Understanding poisson regression.

PubMed

Hayat, Matthew J; Higgins, Melinda

2014-04-01

Nurse investigators often collect study data in the form of counts. Traditional methods of data analysis have historically approached analysis of count data either as if the count data were continuous and normally distributed or with dichotomization of the counts into the categories of occurred or did not occur. These outdated methods for analyzing count data have been replaced with more appropriate statistical methods that make use of the Poisson probability distribution, which is useful for analyzing count data. The purpose of this article is to provide an overview of the Poisson distribution and its use in Poisson regression. Assumption violations for the standard Poisson regression model are addressed with alternative approaches, including addition of an overdispersion parameter or negative binomial regression. An illustrative example is presented with an application from the ENSPIRE study, and regression modeling of comorbidity data is included for illustrative purposes. Copyright 2014, SLACK Incorporated.

Analyzing hospitalization data: potential limitations of Poisson regression.

PubMed

Weaver, Colin G; Ravani, Pietro; Oliver, Matthew J; Austin, Peter C; Quinn, Robert R

2015-08-01

Poisson regression is commonly used to analyze hospitalization data when outcomes are expressed as counts (e.g. number of days in hospital). However, data often violate the assumptions on which Poisson regression is based. More appropriate extensions of this model, while available, are rarely used. We compared hospitalization data between 206 patients treated with hemodialysis (HD) and 107 treated with peritoneal dialysis (PD) using Poisson regression and compared results from standard Poisson regression with those obtained using three other approaches for modeling count data: negative binomial (NB) regression, zero-inflated Poisson (ZIP) regression and zero-inflated negative binomial (ZINB) regression. We examined the appropriateness of each model and compared the results obtained with each approach. During a mean 1.9 years of follow-up, 183 of 313 patients (58%) were never hospitalized (indicating an excess of 'zeros'). The data also displayed overdispersion (variance greater than mean), violating another assumption of the Poisson model. Using four criteria, we determined that the NB and ZINB models performed best. According to these two models, patients treated with HD experienced similar hospitalization rates as those receiving PD {NB rate ratio (RR): 1.04 [bootstrapped 95% confidence interval (CI): 0.49-2.20]; ZINB summary RR: 1.21 (bootstrapped 95% CI 0.60-2.46)}. Poisson and ZIP models fit the data poorly and had much larger point estimates than the NB and ZINB models [Poisson RR: 1.93 (bootstrapped 95% CI 0.88-4.23); ZIP summary RR: 1.84 (bootstrapped 95% CI 0.88-3.84)]. We found substantially different results when modeling hospitalization data, depending on the approach used. Our results argue strongly for a sound model selection process and improved reporting around statistical methods used for modeling count data. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Conditional Poisson models: a flexible alternative to conditional logistic case cross-over analysis.

PubMed

Armstrong, Ben G; Gasparrini, Antonio; Tobias, Aurelio

2014-11-24

The time stratified case cross-over approach is a popular alternative to conventional time series regression for analysing associations between time series of environmental exposures (air pollution, weather) and counts of health outcomes. These are almost always analyzed using conditional logistic regression on data expanded to case-control (case crossover) format, but this has some limitations. In particular adjusting for overdispersion and auto-correlation in the counts is not possible. It has been established that a Poisson model for counts with stratum indicators gives identical estimates to those from conditional logistic regression and does not have these limitations, but it is little used, probably because of the overheads in estimating many stratum parameters. The conditional Poisson model avoids estimating stratum parameters by conditioning on the total event count in each stratum, thus simplifying the computing and increasing the number of strata for which fitting is feasible compared with the standard unconditional Poisson model. Unlike the conditional logistic model, the conditional Poisson model does not require expanding the data, and can adjust for overdispersion and auto-correlation. It is available in Stata, R, and other packages. By applying to some real data and using simulations, we demonstrate that conditional Poisson models were simpler to code and shorter to run than are conditional logistic analyses and can be fitted to larger data sets than possible with standard Poisson models. Allowing for overdispersion or autocorrelation was possible with the conditional Poisson model but when not required this model gave identical estimates to those from conditional logistic regression. Conditional Poisson regression models provide an alternative to case crossover analysis of stratified time series data with some advantages. The conditional Poisson model can also be used in other contexts in which primary control for confounding is by fine stratification.

Spatial variation of pneumonia hospitalization risk in Twin Cities metro area, Minnesota.

PubMed

Iroh Tam, P Y; Krzyzanowski, B; Oakes, J M; Kne, L; Manson, S

2017-11-01

Fine resolution spatial variability in pneumonia hospitalization may identify correlates with socioeconomic, demographic and environmental factors. We performed a retrospective study within the Fairview Health System network of Minnesota. Patients 2 months of age and older hospitalized with pneumonia between 2011 and 2015 were geocoded to their census block group, and pneumonia hospitalization risk was analyzed in relation to socioeconomic, demographic and environmental factors. Spatial analyses were performed using Esri's ArcGIS software, and multivariate Poisson regression was used. Hospital encounters of 17 840 patients were included in the analysis. Multivariate Poisson regression identified several significant associations, including a 40% increased risk of pneumonia hospitalization among census block groups with large, compared with small, populations of ⩾65 years, a 56% increased risk among census block groups in the bottom (first) quartile of median household income compared to the top (fourth) quartile, a 44% higher risk in the fourth quartile of average nitrogen dioxide emissions compared with the first quartile, and a 47% higher risk in the fourth quartile of average annual solar insolation compared to the first quartile. After adjusting for income, moving from the first to the second quartile of the race/ethnic diversity index resulted in a 21% significantly increased risk of pneumonia hospitalization. In conclusion, the risk of pneumonia hospitalization at the census-block level is associated with age, income, race/ethnic diversity index, air quality, and solar insolation, and varies by region-specific factors. Identifying correlates using fine spatial analysis provides opportunities for targeted prevention and control.

Weather variability and the incidence of cryptosporidiosis: comparison of time series poisson regression and SARIMA models.

PubMed

Hu, Wenbiao; Tong, Shilu; Mengersen, Kerrie; Connell, Des

2007-09-01

Few studies have examined the relationship between weather variables and cryptosporidiosis in Australia. This paper examines the potential impact of weather variability on the transmission of cryptosporidiosis and explores the possibility of developing an empirical forecast system. Data on weather variables, notified cryptosporidiosis cases, and population size in Brisbane were supplied by the Australian Bureau of Meteorology, Queensland Department of Health, and Australian Bureau of Statistics for the period of January 1, 1996-December 31, 2004, respectively. Time series Poisson regression and seasonal auto-regression integrated moving average (SARIMA) models were performed to examine the potential impact of weather variability on the transmission of cryptosporidiosis. Both the time series Poisson regression and SARIMA models show that seasonal and monthly maximum temperature at a prior moving average of 1 and 3 months were significantly associated with cryptosporidiosis disease. It suggests that there may be 50 more cases a year for an increase of 1 degrees C maximum temperature on average in Brisbane. Model assessments indicated that the SARIMA model had better predictive ability than the Poisson regression model (SARIMA: root mean square error (RMSE): 0.40, Akaike information criterion (AIC): -12.53; Poisson regression: RMSE: 0.54, AIC: -2.84). Furthermore, the analysis of residuals shows that the time series Poisson regression appeared to violate a modeling assumption, in that residual autocorrelation persisted. The results of this study suggest that weather variability (particularly maximum temperature) may have played a significant role in the transmission of cryptosporidiosis. A SARIMA model may be a better predictive model than a Poisson regression model in the assessment of the relationship between weather variability and the incidence of cryptosporidiosis.

Non-Poisson Processes: Regression to Equilibrium Versus Equilibrium Correlation Functions

DTIC Science & Technology

2004-07-07

ARTICLE IN PRESSPhysica A 347 (2005) 268–2880378-4371/$ - doi:10.1016/j Correspo E-mail adwww.elsevier.com/locate/physaNon- Poisson processes : regression...05.40.a; 89.75.k; 02.50.Ey Keywords: Stochastic processes; Non- Poisson processes ; Liouville and Liouville-like equations; Correlation function...which is not legitimate with renewal non- Poisson processes , is a correct property if the deviation from the exponential relaxation is obtained by time

Modeling health survey data with excessive zero and K responses.

PubMed

Lin, Ting Hsiang; Tsai, Min-Hsiao

2013-04-30

Zero-inflated Poisson regression is a popular tool used to analyze data with excessive zeros. Although much work has already been performed to fit zero-inflated data, most models heavily depend on special features of the individual data. To be specific, this means that there is a sizable group of respondents who endorse the same answers making the data have peaks. In this paper, we propose a new model with the flexibility to model excessive counts other than zero, and the model is a mixture of multinomial logistic and Poisson regression, in which the multinomial logistic component models the occurrence of excessive counts, including zeros, K (where K is a positive integer) and all other values. The Poisson regression component models the counts that are assumed to follow a Poisson distribution. Two examples are provided to illustrate our models when the data have counts containing many ones and sixes. As a result, the zero-inflated and K-inflated models exhibit a better fit than the zero-inflated Poisson and standard Poisson regressions. Copyright © 2012 John Wiley & Sons, Ltd.

Critical elements on fitting the Bayesian multivariate Poisson Lognormal model

NASA Astrophysics Data System (ADS)

Zamzuri, Zamira Hasanah binti

2015-10-01

Motivated by a problem on fitting multivariate models to traffic accident data, a detailed discussion of the Multivariate Poisson Lognormal (MPL) model is presented. This paper reveals three critical elements on fitting the MPL model: the setting of initial estimates, hyperparameters and tuning parameters. These issues have not been highlighted in the literature. Based on simulation studies conducted, we have shown that to use the Univariate Poisson Model (UPM) estimates as starting values, at least 20,000 iterations are needed to obtain reliable final estimates. We also illustrated the sensitivity of the specific hyperparameter, which if it is not given extra attention, may affect the final estimates. The last issue is regarding the tuning parameters where they depend on the acceptance rate. Finally, a heuristic algorithm to fit the MPL model is presented. This acts as a guide to ensure that the model works satisfactorily given any data set.

Studying Resist Stochastics with the Multivariate Poisson Propagation Model

DOE PAGES

Naulleau, Patrick; Anderson, Christopher; Chao, Weilun; ...

2014-01-01

Progress in the ultimate performance of extreme ultraviolet resist has arguably decelerated in recent years suggesting an approach to stochastic limits both in photon counts and material parameters. Here we report on the performance of a variety of leading extreme ultraviolet resist both with and without chemical amplification. The measured performance is compared to stochastic modeling results using the Multivariate Poisson Propagation Model. The results show that the best materials are indeed nearing modeled performance limits.

Nonparametric Bayesian Segmentation of a Multivariate Inhomogeneous Space-Time Poisson Process.

PubMed

Ding, Mingtao; He, Lihan; Dunson, David; Carin, Lawrence

2012-12-01

A nonparametric Bayesian model is proposed for segmenting time-evolving multivariate spatial point process data. An inhomogeneous Poisson process is assumed, with a logistic stick-breaking process (LSBP) used to encourage piecewise-constant spatial Poisson intensities. The LSBP explicitly favors spatially contiguous segments, and infers the number of segments based on the observed data. The temporal dynamics of the segmentation and of the Poisson intensities are modeled with exponential correlation in time, implemented in the form of a first-order autoregressive model for uniformly sampled discrete data, and via a Gaussian process with an exponential kernel for general temporal sampling. We consider and compare two different inference techniques: a Markov chain Monte Carlo sampler, which has relatively high computational complexity; and an approximate and efficient variational Bayesian analysis. The model is demonstrated with a simulated example and a real example of space-time crime events in Cincinnati, Ohio, USA.

Poisson regression models outperform the geometrical model in estimating the peak-to-trough ratio of seasonal variation: a simulation study.

PubMed

Christensen, A L; Lundbye-Christensen, S; Dethlefsen, C

2011-12-01

Several statistical methods of assessing seasonal variation are available. Brookhart and Rothman [3] proposed a second-order moment-based estimator based on the geometrical model derived by Edwards [1], and reported that this estimator is superior in estimating the peak-to-trough ratio of seasonal variation compared with Edwards' estimator with respect to bias and mean squared error. Alternatively, seasonal variation may be modelled using a Poisson regression model, which provides flexibility in modelling the pattern of seasonal variation and adjustments for covariates. Based on a Monte Carlo simulation study three estimators, one based on the geometrical model, and two based on log-linear Poisson regression models, were evaluated in regards to bias and standard deviation (SD). We evaluated the estimators on data simulated according to schemes varying in seasonal variation and presence of a secular trend. All methods and analyses in this paper are available in the R package Peak2Trough[13]. Applying a Poisson regression model resulted in lower absolute bias and SD for data simulated according to the corresponding model assumptions. Poisson regression models had lower bias and SD for data simulated to deviate from the corresponding model assumptions than the geometrical model. This simulation study encourages the use of Poisson regression models in estimating the peak-to-trough ratio of seasonal variation as opposed to the geometrical model. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Incidence and predictors of single drug discontinuation according to the presence of HCV coinfection in HIV patients from the ICONA Foundation Cohort Study.

PubMed

Leone, Sebastiano; Shanyinde, Milensu; Cozzi Lepri, Alessandro; Lampe, Fiona C; Caramello, Pietro; Costantini, Andrea; Giacometti, Andrea; De Luca, Andrea; Cingolani, Antonella; Ceccherini Silberstein, Francesca; Puoti, Massimo; Gori, Andrea; d'Arminio Monforte, Antonella

2018-05-01

To evaluate incidence rates of and predictors for any antiretroviral (ART) drug discontinuation by HCV infection status in a large Italian cohort of HIV infected patients. All patients enrolled in ICONA who started combination antiretroviral therapy (cART) containing abacavir or tenofovir or emtricitabine or lamivudine plus efavirenz or rilpivirine or atazanavir/r or darunavir/r (DRV/r) or lopinavir/r or dolutegravir or elvitegravir or raltegravir were included. Multivariate Poisson regression models were used to determine factors independently associated with single ART drug discontinuation. Inverse probability weighting method to control for potential informative censoring was applied. Data from 10,637 patients were analyzed and 1,030 (9.7%) were HCV-Ab positive. Overall, there were 15,464 ART discontinuations due to any reason in 82,415.9 person-years of follow-up (PYFU) for an incidence rate (IR) of 18.8 (95% confidence interval [95%CI] 18.5-19.1) per 100 PYFU. No difference in IR of ART discontinuation due to any reason between HCV-infected and -uninfected patients was found. In a multivariable Poisson regression model, HCV-infected participants were at higher risk of darunavir/r discontinuation due to any reason (adjusted incidence rate ratio = 1.5, 95%CI 1.01-2.22, p value = 0.045) independently of demographics, HIV-related, ART and life-style factors. Among DRV/r treated patients, we found that HCV-viremic patients had twice the risk of ART discontinuation due to any reason than HCV-aviremic patients. In conclusion, HIV/HCV coinfected patients had a marginal risk increase of DRV/r discontinuation due to any reason compared with those without coinfection.

Increased recurrence rates of hepatocellular carcinoma after DAA therapy in a hepatitis C-infected Egyptian cohort: A comparative analysis.

PubMed

El Kassas, M; Funk, A L; Salaheldin, M; Shimakawa, Y; Eltabbakh, M; Jean, K; El Tahan, A; Sweedy, A T; Afify, S; Youssef, N F; Esmat, G; Fontanet, A

2018-06-01

In Egypt, hepatocellular carcinoma (HCC) is the most common form of cancer and direct-acting antivirals (DAA) are administered on a large scale to patients with chronic HCV infection to reduce the risk. In this unique setting, we aimed to determine the association of DAA exposure with early-phase HCC recurrence in patients with a history of HCV-related liver cancer. This was a prospective cohort study of an HCV-infected population from one Egyptian specialized HCC management centre starting from the time of successful HCC intervention. The incidence rates of HCC recurrence between DAA-exposed and nonexposed patients were compared, starting from date of HCC complete radiological response and censoring after 2 years. DAA exposure was treated as time varying. Two Poisson regressions models were used to control for potential differences in the exposed and nonexposed group; multivariable adjustment and balancing using inverse probability of treatment weighting (IPTW). We included 116 patients: 53 treated with DAAs and 63 not treated with DAAs. There was 37.7% and 25.4% recurrence in each group after a median of 16.0 and 23.0 months of follow-up, respectively. Poisson regression using IPTW demonstrated an association between DAAs and HCC recurrence with an incidence rate ratio of 3.83 (95% CI: 2.02-7.25), which was similar in the multivariable-adjusted model and various sensitivity analyses. These results add important evidence towards the possible role of DAAs in HCC recurrence and stress the need for further mechanistic studies and clinical trials to accurately confirm this role and to identify patient characteristics that may be associated with this event. © 2017 John Wiley & Sons Ltd.

