design and conditional logistic regression to estimate rate ratios (RR) and 95% confidence intervals (CIs) describing associations between RBC transfusion and the risks of hyperkalemia or heart failure. We used single (1:1) and variable (1:m) self-control matching intervals, with adjustment for time-varying confounders. Seven thousand eight hundred twenty-nine individuals met our inclusion criteria; two-thirds were age 50 years or older; 43% were women and 51% had diabetes. Rates of hyperkalemia and heart failure were 7.9/100 person-years (95%CI: 7.3, 8.5) and 16.3/100 person-years (95%CI: 15.5, 17.2), respectively. RBC transfusion was associated with an increased risk of both hyperkalemia (single interval matched RR = 12.0, 95%CI: 1.3, 109; multiple interval matched RR = 6.1, 95%CI: 2.5, 15.1) and heart failure (single interval matched RR = 1.7, 95%CI: 0.3, 9.2; multiple interval matched RR = 3.8, 95%CI: 1.4, 10.3). In patients with advanced CKD, RBC transfusion appears to be associated with an elevated risk of hyperkalemia and heart failure; further investigation into these risks is warranted. Copyright © 2015 John Wiley & Sons, Ltd.

Compound Event Barrier Coverage in Wireless Sensor Networks under Multi-Constraint Conditions.

PubMed

Zhuang, Yaoming; Wu, Chengdong; Zhang, Yunzhou; Jia, Zixi

2016-12-24

It is important to monitor compound event by barrier coverage issues in wireless sensor networks (WSNs). Compound event barrier coverage (CEBC) is a novel coverage problem. Unlike traditional ones, the data of compound event barrier coverage comes from different types of sensors. It will be subject to multiple constraints under complex conditions in real-world applications. The main objective of this paper is to design an efficient algorithm for complex conditions that can combine the compound event confidence. Moreover, a multiplier method based on an active-set strategy (ASMP) is proposed to optimize the multiple constraints in compound event barrier coverage. The algorithm can calculate the coverage ratio efficiently and allocate the sensor resources reasonably in compound event barrier coverage. The proposed algorithm can simplify complex problems to reduce the computational load of the network and improve the network efficiency. The simulation results demonstrate that the proposed algorithm is more effective and efficient than existing methods, especially in the allocation of sensor resources.

Compound Event Barrier Coverage in Wireless Sensor Networks under Multi-Constraint Conditions

PubMed Central

Zhuang, Yaoming; Wu, Chengdong; Zhang, Yunzhou; Jia, Zixi

2016-01-01

It is important to monitor compound event by barrier coverage issues in wireless sensor networks (WSNs). Compound event barrier coverage (CEBC) is a novel coverage problem. Unlike traditional ones, the data of compound event barrier coverage comes from different types of sensors. It will be subject to multiple constraints under complex conditions in real-world applications. The main objective of this paper is to design an efficient algorithm for complex conditions that can combine the compound event confidence. Moreover, a multiplier method based on an active-set strategy (ASMP) is proposed to optimize the multiple constraints in compound event barrier coverage. The algorithm can calculate the coverage ratio efficiently and allocate the sensor resources reasonably in compound event barrier coverage. The proposed algorithm can simplify complex problems to reduce the computational load of the network and improve the network efficiency. The simulation results demonstrate that the proposed algorithm is more effective and efficient than existing methods, especially in the allocation of sensor resources. PMID:28029118

Simulation data for an estimation of the maximum theoretical value and confidence interval for the correlation coefficient.

PubMed

Rocco, Paolo; Cilurzo, Francesco; Minghetti, Paola; Vistoli, Giulio; Pedretti, Alessandro

2017-10-01

The data presented in this article are related to the article titled "Molecular Dynamics as a tool for in silico screening of skin permeability" (Rocco et al., 2017) [1]. Knowledge of the confidence interval and maximum theoretical value of the correlation coefficient r can prove useful to estimate the reliability of developed predictive models, in particular when there is great variability in compiled experimental datasets. In this Data in Brief article, data from purposely designed numerical simulations are presented to show how much the maximum r value is worsened by increasing the data uncertainty. The corresponding confidence interval of r is determined by using the Fisher r → Z transform.

Efficacy of oral azithromycin versus topical tetracycline in mass treatment of endemic trachoma.

PubMed Central

Fraser-Hurt, N.; Bailey, R. L.; Cousens, S.; Mabey, D.; Faal, H.; Mabey, D. C.

2001-01-01

OBJECTIVE: To compare the impact of mass treatment with oral azithromycin and topical tetracycline on the prevalence of active trachoma. METHODS: A total of 1803 inhabitants from 106 households of eight Gambian villages were randomized, in pairs, to receive either three doses of azithromycin at weekly intervals, or daily topical tetracycline over 6 weeks. Ocular examinations were conducted before treatment, and 2, 6 and 12 months after treatment. FINDINGS: Prior to treatment, 16% of the study participants had active trachoma. Two months after treatment, the prevalence of trachoma was 4.6% and 5.1% in the azithromycin and the tetracycline groups, respectively (adjusted odds ratio (OR) = 1.09; 95% confidence interval (CI) = 0.53, 2.02). Subsequently, the prevalence rose to 16% in the tetracycline group, while remaining at 7.7% in the azithromycin group (adjusted OR at 12 months = 0.52; 95% CI = 0.34, 0.80). At 12 months post-treatment, there were fewer new prevalent cases in the azithromycin group, and trachoma resolution was significantly better for this group (adjusted OR = 2.02; 95% CI = 1.42, 3.50). CONCLUSION: Oral azithromycin therefore appears to offer a means for controlling blinding trachoma. It is easy to administer and higher coverages may be possible than have been achieved hitherto. PMID:11477966

Making medical decisions in dependence of genetic background: estimation of the utility of DNA testing in clinical, pharmaco-epidemiological or genetic studies.

PubMed

Nguyen, Thuy Trang; Schäfer, Helmut; Timmesfeld, Nina

2013-05-01

An index measuring the utility of testing a DNA marker before deciding between two alternative treatments is proposed which can be estimated from pharmaco-epidemiological case-control or cohort studies. In the case-control design, external estimates of the prevalence of the disease and of the frequency of the genetic risk variant are required for estimating the utility index. Formulas for point and interval estimates are derived. Empirical coverage probabilities of the confidence intervals were estimated under different scenarios of disease prevalence, prevalence of drug use, and population frequency of the genetic variant. To illustrate our method, we re-analyse pharmaco-epidemiological case-control data on oral contraceptive intake and venous thrombosis in carriers and non-carriers of the factor V Leiden mutation. We also re-analyse cross-sectional data from the Framingham study on a gene-diet interaction between an APOA2 polymorphism and high saturated fat intake on obesity. We conclude that the utility index may be helpful to evaluate and appraise the potential clinical and public health relevance of gene-environment interaction effects detected in genomic and candidate gene association studies and may be a valuable decision support for designing prospective studies on the clinical utility. © 2013 Wiley Periodicals, Inc.

Confidence Intervals for Assessing Heterogeneity in Generalized Linear Mixed Models

ERIC Educational Resources Information Center

Wagler, Amy E.

2014-01-01

Generalized linear mixed models are frequently applied to data with clustered categorical outcomes. The effect of clustering on the response is often difficult to practically assess partly because it is reported on a scale on which comparisons with regression parameters are difficult to make. This article proposes confidence intervals for…

Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

ERIC Educational Resources Information Center

Oort, Frans J.

2011-01-01

In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by…

Characterizing the Mathematics Anxiety Literature Using Confidence Intervals as a Literature Review Mechanism

ERIC Educational Resources Information Center

Zientek, Linda Reichwein; Yetkiner, Z. Ebrar; Thompson, Bruce

2010-01-01

The authors report the contextualization of effect sizes within mathematics anxiety research, and more specifically within research using the Mathematics Anxiety Rating Scale (MARS) and the MARS for Adolescents (MARS-A). The effect sizes from 45 studies were characterized by graphing confidence intervals (CIs) across studies involving (a) adults…

Statistical inference for remote sensing-based estimates of net deforestation

Treesearch

Ronald E. McRoberts; Brian F. Walters

2012-01-01

Statistical inference requires expression of an estimate in probabilistic terms, usually in the form of a confidence interval. An approach to constructing confidence intervals for remote sensing-based estimates of net deforestation is illustrated. The approach is based on post-classification methods using two independent forest/non-forest classifications because...

Estimating Standardized Linear Contrasts of Means with Desired Precision

ERIC Educational Resources Information Center

Bonett, Douglas G.

2009-01-01

L. Wilkinson and the Task Force on Statistical Inference (1999) recommended reporting confidence intervals for measures of effect sizes. If the sample size is too small, the confidence interval may be too wide to provide meaningful information. Recently, K. Kelley and J. R. Rausch (2006) used an iterative approach to computer-generate tables of…

UNDERSTANDING SYSTEMATIC MEASUREMENT ERROR IN THERMAL-OPTICAL ANALYSIS FOR PM BLACK CARBON USING RESPONSE SURFACES AND SURFACE CONFIDENCE INTERVALS

EPA Science Inventory

Results from a NIST-EPA Interagency Agreement on Understanding Systematic Measurement Error in Thermal-Optical Analysis for PM Black Carbon Using Response Surfaces and Surface Confidence Intervals will be presented at the American Association for Aerosol Research (AAAR) 24th Annu...

The impact of effort-reward imbalance on quality of life among Japanese working men.

PubMed

Watanabe, Mayumi; Tanaka, Katsutoshi; Aratake, Yutaka; Kato, Noritada; Sakata, Yumi

2008-07-01

Health-related quality of life (HRQL) is an important measure of health outcome in working and healthy populations. Here, we investigated the impact of effort-reward imbalance (ERI), a representative work-stress model, on HRQL of Japanese working men. The study targeted 1,096 employees from a manufacturing plant in Japan. To assess HRQL and ERI, participants were surveyed using the Japanese version of the Short-Form 8 Health Survey (SF-8) and effort-reward imbalance model. Of the 1,096 employees, 1,057 provided valid responses to the questionnaire. For physical summary scores, the adjusted effort-reward imbalance odds ratios of middle vs. bottom and top vs. bottom tertiles were 0.24 (95% confidence interval, 0.08-0.70) and 0.09 (95% confidence interval, 0.03-0.28), respectively. For mental summary scores, ratios were 0.21 (95% confidence interval, 0.07-0.63) and 0.07 (95% confidence interval, 0.02-0.25), respectively. These findings demonstrate that effort-reward imbalance is independently associated with HRQL among Japanese employees.

Cataract Blindness in Osun State, Nigeria: Results of a Survey

PubMed Central

Kolawole, Olubayo U.; Ashaye, Adeyinka O.; Mahmoud, Abdulraheem O.; Adeoti, Caroline O.

2012-01-01

Purpose: To estimate the burden of blindness and visual impairment due to cataract in Egbedore Local Government Area of Osun State, Nigeria. Materials and Methods: Twenty clusters of 60 individuals who were 50 years or older were selected by systematic random sampling from the entire community. A total of 1,183 persons were examined. Results: The age- and sex-adjusted prevalence of bilateral cataract-related blindness (visual acuity (VA) < 3/60) in people of 50 years and older was 2.0% (95% confidence interval (CI): 1.6–2.4%). The Cataract Surgical Coverage (CSC) (persons) was 12.1% and Couching Coverage (persons) was 11.8%. The age- and sex-adjusted prevalence of bilateral operable cataract (VA < 6/60) in people of 50 years and older was 2.7% (95% CI: 2.3–3.1%). In this last group, the cataract intervention (surgery + couching) coverage was 22.2%. The proportion of patients who could not attain 6/60 vision after surgery were 12.5, 87.5, and 92.9%, respectively, for patients who underwent intraocular lens (IOL) implantation, cataract surgery without IOL implantation and those who underwent couching. “Lack of awareness” (30.4%), “no need for surgery” (17.6%), cost (14.6%), fear (10.2%), “waiting for cataract to mature” (8.8%), AND “surgical services not available” (5.8%) were reasons why individuals with operable cataract did not undergo cataract surgery. Conclusions: Over 600 operable cataracts exist in this region of Nigeria. There is an urgent need for an effective, affordable, and accessible cataract outreach program. Sustained efforts have to be made to increase the number of IOL surgeries, by making IOL surgery available locally at an affordable cost, if not completely free. PMID:23248537

Pandemic vaccination strategies and influenza severe outcomes during the influenza A(H1N1)pdm09 pandemic and the post-pandemic influenza season: the Nordic experience.