Pattern of oral-maxillofacial trauma from violence against women and its associated factors.

PubMed

da Nóbrega, Lorena Marques; Bernardino, Ítalo de Macedo; Barbosa, Kevan Guilherme Nóbrega; E Silva, Jéssica Antoniana Lira; Massoni, Andreza Cristina de Lima Targino; d'Avila, Sérgio

2017-06-01

Violence against women is a global public health problem. The aim of this study was to characterize the profile of women victims of violence and identify factors associated with maxillofacial injuries. A cross-sectional study was performed based on an evaluation of 884 medico-legal and social records of women victims of physical aggression treated at the Center of Forensic Medicine and Dentistry in Brazil. The variables investigated were related to the sociodemographic characteristics of victims, circumstances of aggressions, and patterns of trauma. Descriptive and multivariate statistics using decision tree analysis by the Chi-squared automatic interaction detector (CHAID) algorithm, as well as univariate and multivariate Poisson regression analyses were performed. The occurrence of maxillofacial trauma was 46.4%. The mean age of victims was 29.38 (SD=12.55 years). Based on decision tree, the profile of violence against women can be explained by the aggressor's gender (P<.001) and sociodemographic characteristics of victims, such as marital status (P=.001), place of residence (P=.019), and educational level (P=.014). Based on the final Poisson regression model, women living in suburban areas were more likely to suffer maxillofacial trauma (PR=1.752; CI 95%=1.153-2.662; P=.009) compared to those living in rural areas. Moreover, aggression using a weapon resulted in a lower occurrence of maxillofacial trauma (PR=0.476; CI 95%=0.284-0.799; P=.005) compared to cases of aggression using physical force. The prevalence of oral-maxillofacial trauma was high, and the main associated factors were place of residence and mechanism of aggression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Revascularization Treatment of Emergency Patients with Acute ST-Segment Elevation Myocardial Infarction in Switzerland: Results from a Nationwide, Cross-Sectional Study in Switzerland for 2010-2011.

PubMed

Berlin, Claudia; Jüni, Peter; Endrich, Olga; Zwahlen, Marcel

2016-01-01

Cardiovascular diseases are the leading cause of death worldwide and in Switzerland. When applied, treatment guidelines for patients with acute ST-segment elevation myocardial infarction (STEMI) improve the clinical outcome and should eliminate treatment differences by sex and age for patients whose clinical situations are identical. In Switzerland, the rate at which STEMI patients receive revascularization may vary by patient and hospital characteristics. To examine all hospitalizations in Switzerland from 2010-2011 to determine if patient or hospital characteristics affected the rate of revascularization (receiving either a percutaneous coronary intervention or a coronary artery bypass grafting) in acute STEMI patients. We used national data sets on hospital stays, and on hospital infrastructure and operating characteristics, for the years 2010 and 2011, to identify all emergency patients admitted with the main diagnosis of acute STEMI. We then calculated the proportion of patients who were treated with revascularization. We used multivariable multilevel Poisson regression to determine if receipt of revascularization varied by patient and hospital characteristics. Of the 9,696 cases we identified, 71.6% received revascularization. Patients were less likely to receive revascularization if they were female, and 80 years or older. In the multivariable multilevel Poisson regression analysis, there was a trend for small-volume hospitals performing fewer revascularizations but this was not statistically significant while being female (Relative Proportion = 0.91, 95% CI: 0.86 to 0.97) and being older than 80 years was still associated with less frequent revascularization. Female and older patients were less likely to receive revascularization. Further research needs to clarify whether this reflects differential application of treatment guidelines or limitations in this kind of routine data.

A regularization corrected score method for nonlinear regression models with covariate error.

PubMed

Zucker, David M; Gorfine, Malka; Li, Yi; Tadesse, Mahlet G; Spiegelman, Donna

2013-03-01

Many regression analyses involve explanatory variables that are measured with error, and failing to account for this error is well known to lead to biased point and interval estimates of the regression coefficients. We present here a new general method for adjusting for covariate error. Our method consists of an approximate version of the Stefanski-Nakamura corrected score approach, using the method of regularization to obtain an approximate solution of the relevant integral equation. We develop the theory in the setting of classical likelihood models; this setting covers, for example, linear regression, nonlinear regression, logistic regression, and Poisson regression. The method is extremely general in terms of the types of measurement error models covered, and is a functional method in the sense of not involving assumptions on the distribution of the true covariate. We discuss the theoretical properties of the method and present simulation results in the logistic regression setting (univariate and multivariate). For illustration, we apply the method to data from the Harvard Nurses' Health Study concerning the relationship between physical activity and breast cancer mortality in the period following a diagnosis of breast cancer. Copyright © 2013, The International Biometric Society.

Statistical Analyses of Raw Material Data for MTM45-1/CF7442A-36% RW: CMH Cure Cycle

NASA Technical Reports Server (NTRS)

Coroneos, Rula; Pai, Shantaram, S.; Murthy, Pappu

2013-01-01

This report describes statistical characterization of physical properties of the composite material system MTM45-1/CF7442A, which has been tested and is currently being considered for use on spacecraft structures. This composite system is made of 6K plain weave graphite fibers in a highly toughened resin system. This report summarizes the distribution types and statistical details of the tests and the conditions for the experimental data generated. These distributions will be used in multivariate regression analyses to help determine material and design allowables for similar material systems and to establish a procedure for other material systems. Additionally, these distributions will be used in future probabilistic analyses of spacecraft structures. The specific properties that are characterized are the ultimate strength, modulus, and Poisson??s ratio by using a commercially available statistical package. Results are displayed using graphical and semigraphical methods and are included in the accompanying appendixes.

Zero-inflated Conway-Maxwell Poisson Distribution to Analyze Discrete Data.

PubMed

Sim, Shin Zhu; Gupta, Ramesh C; Ong, Seng Huat

2018-01-09

In this paper, we study the zero-inflated Conway-Maxwell Poisson (ZICMP) distribution and develop a regression model. Score and likelihood ratio tests are also implemented for testing the inflation/deflation parameter. Simulation studies are carried out to examine the performance of these tests. A data example is presented to illustrate the concepts. In this example, the proposed model is compared to the well-known zero-inflated Poisson (ZIP) and the zero- inflated generalized Poisson (ZIGP) regression models. It is shown that the fit by ZICMP is comparable or better than these models.

High prevalence of suicide risk in people living with HIV: who is at higher risk?

PubMed

Passos, Susane Müller Klug; Souza, Luciano Dias de Mattos; Spessato, Bárbara Coiro

2014-01-01

A cross-sectional study was developed to evaluate suicide risk and associated factors in HIV/AIDS patients at a regional reference center for the treatment of HIV/AIDS in southern Brazil. We assessed 211 patients in regard to suicide risk, clinical and sociodemographic characteristics, drug use, depression, and anxiety. Suicide risk was assessed with Mini International Neuropsychiatric Interview, Module C. Multivariate analysis was performed using Poisson regression. Of the total sample, 34.1% were at risk of suicide. In the multivariate analysis, the following variables were independently associated with suicide risk: female gender; age up to 47 years; unemployment; indicative of anxiety; indicative of depression; and abuse or addiction on psychoactive substances. Suicide risk is high in this population. Psychosocial factors should be included in the physical and clinical evaluation, given their strong association with suicide risk.

A test of inflated zeros for Poisson regression models.

PubMed

He, Hua; Zhang, Hui; Ye, Peng; Tang, Wan

2017-01-01

Excessive zeros are common in practice and may cause overdispersion and invalidate inference when fitting Poisson regression models. There is a large body of literature on zero-inflated Poisson models. However, methods for testing whether there are excessive zeros are less well developed. The Vuong test comparing a Poisson and a zero-inflated Poisson model is commonly applied in practice. However, the type I error of the test often deviates seriously from the nominal level, rendering serious doubts on the validity of the test in such applications. In this paper, we develop a new approach for testing inflated zeros under the Poisson model. Unlike the Vuong test for inflated zeros, our method does not require a zero-inflated Poisson model to perform the test. Simulation studies show that when compared with the Vuong test our approach not only better at controlling type I error rate, but also yield more power.

Age and the economics of an emergency medical admission-what factors determine costs?

PubMed

McCabe, J J; Cournane, S; Byrne, D; Conway, R; O'Riordan, D; Silke, B

2017-02-01

The ageing of the population may be anticipated to increase demand on hospital resources. We have investigated the relationship between hospital episode costs and age profile in a single centre. All Emergency Medical admissions (33 732 episodes) to an Irish hospital over a 6-year period, categorized into three age groups, were evaluated against total hospital episode costs. Univariate and adjusted incidence rate ratios (IRRs) were calculated using zero truncated Poisson regression. The total hospital episode cost increased with age ( P < 0.001). The multi-variable Poisson regression model demonstrated that the most important drivers of overall costs were Acute Illness Severity-IRR 1.36 (95% CI: 1.30, 1.41), Sepsis Status -1.46 (95% CI: 1.42, 1.51) and Chronic Disabling Disease Score -1.25 (95% CI: 1.22, 1.27) and the Age Group as exemplified for those 85 years IRR 1.23 (95% CI: 1.15, 1.32). Total hospital episode costs are a product of clinical complexity with contributions from the Acute Illness Severity, Co-Morbidity, Chronic Disabling Disease Score and Sepsis Status. However age is also an important contributor and an increasing patient age profile will have a predictable impact on total hospital episode costs. © The Author 2016. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Use of Segregation Indices, Townsend Index, and Air Toxics Data to Assess Lifetime Cancer Risk Disparities in Metropolitan Charleston, South Carolina, USA

PubMed Central

Rice, LaShanta J.; Jiang, Chengsheng; Wilson, Sacoby M.; Burwell-Naney, Kristen; Samantapudi, Ashok; Zhang, Hongmei

2014-01-01

Background: Studies have demonstrated a relationship between segregation and level of education, occupational opportunities, and risk behaviors, yet a paucity of research has elucidated the association between racial residential segregation, socioeconomic deprivation, and lifetime cancer risk. Objectives: We examined estimated lifetime cancer risk from air toxics by racial composition, segregation, and deprivation in census tracts in Metropolitan Charleston. Methods: Segregation indices were used to measure the distribution of groups of people from different races within neighborhoods. The Townsend Index was used to measure economic deprivation in the study area. Poisson multivariate regressions were applied to assess the association of lifetime cancer risk with segregation indices and Townsend Index along with several sociodemographic measures. Results: Lifetime cancer risk from all pollution sources was 28 persons/million for half of the census tracts in Metropolitan Charleston. Isolation Index and Townsend Index both showed significant correlation with lifetime cancer risk from different sources. This significance still holds after adjusting for other sociodemographic measures in a Poisson regression, and these two indices have stronger effect on lifetime cancer risk compared to the effects of sociodemographic measures. Conclusions: We found that material deprivation, measured by the Townsend Index and segregation measured by the Isolation index, introduced high impact on lifetime cancer risk by air toxics at the census tract level. PMID:24852759

Poisson Regression Analysis of Illness and Injury Surveillance Data

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

Frome E.L., Watkins J.P., Ellis E.D.

2012-12-12

The Department of Energy (DOE) uses illness and injury surveillance to monitor morbidity and assess the overall health of the work force. Data collected from each participating site include health events and a roster file with demographic information. The source data files are maintained in a relational data base, and are used to obtain stratified tables of health event counts and person time at risk that serve as the starting point for Poisson regression analysis. The explanatory variables that define these tables are age, gender, occupational group, and time. Typical response variables of interest are the number of absences duemore » to illness or injury, i.e., the response variable is a count. Poisson regression methods are used to describe the effect of the explanatory variables on the health event rates using a log-linear main effects model. Results of fitting the main effects model are summarized in a tabular and graphical form and interpretation of model parameters is provided. An analysis of deviance table is used to evaluate the importance of each of the explanatory variables on the event rate of interest and to determine if interaction terms should be considered in the analysis. Although Poisson regression methods are widely used in the analysis of count data, there are situations in which over-dispersion occurs. This could be due to lack-of-fit of the regression model, extra-Poisson variation, or both. A score test statistic and regression diagnostics are used to identify over-dispersion. A quasi-likelihood method of moments procedure is used to evaluate and adjust for extra-Poisson variation when necessary. Two examples are presented using respiratory disease absence rates at two DOE sites to illustrate the methods and interpretation of the results. In the first example the Poisson main effects model is adequate. In the second example the score test indicates considerable over-dispersion and a more detailed analysis attributes the over-dispersion to extra-Poisson variation. The R open source software environment for statistical computing and graphics is used for analysis. Additional details about R and the data that were used in this report are provided in an Appendix. Information on how to obtain R and utility functions that can be used to duplicate results in this report are provided.« less

Modeling animal-vehicle collisions using diagonal inflated bivariate Poisson regression.

PubMed

Lao, Yunteng; Wu, Yao-Jan; Corey, Jonathan; Wang, Yinhai

2011-01-01

Two types of animal-vehicle collision (AVC) data are commonly adopted for AVC-related risk analysis research: reported AVC data and carcass removal data. One issue with these two data sets is that they were found to have significant discrepancies by previous studies. In order to model these two types of data together and provide a better understanding of highway AVCs, this study adopts a diagonal inflated bivariate Poisson regression method, an inflated version of bivariate Poisson regression model, to fit the reported AVC and carcass removal data sets collected in Washington State during 2002-2006. The diagonal inflated bivariate Poisson model not only can model paired data with correlation, but also handle under- or over-dispersed data sets as well. Compared with three other types of models, double Poisson, bivariate Poisson, and zero-inflated double Poisson, the diagonal inflated bivariate Poisson model demonstrates its capability of fitting two data sets with remarkable overlapping portions resulting from the same stochastic process. Therefore, the diagonal inflated bivariate Poisson model provides researchers a new approach to investigating AVCs from a different perspective involving the three distribution parameters (λ(1), λ(2) and λ(3)). The modeling results show the impacts of traffic elements, geometric design and geographic characteristics on the occurrences of both reported AVC and carcass removal data. It is found that the increase of some associated factors, such as speed limit, annual average daily traffic, and shoulder width, will increase the numbers of reported AVCs and carcass removals. Conversely, the presence of some geometric factors, such as rolling and mountainous terrain, will decrease the number of reported AVCs. Published by Elsevier Ltd.

Analysis of Blood Transfusion Data Using Bivariate Zero-Inflated Poisson Model: A Bayesian Approach.

PubMed

Mohammadi, Tayeb; Kheiri, Soleiman; Sedehi, Morteza

2016-01-01

Recognizing the factors affecting the number of blood donation and blood deferral has a major impact on blood transfusion. There is a positive correlation between the variables "number of blood donation" and "number of blood deferral": as the number of return for donation increases, so does the number of blood deferral. On the other hand, due to the fact that many donors never return to donate, there is an extra zero frequency for both of the above-mentioned variables. In this study, in order to apply the correlation and to explain the frequency of the excessive zero, the bivariate zero-inflated Poisson regression model was used for joint modeling of the number of blood donation and number of blood deferral. The data was analyzed using the Bayesian approach applying noninformative priors at the presence and absence of covariates. Estimating the parameters of the model, that is, correlation, zero-inflation parameter, and regression coefficients, was done through MCMC simulation. Eventually double-Poisson model, bivariate Poisson model, and bivariate zero-inflated Poisson model were fitted on the data and were compared using the deviance information criteria (DIC). The results showed that the bivariate zero-inflated Poisson regression model fitted the data better than the other models.