PubMed

Gil Cuesta, Julita; Aavitsland, Preben; Englund, Hélène; Gudlaugsson, Ólafur; Hauge, Siri Helene; Lyytikäinen, Outi; Sigmundsdóttir, Guðrún; Tegnell, Anders; Virtanen, Mikko; Krause, Tyra Grove

2016-04-21

During the 2009/10 influenza A(H1N1)pdm09 pandemic, the five Nordic countries adopted different approaches to pandemic vaccination. We compared pandemic vaccination strategies and severe influenza outcomes, in seasons 2009/10 and 2010/11 in these countries with similar influenza surveillance systems. We calculated the cumulative pandemic vaccination coverage in 2009/10 and cumulative incidence rates of laboratory confirmed A(H1N1)pdm09 infections, intensive care unit (ICU) admissions and deaths in 2009/10 and 2010/11. We estimated incidence risk ratios (IRR) in a Poisson regression model to compare those indicators between Denmark and the other countries. The vaccination coverage was lower in Denmark (6.1%) compared with Finland (48.2%), Iceland (44.1%), Norway (41.3%) and Sweden (60.0%). In 2009/10 Denmark had a similar cumulative incidence of A(H1N1)pdm09 ICU admissions and deaths compared with the other countries. In 2010/11 Denmark had a significantly higher cumulative incidence of A(H1N1)pdm09 ICU admissions (IRR: 2.4; 95% confidence interval (CI): 1.9-3.0) and deaths (IRR: 8.3; 95% CI: 5.1-13.5). Compared with Denmark, the other countries had higher pandemic vaccination coverage and experienced less A(H1N1)pdm09-related severe outcomes in 2010/11. Pandemic vaccination may have had an impact on severe influenza outcomes in the post-pandemic season. Surveillance of severe outcomes may be used to compare the impact of influenza between seasons and support different vaccination strategies.

Effect of insurance parity on substance abuse treatment.

PubMed

Azzone, Vanessa; Frank, Richard G; Normand, Sharon-Lise T; Burnam, M Audrey

2011-02-01

This study examined the impact of insurance parity on the use, cost, and quality of substance abuse treatment. The authors compared substance abuse treatment spending and utilization from 1999 to 2002 for continuously enrolled beneficiaries covered by Federal Employees Health Benefit (FEHB) plans, which require parity coverage of mental health and substance use disorders, with spending and utilization among beneficiaries in a matched set of health plans without parity coverage. Logistic regression models estimated the probability of any substance abuse service use. Conditional on use, linear models estimated total and out-of-pocket spending. Logistic regression models for three quality indicators for substance abuse treatment were also estimated: identification of adult enrollees with a new substance abuse diagnosis, treatment initiation, and treatment engagement. Difference-in-difference estimates were computed as (postparity - preparity) differences in outcomes in plans without parity subtracted from those in FEHB plans. There were no significant differences between FEHB and non-FEHB plans in rates of change in average utilization of substance abuse services. Conditional on service utilization, the rate of substance abuse treatment out-of-pocket spending declined significantly in the FEHB plans compared with the non-FEHB plans (mean difference=-$101.09, 95% confidence interval [CI]=-$198.06 to -$4.12), whereas changes in total plan spending per user did not differ significantly. With parity, more patients had new diagnoses of a substance use disorder (difference-in-difference risk=.10%, CI=.02% to .19%). No statistically significant differences were found for rates of initiation and engagement in substance abuse treatment. Findings suggest that for continuously enrolled populations, providing parity of substance abuse treatment coverage improved insurance protection but had little impact on utilization, costs for plans, or quality of care.

Coverage and Influencing Determinants of Influenza Vaccination in Elderly Patients in a Country with a Poor Vaccination Implementation.

PubMed

Ganczak, Maria; Gil, Karolina; Korzeń, Marcin; Bażydło, Marta

2017-06-20

The seasonal influenza vaccination uptake of the elderly in Poland is one of the lowest in Europe. Objective : to assess the vaccination coverage and influencing determinants in patients ≥65 years of age. A cross-sectional study was conducted (November 2015-April 2016) among consecutive patients admitted to a municipal hospital located in the city of Szczecin, North-west Poland. Patients completed researcher-administered, anonymous questionnaires on socio- demographic data/factors related to the vaccination. Results : The response rate: 92.0%. Among 230 patients (79.6% women, median of age 69 years, range 65-89) who agreed to participate, 34.8% (95% Confidence Interval: 28.6-41.0%) were vaccinated. About 15.7% of respondents had not previously heard about the vaccination; 41.3% of those who stated they were vaccinated or planned on being vaccinated the following year, compared to 19.3% of respondents who stated they were not currently vaccinated ( p < 0.001). A multivariable regression analysis revealed that patient factors, such as younger age (Odds Ratio, OR = 7.69), living in the urban area (OR = 7.69), having comorbidities (OR = 2.70), having a vaccinated family member (OR = 3.57), and being informed about vaccination (OR = 5.00) were each associated with greater odds of being immunized. Willingness for vaccination the next year was strongly associated (OR = 8.59) with vaccination status. Conclusions : The influenza vaccination uptake in the elderly population in Poland is disturbingly low. Improved education strategies are needed to increase the uptake. Vaccinated respondents are more likely to plan on being vaccinated the following year. Future interventions related to maximizing vaccination coverage should be more tailored, focusing especially on older patients living in rural areas.

An external evaluation of the Diarrhea Alleviation through Zinc and ORS Treatment (DAZT) program in Gujarat and Uttar Pradesh, India.

PubMed

Lamberti, Laura M; Taneja, Sunita; Mazumder, Sarmila; LeFevre, Amnesty; Black, Robert E; Walker, Christa L Fischer

2015-12-01

To address inadequate coverage of oral rehydration salts (ORS) and zinc supplements for the treatment of diarrhea among children under-five, the Diarrhea Alleviation through Zinc and ORS Treatment (DAZT) program was carried out from 2011-2013 in Gujarat and from 2011-2014 in Uttar Pradesh (UP), India. The program focused on improving the diarrhea treatment practices of public and private sector providers. We conducted cross-sectional household surveys in program districts at baseline and endline and constructed state-specific logistic regression models with generalized estimating equations to assess changes in ORS and zinc treatment during the program period. Between baseline and endline, zinc coverage increased from 2.5% to 22.4% in Gujarat and from 3.1% to 7.0% in UP; ORS coverage increased from 15.3% to 39.6% in Gujarat but did not change in UP. In comparison to baseline, children with diarrhea in the two-weeks preceding the endline survey had higher odds of receiving zinc treatment in both Gujarat (odds ratio, OR = 11.2; 95% confidence interval (CI) 6.4-19.3) and UP (OR = 2.4; 95% CI 1.4-3.9), but the odds of receiving ORS only increased in Gujarat (OR = 3.6; 95% CI 2.7-4.8; UP OR = 0.9; 95% CI 0.7-1.2). Seeking care outside the home, especially from a public sector source, was associated with higher odds of receiving ORS and zinc. During the duration of the DAZT program, there were modest improvements in the treatment of diarrhea among young children. Future programs should build upon and accelerate this trend with continued investment in public and private sector provider training and supply chain sustainability, in addition to targeted caregiver demand generation activities.

Who is left behind on the road to universal facility delivery? A cross-sectional multilevel analysis in rural Tanzania.

PubMed

Kruk, Margaret E; Hermosilla, Sabrina; Larson, Elysia; Vail, Daniel; Chen, Qixuan; Mazuguni, Festo; Byalugaba, Beatrice; Mbaruku, Godfrey

2015-08-01

To examine factors associated with home delivery among women in Pwani Region, Tanzania, which has experienced a rapid rise in facility delivery coverage. Cross-sectional data from a population-based survey of women residing in rural areas of Pwani Region were linked to health facility locations. We fitted multilevel logistic models to examine individual and community factors associated with home delivery. A total of 752 (27.95%) of the 2691 women who completed the survey delivered their last child at home. Women were less likely to deliver at home if they had any primary education [odds ratio (OR) 0.62; 95% confidence interval (CI): 0.50, 0.79], were primiparous (OR: 0.52; 95% CI: 0.37, 0.73), had more exposure to media (OR: 0.80; 95% CI: 0.66, 0.96) or had received more (OR: 0.78; 95% CI: 0.63, 0.96) or better quality antenatal care (ANC) services (OR: 0.48; 95% CI: 0.34, 0.67). Increased wealth was strongly associated with lower odds of home delivery (OR: 0.27; 95% CI: 0.18, 0.39), as was living in a village that grew cash crops (OR: 0.56; 95% CI: 0.35, 0.88). Farther distance to hospital, but not to lower level facilities, was associated with higher likelihood of home delivery (OR 2.49; 95% CI: 1.60, 3.88). Poverty, multiparity, weak ANC and distance to hospital were associated with persistence of home delivery in a region with high coverage of facility delivery. A pro-poor path to universal coverage of safe delivery requires a greater focus on quality of care and more intensive outreach to poor and multiparous women. © 2015 John Wiley & Sons Ltd.

Vaccine effectiveness of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine during a pertussis outbreak in Maine.

PubMed

Terranella, Andrew; Rea, Vicki; Griffith, Matthew; Manning, Susan; Sears, Steven; Farmer, Ann; Martin, Stacey; Patel, Manisha

2016-05-11

Multiple school-associated pertussis outbreaks were reported in Maine from 2010 to 2011. These outbreaks were associated with an overall increase in pertussis cases statewide. Waning of protection in students recently vaccinated with tetanus, diphtheria, and acellular pertussis (Tdap) has been implicated in the increase in reported rates of pertussis nationally. We conducted a retrospective cohort study to evaluate Tdap vaccine effectiveness (VE) among students aged 11-19 years in two schools reporting outbreaks in 2011. All pertussis cases reported from August through November, 2011 at the two schools were included. Vaccination history was verified using provider information, state vaccine registry data, and parental verification. Attack rates (AR) were calculated. VE and duration of protection was calculated as VE=1-(ARvaccinated/ARunvaccinated)×100% using a log binomial regression model. Of 416 students enrolled, 314 were included in the analyses. Twenty-nine cases collectively in Schools A and B. Tdap coverage was 65% at School A and 42% at School B before the start of the outbreak. Among students enrolled in the study, attack rates were 11.9% and 7.7% at Schools A and B, respectively. Overall VE was 68.5% (95% confidence interval (CI) 37.7-86.2). VE was 70.4% (95% CI 17.5-89.4) for School A and 65.2% (95% CI -19.2 to 89.9) for School B. VE <2 years versus ≥2 years from outbreak onset was not significantly different. Tdap was moderately effective in preventing disease among vaccinated students. Vaccine coverage of 65% or less was suboptimal and might contribute to outbreaks. Waning VE was not demonstrated. Increased vaccination coverage rates as well as further evaluation of the role of acellular vaccine on VE is needed. Published by Elsevier Ltd.

Comparing Types of Health Insurance for Children

PubMed Central

DeVoe, Jennifer E.; Tillotson, Carrie J.; Wallace, Lorraine S.; Selph, Shelley; Graham, Alan; Angier, Heather

2015-01-01

Background Many states have expanded public health insurance programs for children, and further expansions were proposed in recent national reform initiatives; yet the expansion of public insurance plans and the inclusion of a public option in state insurance exchange programs sparked controversies and raised new questions with regard to the quality and adequacy of various insurance types. Objectives We aimed to examine the comparative effectiveness of public versus private coverage on parental-reported children’s access to health care in low-income and middle-income families. Methods/Participants/Measures We conducted secondary data analyses of the nationally representative Medical Expenditure Panel Survey, pooling years 2002 to 2006. We assessed univariate and multivariate associations between child’s full-year insurance type and parental-reported unmet health care and preventive counseling needs among children in low-income (n =28,338) and middle-income families (n = 13,160). Results Among children in families earning <200% of the federal poverty level, those with public insurance were significantly less likely to have no usual source of care compared with privately insured children (adjusted relative risk, 0.79; 95% confidence interval, 0.63–0.99). This was the only significant difference in 50 logistic regression models comparing unmet health care and preventive counseling needs among low-income and middle-income children with public versus private coverage. Conclusions The striking similarities in reported rates of unmet needs among children with public versus private coverage in both low-income and middle-income groups suggest that a public children’s insurance option may be equivalent to a private option in guaranteeing access to necessary health care services for all children. PMID:21478781

Written reminders increase vaccine coverage in Danish children - evaluation of a nationwide intervention using The Danish Vaccination Register, 2014 to 2015

PubMed Central

Suppli, Camilla Hiul; Rasmussen, Mette; Valentiner-Branth, Palle; Mølbak, Kåre; Krause, Tyra Grove

2017-01-01

We evaluated a national intervention of sending written reminders to parents of children lacking childhood vaccinations, using the Danish Vaccination Register (DDV). The intervention cohort included the full birth cohort of 124,189 children born in Denmark who reached the age of 2 and 6.5 years from 15 May 2014 to 14 May 2015. The reference cohort comprised 124,427 children who reached the age of 2 and 6.5 years from 15 May 2013 to 14 May 2014. Vaccination coverage was higher in the intervention cohort at 2.5 and 7 years of age. The differences were most pronounced for the second dose of the measles-mumps-rubella vaccine (MMR2) and the diphtheria-tetanus-pertussis-polio vaccine DTaP-IPV4 among the 7-year-olds, with 5.0 percentage points (95% confidence interval (CI): 4.5–5.4) and 6.4 percentage points (95% CI: 6.0–6.9), respectively. Among the 2.5 and 7-year-olds, the proportion of vaccinations in the preceding 6 months was 46% and three times higher, respectively, in the intervention cohort than the reference cohort. This study indicates a marked effect of personalised written reminders, highest for the vaccines given later in the schedule in the older cohort. In addition, the reminders increased awareness about correct registration of vaccinations in DDV. PMID:28488995

HMO market penetration and hospital cost inflation in California.