Analysis of Blood Transfusion Data Using Bivariate Zero-Inflated Poisson Model: A Bayesian Approach

PubMed Central

Mohammadi, Tayeb; Sedehi, Morteza

2016-01-01

Recognizing the factors affecting the number of blood donation and blood deferral has a major impact on blood transfusion. There is a positive correlation between the variables “number of blood donation” and “number of blood deferral”: as the number of return for donation increases, so does the number of blood deferral. On the other hand, due to the fact that many donors never return to donate, there is an extra zero frequency for both of the above-mentioned variables. In this study, in order to apply the correlation and to explain the frequency of the excessive zero, the bivariate zero-inflated Poisson regression model was used for joint modeling of the number of blood donation and number of blood deferral. The data was analyzed using the Bayesian approach applying noninformative priors at the presence and absence of covariates. Estimating the parameters of the model, that is, correlation, zero-inflation parameter, and regression coefficients, was done through MCMC simulation. Eventually double-Poisson model, bivariate Poisson model, and bivariate zero-inflated Poisson model were fitted on the data and were compared using the deviance information criteria (DIC). The results showed that the bivariate zero-inflated Poisson regression model fitted the data better than the other models. PMID:27703493

Concurrent generation of multivariate mixed data with variables of dissimilar types.

PubMed

Amatya, Anup; Demirtas, Hakan

2016-01-01

Data sets originating from wide range of research studies are composed of multiple variables that are correlated and of dissimilar types, primarily of count, binary/ordinal and continuous attributes. The present paper builds on the previous works on multivariate data generation and develops a framework for generating multivariate mixed data with a pre-specified correlation matrix. The generated data consist of components that are marginally count, binary, ordinal and continuous, where the count and continuous variables follow the generalized Poisson and normal distributions, respectively. The use of the generalized Poisson distribution provides a flexible mechanism which allows under- and over-dispersed count variables generally encountered in practice. A step-by-step algorithm is provided and its performance is evaluated using simulated and real-data scenarios.

On Models for Binomial Data with Random Numbers of Trials

PubMed Central

Comulada, W. Scott; Weiss, Robert E.

2010-01-01

Summary A binomial outcome is a count s of the number of successes out of the total number of independent trials n = s + f, where f is a count of the failures. The n are random variables not fixed by design in many studies. Joint modeling of (s, f) can provide additional insight into the science and into the probability π of success that cannot be directly incorporated by the logistic regression model. Observations where n = 0 are excluded from the binomial analysis yet may be important to understanding how π is influenced by covariates. Correlation between s and f may exist and be of direct interest. We propose Bayesian multivariate Poisson models for the bivariate response (s, f), correlated through random effects. We extend our models to the analysis of longitudinal and multivariate longitudinal binomial outcomes. Our methodology was motivated by two disparate examples, one from teratology and one from an HIV tertiary intervention study. PMID:17688514

Burnout among Swedish school teachers - a cross-sectional analysis.

PubMed

Arvidsson, Inger; Håkansson, Carita; Karlson, Björn; Björk, Jonas; Persson, Roger

2016-08-18

Teachers are at high risk of stress-related disorders. This study aimed to examine the occurrence of burnout in a sample of Swedish school-teachers, to test a combined measure of three burnout dimensions on the individual level, to characterize associations between burnout and factors encountered during work and leisure time, and to explore any differences between the genders. A questionnaire of occupational, sociodemographic and life-style factors was answered by 490 teachers in school years 4-9. Outcome measures were (a) the single burnout dimensions of exhaustion, cynicism and professional efficacy (Maslach Burnout Inventory-General Survey), and (b) a combined measure based on high or low values in the three dimensions. The combined measure was used to stratify the study population into four levels (0-3) of burnout. Multivariable Poisson regression was applied on level 2 + 3 vs. level 0 + 1, for variables that we considered as relevant risk factors for burn out. Half of the teachers reported low values in all three dimensions (level 0), whereas 15 were classified as having high burnout in at least two out of the three dimensions (level 2 + 3), and 4 % in all three dimensions (level 3). Almost all psychosocial factors were incrementally more unfavourably reported through the rising levels of burnout, and so were dissatisfaction with the computer workstation, pain, sleep problems and lack of personal recovery. There was no association between gender and rising levels of overall burnout (p > 0.30). Low self-efficacy, poor leadership, high job demands and teaching in higher grades were the variables most clearly associated with burnout in multivariable Poisson regression. Even if circa 50 % of the teachers appear do well with respect to burnout, the results points to the need of implementing multifaceted countermeasures that may serve to reduce burnout.

Early-life factors affect risk of pain and fever in infants during teething periods.

PubMed

Un Lam, Carolina; Hsu, Chin-Ying Stephen; Yee, Robert; Koh, David; Lee, Yung Seng; Chong, Mary Foong-Fong; Cai, Meijin; Kwek, Kenneth; Saw, Seang Mei; Gluckman, Peter; Chong, Yap Seng

2016-11-01

This longitudinal study aimed to investigate the prevalence of teething-related pain and fever and the early-life factors that may affect the risk of experiencing these disturbances within the first 1.5 years of life. Participants were recruited (n = 1033) through the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort (n = 1237). Interviews were performed tri-monthly regarding the prevalence of teething pain and fever in children from 6 to 18 months of age. Crude and multivariable analyses were conducted using Poisson-log regression models. Prevalence rates for teething pain and fever were 35.5 and 49.9 % respectively. Multivariable Poisson regression analysis showed maternal second-hand tobacco smoke (SHS) exposure to increase the risk of both pain (mean ratio = 1.35; p = 0.006) and fever (mean ratio = 1.22; p = 0.025), whereas SHS exposure plus active smoking further increased risk of teething pain in the children (mean ratio = 1.89; p = 0.029). Delivery via Caesarean section increased risk of teething pain (mean ratio = 1.27; p = 0.033), while prenatal plasma vitamin D insufficiency lowered such a risk (mean ratio = 0.62; p = 0.012). Compared to Chinese infants, Indian babies exhibited lower risk of teething pain and fever (both p ≤ 0.001). Early-life factors such as tobacco smoke exposure and vitamin insufficiency during pregnancy, ethnicity and childbirth via Caesarean section may significantly affect the child's susceptibility to teething-related pain and fever. Knowledge of prevalence and risk factors of teething disturbances may better equip primary caregivers and healthcare professionals to accurately detect teething-related local and/or systemic signs/symptoms and effectively facilitate tobacco cessation among pregnant women.

Mixed effect Poisson log-linear models for clinical and epidemiological sleep hypnogram data

PubMed Central

Swihart, Bruce J.; Caffo, Brian S.; Crainiceanu, Ciprian; Punjabi, Naresh M.

2013-01-01

Bayesian Poisson log-linear multilevel models scalable to epidemiological studies are proposed to investigate population variability in sleep state transition rates. Hierarchical random effects are used to account for pairings of subjects and repeated measures within those subjects, as comparing diseased to non-diseased subjects while minimizing bias is of importance. Essentially, non-parametric piecewise constant hazards are estimated and smoothed, allowing for time-varying covariates and segment of the night comparisons. The Bayesian Poisson regression is justified through a re-derivation of a classical algebraic likelihood equivalence of Poisson regression with a log(time) offset and survival regression assuming exponentially distributed survival times. Such re-derivation allows synthesis of two methods currently used to analyze sleep transition phenomena: stratified multi-state proportional hazards models and log-linear models with GEE for transition counts. An example data set from the Sleep Heart Health Study is analyzed. Supplementary material includes the analyzed data set as well as the code for a reproducible analysis. PMID:22241689

Fuzzy classifier based support vector regression framework for Poisson ratio determination

NASA Astrophysics Data System (ADS)

Asoodeh, Mojtaba; Bagheripour, Parisa

2013-09-01

Poisson ratio is considered as one of the most important rock mechanical properties of hydrocarbon reservoirs. Determination of this parameter through laboratory measurement is time, cost, and labor intensive. Furthermore, laboratory measurements do not provide continuous data along the reservoir intervals. Hence, a fast, accurate, and inexpensive way of determining Poisson ratio which produces continuous data over the whole reservoir interval is desirable. For this purpose, support vector regression (SVR) method based on statistical learning theory (SLT) was employed as a supervised learning algorithm to estimate Poisson ratio from conventional well log data. SVR is capable of accurately extracting the implicit knowledge contained in conventional well logs and converting the gained knowledge into Poisson ratio data. Structural risk minimization (SRM) principle which is embedded in the SVR structure in addition to empirical risk minimization (EMR) principle provides a robust model for finding quantitative formulation between conventional well log data and Poisson ratio. Although satisfying results were obtained from an individual SVR model, it had flaws of overestimation in low Poisson ratios and underestimation in high Poisson ratios. These errors were eliminated through implementation of fuzzy classifier based SVR (FCBSVR). The FCBSVR significantly improved accuracy of the final prediction. This strategy was successfully applied to data from carbonate reservoir rocks of an Iranian Oil Field. Results indicated that SVR predicted Poisson ratio values are in good agreement with measured values.

Characterizing the performance of the Conway-Maxwell Poisson generalized linear model.

PubMed

Francis, Royce A; Geedipally, Srinivas Reddy; Guikema, Seth D; Dhavala, Soma Sekhar; Lord, Dominique; LaRocca, Sarah

2012-01-01

Count data are pervasive in many areas of risk analysis; deaths, adverse health outcomes, infrastructure system failures, and traffic accidents are all recorded as count events, for example. Risk analysts often wish to estimate the probability distribution for the number of discrete events as part of doing a risk assessment. Traditional count data regression models of the type often used in risk assessment for this problem suffer from limitations due to the assumed variance structure. A more flexible model based on the Conway-Maxwell Poisson (COM-Poisson) distribution was recently proposed, a model that has the potential to overcome the limitations of the traditional model. However, the statistical performance of this new model has not yet been fully characterized. This article assesses the performance of a maximum likelihood estimation method for fitting the COM-Poisson generalized linear model (GLM). The objectives of this article are to (1) characterize the parameter estimation accuracy of the MLE implementation of the COM-Poisson GLM, and (2) estimate the prediction accuracy of the COM-Poisson GLM using simulated data sets. The results of the study indicate that the COM-Poisson GLM is flexible enough to model under-, equi-, and overdispersed data sets with different sample mean values. The results also show that the COM-Poisson GLM yields accurate parameter estimates. The COM-Poisson GLM provides a promising and flexible approach for performing count data regression. © 2011 Society for Risk Analysis.

Improved quality of care for cardiovascular disease for Latinos seen in high proportion Latino vs low proportion Latino clinics.

PubMed

López, Lenny; Cook, Nakela; Hicks, Leroi

2015-01-01

Primary care practices that concentrate linguistically and culturally appropriate services for Latinos may result in higher cardiology consultation rates and improved process measure performance for patients with coronary artery disease (CAD) and congestive heart failure (CHF). Multivariable Cox proportional-hazards regression was used to assess differences in referral at high proportion (HP) vs low proportion (LP) practices. Multivariable Poisson regression was used to assess the frequency of follow-up consultation. Among the 9,761 patients, 9,168 had CAD, 4,444 had CHF, and 3,851 had both conditions. Latinos comprised 11% of the CAD cohort and 11% of the CHF cohort. Multivariable analyses showed higher consultation rates for Latinos at HP practices for CAD and CHF. Blacks and Whites at HP practices had no significant differences in rates of consultation compared to those in LP practices. Latinos at HP practices had 25% more consultations for CAD and 23% more consultations for CHF than Latinos at LP practices. Latinos at HP clinics had higher overall mean quality performance on clinical measures for both CAD and CHF. Latinos at an LP clinic had the largest improvement in quality performance with consultation. Among Latinos with CAD or CHF receiving care within a single large academic care network, Latino patients at HP practices have higher rates of cardiologist consultation and performance on CVD process measures compared to Latino patients at LP practices. Elucidating the essential components of individual practice environments that provide higher quality of care for Latinos will allow for well designed systems to reduce health care disparities.

A comparison between Poisson and zero-inflated Poisson regression models with an application to number of black spots in Corriedale sheep

PubMed Central

Naya, Hugo; Urioste, Jorge I; Chang, Yu-Mei; Rodrigues-Motta, Mariana; Kremer, Roberto; Gianola, Daniel

2008-01-01

Dark spots in the fleece area are often associated with dark fibres in wool, which limits its competitiveness with other textile fibres. Field data from a sheep experiment in Uruguay revealed an excess number of zeros for dark spots. We compared the performance of four Poisson and zero-inflated Poisson (ZIP) models under four simulation scenarios. All models performed reasonably well under the same scenario for which the data were simulated. The deviance information criterion favoured a Poisson model with residual, while the ZIP model with a residual gave estimates closer to their true values under all simulation scenarios. Both Poisson and ZIP models with an error term at the regression level performed better than their counterparts without such an error. Field data from Corriedale sheep were analysed with Poisson and ZIP models with residuals. Parameter estimates were similar for both models. Although the posterior distribution of the sire variance was skewed due to a small number of rams in the dataset, the median of this variance suggested a scope for genetic selection. The main environmental factor was the age of the sheep at shearing. In summary, age related processes seem to drive the number of dark spots in this breed of sheep. PMID:18558072

Estimating the Depth of the Navy Recruiting Market

DTIC Science & Technology

2016-09-01

recommend that NRC make use of the Poisson regression model in order to determine high-yield ZIP codes for market depth. 14. SUBJECT...recommend that NRC make use of the Poisson regression model in order to determine high-yield ZIP codes for market depth. vi THIS PAGE INTENTIONALLY LEFT...DEPTH OF THE NAVY RECRUITING MARKET by Emilie M. Monaghan September 2016 Thesis Advisor: Lyn R. Whitaker Second Reader: Jonathan K. Alt

A comparison of bivariate, multivariate random-effects, and Poisson correlated gamma-frailty models to meta-analyze individual patient data of ordinal scale diagnostic tests.

PubMed

Simoneau, Gabrielle; Levis, Brooke; Cuijpers, Pim; Ioannidis, John P A; Patten, Scott B; Shrier, Ian; Bombardier, Charles H; de Lima Osório, Flavia; Fann, Jesse R; Gjerdingen, Dwenda; Lamers, Femke; Lotrakul, Manote; Löwe, Bernd; Shaaban, Juwita; Stafford, Lesley; van Weert, Henk C P M; Whooley, Mary A; Wittkampf, Karin A; Yeung, Albert S; Thombs, Brett D; Benedetti, Andrea

2017-11-01

Individual patient data (IPD) meta-analyses are increasingly common in the literature. In the context of estimating the diagnostic accuracy of ordinal or semi-continuous scale tests, sensitivity and specificity are often reported for a given threshold or a small set of thresholds, and a meta-analysis is conducted via a bivariate approach to account for their correlation. When IPD are available, sensitivity and specificity can be pooled for every possible threshold. Our objective was to compare the bivariate approach, which can be applied separately at every threshold, to two multivariate methods: the ordinal multivariate random-effects model and the Poisson correlated gamma-frailty model. Our comparison was empirical, using IPD from 13 studies that evaluated the diagnostic accuracy of the 9-item Patient Health Questionnaire depression screening tool, and included simulations. The empirical comparison showed that the implementation of the two multivariate methods is more laborious in terms of computational time and sensitivity to user-supplied values compared to the bivariate approach. Simulations showed that ignoring the within-study correlation of sensitivity and specificity across thresholds did not worsen inferences with the bivariate approach compared to the Poisson model. The ordinal approach was not suitable for simulations because the model was highly sensitive to user-supplied starting values. We tentatively recommend the bivariate approach rather than more complex multivariate methods for IPD diagnostic accuracy meta-analyses of ordinal scale tests, although the limited type of diagnostic data considered in the simulation study restricts the generalization of our findings. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

IRT-ZIP Modeling for Multivariate Zero-Inflated Count Data

ERIC Educational Resources Information Center

Wang, Lijuan

2010-01-01

This study introduces an item response theory-zero-inflated Poisson (IRT-ZIP) model to investigate psychometric properties of multiple items and predict individuals' latent trait scores for multivariate zero-inflated count data. In the model, two link functions are used to capture two processes of the zero-inflated count data. Item parameters are…

The impact of state safe routes to school-related laws on active travel to school policies and practices in U.S. elementary schools.