PubMed

Robinson, J C

1991-11-20

OBJECTIVE--Health maintenance organizations (HMOs) have stimulated price competition in California hospital markets since 1983, when the state legislature eliminated barriers to selective contracting by conventional health insurance plans. This study measures the impact of HMO-induced price competition on the rate of inflation in average cost per admission for 298 private, non-HMO hospitals between 1982 and 1988. DATA--HMO market penetration was calculated using discharge abstract data on insurance coverage, ZIP code of residence, and hospital of choice for 3.35 million patients in 1983 and 3.41 million patients in 1988. Data on hospital characteristics were obtained from the American Hospital Association and other sources. -HMO coverage grew from an average of 8.3% of all admissions in local hospital markets in 1983 to 17.0% of all admissions in 1988. The average rate of growth in costs per admission between 1982 and 1988 was 9.4% lower in markets with relatively high HMO penetration compared with markets with relatively low HMO penetration (95% confidence interval, 5.2 to 13.8). Cost savings for these 298 hospitals are estimated at $1.04 billion for 1988. CONCLUSION--Price competition between HMOs and conventional health insurers can significantly reduce hospital cost inflation if legislative barriers to selective contracting are removed. The impact of competition in California was modest, however, when evaluated in terms of the 74.5% average rate of California hospital cost inflation during these years.

Socioeconomic assessment and impact of social security on outcome in patients admitted with suspected coronary chest pain in the city of salta, Argentina.

PubMed

León de la Fuente, Ricardo A; Naesgaard, Patrycja A; Nilsen, Stein Tore; Woie, Leik; Aarsland, Torbjoern; Staines, Harry; Nilsen, Dennis W T

2013-01-01

Low socioeconomic status is associated with increased mortality from coronary heart disease. We assessed total mortality, cardiac death, and sudden cardiac death (SCD) in relation to socioeconomic class and social security in 982 patients consecutively admitted with suspected coronary chest pain, living in the city of Salta, northern Argentina. Patients were divided into three socioeconomic classes based on monthly income, residential area, and insurance coverage. Five-year follow-up data were analyzed accordingly, applying univariate and multivariate analyses. At follow-up, 173 patients (17.6%) had died. In 92 patients (9.4%) death was defined as cardiac, of whom 59 patients (6.0%) were characterized as SCD. In the multivariate analysis, the hazard ratios (HRs) for all-cause and cardiac mortality in the highest as compared to the lowest socioeconomic class were 0.42 (95% confidence interval (CI), 0.22-0.80), P = 0.008, and 0.39 (95% CI, 0.15-0.99), P = 0.047, respectively. Comparing patients in the upper socioeconomic class to patients without healthcare coverage, HRs were 0.46 (95% CI, 0.23-0.94), P = 0.032, and 0.37 (95% CI, 0.14-1.01), P = 0.054, respectively. In conclusion, survival was mainly tied to socioeconomic inequalities in this population, and the impact of a social security program needs further attention.

Prevalence of immunity presumed using rabies vaccination history and household factors associated with vaccination status among domestic dogs in Japan.

PubMed

Hidano, Arata; Hayama, Yoko; Tsutsui, Toshiyuki

2012-01-01

Rabies was eliminated in Japan over 50 years ago; however, the recent increase in the movement of humans and animals across the world highlights the potential threat of disease reentry into the country. The immune status against rabies among the dog population in Japan is not well known; thus, the purpose of this study was to estimate the prevalence of dogs with effective immunity from the vaccination history using a web-based survey. We found that 76.9% (95% confidence interval, 75.8-78.1) of dogs in this study population belonged to the population in which 90% were assumed to have the internationally accepted antibody titer. We showed that dogs taken less frequently for walks were less likely to be vaccinated. Additionally, the frequency of encounters with other dogs during walks and the number of individuals in households were associated with vaccination history. To our knowledge, this study is the first report estimating the prevalence of dogs in Japan with effective immunity against rabies. Further, we identified the population with low vaccination coverage as well as the heterogeneous characteristics of vaccination history among the dog population. These findings contribute to the implementation of an efficient strategy for improving the overall vaccination coverage in Japan and the development of a quantitative risk assessment of rabies.

Analyzing recurrent events when the history of previous episodes is unknown or not taken into account: proceed with caution.

PubMed

Navarro, Albert; Casanovas, Georgina; Alvarado, Sergio; Moriña, David

Researchers in public health are often interested in examining the effect of several exposures on the incidence of a recurrent event. The aim of the present study is to assess how well the common-baseline hazard models perform to estimate the effect of multiple exposures on the hazard of presenting an episode of a recurrent event, in presence of event dependence and when the history of prior-episodes is unknown or is not taken into account. Through a comprehensive simulation study, using specific-baseline hazard models as the reference, we evaluate the performance of common-baseline hazard models by means of several criteria: bias, mean squared error, coverage, confidence intervals mean length and compliance with the assumption of proportional hazards. Results indicate that the bias worsen as event dependence increases, leading to a considerable overestimation of the exposure effect; coverage levels and compliance with the proportional hazards assumption are low or extremely low, worsening with increasing event dependence, effects to be estimated, and sample sizes. Common-baseline hazard models cannot be recommended when we analyse recurrent events in the presence of event dependence. It is important to have access to the history of prior-episodes per subject, it can permit to obtain better estimations of the effects of the exposures. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Sex hormones and the risk of type 2 diabetes mellitus: A 9-year follow up among elderly men in Finland.

PubMed

Salminen, Marika; Vahlberg, Tero; Räihä, Ismo; Niskanen, Leo; Kivelä, Sirkka-Liisa; Irjala, Kerttu

2015-05-01

To analyze whether sex hormone levels predict the incidence of type2 diabetes among elderly Finnish men. This was a prospective population-based study, with a 9-year follow up period. The study population in the municipality of Lieto, Finland, consisted of elderly (age ≥64 years) men free of type 2 diabetes at baseline in 1998-1999 (n = 430). Body mass index and cardiovascular disease-adjusted hazard ratios and their 95% confidence intervals for type 2 diabetes predicted by testosterone, free testosterone, sex hormone-binding globulin, luteinizing hormone, and testosterone/luteinizing hormone were estimated. A total of 30 new cases of type 2 diabetes developed during the follow-up period. After adjustment, only higher levels of testosterone (hazard ratio for one-unit increase 0.93, 95% confidence interval 0.87-0.99, P = 0.020) and free testosterone (hazard ratio for 10-unit increase 0.96, 95% confidence interval 0.91-1.00, P = 0.044) were associated with a lower risk of incident type 2 diabetes during the follow up. These associations (0.94, 95% confidence interval 0.87-1.00, P = 0.050 and 0.95, 95% confidence interval 0.90-1.00, P = 0.035, respectively) persisted even after additional adjustment of sex hormone-binding globulin. Higher levels of testosterone and free testosterone independently predicted a reduced risk of type 2 diabetes in the elderly men. © 2014 Japan Geriatrics Society.

N-acetyltransferase 2 gene polymorphism as a biomarker for susceptibility to bladder cancer in Bangladeshi population.

PubMed

Hosen, Md Bayejid; Islam, Jahidul; Salam, Md Abdus; Islam, Md Fakhrul; Hawlader, M Zakir Hossain; Kabir, Yearul

2015-03-01

To investigate the association between the three most common single nucleotide polymorphisms of the N-acetyltransferase 2 gene together with cigarette smoking and the risk of developing bladder cancer and its aggressiveness. A case-control study on 102 bladder cancer patients and 140 control subjects was conducted. The genomic DNA was extracted from peripheral white blood cells and N-acetyltransferase 2 alleles were differentiated by polymerase chain reaction-based restriction fragment length polymorphism methods. Bladder cancer risk was estimated as odds ratio and 95% confidence interval using binary logistic regression models adjusting for age and gender. Overall, N-acetyltransferase 2 slow genotypes were associated with bladder cancer risk (odds ratio=4.45; 95% confidence interval=2.26-8.77). The cigarette smokers with slow genotypes were found to have a sixfold increased risk to develop bladder cancer (odds ratio=6.05; 95% confidence interval=2.23-15.82). Patients with slow acetylating genotypes were more prone to develop high-grade (odds ratio=6.63; 95% confidence interval=1.15-38.13; P<0.05) and invasive (odds ratio=10.6; 95% confidence interval=1.00-111.5; P=0.05) tumor. N-acetyltransferase 2 slow genotype together with tobacco smoking increases bladder cancer risk. Patients with N-acetyltransferase 2 slow genotypes were more likely to develop a high-grade and invasive tumor. N-acetyltransferase 2 slow genotype is an important genetic determinant for bladder cancer in Bangladesh population. © 2014 Wiley Publishing Asia Pty Ltd.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors and fracture risk in patients with type 2 diabetes mellitus: A meta-analysis.

PubMed

Ruanpeng, Darin; Ungprasert, Patompong; Sangtian, Jutarat; Harindhanavudhi, Tasma

2017-09-01

Sodium-glucose cotransporter 2 (SGLT2) inhibitors could potentially alter calcium and phosphate homeostasis and may increase the risk of bone fracture. The current meta-analysis was conducted to investigate the fracture risk among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors. Randomized controlled trials that compared the efficacy of SGLT2 inhibitors to placebo were identified. The risk ratios of fracture among patients who received SGLT2 inhibitors versus placebo were extracted from each study. Pooled risk ratios and 95% confidence intervals were calculated using a random-effect, Mantel-Haenszel analysis. A total of 20 studies with 8286 patients treated with SGLT2 inhibitors were included. The pooled risk ratio of bone fracture in patients receiving SGLT2 inhibitors versus placebo was 0.67 (95% confidence interval, 0.42-1.07). The pooled risk ratio for canagliflozin, dapagliflozin, and empagliflozin was 0.66 (95% confidence interval, 0.37-1.19), 0.84 (95% confidence interval, 0.22-3.18), and 0.57 (95% confidence interval, 0.20-1.59), respectively. Increased risk of bone fracture among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors compared with placebo was not observed in this meta-analysis. However, the results were limited by short duration of treatment/follow-up and low incidence of the event of interest. Copyright © 2017 John Wiley & Sons, Ltd.

Influence of gender role attitudes on smoking and drinking among girls from Jujuy, Argentina.

PubMed

Mejia, Raul; Kaplan, Celia P; Alderete, Ethel; Gregorich, Steven E; Pérez-Stable, Eliseo J

2013-09-01

Evaluate effect of gender role attitudes on tobacco and alcohol use among Argentinean girls. Cross-sectional survey of 10th grade students attending 27 randomly selected schools in Jujuy, Argentina. Questions about tobacco and alcohol use were adapted from global youth surveys. Five items with 5-point response options of agreement-disagreement assessed attitude towards egalitarian (higher score) gender roles. 2133 girls, aged 13-18 years, 71% Indigenous, 22% mixed Indigenous/European, and 7% European responded. Of these, 60% had ever smoked, 32% were current smokers, 58% ever drinkers, 27% drank in previous month, and 13% had ≥5 drinks on one occasion. Mean response to the gender role scale was 3.49 (95% Confidence Intervals = 3.41-3.57) out of 5 tending toward egalitarian attitudes. Logistic regression models using the gender role scale score as the main predictor and adjusting for demographic and social confounders showed that egalitarian gender role was associated with ever smoking (Odds Ratio = 1.25; 95% Confidence Intervals 1.09-1.44), ever drinking (Odds Ratio = 1.24; 95% Confidence Intervals 1.10-1.40), drinking in prior month (Odds Ratio = 1.21; 95% Confidence Intervals 1.07-1.37) and ≥5 drinks on one occasion (Odds Ratio = 1.15; 95% Confidence Intervals 1.00-1.33), but was not significant for current smoking. Girls in Jujuy who reported more egalitarian gender role attitudes had higher odds of smoking or drinking. Copyright © 2013 Elsevier Inc. All rights reserved.

Hostility and the risk of peptic ulcer in the GAZEL cohort.

PubMed

Lemogne, Cédric; Schuster, Jean-Pierre; Levenstein, Susan; Melchior, Maria; Nabi, Hermann; Ducimetière, Pierre; Limosin, Frédéric; Goldberg, Marcel; Zins, Marie; Consoli, Silla M

2015-02-01

Evidence for an association between hostility and peptic ulcer mainly relies on cross-sectional studies. Prospective studies are rare and have not used a validated measure of hostility. This prospective study aimed to examine the association between hostility and peptic ulcer in the large-scale French GAZEL cohort. In 1993, 14,674 participants completed the Buss and Durkee Hostility Inventory. Participants were annually followed-up from 1994 to 2011. Diagnosis of peptic ulcer was self-reported. The association between hostility scores and ulcer incidence was measured by hazard ratios (HR) and 95% confidence intervals computed through Cox regression. Among 13,539 participants free of peptic ulcer history at baseline, 816 reported a peptic ulcer during a mean follow-up of 16.8 years. Adjusting for potential confounders, including smoking, occupational grade, and a proxy for nonsteroidal anti-inflammatory drug exposure, ulcer incidence was positively associated with total hostility (HR per SD: 1.23, confidence interval: 1.14-1.31), behavioral hostility (HR per SD: 1.13, confidence interval: 1.05-1.21), cognitive hostility (HR per SD: 1.26, confidence interval: 1.18-1.35), and irritability (HR per SD: 1.20, confidence interval: 1.12-1.29). The risk of peptic ulcer increased from the lowest to the highest quartile for all hostility measures (p for linear trend < .05). Hostility might be associated with an increased risk of peptic ulcer. Should these results be replicated, further studies would be needed to explore the underlying mechanisms.

Albumin treatment regimen for type 1 hepatorenal syndrome: a dose-response meta-analysis.

PubMed

Salerno, Francesco; Navickis, Roberta J; Wilkes, Mahlon M

2015-11-25

Recommended treatment for type 1 hepatorenal syndrome consists of albumin and vasoconstrictor. The optimal albumin dose remains poorly characterized. This meta-analysis aimed to determine the impact of albumin dose on treatment outcomes. Clinical studies of type 1 hepatorenal syndrome treatment with albumin and vasoconstrictor were sought. Search terms included: hepatorenal syndrome; albumin; vasoconstrictor; terlipressin; midodrine; octreotide; noradrenaline; and norepinephrine. A meta-analysis was performed of hepatorenal syndrome reversal and survival in relation to albumin dose. Nineteen clinical studies with 574 total patients were included, comprising 8 randomized controlled trials, 8 prospective studies and 3 retrospective studies. The pooled percentage of patients achieving hepatorenal syndrome reversal was 49.5% (95% confidence interval, 40.0-59.1%). Increments of 100 g in cumulative albumin dose were accompanied by significantly increased survival (hazard ratio, 1.15; 95% confidence interval, 1.02-1.31; p = 0.023). A non-significant increase of similar magnitude in hepatorenal syndrome reversal was also observed (odds ratio, 1.15; 95% confidence interval, 0.97-1.37; p = 0.10). Expected survival rates at 30 days among patients receiving cumulative albumin doses of 200, 400 and 600 g were 43.2% (95% confidence interval, 36.4-51.3%), 51.4% (95% confidence interval, 46.3-57.1%) and 59.0% (95% confidence interval, 51.9-67.2), respectively. Neither survival nor hepatorenal syndrome reversal was significantly affected by vasoconstrictor dose or type, treatment duration, age, baseline serum creatinine, bilirubin or albumin, baseline mean arterial pressure, or study design, size or time period. This meta-analysis suggests a dose-response relationship between infused albumin and survival in patients with type 1 hepatorenal syndrome. The meta-analysis provides the best current evidence on the potential role of albumin dose selection in improving outcomes of treatment for type 1 HRS and furnishes guidance for the design of future dose-ranging studies.

Prevalence of orofacial clefts and risks for nonsyndromic cleft lip with or without cleft palate in newborns at a university hospital from West Mexico.

PubMed

Corona-Rivera, Jorge Román; Bobadilla-Morales, Lucina; Corona-Rivera, Alfredo; Peña-Padilla, Christian; Olvera-Molina, Sandra; Orozco-Martín, Miriam A; García-Cruz, Diana; Ríos-Flores, Izabel M; Gómez-Rodríguez, Brian Gabriel; Rivas-Soto, Gemma; Pérez-Molina, J Jesús

2018-02-19

We determined the overall prevalence of typical orofacial clefts and the potential risks for nonsyndromic cleft lip with or without cleft palate in a university hospital from West México. For the prevalence, 227 liveborn infants with typical orofacial clefts were included from a total of 81,193 births occurred during the period 2009-2016 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Guadalajara, Jalisco, Mexico). To evaluate potential risks, a case-control study was conducted among 420 newborns, including only those 105 patients with nonsyndromic cleft lip with or without cleft palate (cases), and 315 infants without birth defects (controls). Data were analyzed using multivariable logistic regression analysis expressed as adjusted odds ratio with 95% confidence intervals . The overall prevalence for typical orofacial clefts was 28 per 10,000 (95% confidence interval: 24.3-31.6), or 1 per 358 live births. The mean values for the prepregnancy weight, antepartum weight, and pre-pregnancy body mass index were statistically higher among the mothers of cases. Infants with nonsyndromic cleft lip with or without cleft palate had a significantly higher risk for previous history of any type of congenital anomaly (adjusted odds ratio: 2.7; 95% confidence interval: 1.4-5.1), history of a relative with cleft lip with or without cleft palate (adjusted odds ratio: 19.6; 95% confidence interval: 8.2-47.1), and first-trimester exposures to progestogens (adjusted odds ratio: 6.8; 95% CI 1.8-25.3), hyperthermia (adjusted odds ratio: 3.4; 95% confidence interval: 1.1-10.6), and common cold (adjusted odds ratio: 3.6; 95% confidence interval: 1.1-11.9). These risks could have contributed to explain the high prevalence of orofacial clefts in our region of Mexico, emphasizing that except for history of relatives with cleft lip with or without cleft palate, most are susceptible of modification. © 2018 Japanese Teratology Society.

Fixed ratio combinations of glucagon like peptide 1 receptor agonists with basal insulin: a systematic review and meta-analysis.

PubMed

Liakopoulou, Paraskevi; Liakos, Aris; Vasilakou, Despoina; Athanasiadou, Eleni; Bekiari, Eleni; Kazakos, Kyriakos; Tsapas, Apostolos

2017-06-01

Basal insulin controls primarily fasting plasma glucose but causes hypoglycaemia and weight gain, whilst glucagon like peptide 1 receptor agonists induce weight loss without increasing risk for hypoglycaemia. We conducted a systematic review and meta-analysis of randomised controlled trials to investigate the efficacy and safety of fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists. We searched Medline, Embase, and the Cochrane Library as well as conference abstracts up to December 2016. We assessed change in haemoglobin A 1c , body weight, and incidence of hypoglycaemia and gastrointestinal adverse events. We included eight studies with 5732 participants in the systematic review. Switch from basal insulin to fixed ratio combinations with a glucagon like peptide 1 receptor agonist was associated with 0.72% reduction in haemoglobin A 1c [95% confidence interval -1.03 to -0.41; I 2  = 93%] and 2.35 kg reduction in body weight (95% confidence interval -3.52 to -1.19; I 2  = 93%), reducing also risk for hypoglycaemia [odds ratio 0.70; 95% confidence interval 0.57 to 0.86; I 2  = 85%] but increasing incidence of nausea (odds ratio 6.89; 95% confidence interval 3.73-12.74; I 2  = 79%). Similarly, switching patients from treatment with a glucagon like peptide 1 receptor agonist to a fixed ratio combination with basal insulin was associated with 0.94% reduction in haemoglobin A 1c (95% confidence interval -1.11 to -0.77) and an increase in body weight by 2.89 kg (95% confidence interval 2.17-3.61). Fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists improve glycaemic control whilst balancing out risk for hypoglycaemia and gastrointestinal side effects.

Neonatal Infection in Children With Cerebral Palsy: A Registry-Based Cohort Study.

PubMed

Smilga, Anne-Sophie; Garfinkle, Jarred; Ng, Pamela; Andersen, John; Buckley, David; Fehlings, Darcy; Kirton, Adam; Wood, Ellen; van Rensburg, Esias; Shevell, Michael; Oskoui, Maryam

2018-03-01

The goal of this study was to explore the association between neonatal infection and outcomes in children with cerebral palsy. We conducted a retrospective cohort study using the Canadian CP Registry. Neonatal infection was defined as meeting one of the following criteria: (1) septicemia, (2) septic shock, or (3) administration of antibiotics for ≥10 days. Phenotypic profiles of children with cerebral palsy with and without an antecedent neonatal infection were compared. Subgroup analysis was performed, stratified by gestational age (term versus preterm). Of the 1229 registry participants, 505 (41.1%) were preterm, and 192 (15.6%) met the criteria for neonatal infection with 29% of preterm children having a neonatal infection compared with 6.5% in term-born children. Children with prior neonatal infection were more likely to have a white matter injury (odds ratio 2.2, 95% confidence interval 1.5 to 3.2), spastic diplegic neurological subtype (odds ratio 1.6, 95% confidence interval 1.1 to 2.3), and sensorineural auditory impairment (odds ratio 2.1, 95% confidence interval 1.4 to 3.3). Among preterm children, neonatal infection was not associated with a difference in phenotypic profile. Term-born children with neonatal infection were more likely to have spastic triplegia or quadriplegia (odds ratio 2.4, 95% confidence interval 1.3 to 4.3), concomitant white matter and cortical injury (odds ratio 4.1, 95% confidence interval 1.6 to 10.3), and more severe gross motor ability (Gross Motor Function Classification System IV to V) (odds ratio 2.6, 95% confidence interval 1.4 to 4.8) compared with preterm children. Findings suggest a role of systemic infection on the developing brain in term-born infants, and the possibility to develop targeted therapeutic and preventive strategies to reduce cerebral palsy morbidity. Copyright © 2017. Published by Elsevier Inc.

T-category remains an important prognostic factor for oropharyngeal carcinoma in the era of human papillomavirus.

PubMed

Mackenzie, P; Pryor, D; Burmeister, E; Foote, M; Panizza, B; Burmeister, B; Porceddu, S

2014-10-01

To determine prognostic factors for locoregional relapse (LRR), distant relapse and all-cause death in a contemporary cohort of locoregionally advanced oropharyngeal squamous cell carcinoma (OSCC) treated with definitive chemoradiotherapy or radiotherapy alone. OSCC patients treated with definitive radiotherapy between 2005 and 2010 were identified from a prospective head and neck database. Patient age, gender, smoking history, human papillomavirus (HPV) status, T- and N-category, lowest involved nodal level and gross tumour volume of the primary (GTV-p) and nodal (GTV-n) disease were analysed in relation to LRR, distant relapse and death by way of univariate and multivariate analysis. In total, 130 patients were identified, 88 HPV positive, with a median follow-up of 42 months. On multivariate analysis HPV status was a significant predictor of LRR (hazard ratio 0.15; 95% confidence interval 0.05-0.51) and death (hazard ratio 0.29; 95% confidence interval 0.14-0.59) but not distant relapse (hazard ratio 0.53, 95% confidence interval 0.22-1.27). Increasing T-category was associated with a higher risk of LRR (hazard ratio 1.80 for T3/4 versus T1/2; 95% confidence interval 1.08-2.99), death (hazard ratio 1.37, 95% confidence interval 1.06-1.77) and distant relapse (hazard ratio 1.35; 95% confidence interval 1.00-1.83). Increasing GTV-p was associated with increased risk of distant relapse and death. N3 disease and low neck nodes were significant for LRR, distant relapse and death on univariate analysis only. Tumour HPV status was the strongest predictor of LRR and death. T-category is more predictive of distant relapse and may provide additional prognostic value for LRR and death when accounting for HPV status. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

The Hospital Anxiety and Depression Scale (HADS) and the 9-item Patient Health Questionnaire (PHQ-9) as screening instruments for depression in patients with cancer.