PubMed

Chriqui, Jamie F; Taber, Daniel R; Slater, Sandy J; Turner, Lindsey; Lowrey, Kerri McGowan; Chaloupka, Frank J

2012-01-01

This study examined the relationship between state laws requiring minimum bussing distances, hazardous route exemptions, sidewalks, crossing guards, speed zones, and traffic control measures around schools and active travel to school (ATS) policies/practices in nationally representative samples of U.S. public elementary schools between 2007-2009. The state laws and school data were compiled through primary legal research and annual mail-back surveys of principals, respectively. Multivariate logistic and zero-inflated poisson regression indicated that all state law categories (except for sidewalks) relate to ATS. These laws should be considered in addition to formal safe routes to school programs as possible influences on ATS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Back pain prevalence and associated factors in children and adolescents: an epidemiological population study

PubMed Central

Noll, Matias; Candotti, Cláudia Tarragô; da Rosa, Bruna Nichele; Loss, Jefferson Fagundes

2016-01-01

ABSTRACT OBJECTIVE To identify the prevalence of back pain among Brazilian school children and the factors associated with this pain. METHODS All 1,720 schoolchildren from the fifth to the eight grade attending schools from the city of Teutonia, RS, Southern Brazil, were invited to participate in the study. From these, 1,597 children participated. We applied the Back Pain and Body Posture Evaluation Instrument. The dependent variable was back pain, while the independent one were demographic, socioeconomic, behavior and heredity data. The prevalence ratio was estimated by multivariate analysis using the Poisson regression model (α = 0.05). RESULTS The prevalence of back pain in the last three months was 55.7% (n = 802). The multivariate analysis showed that back pain is associated with the variables: sex, parents with back pain, weekly frequency of physical activity, daily time spent watching television, studying in bed, sitting posture to write and use the computer, and way of carrying the backpack. CONCLUSIONS The prevalence of back pain in schoolchildren is high and it is associated with demographic, behavior and heredity aspects. PMID:27305406

Epidemiology of uveitis among the Chinese population in Taiwan: a population-based study.

PubMed

Hwang, De-Kuang; Chou, Yiing-Jeng; Pu, Cheng-Yun; Chou, Pesus

2012-11-01

This study aimed to investigate the incidence and prevalence of uveitis in Taiwan, and then analyzed the risk factors related to uveitis using multivariate regression. Population-based cohort study using medical claims data. We randomly selected 1 000 000 residents from the Taiwan National Health Insurance Research Database. All participants with correct registry data (96%) were included in the study. The study period was from 2000 to 2008. All types of uveitis were identified using the International Classification of Diseases, 9th revision, Clinical Modification diagnostic codes. The annual incidence and cumulative prevalence of uveitis were calculated. A univariate and a multivariate Poisson regression were used to determine the risk factors associated with uveitis. The first diagnosis of uveitis noted during the study period. The annual cumulative incidence rate of uveitis ranged from 102.2 to 122.0 cases per 100 000 persons over the study period, and the average incidence density was 111.3 cases per 100 000 person-years (95% confidence interval, 108.4-114.1). The cumulative prevalence was found to have increased from 318.8 cases per 100 000 persons in 2003 to 622.7 cases per 100 000 persons in 2008. Anterior uveitis was the most common location and accounted for 77.7% of all incident cases, which was followed by panuveitis, posterior uveitis, and intermediate uveitis. Multivariate regression analysis showed that males, the elderly, and individuals who lived in an urban area had higher incidence rates for uveitis. The epidemiology of uveitis in Taiwan differs from most previous studies in other countries. The incidence of uveitis in Taiwan has increased significantly recently. The elderly and individuals living in urban areas are the populations that are most commonly affected by uveitis. These findings are consistent with suggestions found in several recent studies. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The influence of oral health conditions, socioeconomic status and home environment factors on schoolchildren's self-perception of quality of life.

PubMed

Paula, Janice S; Leite, Isabel Cg; Almeida, Anderso B; Ambrosano, Glaucia Mb; Pereira, Antônio C; Mialhe, Fábio L

2012-01-13

The objective this study was to investigate the influence of clinical conditions, socioeconomic status, home environment, subjective perceptions of parents and schoolchildren about general and oral health on schoolchildren's oral health-related quality of life (OHRQoL). A sample of 515 schoolchildren, aged 12 years was randomly selected by conglomerate analysis from public and private schools in the city of Juiz de Fora, Brazil. The schoolchildren were clinically examined for presence of caries lesions (DMFT and dmft index), dental trauma, enamel defects, periodontal status (presence/absence of bleeding), dental treatment and orthodontic treatment needs (DAI). The SiC index was calculated. The participants were asked to complete the Brazilian version of Child Perceptions Questionnaire (CPQ11-14) and a questionnaire about home environment. Questions were asked about the presence of general diseases and children's self-perception of their general and oral health status. In addition, a questionnaire was sent to their parents inquiring about their socioeconomic status (family income, parents' education level, home ownership) and perceptions about the general and oral health of their school-aged children. The chi-square test was used for comparisons between proportions. Poisson's regression was used for multivariate analysis with adjustment for variances. Univariate analysis revealed that school type, monthly family income, mother's education, family structure, number of siblings, use of cigarettes, alcohol and drugs in the family, parents' perception of oral health of schoolchildren, schoolchildren's self perception their general and oral health, orthodontic treatment needs were significantly associated with poor OHRQoL (p < 0.001). After adjusting for potential confounders, variables were included in a Multivariate Poisson regression. It was found that the variables children's self perception of their oral health status, monthly family income, gender, orthodontic treatment need, mother's education, number of siblings, and household overcrowding showed a strong negative effect on oral health-related quality of life. It was concluded that the clinical, socioeconomic and home environment factors evaluated exerted a negative impact on the oral health-related quality of life of schoolchildren, demonstrating the importance of health managers addressing all these factors when planning oral health promotion interventions for this population.

A comparison of methods for the analysis of binomial clustered outcomes in behavioral research.

PubMed

Ferrari, Alberto; Comelli, Mario

2016-12-01

In behavioral research, data consisting of a per-subject proportion of "successes" and "failures" over a finite number of trials often arise. This clustered binary data are usually non-normally distributed, which can distort inference if the usual general linear model is applied and sample size is small. A number of more advanced methods is available, but they are often technically challenging and a comparative assessment of their performances in behavioral setups has not been performed. We studied the performances of some methods applicable to the analysis of proportions; namely linear regression, Poisson regression, beta-binomial regression and Generalized Linear Mixed Models (GLMMs). We report on a simulation study evaluating power and Type I error rate of these models in hypothetical scenarios met by behavioral researchers; plus, we describe results from the application of these methods on data from real experiments. Our results show that, while GLMMs are powerful instruments for the analysis of clustered binary outcomes, beta-binomial regression can outperform them in a range of scenarios. Linear regression gave results consistent with the nominal level of significance, but was overall less powerful. Poisson regression, instead, mostly led to anticonservative inference. GLMMs and beta-binomial regression are generally more powerful than linear regression; yet linear regression is robust to model misspecification in some conditions, whereas Poisson regression suffers heavily from violations of the assumptions when used to model proportion data. We conclude providing directions to behavioral scientists dealing with clustered binary data and small sample sizes. Copyright © 2016 Elsevier B.V. All rights reserved.

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

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

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

DOE PAGES

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

2015-11-19

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

[Factors associated with the consumption of school meals by Brazilian adolescents: results of the PeNSE survey 2012].

PubMed

Locatelli, Nathália Tarossi; Canella, Daniela Silva; Bandoni, Daniel Henrique

2017-05-18

The aim was to study the association between socio-demographic and routine dietary variables and consumption of school meals by adolescents enrolled in public schools in Brazil. The study used data used from the National School Health Survey (PeNSE) 2012. To assess differences between schoolchildren based on whether or not they ate school meals, the study used Pearson's chi-square test, and associations were analyzed with univariate and multivariate Poisson regression models. Of the 86,660 students included in the study, 22.8% eat school meals. Higher consumption of school meals is associated with male gender, brown skin color, residence outside state capitals, working, and low maternal schooling, for those that ate breakfast and lunch with their parents. The findings are relevant for planning strategies to encourage consumption of school meals.

[Health and health-related behaviors according to sexual attraction and behavior].

PubMed

Pérez, Glòria; Martí-Pastor, Marc; Gotsens, Mercè; Bartoll, Xavier; Diez, Elia; Borrell, Carme

2015-01-01

to Describe perceived health, mental health and certain health-related behaviors according to sexual attraction and behavior in the population residing in Barcelona in 2011. Perceived health, mental health, chronic conditions and health-related behaviors were analyzed in 2675 people aged 15 to 64 years. The Barcelona Health Survey for 2011 was used, which included questions on sexual attraction and behavior. Multivariate robust Poisson regression models were fitted to obtain adjusted prevalence ratios. People feeling same-sex attraction reported a higher prevalence of worse perceived and mental health. These people and those who had had sex with persons of the same sex more frequently reported harmful health-related behaviors. Lesbian, gay, transgender and bisexual people may have health problems that should be explored in depth, prevented, and attended. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Predicting crash frequency for multi-vehicle collision types using multivariate Poisson-lognormal spatial model: A comparative analysis.

PubMed

Hosseinpour, Mehdi; Sahebi, Sina; Zamzuri, Zamira Hasanah; Yahaya, Ahmad Shukri; Ismail, Noriszura

2018-06-01

According to crash configuration and pre-crash conditions, traffic crashes are classified into different collision types. Based on the literature, multi-vehicle crashes, such as head-on, rear-end, and angle crashes, are more frequent than single-vehicle crashes, and most often result in serious consequences. From a methodological point of view, the majority of prior studies focused on multivehicle collisions have employed univariate count models to estimate crash counts separately by collision type. However, univariate models fail to account for correlations which may exist between different collision types. Among others, multivariate Poisson lognormal (MVPLN) model with spatial correlation is a promising multivariate specification because it not only allows for unobserved heterogeneity (extra-Poisson variation) and dependencies between collision types, but also spatial correlation between adjacent sites. However, the MVPLN spatial model has rarely been applied in previous research for simultaneously modelling crash counts by collision type. Therefore, this study aims at utilizing a MVPLN spatial model to estimate crash counts for four different multi-vehicle collision types, including head-on, rear-end, angle, and sideswipe collisions. To investigate the performance of the MVPLN spatial model, a two-stage model and a univariate Poisson lognormal model (UNPLN) spatial model were also developed in this study. Detailed information on roadway characteristics, traffic volume, and crash history were collected on 407 homogeneous segments from Malaysian federal roads. The results indicate that the MVPLN spatial model outperforms the other comparing models in terms of goodness-of-fit measures. The results also show that the inclusion of spatial heterogeneity in the multivariate model significantly improves the model fit, as indicated by the Deviance Information Criterion (DIC). The correlation between crash types is high and positive, implying that the occurrence of a specific collision type is highly associated with the occurrence of other crash types on the same road segment. These results support the utilization of the MVPLN spatial model when predicting crash counts by collision manner. In terms of contributing factors, the results show that distinct crash types are attributed to different subsets of explanatory variables. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bayesian semi-parametric analysis of Poisson change-point regression models: application to policy making in Cali, Colombia.

PubMed

Park, Taeyoung; Krafty, Robert T; Sánchez, Alvaro I

2012-07-27

A Poisson regression model with an offset assumes a constant baseline rate after accounting for measured covariates, which may lead to biased estimates of coefficients in an inhomogeneous Poisson process. To correctly estimate the effect of time-dependent covariates, we propose a Poisson change-point regression model with an offset that allows a time-varying baseline rate. When the nonconstant pattern of a log baseline rate is modeled with a nonparametric step function, the resulting semi-parametric model involves a model component of varying dimension and thus requires a sophisticated varying-dimensional inference to obtain correct estimates of model parameters of fixed dimension. To fit the proposed varying-dimensional model, we devise a state-of-the-art MCMC-type algorithm based on partial collapse. The proposed model and methods are used to investigate an association between daily homicide rates in Cali, Colombia and policies that restrict the hours during which the legal sale of alcoholic beverages is permitted. While simultaneously identifying the latent changes in the baseline homicide rate which correspond to the incidence of sociopolitical events, we explore the effect of policies governing the sale of alcohol on homicide rates and seek a policy that balances the economic and cultural dependencies on alcohol sales to the health of the public.

Comparison of robustness to outliers between robust poisson models and log-binomial models when estimating relative risks for common binary outcomes: a simulation study.

PubMed

Chen, Wansu; Shi, Jiaxiao; Qian, Lei; Azen, Stanley P

2014-06-26

To estimate relative risks or risk ratios for common binary outcomes, the most popular model-based methods are the robust (also known as modified) Poisson and the log-binomial regression. Of the two methods, it is believed that the log-binomial regression yields more efficient estimators because it is maximum likelihood based, while the robust Poisson model may be less affected by outliers. Evidence to support the robustness of robust Poisson models in comparison with log-binomial models is very limited. In this study a simulation was conducted to evaluate the performance of the two methods in several scenarios where outliers existed. The findings indicate that for data coming from a population where the relationship between the outcome and the covariate was in a simple form (e.g. log-linear), the two models yielded comparable biases and mean square errors. However, if the true relationship contained a higher order term, the robust Poisson models consistently outperformed the log-binomial models even when the level of contamination is low. The robust Poisson models are more robust (or less sensitive) to outliers compared to the log-binomial models when estimating relative risks or risk ratios for common binary outcomes. Users should be aware of the limitations when choosing appropriate models to estimate relative risks or risk ratios.

Sex-Based Differences in Rates, Causes, and Predictors of Death Among Injection Drug Users in Vancouver, Canada

PubMed Central

Hayashi, Kanna; Dong, Huiru; Marshall, Brandon D. L.; Milloy, Michael-John; Montaner, Julio S. G.; Wood, Evan; Kerr, Thomas

2016-01-01

In the present study, we sought to identify rates, causes, and predictors of death among male and female injection drug users (IDUs) in Vancouver, British Columbia, Canada, during a period of expanded public health interventions. Data from prospective cohorts of IDUs in Vancouver were linked to the provincial database of vital statistics to ascertain rates and causes of death between 1996 and 2011. Mortality rates were analyzed using Poisson regression and indirect standardization. Predictors of mortality were identified using multivariable Cox regression models stratified by sex. Among the 2,317 participants, 794 (34.3%) of whom were women, there were 483 deaths during follow-up, with a rate of 32.1 (95% confidence interval (CI): 29.3, 35.0) deaths per 1,000 person-years. Standardized mortality ratios were 7.28 (95% CI: 6.50, 8.14) for men and 15.56 (95% CI: 13.31, 18.07) for women. During the study period, mortality rates related to infection with human immunodeficiency virus (HIV) declined among men but remained stable among women. In multivariable analyses, HIV seropositivity was independently associated with mortality in both sexes (all P < 0.05). The excess mortality burden among IDUs in our cohorts was primarily attributable to HIV infection; compared with men, women remained at higher risk of HIV-related mortality, indicating a need for sex-specific interventions to reduce mortality among female IDUs in this setting. PMID:26865265

Poisson-Based Inference for Perturbation Models in Adaptive Spelling Training

ERIC Educational Resources Information Center

Baschera, Gian-Marco; Gross, Markus

2010-01-01

We present an inference algorithm for perturbation models based on Poisson regression. The algorithm is designed to handle unclassified input with multiple errors described by independent mal-rules. This knowledge representation provides an intelligent tutoring system with local and global information about a student, such as error classification…

Occurrence of depressive tendency and associated social factors among elderly persons forced by the Great East Japan Earthquake and nuclear disaster to live as long-term evacuees: a prospective cohort study.