PubMed

Hartung, Tim J; Friedrich, Michael; Johansen, Christoffer; Wittchen, Hans-Ulrich; Faller, Herman; Koch, Uwe; Brähler, Elmar; Härter, Martin; Keller, Monika; Schulz, Holger; Wegscheider, Karl; Weis, Joachim; Mehnert, Anja

2017-11-01

Depression screening in patients with cancer is recommended by major clinical guidelines, although the evidence on individual screening tools is limited for this population. Here, the authors assess and compare the diagnostic accuracy of 2 established screening instruments: the depression modules of the 9-item Patient Health Questionnaire (PHQ-9) and the Hospital Anxiety and Depression Scale (HADS-D), in a representative sample of patients with cancer. This multicenter study was conducted with a proportional, stratified, random sample of 2141 patients with cancer across all major tumor sites and treatment settings. The PHQ-9 and HADS-D were assessed and compared in terms of diagnostic accuracy and receiver operating characteristic (ROC) curves for Diagnostic and Statistical Manual of Mental Disorders, 4th edition diagnosis of major depressive disorder using the Composite International Diagnostic Interview for Oncology as the criterion standard. The diagnostic accuracy of the PHQ-9 and HADS-D was fair for diagnosing major depressive disorder, with areas under the ROC curves of 0.78 (95% confidence interval, 0.76-0.79) and 0.75 (95% confidence interval, 0.74-0.77), respectively. The 2 questionnaires did not differ significantly in their areas under the ROC curves (P = .15). The PHQ-9 with a cutoff score ≥7 had the best screening performance, with a sensitivity of 83% (95% confidence interval, 78%-89%) and a specificity of 61% (95% confidence interval, 59%-63%). The American Society of Clinical Oncology guideline screening algorithm had a sensitivity of 44% (95% confidence interval, 36%-51%) and a specificity of 84% (95% confidence interval, 83%-85%). In patients with cancer, the screening performance of both the PHQ-9 and the HADS-D was limited compared with a standardized diagnostic interview. Costs and benefits of routinely screening all patients with cancer should be weighed carefully. Cancer 2017;123:4236-4243. © 2017 American Cancer Society. © 2017 American Cancer Society.

Variable impact on mortality of AIDS-defining events diagnosed during combination antiretroviral therapy: not all AIDS-defining conditions are created equal.

PubMed

Mocroft, Amanda; Sterne, Jonathan A C; Egger, Matthias; May, Margaret; Grabar, Sophie; Furrer, Hansjakob; Sabin, Caroline; Fatkenheuer, Gerd; Justice, Amy; Reiss, Peter; d'Arminio Monforte, Antonella; Gill, John; Hogg, Robert; Bonnet, Fabrice; Kitahata, Mari; Staszewski, Schlomo; Casabona, Jordi; Harris, Ross; Saag, Michael

2009-04-15

The extent to which mortality differs following individual acquired immunodeficiency syndrome (AIDS)-defining events (ADEs) has not been assessed among patients initiating combination antiretroviral therapy. We analyzed data from 31,620 patients with no prior ADEs who started combination antiretroviral therapy. Cox proportional hazards models were used to estimate mortality hazard ratios for each ADE that occurred in >50 patients, after stratification by cohort and adjustment for sex, HIV transmission group, number of antiretroviral drugs initiated, regimen, age, date of starting combination antiretroviral therapy, and CD4+ cell count and HIV RNA load at initiation of combination antiretroviral therapy. ADEs that occurred in <50 patients were grouped together to form a "rare ADEs" category. During a median follow-up period of 43 months (interquartile range, 19-70 months), 2880 ADEs were diagnosed in 2262 patients; 1146 patients died. The most common ADEs were esophageal candidiasis (in 360 patients), Pneumocystis jiroveci pneumonia (320 patients), and Kaposi sarcoma (308 patients). The greatest mortality hazard ratio was associated with non-Hodgkin's lymphoma (hazard ratio, 17.59; 95% confidence interval, 13.84-22.35) and progressive multifocal leukoencephalopathy (hazard ratio, 10.0; 95% confidence interval, 6.70-14.92). Three groups of ADEs were identified on the basis of the ranked hazard ratios with bootstrapped confidence intervals: severe (non-Hodgkin's lymphoma and progressive multifocal leukoencephalopathy [hazard ratio, 7.26; 95% confidence interval, 5.55-9.48]), moderate (cryptococcosis, cerebral toxoplasmosis, AIDS dementia complex, disseminated Mycobacterium avium complex, and rare ADEs [hazard ratio, 2.35; 95% confidence interval, 1.76-3.13]), and mild (all other ADEs [hazard ratio, 1.47; 95% confidence interval, 1.08-2.00]). In the combination antiretroviral therapy era, mortality rates subsequent to an ADE depend on the specific diagnosis. The proposed classification of ADEs may be useful in clinical end point trials, prognostic studies, and patient management.

Out-of-range INR values and outcomes among new warfarin patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Wang, Li; Baser, Onur; Damaraju, Chandrasekharrao V; Schein, Jeffrey R

2015-02-01

Although efficacious in stroke prevention in non-valvular atrial fibrillation, many warfarin patients are sub-optimally managed. To evaluate the association of international normalized ratio control and clinical outcomes among new warfarin patients with non-valvular atrial fibrillation. Adult non-valvular atrial fibrillation patients (≥18 years) initiating warfarin treatment were selected from the US Veterans Health Administration dataset between 10/2007 and 9/2012. Valid international normalized ratio values were examined from the warfarin initiation date through the earlier of the first clinical outcome, end of warfarin exposure or death. Each patient contributed multiple in-range and out-of-range time periods. The relative risk ratios of clinical outcomes associated with international normalized ratio control were estimated. 34,346 patients were included for analysis. During the warfarin exposure period, the incidence of events per 100 person-years was highest when patients had international normalized ratio <2:13.66 for acute coronary syndrome; 10.30 for ischemic stroke; 2.93 for transient ischemic attack; 1.81 for systemic embolism; and 4.55 for major bleeding. Poisson regression confirmed that during periods with international normalized ratio <2, patients were at increased risk of developing acute coronary syndrome (relative risk ratio: 7.9; 95 % confidence interval 6.9-9.1), ischemic stroke (relative risk ratio: 7.6; 95 % confidence interval 6.5-8.9), transient ischemic attack (relative risk ratio: 8.2; 95 % confidence interval 6.1-11.2), systemic embolism (relative risk ratio: 6.3; 95 % confidence interval 4.4-8.9) and major bleeding (relative risk ratio: 2.6; 95 % confidence interval 2.2-3.0). During time periods with international normalized ratio >3, patients had significantly increased risk of major bleeding (relative risk ratio: 1.5; 95 % confidence interval 1.2-2.0). In a Veterans Health Administration non-valvular atrial fibrillation population, exposure to out-of-range international normalized ratio values was associated with significantly increased risk of adverse clinical outcomes.

The prevalence of diagnosed tourette syndrome in Canada: A national population-based study.

PubMed

Yang, Jaeun; Hirsch, Lauren; Martino, Davide; Jette, Nathalie; Roberts, Jodie; Pringsheim, Tamara

2016-11-01

The objective of this study was to examine: (1) the prevalence of diagnosed Tourette syndrome in Canada by sex in youth (aged 12-17) and adults and (2) socioeconomic factors in this population. The majority of epidemiological studies of tics have focused on children and youth, with few studies describing the prevalence of tics in adult populations. Canadian data on Tourette syndrome prevalence were derived from the Canadian Community Health Survey 2010 and 2011 cycles, a Statistics Canada population-based cross-sectional survey that collects information related to health status. We determined the prevalence of diagnosed Tourette syndrome and examined sociodemographic factors, including age, sex, education, income, employment, and birthplace. Overall, 122,884 Canadians participated in the surveys, with 122 participants diagnosed with Tourette syndrome. The prevalence of Tourette syndrome was higher in males in youth: 6.03 per 1000 (95% confidence interval: 3.24-8.81) in males versus 0.48 per 1,000 (95% confidence interval: 0.05-0.91) in females, with a prevalence risk ratio of 5.31 (95% confidence interval: 2.38-11.81). In adults, the prevalence of Tourette syndrome was 0.89 per 1,000 (95% confidence interval: 0.48-1.29) in males versus 0.44 (95% confidence interval: 0.16.0-0.71) in females, with a prevalence risk ratio of 1.93 (95% confidence interval: 1.21-3.08). After adjusting for age and sex, adults with Tourette syndrome had lower odds of receiving postsecondary education or being employed and higher odds of having income lower than the median and receiving governmental support. Data on the prevalence of Tourette syndrome in adults are scarce because most studies focus on children. Our data demonstrate a decreasing prevalence risk ratio for sex in adults compared to children. A diagnosis of Tourette syndrome is associated with lower education, income, and employment in adulthood. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Stroke preparedness in children: translating knowledge into behavioral intent: a systematic review and meta-analysis.

PubMed

Ottawa, Cassandra; Sposato, Luciano A; Nabbouh, Fadl; Saposnik, Gustavo

2015-10-01

If translated into behavioral intent, improving stroke knowledge may potentially impact on better outcomes. Children are an attractive target population since they can drive familial behavioral changes. However, the impact of interventions on stroke knowledge among children is unclear. We performed a systematic review and meta-analysis to investigate whether educational interventions targeting children improve stroke knowledge and lead to behavioral changes. We searched Ovid, PubMed, and Embase between January 2000 and December 2014. We included studies written in English reporting the number of children aged 6-15 years undergoing educational interventions on stroke and providing the results for baseline and early and late postintervention tests. We compared the proportion of correct answers between baseline, early, and late responses for two endpoints: knowledge and behavioral intent. Of the initial 58 articles found, we included nine that met the inclusion criteria. Compared with baseline tests (51·7%, 95% confidence interval 40·9-62·4), there was improvement in stroke knowledge in early (74·0%, 95% confidence interval 64·4-82·5, P = 0·002) and late (67·3%, 95% confidence interval 55·4-78·2, P = 0·027) responses. There was improvement in the early (92·1%, 95% confidence interval 86·0-96·6, P < 0·001) and late (83·9%, 95% confidence interval 73·5-92·1, P = 0·001) responses for behavioral intent compared with the baseline assessment (63·8%, 95% confidence interval 53·5-73·4). Children are a potentially attractive target population for improvement in stroke knowledge and behavioral intent, both in the short and long term. Our findings may support the implementation of large-scale stroke educational initiatives targeting children. © 2015 World Stroke Organization.

Suicide in patients with gastric cancer: a population-based study.

PubMed

Sugawara, Akitomo; Kunieda, Etsuo

2016-09-01

We conducted this study to examine the rate of suicide in patients with gastric cancer and to identify factors associated with increased risk of suicide using the Surveillance, Epidemiology, and End Results database. The database was queried for patients who were diagnosed with gastric cancer from 1998 to 2011. The rate of suicide and standardized mortality ratio were calculated. Multivariable analyses were conducted to identify factors associated with increased risk of suicide. A total of 65 535 patients with 109 597 person-years of follow-up were included. A total of 68 patients died of suicide. The age-adjusted rate of suicide was 34.6 per 100 000 person-years (standardized mortality ratios, 4.07; 95% confidence interval, 3.18-5.13). The rate of suicide was highest within the first 3 months after cancer diagnosis (standardized mortality ratios, 67.67; 95% confidence interval, 40.74-106.15). Results of multivariable analyses showed that male sex (incidence rate ratio, 7.15; 95% confidence interval, 3.05-16.78; P < 0.0001), White race (incidence rate ratio, 3.23; 95% confidence interval, 1.00-10.35; P = 0.0491), unmarried status (incidence rate ratio, 2.01; 95% confidence interval, 1.22-3.30; P = 0.0060) and distant stage disease (incidence rate ratio, 2.90; 95% confidence interval, 1.72-4.92; P < 0.0001) were significantly associated with increased risk of suicide. Patients with gastric cancer have an ~4-fold higher risk of suicide compared with the general US population. The suicide risk is highest within the first 3 months after diagnosis. Male sex, White race, unmarried status and distant stage disease are significantly associated with increased risk of suicide. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Integrating palliative care across settings: A retrospective cohort study of a hospice home care programme for cancer patients.

PubMed

Tan, Woan Shin; Lee, Angel; Yang, Sze Yee; Chan, Susan; Wu, Huei Yaw; Ng, Charis Wei Ling; Heng, Bee Hoon

2016-07-01

Terminally ill patients at the end-of-life do transit between care settings due to their complex care needs. Problems of care fragmentation could result in poor quality of care. We aimed to evaluate the impact of an integrated hospice home care programme on acute care service usage and on the share of home deaths. The retrospective study cohort comprised patients who were diagnosed with cancer, had an expected prognosis of 1 year or less, and were referred to a home hospice. The intervention group comprised deceased patients enrolled in the integrated hospice home care programme between September 2012 and June 2014. The historical comparison group comprised deceased patients who were referred to other home hospices between January 2007 and January 2011. There were 321 cases and 593 comparator subjects. Relative to the comparator group, the share of hospital deaths was significantly lower for programme participants (12.1% versus 42.7%). After adjusting for differences at baseline, the intervention group had statistically significantly lower emergency department visits at 30 days (incidence rate ratio: 0.38; 95% confidence interval: 0.31-0.47), 60 days (incidence rate ratio: 0.61; 95% confidence interval: 0.54-0.69) and 90 days (incidence rate ratio: 0.69; 95% confidence interval: 0.62-0.77) prior to death. Similar results held for the number of hospitalisations at 30 days (incidence rate ratio: 0.48; 95% confidence interval: 0.40-0.58), 60 days (incidence rate ratio: 0.71; 95% confidence interval: 0.62-0.82) and 90 days (incidence rate ratio: 0.77; 95% confidence interval: 0.68-0.88) prior to death. Our results demonstrated that by integrating services between acute care and home hospice care, a reduction in acute care service usage could occur. © The Author(s) 2016.

Prevalence of dry eye syndrome in an adult population.

PubMed

Hashemi, Hassan; Khabazkhoob, Mehdi; Kheirkhah, Ahmad; Emamian, Mohammad Hassan; Mehravaran, Shiva; Shariati, Mohammad; Fotouhi, Akbar

2014-04-01

To determine the prevalence of dry eye syndrome in the general 40- to 64-year-old population of Shahroud, Iran. Population-based cross-sectional study. Through cluster sampling, 6311 people were selected and 5190 participated. Assessment of dry eye was done in a random subsample of 1008 people. Subjective assessment for dry eye syndrome was performed using Ocular Surface Disease Index questionnaire. In addition, the following objective tests of dry eye syndrome were employed: Schirmer test, tear break-up time, and fluorescein and Rose Bengal staining using the Oxford grading scheme. Those with an Ocular Surface Disease Index score ≥23 were considered symptomatic, and dry eye syndrome was defined as having symptoms and at least one positive objective sign. The prevalence of dry eye syndrome was 8.7% (95% confidence interval 6.9-10.6). Assessment of signs showed an abnormal Schirmer score in 17.8% (95% confidence interval 15.5-20.0), tear break-up time in 34.2% (95% confidence interval 29.5-38.8), corneal fluorescein staining (≥1) in 11.3% (95% confidence interval 8.5-14.1) and Rose Bengal staining (≥3 for cornea and/or conjunctiva) in 4.9% (95% confidence interval 3.4-6.5). According to the Ocular Surface Disease Index scores, 18.3% (95% confidence interval 15.9-20.6) had dry eye syndrome symptoms. The prevalence of dry eye syndrome was significantly higher in women (P = 0.010) and not significantly associated with age (P = 0.291). The objective dry eye syndrome signs significantly increased with age. Based on the findings, the prevalence of dry eye syndrome in the studied population is in the mid-range. The prevalence is higher in women. Also, objective tests tend to turn abnormal at higher age. Pterygium is associated with dry eye syndrome and increased its symptoms. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis.

PubMed

Zhu, Juanjuan; Li, Wei; Zhou, Jihong; Chen, Yuqing; Zhao, Chenling; Zhang, Ting; Peng, Wenjia; Wang, Xiaojing

2017-07-01

This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ significantly.

Antecedents and neuroimaging patterns in cerebral palsy with epilepsy and cognitive impairment: a population-based study in children born at term.

PubMed

Ahlin, Kristina; Jacobsson, Bo; Nilsson, Staffan; Himmelmann, Kate

2017-07-01

Antecedents of accompanying impairments in cerebral palsy and their relation to neuroimaging patterns need to be explored. A population-based study of 309 children with cerebral palsy born at term between 1983 and 1994. Prepartum, intrapartum, and postpartum variables previously studied as antecedents of cerebral palsy type and motor severity were analyzed in children with cerebral palsy and cognitive impairment and/or epilepsy, and in children with cerebral palsy without these accompanying impairments. Neuroimaging patterns and their relation to identified antecedents were analyzed. Data were retrieved from the cerebral palsy register of western Sweden, and from obstetric and neonatal records. Children with cerebral palsy and accompanying impairments more often had low birthweight (kg) (odds ratio 0.5, 95% confidence interval 0.3-0.8), brain maldevelopment known at birth (p = 0.007, odds ratio ∞) and neonatal infection (odds ratio 5.4, 95% confidence interval 1.04-28.4). Moreover, neuroimaging patterns of maldevelopment (odds ratio 7.2, 95% confidence interval 2.9-17.2), cortical/subcortical lesions (odds ratio 5.3, 95% confidence interval 2.3-12.2) and basal ganglia lesions (odds ratio 7.6, 95% confidence interval 1.4-41.3) were more common, wheras white matter injury was found significantly less often (odds ratio 0.2, 95% confidence interval 0.1-0.5). In most children with maldevelopment, the intrapartum and postpartum periods were uneventful (p < 0.05). Cerebral maldevelopment was associated with prepartum antecedents, whereas subcortical/cortical and basal ganglia lesions were associated with intrapartum and postpartum antecedents. No additional factor other than those related to motor impairment was associated with epilepsy and cognitive impairment in cerebral palsy. Timing of antecedents deemed important for the development of cerebral palsy with accompanying impairments were supported by neuroimaging patterns. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Breast cancer biology varies by method of detection and may contribute to overdiagnosis.

PubMed

Hayse, Brandon; Hooley, Regina J; Killelea, Brigid K; Horowitz, Nina R; Chagpar, Anees B; Lannin, Donald R

2016-08-01

Recently, it has been suggested that screening mammography may result in some degree of overdiagnosis (ie, detection of breast cancers that would never become clinically important within the lifespan of the patient). The extent and biology of these overdiagnosed cancers, however, is not well understood, and the effect of newer screening modalities on overdiagnosis is unknown. We performed a retrospective review of a prospectively collected database of breast cancers diagnosed at the Yale Breast Center from 2004-2014. The mode of initial presentation was categorized into 5 groups: screening mammogram, screening magnetic resonance imaging, screening ultrasonography, self-detected masses, and physician-detected masses. Compared with cancers presenting with masses, cancers detected by image-based screening were more likely to present with ductal carcinoma-in-situ or T1 cancers (P < .001). In addition to a simple stage shift, however, cancers detected by image-based screening were also more likely to be luminal and low-grade cancers; symptomatic cancers were more likely high-grade and triple-negative (P < .001, respectively). On a multivariate analysis, adjusting for age, race, and tumor size, cancers detected by mammogram, US, and magnetic resonance imaging had greater odds of being luminal (odds ratio 1.8, 95% confidence interval, 1.5-2.3; odds ratio 2.2, 95% confidence interval, 1.1-4.7; and odds ratio 4.7, 95% confidence interval, 2.1-10.6, respectively), and low-grade (odds ratio 2.2, 95% confidence interval, 1.6-2.9; odds ratio 4.9, 95% confidence interval, 2.7-8.9; and odds ratio 4.6, 95% confidence interval, 2.6-8.1, respectively) compared with cancers presenting with self-detected masses. Screening detects cancers with more indolent biology, potentially contributing to the observed rate of overdiagnosis. With magnetic resonance imaging and US being used more commonly for screening, the rate of overdiagnosis may increase further. Copyright © 2016. Published by Elsevier Inc.

Peritoneal Dialysis Access Revision in Children: Causes, Interventions, and Outcomes.

PubMed

Borzych-Duzalka, Dagmara; Aki, T Fazil; Azocar, Marta; White, Colin; Harvey, Elizabeth; Mir, Sevgi; Adragna, Marta; Serdaroglu, Erkin; Sinha, Rajiv; Samaille, Charlotte; Vanegas, Juan Jose; Kari, Jameela; Barbosa, Lorena; Bagga, Arvind; Galanti, Monica; Yavascan, Onder; Leozappa, Giovanna; Szczepanska, Maria; Vondrak, Karel; Tse, Kei-Chiu; Schaefer, Franz; Warady, Bradley A

2017-01-06

Little published information is available about access failure in children undergoing chronic peritoneal dialysis. Our objectives were to evaluate frequency, risk factors, interventions, and outcome of peritoneal dialysis access revision. Data were derived from 824 incident and 1629 prevalent patients from 105 pediatric nephrology centers enrolled in the International Pediatric Peritoneal Dialysis Network Registry between 2007 and 2015. In total, 452 access revisions were recorded in 321 (13%) of 2453 patients over 3134 patient-years of follow-up, resulting in an overall access revision rate of 0.14 per treatment year. Among 824 incident patients, 186 (22.6%) underwent 188 access revisions over 1066 patient-years, yielding an access revision rate of 0.17 per treatment year; 83% of access revisions in incident patients were reported within the first year of peritoneal dialysis treatment. Catheter survival rates in incident patients were 84%, 80%, 77%, and 73% at 12, 24, 36, and 48 months, respectively. By multivariate logistic regression analysis, risk of access revision was associated with younger age (odds ratio, 0.93; 95% confidence interval, 0.92 to 0.95; P<0.001), diagnosis of congenital anomalies of the kidney and urinary tract (odds ratio, 1.28; 95% confidence interval, 1.03 to 1.59; P=0.02), coexisting ostomies (odds ratio, 1.42; 95% confidence interval, 1.07 to 1.87; P=0.01), presence of swan neck tunnel with curled intraperitoneal portion (odds ratio, 1.30; 95% confidence interval, 1.04 to 1.63; P=0.02), and high gross national income (odds ratio, 1.10; 95% confidence interval, 1.02 to 1.19; P=0.01). Main reasons for access revisions included mechanical malfunction (60%), peritonitis (16%), exit site infection (12%), and leakage (6%). Need for access revision increased the risk of peritoneal dialysis technique failure or death (hazard ratio, 1.35; 95% confidence interval, 1.10 to 1.65; P=0.003). Access dysfunction due to mechanical causes doubled the risk of technique failure compared with infectious causes (hazard ratio, 1.95; 95% confidence interval, 1.20 to 2.30; P=0.03). Peritoneal dialysis catheter revisions are common in pediatric patients on peritoneal dialysis and complicate provision of chronic peritoneal dialysis. Attention to potentially modifiable risk factors by pediatric nephrologists and pediatric surgeons should be encouraged. Copyright © 2016 by the American Society of Nephrology.

Peritoneal Dialysis Access Revision in Children: Causes, Interventions, and Outcomes

PubMed Central

Aki, T. Fazil; Azocar, Marta; White, Colin; Harvey, Elizabeth; Mir, Sevgi; Adragna, Marta; Serdaroglu, Erkin; Sinha, Rajiv; Samaille, Charlotte; Vanegas, Juan Jose; Kari, Jameela; Barbosa, Lorena; Bagga, Arvind; Galanti, Monica; Yavascan, Onder; Leozappa, Giovanna; Szczepanska, Maria; Vondrak, Karel; Tse, Kei-Chiu; Schaefer, Franz; Warady, Bradley A.