PubMed

Kuroda, Yujiro; Iwasa, Hajime; Goto, Aya; Yoshida, Kazuki; Matsuda, Kumiko; Iwamitsu, Yumi; Yasumura, Seiji

2017-09-03

This study examined the incidence of depression and associated factors among elderly persons from Iitate village after the March 2011 earthquake. This was a prospective cohort study. As a baseline survey, in May 2010 a self-assessment Basic Checklist (BCL) was distributed to 1611 elderly villagers, of which 1277 responded. Of these respondents, 885 without a tendency to depression (69.3%) were given a follow-up survey in May 2013. The BCL was used to assess depression tendency, instrumental activities of daily living (IADL), physical function, nutritional status, oral function, homeboundness, cognitive function and social activities. Univariate analysis was used to examine differences in risk between those with a presence of depression tendency (PDT) and those without (non-PDT) depending on demographic and BCL variables. Variables found to be significant were analysed by Poisson regression analysis. Of the 438 respondents in the second survey, 163 (37.2%) showed depression tendency. PDT risk was significantly increased by female gender, age, history of diabetes and cognitive disorder. It was significantly reduced by increased IADL. Engagement in social activities decreased PDT risk in rental accommodation. Renters faced a higher risk of PDT than persons evacuated in groups to purpose-built housing. The inclusion of social activities in the multivariate Poisson regression analysis weakened this effect. Female gender, a history of diabetes, reduced IADL and a tendency to cognitive disorder each independently affected PDT risk. These findings may inform future responses to earthquakes and the technical disasters that may accompany them. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Inequalities in financial risk protection in Bangladesh: an assessment of universal health coverage.

PubMed

Islam, Md Rashedul; Rahman, Md Shafiur; Islam, Zobida; Nurs, Cherri Zhang B; Sultana, Papia; Rahman, Md Mizanur

2017-04-04

Financial risk protection and equity are major components of universal health coverage (UHC), which is defined as ensuring access to health services for all citizens without any undue financial burden. We investigated progress towards UHC financial risk indicators and assessed variability of inequalities in financial risk protection indicators by wealth quintile. We further examined the determinants of different financial hardship indicators related to healthcare costs. A cross-sectional, three-stage probability survey was conducted in Bangladesh, which collected information from 1600 households from August to November 2011. Catastrophic health payments, impoverishment, and distress financing (borrowing or selling assets) were treated as financial hardship indicators in UHC. Poisson regression models were used to identify the determinants of catastrophic payment, impoverishment and distress financing separately. Slope, relative and concentration indices of inequalities were used to assess wealth-based inequalities in financial hardship indicators. The study found that around 9% of households incurred catastrophic payments, 7% faced distress financing, and 6% experienced impoverishing health payments in Bangladesh. Slope index of inequality indicated that the incidence of catastrophic health payment and distress financing among the richest households were 12 and 9 percentage points lower than the poorest households respectively. Multivariable Poisson regression models revealed that all UHC financial hardship indicators were significantly higher among household that had members who received inpatient care or were in the poorest quintile. The presence of a member with chronic illness in a household increased the risk of impoverishment by nearly double. This study identified a greater inequality in UHC financial hardship indicators. Rich households in Bangladesh were facing disproportionately less financial hardship than the poor ones. Households can be protected from financial hardship associated with healthcare costs by implementing risk pooling mechanism, increasing GDP spending on health, and properly monitoring subsidized programs in public health facilities.

Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria

PubMed Central

Dzhambov, Angel M; Dimitrova, Donka D

2016-01-01

Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to Lden 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM)2.5 25.0-66.8 μg/m3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). Lden remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria. PMID:27157686

Mortality among 24,865 workers exposed to polychlorinated biphenyls (PCBs) in three electrical capacitor manufacturing plants: a ten-year update.

PubMed

Ruder, Avima M; Hein, Misty J; Hopf, Nancy B; Waters, Martha A

2014-03-01

The objective of this analysis was to evaluate mortality among a cohort of 24,865 capacitor-manufacturing workers exposed to polychlorinated biphenyls (PCBs) at plants in Indiana, Massachusetts, and New York and followed for mortality through 2008. Cumulative PCB exposure was estimated using plant-specific job-exposure matrices. External comparisons to US and state-specific populations used standardized mortality ratios, adjusted for gender, race, age and calendar year. Among long-term workers employed 3 months or longer, within-cohort comparisons used standardized rate ratios and multivariable Poisson regression modeling. Through 2008, more than one million person-years at risk and 8749 deaths were accrued. Among long-term employees, all-cause and all-cancer mortality were not elevated; of the a priori outcomes assessed only melanoma mortality was elevated. Mortality was elevated for some outcomes of a priori interest among subgroups of long-term workers: all cancer, intestinal cancer and amyotrophic lateral sclerosis (women); melanoma (men); melanoma and brain and nervous system cancer (Indiana plant); and melanoma and multiple myeloma (New York plant). Standardized rates of stomach and uterine cancer and multiple myeloma mortality increased with estimated cumulative PCB exposure. Poisson regression modeling showed significant associations with estimated cumulative PCB exposure for prostate and stomach cancer mortality. For other outcomes of a priori interest--rectal, liver, ovarian, breast, and thyroid cancer, non-Hodgkin lymphoma, Alzheimer disease, and Parkinson disease--neither elevated mortality nor positive associations with PCB exposure were observed. Associations between estimated cumulative PCB exposure and stomach, uterine, and prostate cancer and myeloma mortality confirmed our previous positive findings. Published by Elsevier GmbH.

Mortality among 24,865 workers exposed to polychlorinated biphenyls (PCBs) in three electrical capacitor manufacturing plants: A ten-year update

PubMed Central

Ruder, Avima M.; Hein, Misty J.; Hopf, Nancy B.; Waters, Martha A.

2015-01-01

The objective of this analysis was to evaluate mortality among a cohort of 24,865 capacitor-manufacturing workers exposed to polychlorinated biphenyls (PCBs) at plants in Indiana, Massachusetts, and New York and followed for mortality through 2008. Cumulative PCB exposure was estimated using plant-specific job-exposure matrices. External comparisons to US and state-specific populations used standardized mortality ratios, adjusted for gender, race, age and calendar year. Among long-term workers employed 3 months or longer, within-cohort comparisons used standardized rate ratios and multivariable Poisson regression modeling. Through 2008, more than one million person-years at risk and 8749 deaths were accrued. Among long-term employees, all-cause and all-cancer mortality were not elevated; of the a priori outcomes assessed only melanoma mortality was elevated. Mortality was elevated for some outcomes of a priori interest among subgroups of long-term workers: all cancer, intestinal cancer and amyotrophic lateral sclerosis (women); melanoma (men); melanoma and brain and nervous system cancer (Indiana plant); and melanoma and multiple myeloma (New York plant). Standardized rates of stomach and uterine cancer and multiple myeloma mortality increased with estimated cumulative PCB exposure. Poisson regression modeling showed significant associations with estimated cumulative PCB exposure for prostate and stomach cancer mortality. For other outcomes of a priori interest – rectal, liver, ovarian, breast, and thyroid cancer, non-Hodgkin lymphoma, Alzheimer disease, and Parkinson disease – neither elevated mortality nor positive associations with PCB exposure were observed. Associations between estimated cumulative PCB exposure and stomach, uterine, and prostate cancer and myeloma mortality confirmed our previous positive findings. PMID:23707056

Silicosis prevalence and risk factors in semi-precious stone mining in Brazil.

PubMed

Souza, Tamires P; Watte, Guilherme; Gusso, Alaíde M; Souza, Rafaela; Moreira, José da S; Knorst, Marli M

2017-06-01

Underground mining generates large amounts of dust and exposes workers to silica. This study aims to determine the prevalence and predictor factors for the development of silicosis among semi-precious-stone mineworkers in southern Brazil working in a self-administered cooperative. In a cross-sectional study of 348 current workers and retirees, demographic data, medical, and occupational history were collected through an interview performed by a nurse and medical record review. Risk factor associations were studied by Poisson multivariate regression. The overall prevalence of silicosis was 37%, while in current miners it was 28%. Several risk factors for silicosis were identified in the univariate analysis. Inadequate ventilation in the underground galleries combined with dry drilling, duration of silica exposure, and (inversely) education remained significant in the multivariate analysis (P < 0.05). This study is unusual in studying semi-precious stone mineworkers in a self-administered worker cooperative with limited resources. The prevalence of silicosis was very high. A number of recommendations are made-including technical support for worker cooperatives, surveillance of silica exposure and silicosis, exposure reduction measures, and benefits allowing impaired miners to leave the industry. © 2017 Wiley Periodicals, Inc.

Simulation on Poisson and negative binomial models of count road accident modeling

NASA Astrophysics Data System (ADS)

Sapuan, M. S.; Razali, A. M.; Zamzuri, Z. H.; Ibrahim, K.

2016-11-01

Accident count data have often been shown to have overdispersion. On the other hand, the data might contain zero count (excess zeros). The simulation study was conducted to create a scenarios which an accident happen in T-junction with the assumption the dependent variables of generated data follows certain distribution namely Poisson and negative binomial distribution with different sample size of n=30 to n=500. The study objective was accomplished by fitting Poisson regression, negative binomial regression and Hurdle negative binomial model to the simulated data. The model validation was compared and the simulation result shows for each different sample size, not all model fit the data nicely even though the data generated from its own distribution especially when the sample size is larger. Furthermore, the larger sample size indicates that more zeros accident count in the dataset.

Dependent Neyman type A processes based on common shock Poisson approach

NASA Astrophysics Data System (ADS)

Kadilar, Gamze Özel; Kadilar, Cem

2016-04-01

The Neyman type A process is used for describing clustered data since the Poisson process is insufficient for clustering of events. In a multivariate setting, there may be dependencies between multivarite Neyman type A processes. In this study, dependent form of the Neyman type A process is considered under common shock approach. Then, the joint probability function are derived for the dependent Neyman type A Poisson processes. Then, an application based on forest fires in Turkey are given. The results show that the joint probability function of the dependent Neyman type A processes, which is obtained in this study, can be a good tool for the probabilistic fitness for the total number of burned trees in Turkey.

An Evaluation of the Euroncap Crash Test Safety Ratings in the Real World

PubMed Central

Segui-Gomez, Maria; Lopez-Valdes, Francisco J.; Frampton, Richard

2007-01-01

We investigated whether the rating obtained in the EuroNCAP test procedures correlates with injury protection to vehicle occupants in real crashes using data in the UK Cooperative Crash Injury Study (CCIS) database from 1996 to 2005. Multivariate Poisson regression models were developed, using the Abbreviated Injury Scale (AIS) score by body region as the dependent variable and the EuroNCAP score for that particular body region, seat belt use, mass ratio and Equivalent Test Speed (ETS) as independent variables. Our models identified statistically significant relationships between injury severity and safety belt use, mass ratio and ETS. We could not identify any statistically significant relationships between the EuroNCAP body region scores and real injury outcome except for the protection to pelvis-femur-knee in frontal impacts where scoring “green” is significantly better than scoring “yellow” or “red”.

Poor safety climate, long work hours, and musculoskeletal discomfort among Latino horse farm workers.

PubMed

Swanberg, Jennifer; Clouser, Jessica Miller; Gan, Wenqi; Flunker, John C; Westneat, Susan; Browning, Steven R

2017-09-03

This study investigated the prevalence of self-reported musculoskeletal discomfort (MSD) and work-related factors associated with elevated MSD among Latino thoroughbred farm workers. Participants (N = 225) were recruited using a community-based purposive sampling approach to participate in in-person interviews. Of these workers, 85% experienced MSD. MSD was divided into tertiles; the upper tertile was defined as elevated. Multivariable Poisson regression revealed associations between any elevated MSD and longer tenure on horse farms, longer work hours, and poor safety climate. Elevated neck/back MSD was associated with longer tenure, longer work hours, and poor safety climate. Elevated upper extremity MSD was associated with age and poor safety climate. Elevated lower extremity MSD was associated with longer tenure, longer work hours, and being female. Musculoskeletal discomfort is common among these workers. Improving safety climate and minimizing long work hours is recommended.

Exploring the Association of Homicides in Northern Mexico and Healthcare Access for US Residents.

PubMed

Geissler, Kimberley H; Becker, Charles; Stearns, Sally C; Thirumurthy, Harsha; Holmes, George M

2015-08-01

Many legal residents in the United States (US)-Mexico border region cross from the US into Mexico for medical treatment and pharmaceuticals. We analyzed whether recent increases in homicides in Mexico are associated with reduced healthcare access for US border residents. We used data on healthcare access, legal entries to the US from Mexico, and Mexican homicide rates (2002-2010). Poisson regression models estimated associations between homicide rates and total legal US entries. Multivariate difference-in-difference linear probability models evaluated associations between Mexican homicide rates and self-reported measures of healthcare access for US residents. Increased homicide rates were associated with decreased legal entries to the US from Mexico. Contrary to expectations, homicides did not have significant associations with healthcare access measures for legal residents in US border counties. Despite a decrease in border crossings, increased violence in Mexico did not appear to negatively affect healthcare access for US border residents.

Environmental variability and the transmission of haemorrhagic fever with renal syndrome in Changsha, People's Republic of China.

PubMed

Xiao, H; Gao, L D; Li, X J; Lin, X L; Dai, X Y; Zhu, P J; Chen, B Y; Zhang, X X; Zhao, J; Tian, H Y

2013-09-01

The transmission of haemorrhagic fever with renal syndrome (HFRS) is influenced by climatic, reservoir and environmental variables. The epidemiology of the disease was studied over a 6-year period in Changsha. Variables relating to climate, environment, rodent host distribution and disease occurrence were collected monthly and analysed using a time-series adjusted Poisson regression model. It was found that the density of the rodent host and multivariate El Niño Southern Oscillation index had the greatest effect on the transmission of HFRS with lags of 2–6 months. However, a number of climatic and environmental factors played important roles in affecting the density and transmission potential of the rodent host population. It was concluded that the measurement of a number of these variables could be used in disease surveillance to give useful advance warning of potential disease epidemics.

Geographically weighted poisson regression semiparametric on modeling of the number of tuberculosis cases (Case study: Bandung city)

NASA Astrophysics Data System (ADS)

Octavianty, Toharudin, Toni; Jaya, I. G. N. Mindra

2017-03-01

Tuberculosis (TB) is a disease caused by a bacterium, called Mycobacterium tuberculosis, which typically attacks the lungs but can also affect the kidney, spine, and brain (Centers for Disease Control and Prevention). Indonesia had the largest number of TB cases after India (Global Tuberculosis Report 2015 by WHO). The distribution of Mycobacterium tuberculosis genotypes in Indonesia showed the high genetic diversity and tended to vary by geographic regions. For instance, in Bandung city, the prevalence rate of TB morbidity is quite high. A number of TB patients belong to the counted data. To determine the factors that significantly influence the number of tuberculosis patients in each location of the observations can be used statistical analysis tool that is Geographically Weighted Poisson Regression Semiparametric (GWPRS). GWPRS is an extension of the Poisson regression and GWPR that is influenced by geographical factors, and there is also variables that influence globally and locally. Using the TB Data in Bandung city (in 2015), the results show that the global and local variables that influence the number of tuberculosis patients in every sub-district.

A Model Comparison for Count Data with a Positively Skewed Distribution with an Application to the Number of University Mathematics Courses Completed

ERIC Educational Resources Information Center

Liou, Pey-Yan

2009-01-01

The current study examines three regression models: OLS (ordinary least square) linear regression, Poisson regression, and negative binomial regression for analyzing count data. Simulation results show that the OLS regression model performed better than the others, since it did not produce more false statistically significant relationships than…

Relative age effect in elite soccer: More early-born players, but no better valued, and no paragon clubs or countries

PubMed Central

Doyle, John R.

2018-01-01

The paper analyses two datasets of elite soccer players (top 1000 professionals and UEFA Under-19 Youth League). In both, we find a Relative Age Effect (RAE) for frequency, but not for value. That is, while there are more players born at the start of the competition year, their transfer values are no higher, nor are they given more game time. We use Poisson regression to derive a transparent index of the discrimination present in RAE. Also, because Poisson is valid for small frequency counts, it supports analysis at the disaggregated levels of country and club. From this, we conclude there are no paragon clubs or countries immune to RAE; that is clubs and countries do not differ systematically in the RAE they experience; also, that Poisson regression is a powerful and flexible method of analysing RAE data. PMID:29420576

[The warning model and influence of climatic changes on hemorrhagic fever with renal syndrome in Changsha city].

PubMed

Xiao, Hong; Tian, Huai-yu; Zhang, Xi-xing; Zhao, Jian; Zhu, Pei-juan; Liu, Ru-chun; Chen, Tian-mu; Dai, Xiang-yu; Lin, Xiao-ling

2011-10-01

To realize the influence of climatic changes on the transmission of hemorrhagic fever with renal syndrome (HFRS), and to explore the adoption of climatic factors in warning HFRS. A total of 2171 cases of HFRS and the synchronous climatic data in Changsha from 2000 to 2009 were collected to a climate-based forecasting model for HFRS transmission. The Cochran-Armitage trend test was employed to explore the variation trend of the annual incidence of HFRS. Cross-correlations analysis was then adopted to assess the time-lag period between the climatic factors, including monthly average temperature, relative humidity, rainfall and Multivariate Elño-Southern Oscillation Index (MEI) and the monthly HFRS cases. Finally the time-series Poisson regression model was constructed to analyze the influence of different climatic factors on the HFRS transmission. The annual incidence of HFRS in Changsha between 2000 - 2009 was 13.09/100 000 (755 cases), 9.92/100 000 (578 cases), 5.02/100 000 (294 cases), 2.55/100 000 (150 cases), 1.13/100 000 (67 cases), 1.16/100 000 (70 cases), 0.95/100 000 (58 cases), 1.40/100 000 (87 cases), 0.75/100 000 (47 cases) and 1.02/100 000 (65 cases), respectively. The incidence showed a decline during these years (Z = -5.78, P < 0.01). The results of Poisson regression model indicated that the monthly average temperature (18.00°C, r = 0.26, P < 0.01, 1-month lag period; IRR = 1.02, 95%CI: 1.00 - 1.03, P < 0.01), relative humidity (75.50%, r = 0.62, P < 0.01, 3-month lag period; IRR = 1.03, 95%CI: 1.02 - 1.04, P < 0.01), rainfall (112.40 mm, r = 0.25, P < 0.01, 6-month lag period; IRR = 1.01, 95CI: 1.01 - 1.02, P = 0.02), and MEI (r = 0.31, P < 0.01, 3-month lag period; IRR = 0.77, 95CI: 0.67 - 0.88, P < 0.01) were closely associated with monthly HFRS cases (18.10 cases). Climate factors significantly influence the incidence of HFRS. If the influence of variable-autocorrelation, seasonality, and long-term trend were controlled, the accuracy of forecasting by the time-series Poisson regression model in Changsha would be comparatively high, and we could forecast the incidence of HFRS in advance.

Injury Rates in Age-Only Versus Age-and-Weight Playing Standard Conditions in American Youth Football

PubMed Central

Kerr, Zachary Y.; Marshall, Stephen W.; Simon, Janet E.; Hayden, Ross; Snook, Erin M.; Dodge, Thomas; Gallo, Joseph A.; Valovich McLeod, Tamara C.; Mensch, James; Murphy, Joseph M.; Nittoli, Vincent C.; Dompier, Thomas P.; Ragan, Brian; Yeargin, Susan W.; Parsons, John T.

2015-01-01

Background: American youth football leagues are typically structured using either age-only (AO) or age-and-weight (AW) playing standard conditions. These playing standard conditions group players by age in the former condition and by a combination of age and weight in the latter condition. However, no study has systematically compared injury risk between these 2 playing standards. Purpose: To compare injury rates between youth tackle football players in the AO and AW playing standard conditions. Study Design: Cohort study; Level of evidence, 2. Methods: Athletic trainers evaluated and recorded injuries at each practice and game during the 2012 and 2013 football seasons. Players (age, 5-14 years) were drawn from 13 recreational leagues across 6 states. The sample included 4092 athlete-seasons (AW, 2065; AO, 2027) from 210 teams (AW, 106; O, 104). Injury rate ratios (RRs) with 95% CIs were used to compare the playing standard conditions. Multivariate Poisson regression was used to estimate RRs adjusted for residual effects of age and clustering by team and league. There were 4 endpoints of interest: (1) any injury, (2) non–time loss (NTL) injuries only, (3) time loss (TL) injuries only, and (4) concussions only. Results: Over 2 seasons, the cohort accumulated 1475 injuries and 142,536 athlete-exposures (AEs). The most common injuries were contusions (34.4%), ligament sprains (16.3%), concussions (9.6%), and muscle strains (7.8%). The overall injury rate for both playing standard conditions combined was 10.3 per 1000 AEs (95% CI, 9.8-10.9). The TL injury, NTL injury, and concussion rates in both playing standard conditions combined were 3.1, 7.2, and 1.0 per 1000 AEs, respectively. In multivariate Poisson regression models controlling for age, team, and league, no differences were found between playing standard conditions in the overall injury rate (RRoverall, 1.1; 95% CI, 0.4-2.6). Rates for the other 3 endpoints were also similar (RRNTL, 1.1 [95% CI, 0.4-3.0]; RRTL, 0.9 [95% CI, 0.4-1.9]; RRconcussion, 0.6 [95% CI, 0.3-1.4]). Conclusion: For the injury endpoints examined in this study, the injury rates were similar in the AO and AW playing standards. Future research should examine other policies, rules, and behavioral factors that may affect injury risk within youth football. PMID:26672778

Gun carrying among freshmen and sophomores in Chicago, New York City and Los Angeles public schools: the Youth Risk Behavior Survey, 2007-2013.

PubMed

Kemal, Samaa; Sheehan, Karen; Feinglass, Joe

2018-04-10

This study evaluated trends and risk factors over time for self-reported gun carrying among freshman and sophomore public school students in Chicago, New York City and Los Angeles, chosen as high profile cities with different levels of firearm violence. The study used four biennial waves (2007-2013) of the Youth Risk Behavior Survey (YRBS), an anonymous, voluntary survey of public high school students. Analyses were restricted to freshman and sophomores given significant high school dropout rates among older students. School population weighted results are presented based on the YRBS complex survey design, including comparisons of reported gun carrying across survey waves and cities. A violence index was created from eight survey items that capture students' perceived threat level. Chi square tests and multivariable Poisson regression analyses were used to test the significance of differences across cities and over time in the likelihood of gun carrying controlling for sociodemographic characteristics, mental health risk factors and behavioral risk factors. The study included a total weighted population estimate of 1,137,449 students across the three cities and four survey waves. Mean self-reported gun carrying across all survey waves was 8.89% in Chicago, 4.09% in New York City, and 6.03% in Los Angeles (p < 0.001). There were no significant changes in gun carrying prevalence within each individual city over the survey waves. Multivariable Poisson regression estimates showed increased likelihood for gun carrying among males (IRR 1.41, CI 1.27-1.58), among non-Hispanic Blacks (IRR 1.26, CI 1.07-1.48), and among those who reported a higher violence index. Each additional violence index count increase was associated with a 1.74 times (CI 1.70-1.78) increased likelihood for gun carrying. There was a much higher self-reported rate of gun carrying and a higher burden of violence exposure in Chicago as compared to New York City and Los Angeles. Students' exposure to violence extended to other stressors illuminated by the YRBS including fighting, perceptions of safety, and other high-risk behaviors. Through the violence index we created, we are better able to categorize the most high-risk individuals and describe the magnitude of their increased likelihood to carry a gun.

Climate variations and salmonellosis transmission in Adelaide, South Australia: a comparison between regression models

NASA Astrophysics Data System (ADS)

Zhang, Ying; Bi, Peng; Hiller, Janet

2008-01-01

This is the first study to identify appropriate regression models for the association between climate variation and salmonellosis transmission. A comparison between different regression models was conducted using surveillance data in Adelaide, South Australia. By using notified salmonellosis cases and climatic variables from the Adelaide metropolitan area over the period 1990-2003, four regression methods were examined: standard Poisson regression, autoregressive adjusted Poisson regression, multiple linear regression, and a seasonal autoregressive integrated moving average (SARIMA) model. Notified salmonellosis cases in 2004 were used to test the forecasting ability of the four models. Parameter estimation, goodness-of-fit and forecasting ability of the four regression models were compared. Temperatures occurring 2 weeks prior to cases were positively associated with cases of salmonellosis. Rainfall was also inversely related to the number of cases. The comparison of the goodness-of-fit and forecasting ability suggest that the SARIMA model is better than the other three regression models. Temperature and rainfall may be used as climatic predictors of salmonellosis cases in regions with climatic characteristics similar to those of Adelaide. The SARIMA model could, thus, be adopted to quantify the relationship between climate variations and salmonellosis transmission.

Evolving Epidemiology of Staphylococcus aureus Bacteremia.

PubMed

Rhee, Yoona; Aroutcheva, Alla; Hota, Bala; Weinstein, Robert A; Popovich, Kyle J

2015-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections due to USA300 have become widespread in community and healthcare settings. It is unclear whether risk factors for bloodstream infections (BSIs) differ by strain type. To examine the epidemiology of S. aureus BSIs, including USA300 and non-USA300 MRSA strains. Retrospective observational study with molecular analysis. Large urban public hospital. Individuals with S. aureus BSIs from January 1, 2007 through December 31, 2013. We used electronic surveillance data to identify cases of S. aureus BSI. Available MRSA isolates were analyzed by pulsed-field gel electrophoresis. Poisson regression was used to evaluate changes in BSI incidence over time. Risk factor data were collected by medical chart review and logistic regression was used for multivariate analysis of risk factors. A total of 1,015 cases of S. aureus BSIs were identified during the study period; 36% were due to MRSA. The incidence of hospital-onset (HO) MRSA BSIs decreased while that of community-onset (CO) MRSA BSIs remained stable. The rate of CO- and HO- methicillin-susceptible S. aureus infections both decreased over time. More than half of HO-MRSA BSIs were due to the USA300 strain type and for 4 years, the proportion of HO-MRSA BSIs due to USA300 exceeded 60%. On multivariate analysis, current or former drug use was the only epidemiologic risk factor for CO- or HO-MRSA BSIs due to USA300 strains. USA300 MRSA is endemic in communities and hospitals and certain populations (eg, those who use illicit drugs) may benefit from enhanced prevention efforts in the community.

Association of sex hormones with incident 10-year cardiovascular disease and mortality in women.

PubMed

Schaffrath, Gotja; Kische, Hanna; Gross, Stefan; Wallaschofski, Henri; Völzke, Henry; Dörr, Marcus; Nauck, Matthias; Keevil, Brian G; Brabant, Georg; Haring, Robin

2015-12-01

The aims of this study were to ascertain whether women with high levels of serum total testosterone (TT) or low levels of sex hormone-binding globulin (SHBG) are more likely to develop cardiovascular disease (CVD), and to investigate potential associations between sex hormones and mortality (all-cause, as well as cause-specific) in the general population. Data on 2129 women with a mean age of 49.0 years were obtained from the population-based Study of Health in Pomerania over a median follow-up of 10.9 years. Associations of baseline levels of TT, SHBG, and rostenedione (ASD), and free testosterone (fT), and of the free androgen index (FAI), with follow-up CVD morbidity, as well as all-cause and CVD mortality, were analyzed using multivariable regression modeling. At baseline the prevalence rate of CVD was 17.8% (378 women) and the incidence of CVD over the follow-up was 50.9 per 1000 person-years. We detected an inverse association between SHBG and baseline CVD in age-adjusted models (relative risk per standard deviation increase: 0.83; 95% confidence interval: 0.74-0.93). We did not detect any significant associations between sex hormone concentrations and incident CVD in age- and multivariable-adjusted Poisson regression models. Furthermore, none of the sex hormones (TT, SHBG, ASD, fT, FAI) were associated with all-cause mortality. This population-based cohort study did not yield any consistent associations between sex hormones in women and incident CVD or mortality risk. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Application of zero-inflated poisson mixed models in prognostic factors of hepatitis C.

PubMed

Akbarzadeh Baghban, Alireza; Pourhoseingholi, Asma; Zayeri, Farid; Jafari, Ali Akbar; Alavian, Seyed Moayed

2013-01-01

In recent years, hepatitis C virus (HCV) infection represents a major public health problem. Evaluation of risk factors is one of the solutions which help protect people from the infection. This study aims to employ zero-inflated Poisson mixed models to evaluate prognostic factors of hepatitis C. The data was collected from a longitudinal study during 2005-2010. First, mixed Poisson regression (PR) model was fitted to the data. Then, a mixed zero-inflated Poisson model was fitted with compound Poisson random effects. For evaluating the performance of the proposed mixed model, standard errors of estimators were compared. The results obtained from mixed PR showed that genotype 3 and treatment protocol were statistically significant. Results of zero-inflated Poisson mixed model showed that age, sex, genotypes 2 and 3, the treatment protocol, and having risk factors had significant effects on viral load of HCV patients. Of these two models, the estimators of zero-inflated Poisson mixed model had the minimum standard errors. The results showed that a mixed zero-inflated Poisson model was the almost best fit. The proposed model can capture serial dependence, additional overdispersion, and excess zeros in the longitudinal count data.

Bayesian multivariate Poisson abundance models for T-cell receptor data.

PubMed

Greene, Joshua; Birtwistle, Marc R; Ignatowicz, Leszek; Rempala, Grzegorz A

2013-06-07

A major feature of an adaptive immune system is its ability to generate B- and T-cell clones capable of recognizing and neutralizing specific antigens. These clones recognize antigens with the help of the surface molecules, called antigen receptors, acquired individually during the clonal development process. In order to ensure a response to a broad range of antigens, the number of different receptor molecules is extremely large, resulting in a huge clonal diversity of both B- and T-cell receptor populations and making their experimental comparisons statistically challenging. To facilitate such comparisons, we propose a flexible parametric model of multivariate count data and illustrate its use in a simultaneous analysis of multiple antigen receptor populations derived from mammalian T-cells. The model relies on a representation of the observed receptor counts as a multivariate Poisson abundance mixture (m PAM). A Bayesian parameter fitting procedure is proposed, based on the complete posterior likelihood, rather than the conditional one used typically in similar settings. The new procedure is shown to be considerably more efficient than its conditional counterpart (as measured by the Fisher information) in the regions of m PAM parameter space relevant to model T-cell data. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Negative Binomial Regression Model for Accuracy Tests

ERIC Educational Resources Information Center

Hung, Lai-Fa

2012-01-01

Rasch used a Poisson model to analyze errors and speed in reading tests. An important property of the Poisson distribution is that the mean and variance are equal. However, in social science research, it is very common for the variance to be greater than the mean (i.e., the data are overdispersed). This study embeds the Rasch model within an…

Error Covariance Penalized Regression: A novel multivariate model combining penalized regression with multivariate error structure.

PubMed

Allegrini, Franco; Braga, Jez W B; Moreira, Alessandro C O; Olivieri, Alejandro C

2018-06-29

A new multivariate regression model, named Error Covariance Penalized Regression (ECPR) is presented. Following a penalized regression strategy, the proposed model incorporates information about the measurement error structure of the system, using the error covariance matrix (ECM) as a penalization term. Results are reported from both simulations and experimental data based on replicate mid and near infrared (MIR and NIR) spectral measurements. The results for ECPR are better under non-iid conditions when compared with traditional first-order multivariate methods such as ridge regression (RR), principal component regression (PCR) and partial least-squares regression (PLS). Copyright © 2018 Elsevier B.V. All rights reserved.