2017-01-01

Background and objectives Little published information is available about access failure in children undergoing chronic peritoneal dialysis. Our objectives were to evaluate frequency, risk factors, interventions, and outcome of peritoneal dialysis access revision. Design, setting, participants, & measurements Data were derived from 824 incident and 1629 prevalent patients from 105 pediatric nephrology centers enrolled in the International Pediatric Peritoneal Dialysis Network Registry between 2007 and 2015. Results In total, 452 access revisions were recorded in 321 (13%) of 2453 patients over 3134 patient-years of follow-up, resulting in an overall access revision rate of 0.14 per treatment year. Among 824 incident patients, 186 (22.6%) underwent 188 access revisions over 1066 patient-years, yielding an access revision rate of 0.17 per treatment year; 83% of access revisions in incident patients were reported within the first year of peritoneal dialysis treatment. Catheter survival rates in incident patients were 84%, 80%, 77%, and 73% at 12, 24, 36, and 48 months, respectively. By multivariate logistic regression analysis, risk of access revision was associated with younger age (odds ratio, 0.93; 95% confidence interval, 0.92 to 0.95; P<0.001), diagnosis of congenital anomalies of the kidney and urinary tract (odds ratio, 1.28; 95% confidence interval, 1.03 to 1.59; P=0.02), coexisting ostomies (odds ratio, 1.42; 95% confidence interval, 1.07 to 1.87; P=0.01), presence of swan neck tunnel with curled intraperitoneal portion (odds ratio, 1.30; 95% confidence interval, 1.04 to 1.63; P=0.02), and high gross national income (odds ratio, 1.10; 95% confidence interval, 1.02 to 1.19; P=0.01). Main reasons for access revisions included mechanical malfunction (60%), peritonitis (16%), exit site infection (12%), and leakage (6%). Need for access revision increased the risk of peritoneal dialysis technique failure or death (hazard ratio, 1.35; 95% confidence interval, 1.10 to 1.65; P=0.003). Access dysfunction due to mechanical causes doubled the risk of technique failure compared with infectious causes (hazard ratio, 1.95; 95% confidence interval, 1.20 to 2.30; P=0.03). Conclusions Peritoneal dialysis catheter revisions are common in pediatric patients on peritoneal dialysis and complicate provision of chronic peritoneal dialysis. Attention to potentially modifiable risk factors by pediatric nephrologists and pediatric surgeons should be encouraged. PMID:27899416

Toxoplasma gondii exposure and epilepsy: A matched case-control study in a public hospital in northern Mexico.

PubMed

Alvarado-Esquivel, Cosme; Rico-Almochantaf, Yazmin Del Rosario; Hernández-Tinoco, Jesús; Quiñones-Canales, Gerardo; Sánchez-Anguiano, Luis Francisco; Torres-González, Jorge; Ramírez-Valles, Eda Guadalupe; Minjarez-Veloz, Andrea

2018-01-01

This study aimed to determine the association between infection with Toxoplasma gondii and epilepsy in patients attended to in a public hospital in the northern Mexican city of Durango. We performed an age- and gender-matched case-control study of 99 patients suffering from epilepsy and 99 without epilepsy. Sera of participants were analyzed for anti- T. gondii IgG and IgM antibodies using commercially available enzyme-linked immunoassays. Seropositive samples to T. gondii were further analyzed for detection of T. gondii DNA by polymerase chain reaction. Anti- T. gondii IgG antibodies were found in 10 (10.1%) of the 99 cases and in 6 (6.1%) of the 99 controls (odds ratio = 1.74; 95% confidence interval: 0.60-4.99; p = 0.43). High (> 150 IU/mL) levels of anti- T. gondii IgG antibodies were found in 6 of the 99 cases and in 4 of the 99 controls (odds ratio = 1.53; 95% confidence interval: 0.41-5.60; p = 0.74). Anti- T. gondii IgM antibodies were found in 2 of the 10 IgG seropositive cases, and in 2 of the 6 IgG seropositive controls (odds ratio = 0.50; 95% confidence interval: 0.05-4.97; p = 0.60). T. gondii DNA was not found in any of the 10 anti- T. gondii IgG positive patients. Bivariate analysis of IgG seropositivity to T. gondii and International Statistical Classification of Diseases and related Health Problems, 10th Edition codes of epilepsy showed an association between seropositivity and G40.1 code (odds ratio = 22.0; 95% confidence interval: 2.59-186.5; p = 0.008). Logistic regression analysis showed an association between T. gondii infection and consumption of goat meat (odds ratio = 6.5; 95% confidence interval: 1.22-34.64; p = 0.02), unwashed raw vegetables (odds ratio = 26.3; 95% confidence interval: 2.61-265.23; p = 0.006), and tobacco use (odds ratio = 6.2; 95% confidence interval: 1.06-36.66; p = 0.04). Results suggest that T. gondii infection does not increase the risk of epilepsy in our setting; however, infection might be linked to specific types of epilepsy. Factors associated with T. gondii infection found in this study may aid in the design of preventive measures against toxoplasmosis.

Association of protein tyrosine phosphatase, non-receptor type 22 +1858C→T polymorphism and susceptibility to vitiligo: Systematic review and meta-analysis.

PubMed

Agarwal, Silky; Changotra, Harish

2017-01-01

Protein tyrosine phosphatase, non-receptor type 22 gene, which translates to lymphoid tyrosine phosphatase, is considered to be a susceptibility gene marker associated with several autoimmune diseases. Several studies have demonstrated the association of protein tyrosine phosphatase, non-receptor type 22 +1858C→T polymorphism with vitiligo. However, these studies showed conflicting results. Meta-analysis of the same was conducted earlier that included fewer number of publications in their study. We performed a meta-analysis of a total of seven studies consisting of 2094 cases and 3613 controls to evaluate the possible association of protein tyrosine phosphatase, non-receptor type 22 +1858C>T polymorphism with vitiligo susceptibility. We conducted a literature search in PubMed, Google Scholar and Dogpile for all published paper on protein tyrosine phosphatase, non-receptor type 22 +1858C→T polymorphism and vitiligo risk till June 2016. Data analysis was performed by RevMan 5.3 and comprehensive meta-analysis v3.0 software. Meta-analysis showed an overall significant association of protein tyrosine phosphatase, non- receptor type 22 +1858C→T polymorphism with vitiligo in all models (allelic model [T vs. C]: odds ratio = 1.50, 95% confidence interval [1.32-1.71], P< 0.001; dominant model [TT + CT vs. CC]: odds ratio = 1.61, 95% confidence interval [1.16-2.24], P = 0.004; recessive model [TT vs. CT + CC]: odds ratio = 4.82, 95% confidence interval [1.11-20.92], P = 0.04; homozygous model [TT vs. CC]: odds ratio = 5.34, 95% confidence interval [1.23-23.24], P = 0.03; co-dominant model [CT vs. CC]: odds ratio = 1.52, 95% confidence interval [1.09-2.13], P = 0.01). No publication bias was detected in the funnel plot study. Limited ethnic-based studies, unable to satisfy data by gender or vitiligo-type are some limitations of the present meta-analysis. Stratifying data by ethnicity showed an association of protein tyrosine phosphatase, non-receptor type 22 +1858C→T with vitiligo in European population (odds ratio = 1.53, 95% confidence interval [1.34-1.75], P< 0.001) but not in Asian population (odds ratio = 0.59, 95% confidence interval [0.26-1.32], P = 0.2). In conclusion, protein tyrosine phosphatase, non-receptor type 22 +1858 T allele predisposes European individuals to vitiligo.

Failure probability of three designs of zirconia crowns

PubMed Central

Ramos, G. Freitas; Monteiro, E. Barbosa Carmona; Bottino, M.A.; Zhang, Y.; de Melo, R. Marques

2015-01-01

Objectives This study utilized a 2-parameter Weibull analysis for evaluation of lifetime of fully or partially porcelain-/glaze-veneered zirconia crowns after fatigue test. Methods Sixty first molars were selected and prepared for full-coverage crowns with three different designs(n = 20): Traditional –crowns with zirconia framework covered with feldspathic porcelain; Modified– crowns partially covered with veneering porcelain; and Monolithic–full-contour zirconia crowns. All specimens were treated with a glaze layer. Specimens were subjected to mechanical cycling (100N, 3Hz) with a piston with hemispherical tip (Ø=6 mm) until the specimens failed or up to 2×106 cycles. Every 500,000 cycles intervals, the fatigue tests were interrupted, and stereomicroscopy (10 X) was used to inspect the specimens for damage. We performed Weibull analysis of interval data to calculate the number of failures in each interval. Results The types and number of failures according to the groups were: cracking (Traditional-13, Modified-6) and chipping (Traditional-4) of the feldspathic porcelain, followed by delamination (Traditional-1) at the veneer/core interface and debonding (Monollithic-2) at the cementation interface. Weibull parameters (beta, scale; and eta, shape), with a two-sided confidence interval of 95%, were: Traditional – 1.25 and 0.9 × 106cycles; Modified– 0.58 and 11.7 × 106 cycles; and Monolithic – 1.05 and 16.5 × 106 cycles. Traditional crowns showed greater susceptibility to fatigue, the Modified group presented higher propensity to early failures, and the Monolithic group showed no susceptibility to fatigue. The Modified and Monolithic groups presented the highest number of crowns with no failures after the fatigue test. Conclusions The three crown designs presented significantly different behaviors under fatigue. The Modified and the Monolithic groups presented less probability to failure after 2×106cycles. PMID:26509988

Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa.

PubMed

Padfield, Gareth J; Escudero, Carolina A; DeSouza, Astrid M; Steinberg, Christian; Gibbs, Karen; Puyat, Joseph H; Lam, Pei Yoong; Sanatani, Shubhayan; Sherwin, Elizabeth; Potts, James E; Sandor, George; Krahn, Andrew D

2016-02-09

Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa. © 2016 American Heart Association, Inc.

Accuracy assessment of percent canopy cover, cover type, and size class

Treesearch

H. T. Schreuder; S. Bain; R. C. Czaplewski

2003-01-01

Truth for vegetation cover percent and type is obtained from very large-scale photography (VLSP), stand structure as measured by size classes, and vegetation types from a combination of VLSP and ground sampling. We recommend using the Kappa statistic with bootstrap confidence intervals for overall accuracy, and similarly bootstrap confidence intervals for percent...

Confidence Intervals for Effect Sizes: Compliance and Clinical Significance in the "Journal of Consulting and Clinical Psychology"

ERIC Educational Resources Information Center

Odgaard, Eric C.; Fowler, Robert L.

2010-01-01

Objective: In 2005, the "Journal of Consulting and Clinical Psychology" ("JCCP") became the first American Psychological Association (APA) journal to require statistical measures of clinical significance, plus effect sizes (ESs) and associated confidence intervals (CIs), for primary outcomes (La Greca, 2005). As this represents the single largest…

SIMREL: Software for Coefficient Alpha and Its Confidence Intervals with Monte Carlo Studies

ERIC Educational Resources Information Center

Yurdugul, Halil

2009-01-01

This article describes SIMREL, a software program designed for the simulation of alpha coefficients and the estimation of its confidence intervals. SIMREL runs on two alternatives. In the first one, if SIMREL is run for a single data file, it performs descriptive statistics, principal components analysis, and variance analysis of the item scores…

Performing Contrast Analysis in Factorial Designs: From NHST to Confidence Intervals and Beyond

ERIC Educational Resources Information Center

Wiens, Stefan; Nilsson, Mats E.

2017-01-01

Because of the continuing debates about statistics, many researchers may feel confused about how to analyze and interpret data. Current guidelines in psychology advocate the use of effect sizes and confidence intervals (CIs). However, researchers may be unsure about how to extract effect sizes from factorial designs. Contrast analysis is helpful…

Simultaneous confidence sets for several effective doses.

PubMed

Tompsett, Daniel M; Biedermann, Stefanie; Liu, Wei

2018-04-03

Construction of simultaneous confidence sets for several effective doses currently relies on inverting the Scheffé type simultaneous confidence band, which is known to be conservative. We develop novel methodology to make the simultaneous coverage closer to its nominal level, for both two-sided and one-sided simultaneous confidence sets. Our approach is shown to be considerably less conservative than the current method, and is illustrated with an example on modeling the effect of smoking status and serum triglyceride level on the probability of the recurrence of a myocardial infarction. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessing Measurement Error in Medicare Coverage From the National Health Interview Survey

PubMed Central

Gindi, Renee; Cohen, Robin A.

2012-01-01

Objectives Using linked administrative data, to validate Medicare coverage estimates among adults aged 65 or older from the National Health Interview Survey (NHIS), and to assess the impact of a recently added Medicare probe question on the validity of these estimates. Data sources Linked 2005 NHIS and Master Beneficiary Record and Payment History Update System files from the Social Security Administration (SSA). Study design We compared Medicare coverage reported on NHIS with “benchmark” benefit records from SSA. Principal findings With the addition of the probe question, more reports of coverage were captured, and the agreement between the NHIS-reported coverage and SSA records increased from 88% to 95%. Few additional overreports were observed. Conclusions Increased accuracy of the Medicare coverage status of NHIS participants was achieved with the Medicare probe question. Though some misclassification remains, data users interested in Medicare coverage as an outcome or correlate can use this survey measure with confidence. PMID:24800138

Comparing models of change to estimate the mediated effect in the pretest-posttest control group design

PubMed Central

Valente, Matthew J.; MacKinnon, David P.