Diabetes and work: 12-year national follow-up study of the association of diabetes incidence with socioeconomic group, age, gender and country of origin.

PubMed

Poulsen, Kjeld; Cleal, Bryan; Willaing, Ingrid

2014-12-01

To investigate the extent and socioeconomic distribution of incident diabetes among the Danish working-age population. The Danish National Diabetes Register was linked with socioeconomic and population-based registers covering the entire population. We analysed the 12-year diabetes incidence using multivariate Poisson regression for 2,086,682 people, adjusting for gender, 10-year age groups, main population groups defined by country of origin, and seven socioeconomic groups: professionals, managers, technicians, workers skilled at basic level, unskilled workers, unemployed and pensioners. The crude 12-year incidence of diabetes was 5.8%. The saturated multivariate model, adjusted for gender, age, country of origin and socioeconomic status; showed a relative risk (RR) for diabetes incidence of 1.44 for male (reference: female), 3.95 for the age range of 50-59 years (reference: 30-39 years), 2.07 for unskilled workers (reference: professionals) and 2.15 for people from countries of 'non-Western origin' (reference: Danish origin). Diabetes incidence increases with age, male gender and low socioeconomic status; and also among people from countries of 'non-Western origin'. The results indicate that getting a more senior workforce will substantially increase the proportion of workers with diabetes, especially among already vulnerable groups. © 2014 the Nordic Societies of Public Health.

The role of area-level deprivation and gender in participation in population-based faecal immunochemical test (FIT) colorectal cancer screening.

PubMed

Clarke, Nicholas; McNamara, Deirdre; Kearney, Patricia M; O'Morain, Colm A; Shearer, Nikki; Sharp, Linda

2016-12-01

This study aimed to investigate the effects of sex and deprivation on participation in a population-based faecal immunochemical test (FIT) colorectal cancer screening programme. The study population included 9785 individuals invited to participate in two rounds of a population-based biennial FIT-based screening programme, in a relatively deprived area of Dublin, Ireland. Explanatory variables included in the analysis were sex, deprivation category of area of residence and age (at end of screening). The primary outcome variable modelled was participation status in both rounds combined (with "participation" defined as having taken part in either or both rounds of screening). Poisson regression with a log link and robust error variance was used to estimate relative risks (RR) for participation. As a sensitivity analysis, data were stratified by screening round. In both the univariable and multivariable models deprivation was strongly associated with participation. Increasing affluence was associated with higher participation; participation was 26% higher in people resident in the most affluent compared to the most deprived areas (multivariable RR=1.26: 95% CI 1.21-1.30). Participation was significantly lower in males (multivariable RR=0.96: 95%CI 0.95-0.97) and generally increased with increasing age (trend per age group, multivariable RR=1.02: 95%CI, 1.01-1.02). No significant interactions between the explanatory variables were found. The effects of deprivation and sex were similar by screening round. Deprivation and male gender are independently associated with lower uptake of population-based FIT colorectal cancer screening, even in a relatively deprived setting. Development of evidence-based interventions to increase uptake in these disadvantaged groups is urgently required. Copyright © 2016. Published by Elsevier Inc.

Estimation of parameters in Shot-Noise-Driven Doubly Stochastic Poisson processes using the EM algorithm--modeling of pre- and postsynaptic spike trains.

PubMed

Mino, H

2007-01-01

To estimate the parameters, the impulse response (IR) functions of some linear time-invariant systems generating intensity processes, in Shot-Noise-Driven Doubly Stochastic Poisson Process (SND-DSPP) in which multivariate presynaptic spike trains and postsynaptic spike trains can be assumed to be modeled by the SND-DSPPs. An explicit formula for estimating the IR functions from observations of multivariate input processes of the linear systems and the corresponding counting process (output process) is derived utilizing the expectation maximization (EM) algorithm. The validity of the estimation formula was verified through Monte Carlo simulations in which two presynaptic spike trains and one postsynaptic spike train were assumed to be observable. The IR functions estimated on the basis of the proposed identification method were close to the true IR functions. The proposed method will play an important role in identifying the input-output relationship of pre- and postsynaptic neural spike trains in practical situations.

Bayesian Poisson hierarchical models for crash data analysis: Investigating the impact of model choice on site-specific predictions.

PubMed

Khazraee, S Hadi; Johnson, Valen; Lord, Dominique

2018-08-01

The Poisson-gamma (PG) and Poisson-lognormal (PLN) regression models are among the most popular means for motor vehicle crash data analysis. Both models belong to the Poisson-hierarchical family of models. While numerous studies have compared the overall performance of alternative Bayesian Poisson-hierarchical models, little research has addressed the impact of model choice on the expected crash frequency prediction at individual sites. This paper sought to examine whether there are any trends among candidate models predictions e.g., that an alternative model's prediction for sites with certain conditions tends to be higher (or lower) than that from another model. In addition to the PG and PLN models, this research formulated a new member of the Poisson-hierarchical family of models: the Poisson-inverse gamma (PIGam). Three field datasets (from Texas, Michigan and Indiana) covering a wide range of over-dispersion characteristics were selected for analysis. This study demonstrated that the model choice can be critical when the calibrated models are used for prediction at new sites, especially when the data are highly over-dispersed. For all three datasets, the PIGam model would predict higher expected crash frequencies than would the PLN and PG models, in order, indicating a clear link between the models predictions and the shape of their mixing distributions (i.e., gamma, lognormal, and inverse gamma, respectively). The thicker tail of the PIGam and PLN models (in order) may provide an advantage when the data are highly over-dispersed. The analysis results also illustrated a major deficiency of the Deviance Information Criterion (DIC) in comparing the goodness-of-fit of hierarchical models; models with drastically different set of coefficients (and thus predictions for new sites) may yield similar DIC values, because the DIC only accounts for the parameters in the lowest (observation) level of the hierarchy and ignores the higher levels (regression coefficients). Copyright © 2018. Published by Elsevier Ltd.

Combined analysis of magnetic and gravity anomalies using normalized source strength (NSS)

NASA Astrophysics Data System (ADS)

Li, L.; Wu, Y.

2017-12-01

Gravity field and magnetic field belong to potential fields which lead inherent multi-solution. Combined analysis of magnetic and gravity anomalies based on Poisson's relation is used to determinate homology gravity and magnetic anomalies and decrease the ambiguity. The traditional combined analysis uses the linear regression of the reduction to pole (RTP) magnetic anomaly to the first order vertical derivative of the gravity anomaly, and provides the quantitative or semi-quantitative interpretation by calculating the correlation coefficient, slope and intercept. In the calculation process, due to the effect of remanent magnetization, the RTP anomaly still contains the effect of oblique magnetization. In this case the homology gravity and magnetic anomalies display irrelevant results in the linear regression calculation. The normalized source strength (NSS) can be transformed from the magnetic tensor matrix, which is insensitive to the remanence. Here we present a new combined analysis using NSS. Based on the Poisson's relation, the gravity tensor matrix can be transformed into the pseudomagnetic tensor matrix of the direction of geomagnetic field magnetization under the homologous condition. The NSS of pseudomagnetic tensor matrix and original magnetic tensor matrix are calculated and linear regression analysis is carried out. The calculated correlation coefficient, slope and intercept indicate the homology level, Poisson's ratio and the distribution of remanent respectively. We test the approach using synthetic model under complex magnetization, the results show that it can still distinguish the same source under the condition of strong remanence, and establish the Poisson's ratio. Finally, this approach is applied in China. The results demonstrated that our approach is feasible.

Marginalized zero-inflated negative binomial regression with application to dental caries

PubMed Central

Preisser, John S.; Das, Kalyan; Long, D. Leann; Divaris, Kimon

2015-01-01

The zero-inflated negative binomial regression model (ZINB) is often employed in diverse fields such as dentistry, health care utilization, highway safety, and medicine to examine relationships between exposures of interest and overdispersed count outcomes exhibiting many zeros. The regression coefficients of ZINB have latent class interpretations for a susceptible subpopulation at risk for the disease/condition under study with counts generated from a negative binomial distribution and for a non-susceptible subpopulation that provides only zero counts. The ZINB parameters, however, are not well-suited for estimating overall exposure effects, specifically, in quantifying the effect of an explanatory variable in the overall mixture population. In this paper, a marginalized zero-inflated negative binomial regression (MZINB) model for independent responses is proposed to model the population marginal mean count directly, providing straightforward inference for overall exposure effects based on maximum likelihood estimation. Through simulation studies, the finite sample performance of MZINB is compared to marginalized zero-inflated Poisson, Poisson, and negative binomial regression. The MZINB model is applied in the evaluation of a school-based fluoride mouthrinse program on dental caries in 677 children. PMID:26568034

Spatial variation of natural radiation and childhood leukaemia incidence in Great Britain.

PubMed

Richardson, S; Monfort, C; Green, M; Draper, G; Muirhead, C

This paper describes an analysis of the geographical variation of childhood leukaemia incidence in Great Britain over a 15 year period in relation to natural radiation (gamma and radon). Data at the level of the 459 district level local authorities in England, Wales and regional districts in Scotland are analysed in two complementary ways: first, by Poisson regressions with the inclusion of environmental covariates and a smooth spatial structure; secondly, by a hierarchical Bayesian model in which extra-Poisson variability is modelled explicitly in terms of spatial and non-spatial components. From this analysis, we deduce a strong indication that a main part of the variability is accounted for by a local neighbourhood 'clustering' structure. This structure is furthermore relatively stable over the 15 year period for the lymphocytic leukaemias which make up the majority of observed cases. We found no evidence of a positive association of childhood leukaemia incidence with outdoor or indoor gamma radiation levels. There is no consistent evidence of any association with radon levels. Indeed, in the Poisson regressions, a significant positive association was only observed for one 5-year period, a result which is not compatible with a stable environmental effect. Moreover, this positive association became clearly non-significant when over-dispersion relative to the Poisson distribution was taken into account.

Decoding and modelling of time series count data using Poisson hidden Markov model and Markov ordinal logistic regression models.

PubMed

Sebastian, Tunny; Jeyaseelan, Visalakshi; Jeyaseelan, Lakshmanan; Anandan, Shalini; George, Sebastian; Bangdiwala, Shrikant I

2018-01-01

Hidden Markov models are stochastic models in which the observations are assumed to follow a mixture distribution, but the parameters of the components are governed by a Markov chain which is unobservable. The issues related to the estimation of Poisson-hidden Markov models in which the observations are coming from mixture of Poisson distributions and the parameters of the component Poisson distributions are governed by an m-state Markov chain with an unknown transition probability matrix are explained here. These methods were applied to the data on Vibrio cholerae counts reported every month for 11-year span at Christian Medical College, Vellore, India. Using Viterbi algorithm, the best estimate of the state sequence was obtained and hence the transition probability matrix. The mean passage time between the states were estimated. The 95% confidence interval for the mean passage time was estimated via Monte Carlo simulation. The three hidden states of the estimated Markov chain are labelled as 'Low', 'Moderate' and 'High' with the mean counts of 1.4, 6.6 and 20.2 and the estimated average duration of stay of 3, 3 and 4 months, respectively. Environmental risk factors were studied using Markov ordinal logistic regression analysis. No significant association was found between disease severity levels and climate components.

Prediction of forest fires occurrences with area-level Poisson mixed models.

PubMed

Boubeta, Miguel; Lombardía, María José; Marey-Pérez, Manuel Francisco; Morales, Domingo

2015-05-01

The number of fires in forest areas of Galicia (north-west of Spain) during the summer period is quite high. Local authorities are interested in analyzing the factors that explain this phenomenon. Poisson regression models are good tools for describing and predicting the number of fires per forest areas. This work employs area-level Poisson mixed models for treating real data about fires in forest areas. A parametric bootstrap method is applied for estimating the mean squared errors of fires predictors. The developed methodology and software are applied to a real data set of fires in forest areas of Galicia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Population-based study of survival for women with serous cancer of the ovary, fallopian tube, peritoneum or undesignated origin - on behalf of the Swedish gynecological cancer group (SweGCG).

PubMed

Dahm-Kähler, Pernilla; Borgfeldt, Christer; Holmberg, Erik; Staf, Christian; Falconer, Henrik; Bjurberg, Maria; Kjölhede, Preben; Rosenberg, Per; Stålberg, Karin; Högberg, Thomas; Åvall-Lundqvist, Elisabeth

2017-01-01

The aim of the study was to determine survival outcome in patients with serous cancer in the ovary, fallopian tube, peritoneum and of undesignated origin. Nation-wide population-based study of women≥18years with histologically verified non-uterine serous cancer, included in the Swedish Quality Registry for primary cancer of the ovary, fallopian tube and peritoneum diagnosed 2009-2013. Relative survival (RS) was estimated using the Ederer II method. Simple and multivariable analyses were estimated by Poisson regression models. Of 5627 women identified, 1246 (22%) had borderline tumors and 4381 had malignant tumors. In total, 2359 women had serous cancer; 71% originated in the ovary (OC), 9% in the fallopian tube (FTC), 9% in the peritoneum (PPC) and 11% at an undesignated primary site (UPS). Estimated RS at 5-years was 37%; for FTC 54%, 40% for OC, 34% for PPC and 13% for UPS. In multivariable regression analyses restricted to women who had undergone primary or interval debulking surgery for OC, FTC and PPC, site of origin was not independently associated with survival. Significant associations with worse survival were found for advanced stages (RR 2.63, P<0.001), moderate (RR 1.90, P<0.047) and poor differentiation (RR 2.20, P<0.009), neoadjuvant chemotherapy (RR1.33, P<0.022), residual tumor (RR 2.65, P<0.001) and platinum single (2.34, P<0.001) compared to platinum combination chemotherapy. Survival was poorer for serous cancer at UPS than for ovarian, fallopian tube and peritoneal cancer. Serous cancer at UPS needs to be addressed when reporting and comparing survival rates of ovarian cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis of fall injuries by body mass index.

PubMed

Ren, Jun; Waclawczyk, Amanda; Hartfield, Doug; Yu, Shicheng; Kuang, Xiangyu; Zhang, Hongrui; Alamgir, Hasanat

2014-05-01

To examine the association of body mass index (BMI) and fall injuries. Data were derived from the 2010 Behavioral Risk Factor Surveillance System and included subjects aged 45 years and older from Texas. The outcome was self-reported falls that resulted in injury to the respondents. Analysis of fall injuries by BMI was conducted and standard errors, 95% confidence intervals (CIs), and coefficients of variation were reported. Complex sample multivariate Poisson regression was used to examine the association of BMI and fall injuries. A total of 18,077 subjects were surveyed in 2010, and 13,235 subjects were aged 45 years old and older. The mean BMI was higher (29.94 vs 28.32 kg/m(2)) among those who reported fall injuries compared with those who did not. The fall injuries reported by obese respondents (relative risk [RR] 1.67) were found to be significantly (P = 0.031) higher compared with normal-weight respondents in the multivariate regression. Other risk factors that had significant association with fall injuries (when adjusted for BMI) were activity limitations (RR 5.00, 95% CI 3.36-7.46) compared with no limitations, and not having formal employment (homemaker: RR 2.68, 95% CI 1.33-5.37; unable to work: RR 5.01, 95% CI 1.87-13.29; out of work and students: RR 3.21, 95% CI 1.41-7.29) compared with the employed population. There is a significant association between obesity and fall injuries in adults aged 45 years old and older in Texas. Interventions in fall prevention, although generally targeted at present to older adults, also should take into account the weight status of the subjects.

Comparison of perioperative outcomes between open and robotic radical cystectomy: a population based analysis.