2017-01-01

Models to assess mediation in the pretest-posttest control group design are understudied in the behavioral sciences even though it is the design of choice for evaluating experimental manipulations. The paper provides analytical comparisons of the four most commonly used models used to estimate the mediated effect in this design: Analysis of Covariance (ANCOVA), difference score, residualized change score, and cross-sectional model. Each of these models are fitted using a Latent Change Score specification and a simulation study assessed bias, Type I error, power, and confidence interval coverage of the four models. All but the ANCOVA model make stringent assumptions about the stability and cross-lagged relations of the mediator and outcome that may not be plausible in real-world applications. When these assumptions do not hold, Type I error and statistical power results suggest that only the ANCOVA model has good performance. The four models are applied to an empirical example. PMID:28845097

Comparing models of change to estimate the mediated effect in the pretest-posttest control group design.

PubMed

Valente, Matthew J; MacKinnon, David P

2017-01-01

Models to assess mediation in the pretest-posttest control group design are understudied in the behavioral sciences even though it is the design of choice for evaluating experimental manipulations. The paper provides analytical comparisons of the four most commonly used models used to estimate the mediated effect in this design: Analysis of Covariance (ANCOVA), difference score, residualized change score, and cross-sectional model. Each of these models are fitted using a Latent Change Score specification and a simulation study assessed bias, Type I error, power, and confidence interval coverage of the four models. All but the ANCOVA model make stringent assumptions about the stability and cross-lagged relations of the mediator and outcome that may not be plausible in real-world applications. When these assumptions do not hold, Type I error and statistical power results suggest that only the ANCOVA model has good performance. The four models are applied to an empirical example.

Estimating the force of measles virus infection from hospitalised cases in Lusaka, Zambia.

PubMed

Scott, Susana; Mossong, Joel; Moss, William J; Cutts, Felicity T; Kasolo, Francis; Sinkala, Moses; Cousens, Simon

2004-12-21

Estimates of the force of infection (the rate at which susceptible individuals acquire infection) are essential for modelling the transmission dynamics of infectious diseases and can be a useful tool in evaluating mass vaccination strategies. Few estimates exist of the force of infection of measles virus in sub-Saharan Africa. A mathematical model was applied to age-specific recorded hospital admissions between September 1996 and September 1999 to estimate the force of measles virus infection in Lusaka, Zambia. The average force of infection was estimated to be 20% per year (95% confidence intervals (CI) 16.5, 23.5) which was insensitive to varying assumptions about vaccine coverage. The force of infection varied from year to year (P < 0.001) reflecting the cyclic pattern of measles incidence. The estimated probability of a case being hospitalised decreased with age, consistent with less severe disease in older children. Estimates of the force of infection using routinely available data were consistent with those based upon serological surveys in other sub-Saharan African countries.

Predicting treatment effect from surrogate endpoints and historical trials: an extrapolation involving probabilities of a binary outcome or survival to a specific time

PubMed Central

Sargent, Daniel J.; Buyse, Marc; Burzykowski, Tomasz

2011-01-01

SUMMARY Using multiple historical trials with surrogate and true endpoints, we consider various models to predict the effect of treatment on a true endpoint in a target trial in which only a surrogate endpoint is observed. This predicted result is computed using (1) a prediction model (mixture, linear, or principal stratification) estimated from historical trials and the surrogate endpoint of the target trial and (2) a random extrapolation error estimated from successively leaving out each trial among the historical trials. The method applies to either binary outcomes or survival to a particular time that is computed from censored survival data. We compute a 95% confidence interval for the predicted result and validate its coverage using simulation. To summarize the additional uncertainty from using a predicted instead of true result for the estimated treatment effect, we compute its multiplier of standard error. Software is available for download. PMID:21838732

Taste of Clindamycin and Acetaminophen.

PubMed

Hashiba, Kimberlee A; Wo, Shane R; Yamamoto, Loren G

2017-02-01

This study evaluated the taste palatability of liquid clindamycin and acetaminophen products on the market. Subjects rated the palatability of 3 clindamycin suspensions, 1 amoxicillin suspension (tasted twice), an acetaminophen elixir, and an acetaminophen suspension in a randomized blinded fashion on a 0 to 5 scale. Forty-six adults aged 20 to 82 years volunteered for this study. Means (and 95% confidence intervals) were as follows: amoxicillin-first taste 3.6 (3.3-3.9), amoxicillin-second taste 3.5 (3.2-3.7). Clindamycin Rising, Perrigo, Greenstone; 2.0 (1.6-2.5), 3.0 (2.7-3.3), and 2.2 (1.8-2.6), respectively. Acetaminophen elixir 0.6 (0.4-0.8) and acetaminophen suspension 3.4 (3.1-3.6). One clindamycin tasted significantly better than the others. Additionally, although 2 acetaminophen formulations are currently available over-the-counter, the suspension is more palatable and less costly. Medicaid drug programs that perpetuate the use of elixir should change their coverage to save money and provide patients access to better tasting acetaminophen.

The cost of routine Aedes aegypti control and of insecticide-treated curtain implementation.

PubMed

Baly, Alberto; Flessa, Steffen; Cote, Marilys; Thiramanus, Thirapong; Vanlerberghe, Veerle; Villegas, Elci; Jirarojwatana, Somchai; Van der Stuyft, Patrick

2011-05-01

Insecticide-treated curtains (ITCs) are promoted for controlling the Dengue vector Aedes aegypti. We assessed the cost of the routine Aedes control program (RACP) and the cost of ITC implementation through the RACP and health committees in Venezuela and through health volunteers in Thailand. The yearly cost of the RACP per household amounted to US$2.14 and $1.89, respectively. The ITC implementation cost over three times more, depending on the channel used. In Venezuela the RACP was the most efficient implementation-channel. It spent US$1.90 (95% confidence interval [CI]: 1.83; 1.97) per curtain distributed, of which 76.9% for the curtain itself. Implementation by health committees cost significantly (P = 0.02) more: US$2.32 (95% CI: 1.93; 2.61) of which 63% for the curtain. For ITC implementation to be at least as cost-effective as the RACP, at equal effectiveness and actual ITC prices, the attained curtain coverage and the adulticiding effect should last for 3 years.

The Cost of Routine Aedes aegypti Control and of Insecticide-Treated Curtain Implementation

PubMed Central

Baly, Alberto; Flessa, Steffen; Cote, Marilys; Thiramanus, Thirapong; Vanlerberghe, Veerle; Villegas, Elci; Jirarojwatana, Somchai; Van der Stuyft, Patrick

2011-01-01

Insecticide-treated curtains (ITCs) are promoted for controlling the Dengue vector Aedes aegypti. We assessed the cost of the routine Aedes control program (RACP) and the cost of ITC implementation through the RACP and health committees in Venezuela and through health volunteers in Thailand. The yearly cost of the RACP per household amounted to US$2.14 and $1.89, respectively. The ITC implementation cost over three times more, depending on the channel used. In Venezuela the RACP was the most efficient implementation-channel. It spent US$1.90 (95% confidence interval [CI]: 1.83; 1.97) per curtain distributed, of which 76.9% for the curtain itself. Implementation by health committees cost significantly (P = 0.02) more: US$2.32 (95% CI: 1.93; 2.61) of which 63% for the curtain. For ITC implementation to be at least as cost-effective as the RACP, at equal effectiveness and actual ITC prices, the attained curtain coverage and the adulticiding effect should last for 3 years. PMID:21540384

Frequency of depression in type 2 diabetes mellitus and an analysis of predictive factors.

PubMed

Arshad, Abdul Rehman; Alvi, Kamran Yousaf

2016-04-01

To determine frequency of depression in patients with diabetes mellitus type 2 and to identify predictive factors. The observational study was carried out at 1 Mountain Medical Battalion, Bagh, Azad Kashmir, Pakistan, from June 2013 to May 2014, and comprised type 2 diabetic patients who were not using anti-depressants and did not have history of other psychiatric illnesses. Demographic data, duration of diabetes, presence of hypertension and type of treatment were recorded and body mass index was calculated. Patient Health Questionnaire-9, translated into Urdu, was administered during face-to-face interviews. Scores >5 indicated depression, which was classified into different grades of severity using standard cut-off values. Of the 133 patients, 51(38.35%) were depressed. Depression was mild in 34(26%), moderate in 12(9.6%), moderately severe in 4(2.9%) and severe in 1(0.7%) patient. On univariate binary logistic regression, female gender (odds ratio=3.07; 95% confidence interval = 1.43, 6.59), lesser education (odds ratio = 0.90; 95% confidence interval 0.84, 0.97) shorter duration of diabetes (odds ratio=0.87; 95% confidence interval = 0.80, 0.96) and higher body mass index (odds ratio=1.41; 95% confidence interval = 1.05, 1.25) were significantly associated with depression. Only shorter duration of diabetes (odds ratio=0.90; 95% confidence interval = 0.82, 0.99) remained significant after adjustment for confounders. Age, level of education, glycaemic control and type of treatment did not predict depression. A significant proportion of type 2 diabetics were depressed. Shorter duration of diabetes reliably predicted depression in these patients.

A prospective observational cohort study to assess the incidence of acute otitis media among children 0-5 years of age in Southern Brazil.

PubMed

Lanzieri, Tatiana M; Cunha, Clóvis Arns da; Cunha, Rejane B; Arguello, D Fermin; Devadiga, Raghavendra; Sanchez, Nervo; Barria, Eduardo Ortega

To estimate acute otitis media incidence among young children and impact on quality of life of parents/caregivers in a southern Brazilian city. Prospective cohort study including children 0-5 years of age registered at a private pediatric practice. Acute otitis media episodes diagnosed by a pediatrician and impact on quality of life of parents/caregivers were assessed during a 12-month follow-up. During September 2008-March 2010, of 1,136 children enrolled in the study, 1074 (95%) were followed: 55.0% were ≤2 years of age, 52.3% males, 94.7% white, and 69.2% had previously received pneumococcal vaccine in private clinics. Acute otitis media incidence per 1000 person-years was 95.7 (95% confidence interval: 77.2-117.4) overall, 105.5 (95% confidence interval: 78.3-139.0) in children ≤2 years of age and 63.6 (95% confidence interval: 43.2-90.3) in children 3-5 years of age. Acute otitis media incidence per 1000 person-years was 86.3 (95% confidence interval: 65.5-111.5) and 117.1 (95% confidence interval: 80.1-165.3) among vaccinated and unvaccinated children, respectively. Nearly 68.9% of parents reported worsening of their overall quality of life. Acute otitis media incidence among unvaccinated children in our study may be useful as baseline data to assess impact of pneumococcal vaccine introduction in the Brazilian National Immunization Program in April 2010. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Risk factors for gametocyte carriage in uncomplicated falciparum malaria in children before and after artemisinin-based combination treatments.

PubMed

Sowunmi, Akintunde; Okuboyejo, Titilope M; Gbotosho, Grace O; Happi, Christian T

2011-01-01

Artemisinin-based combination treatments (ACTs) are the recommended first-line antimalarials globally, but their influence on the risk factors associated with gametocyte carriage has had little evaluation in endemic areas. The risk factors associated with gametocytaemia at presentation and after ACTs were evaluated in 835 children assigned to artesunate, artesunate-amodiaquine, artesunate-mefloquine or artemether-lumefantrine. Gametocyte carriage at enrolment was 8.4%. During follow-up, 24 patients (2.8%) developed gametocytaemia, which in 83% (20 patients) had developed by day 7 following treatment. In a multiple regression model, 2 factors were independent risk factors for the presence of gametocytaemia at enrolment, namely age <3 years (adjusted odds ratio 2.03, 95% confidence interval 1.01-4.05; p = 0.04) and enrolment before 2009 (adjusted odds ratio 4.2, 95% confidence interval 2.09-8.44; p < 0.001). Haematocrit <25% and parasitaemia <50,000/μl blood were associated with an increased risk of gametocytaemia. Following treatment, 3 factors were independent risk factors for gametocytaemia, namely gametocytaemia at enrolment (adjusted odds ratio 46.39, 95% confidence interval 22.3-96.46; p < 0.0001) and treatment with artesunate (adjusted odds ratio 6.74, 95% confidence interval 1.79-25.27; p = 0.005) or artesunate-mefloquine (adjusted odds ratio 9.66, 95% confidence interval 2.87-32.46; p < 0.0.0001) relative to other ACTs. ACTs modified the risk factors associated with gametocyte carriage after use. Copyright © 2012 S. Karger AG, Basel.