PubMed

Nazzani, Sebastiano; Mazzone, Elio; Preisser, Felix; Bandini, Marco; Tian, Zhe; Marchioni, Michele; Ratti, Dario; Motta, Gloria; Zorn, Kevin Christopher; Briganti, Alberto; Shariat, Shahrokh F; Montanari, Emanuele; Carmignani, Luca; Karakiewicz, Pierre I

2018-05-30

Radical cystectomy represents the standard of care for muscle invasive bladder cancer (MIBC). Due to its novelty the use of robotic radical cystectomy (RARC) is still under debate. We examined intraoperative and postoperative morbidity and mortality as well as impact on length of stay (LOS) and total hospital charges (THCGs) of RARC compared to open radical cystectomy (ORC). Within National Inpatient Sample (NIS) (2008-2013), we identified patients with non-metastatic bladder cancer treated with either ORC or RARC. We relied on inverse probability of treatment weighting (IPTW) to reduce the effect of inherent differences between ORC vs. RARC. Multivariable logistic regression (MLR) and multivariable Poisson regression models (MPR) were used. Of all 10 027 patients, 12.6% underwent RARC. Between 2008 and 2013, RARC rates increased from 0.8 to 20.4% [Estimated annual percentage change (EAPC): +26.5%, CI: +11.1 to +48.3; p=0.035] and RARC THCGs decreased from 45 981 to 31 749 United States Dollars (EAPC: -6.8%, CI: -9.6 to -3.9; p=0.01). In MLR models RARC resulted in lower rates of overall complications (OR: 0.6; p <0.001) and transfusions (OR: 0.44; p <0.001). In MPR models, RARC was associated with shorter LOS [relative risk(RR)0.91 ; p <0.001]. Finally, higher THCGs (OR: 1.09; p <0.001) were recorded for RARC. Data are retrospective and no tumor characteristics were available. RARC is related to lower rates of overall complications and transfusions rates. In consequence, RARC is a safe and feasible technique in select muscle invasive bladder cancer patients. Moreover, RARC is associated with shorter LOS albeit higher THCGs.  .

The pattern of choosing dialysis modality and related mortality outcomes in Korea: a national population-based study

PubMed Central

Kim, Hyung Jong; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Park, Hyeong-Cheon; Kang, Shin-Wook; Kim, Kyoung Hoon; Ryu, Dong-Ryeol; Kim, Hyunwook

2017-01-01

Background/Aims Since comorbidities are major determinants of modality choice, and also interact with dialysis modality on mortality outcomes, we examined the pattern of modality choice according to comorbidities and then evaluated how such choices affected mortality in incident dialysis patients. Methods We analyzed 32,280 incident dialysis patients in Korea. Patterns in initial dialysis choice were assessed by multivariate logistic regression analyses. Multivariate Poisson regression analyses were performed to evaluate the effects of interactions between comorbidities and dialysis modality on mortality and to quantify these interactions using the synergy factor. Results Prior histories of myocardial infarction (p = 0.031), diabetes (p = 0.001), and congestive heart failure (p = 0.003) were independent factors favoring the initiation with peritoneal dialysis (PD), but were associated with increased mortality with PD. In contrast, a history of cerebrovascular disease and 1-year increase in age favored initiation with hemodialysis (HD) and were related to a survival benefit with HD (p < 0.001, both). While favoring initiation with HD, having Medical Aid (p = 0.001) and male gender (p = 0.047) were related to increased mortality with HD. Furthermore, although the severity of comorbidities did not inf luence dialysis modality choice, mortality in incident PD patients was significantly higher compared to that in HD patients as the severity of comorbidities increased (p for trend < 0.001). Conclusions Some comorbidities exerted independent effects on initial choice of dialysis modality, but this choice did not always lead to the best results. Further analyses of the pattern of choosing dialysis modality according to baseline comorbid conditions and related consequent mortality outcomes are needed. PMID:28651309

A semi-nonparametric Poisson regression model for analyzing motor vehicle crash data.

PubMed

Ye, Xin; Wang, Ke; Zou, Yajie; Lord, Dominique

2018-01-01

This paper develops a semi-nonparametric Poisson regression model to analyze motor vehicle crash frequency data collected from rural multilane highway segments in California, US. Motor vehicle crash frequency on rural highway is a topic of interest in the area of transportation safety due to higher driving speeds and the resultant severity level. Unlike the traditional Negative Binomial (NB) model, the semi-nonparametric Poisson regression model can accommodate an unobserved heterogeneity following a highly flexible semi-nonparametric (SNP) distribution. Simulation experiments are conducted to demonstrate that the SNP distribution can well mimic a large family of distributions, including normal distributions, log-gamma distributions, bimodal and trimodal distributions. Empirical estimation results show that such flexibility offered by the SNP distribution can greatly improve model precision and the overall goodness-of-fit. The semi-nonparametric distribution can provide a better understanding of crash data structure through its ability to capture potential multimodality in the distribution of unobserved heterogeneity. When estimated coefficients in empirical models are compared, SNP and NB models are found to have a substantially different coefficient for the dummy variable indicating the lane width. The SNP model with better statistical performance suggests that the NB model overestimates the effect of lane width on crash frequency reduction by 83.1%.

Effect of motivational interviewing on rates of early childhood caries: a randomized trial.

PubMed

Harrison, Rosamund; Benton, Tonya; Everson-Stewart, Siobhan; Weinstein, Phil

2007-01-01

The purposes of this randomized controlled trial were to: (1) test motivational interviewing (MI) to prevent early childhood caries; and (2) use Poisson regression for data analysis. A total of 240 South Asian children 6 to 18 months old were enrolled and randomly assigned to either the MI or control condition. Children had a dental exam, and their mothers completed pretested instruments at baseline and 1 and 2 years postintervention. Other covariates that might explain outcomes over and above treatment differences were modeled using Poisson regression. Hazard ratios were produced. Analyses included all participants whenever possible. Poisson regression supported a protective effect of MI (hazard ratio [HR]=0.54 (95%CI=035-0.84)-that is, the M/ group had about a 46% lower rate of dmfs at 2 years than did control children. Similar treatment effect estimates were obtained from models that included, as alternative outcomes, ds, dms, and dmfs, including "white spot lesions." Exploratory analyses revealed that rates of dmfs were higher in children whose mothers had: (1) prechewed their food; (2) been raised in a rural environment; and (3) a higher family income (P<.05). A motivational interviewing-style intervention shows promise to promote preventive behaviors in mothers of young children at high risk for caries.

Exploring the association of homicides in northern Mexico and healthcare access for US residents

PubMed Central

Geissler, Kimberley; Becker, Charles; Stearns, Sally; Thirumurthy, Harsha; Holmes, George M.

2016-01-01

Background Many legal residents in the United States (US)-Mexico border region cross from the US into Mexico for medical treatment and pharmaceuticals. We analyzed whether recent increases in homicides in Mexico are associated with reduced healthcare access for US border residents. Methods We used data on healthcare access, legal entries to the US from Mexico, and Mexican homicide rates (2002–2010). Poisson regression models estimated associations between homicide rates and total legal US entries. Multivariate difference-in-difference linear probability models evaluated associations between Mexican homicide rates and self-reported measures of healthcare access for US residents. Results Increased homicide rates were associated with decreased legal entries to the US from Mexico. Contrary to expectations, homicides did not have significant associations with healthcare access measures for legal residents in US border counties. Conclusions Despite a decrease in border crossings, increased violence in Mexico did not appear to negatively affect access for US border residents. PMID:24917240

Association between perception of maternal bonding styles and social anxiety disorder among young women.

PubMed

Castelli, Rochele D; Quevedo, Luciana de Á; Coelho, Fábio M; Lopez, Mariane A; da Silva, Ricardo A; Böhm, Denise M; Souza, Luciano D; de Matos, Mariana B; Pinheiro, Karen A; Pinheiro, Ricardo T

2015-01-01

To evaluate the association between social anxiety disorder (SAD) and perceived maternal bonding styles among young women during pregnancy and 30 months after childbirth. A cohort of young women from the city of Pelotas, Brazil was followed up from pregnancy to 30 months postpartum. The Mini Neuropsychiatric Interview Plus was used to assess SAD and the Parental Bonding Instrument was administered to measure maternal bonding styles. Poisson regression with robust variance was used for multivariable analysis. After adjusting for potential confounding factors, SAD prevalence was 6.39 times higher among young women who perceived their mothers as neglectful (prevalence ratio [PR] 6.39; 95% confidence interval [95%CI] 1.2-32.0), and 5.57 times higher in women who perceived their mothers as affectionless controlling (PR = 5.57; 95%CI 1.5-19.7) when compared with those who received optimal care. Maternal bonding style may have an influence on the development of SAD. Therefore, support and early prevention strategies should be offered to the family.

Gender Differences in Factors Associated With Anal Intercourse Among Heterosexual Adolescents in Singapore.

PubMed

Ng, Junice Y S; Wong, Mee-Lian; Chan, Roy K W; Sen, Priya; Chio, Martin T W; Koh, David

2015-08-01

Using a cross-sectional survey, we examined the gender differences in prevalence of and factors associated with anal sex among adolescents attending the only public STI clinic in Singapore. Data were collected from 1035 sexually active adolescents aged 14 to 19 and analyzed using Poisson regression. Prevalence of anal intercourse was 28%, with significantly more females (32%) than males (23%) ever engaged in it. On multivariate analysis, the factors associated with anal intercourse for both genders were oral sex and the nonuse of contraception at last sex. For males, anal intercourse was associated with younger age of sexual debut and greater perceived external control. Among females, it was associated with higher rebellious scores and lack of confidence to resist peer pressure to engage in sex. Consistent condom use for anal sex was 22% and 8% for males and females, respectively. STI prevention programs for adolescents should address anal sex, be gender-specific, and take into consideration individual personality characteristics.

Work organization, exposure to workplace hazards and sickness presenteeism in the European employed population.

PubMed

d'Errico, Angelo; Ardito, Chiara; Leombruni, Roberto

2016-01-01

Aim of the study was to identify work organization features and workplace hazards associated with sickness presenteeism (SP) among European workers. The study was conducted on data from the European Working Conditions Survey 2010 and included a study population of 30,279 employees. The relationship between work-related factors and SP was assessed through Poisson multivariate robust regression models, adjusting for significant (P < 0.05) individual and work-related characteristics. SP for at least 2 days in the previous year was reported by 35% of the workers. In fully adjusted model, several psychosocial (decision authority, skill discretion, reward, abuse; psychological, cognitive, and emotional demand), and organizational factors (shift work, working with clients, long work hours) were positively associated with SP, whereas job insecurity and exposure to physical factors (lifting or moving people, vibration) decreased SP risk. Our results support the importance of work-related factors, especially psychosocial exposures and organizational features, in determining workers' SP. © 2015 Wiley Periodicals, Inc.

Depression and HIV risk among men who have sex with men in Tanzania.

PubMed

Ahaneku, Hycienth; Ross, Michael W; Nyoni, Joyce E; Selwyn, Beatrice; Troisi, Catherine; Mbwambo, Jessie; Adeboye, Adeniyi; McCurdy, Sheryl

2016-01-01

Studies have shown high rates of depression among men who have sex with men (MSM) in developed countries. Studies have also shown association between depression and HIV risk among MSM. However, very little research has been done on depression among African MSM. We assessed depression and HIV risk among a sample of MSM in Tanzania. We reviewed data on 205 MSM who were recruited from two Tanzanian cities using the respondent driven sampling method. Demographic and behavioral data were collected using a structured questionnaire. HIV and sexually transmitted infections data were determined from biological tests. Depression scores were assessed using the Patient Health Questionnaire (PHQ-9). For the analysis, depression scores were dichotomized as depressed (PHQ > 4) and not depressed (PHQ ≤ 4). Bivariate and multivariable Poisson regression analyses were conducted to assess factors associated with depression. The prevalence of depression in the sample was 46.3%. The mean (±SD) age of the sample was 25 (±5) years. In bivariate analysis, depression was associated with self-identifying as gay (p = .001), being HIV positive (p < .001: <8% of MSM knew they were HIV infected) and having a high number of sexual partners in the last 6 months (p = .001). Depression was also associated with sexual (p = .007), physical (p = .003) and verbal (p < .001) abuse. In the Poisson regression analysis, depression was associated with verbal abuse (APR = 1.91, CI = 1.30-2.81). Depression rates were high among MSM in Tanzania. It is also associated with abuse, HIV and HIV risk behaviors. Thus, reducing the risk of depression may be helpful in reducing the risk of HIV among MSM in Africa. We recommend the colocation of mental health and HIV preventive services as a cost-effective means of addressing both depression and HIV risk among MSM in Africa.

Reporting quality of randomised controlled trial abstracts on age-related macular degeneration health care: a cross-sectional quantification of the adherence to CONSORT abstract reporting recommendations.

PubMed

Baulig, Christine; Krummenauer, Frank; Geis, Berit; Tulka, Sabrina; Knippschild, Stephanie

2018-05-22

To assess the reporting quality of randomised controlled trial (RCT) abstracts on age-related macular degeneration (AMD) healthcare, to evaluate the adherence to the Consolidated Standards of Reporting Trials (CONSORT) statement's recommendations on minimum abstract information and to identify journal characteristics associated with abstract reporting quality. Cross-sectional evaluation of RCT abstracts on AMD healthcare. A PubMed search was implemented to identify RCT abstracts on AMD healthcare published in the English language between January 2004 and December 2013. Data extraction was performed by two parallel readers independently by means of a documentation format in accordance with the 16 items of the CONSORT checklist for abstracts. The total number of criteria fulfilled by an abstract was derived as primary endpoint of the investigation; incidence rate ratios (IRRs) with unadjusted 95% CI were estimated by means of multiple Poisson regression to identify journal and article characteristics (publication year, multicentre design, structured abstract recommendations, effective sample size, effective abstract word counts and journal impact factor) possibly associated with the total number of fulfilled items. 136 of 673 identified abstracts (published in 36 different journals) fulfilled all eligibility criteria. The median number of fulfilled items was 7 (95% CI 7 to 8). No abstract reported all 16 recommended items; the maximum total number was 14, the minimum 3 of 16 items. Multivariate analysis only demonstrated the abstracts' word counts as being significantly associated with a better reporting of abstracts (Poisson regression-based IRR 1.002, 95% CI 1.001 to 1.003). Reporting quality of RCT abstracts on AMD investigations showed a considerable potential for improvement to meet the CONSORT abstract reporting recommendations. Furthermore, word counts of abstracts were identified as significantly associated with the overall abstract reporting quality. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Seropositivity for Anti-HCV Core Antigen is Independently Associated With Increased All-Cause, Cardiovascular, and Liver Disease-Related Mortality in Hemodialysis Patients

PubMed Central

Ohsawa, Masaki; Kato, Karen; Tanno, Kozo; Itai, Kazuyoshi; Fujishima, Yosuke; Okayama, Akira; Turin, Tanvir Chowdhury; Onoda, Toshiyuki; Suzuki, Kazuyuki; Nakamura, Motoyuki; Kawamura, Kazuko; Akiba, Takashi; Sakata, Kiyomi; Fujioka, Tomoaki

2011-01-01

Background It is not known whether chronic or past hepatitis C virus (HCV) infection contributes to the high mortality rate in hemodialysis patients. Methods This prospective study of 1077 adult hemodialysis patients without hepatitis B virus infection used Poisson regression analysis to estimate crude and sex- and age-adjusted rates (per 1000 patient-years) of all-cause, cardiovascular, infectious disease-related and liver disease-related mortality in patients negative for HCV antibody (group A), patients positive for HCV antibody and negative for anti-HCV core antigen (group B), and patients positive for anti-HCV core antigen (group C). The relative risks (RRs) for each cause of death in group B vs group C as compared with those in group A were also estimated by Poisson regression analysis after multivariate adjustment. Results A total of 407 patients died during the 5-year observation period. The sex- and age-adjusted mortality rate was 71.9 in group A, 80.4 in group B, and 156 in group C. The RRs (95% CI) for death in group B vs group C were 1.23 (0.72 to 2.12) vs 1.60 (1.13 to 2.28) for all-cause death, 0.75 (0.28 to 2.02) vs 1.64 (0.98 to 2.73) for cardiovascular death, 1.64 (0.65 to 4.15) vs 1.58 (0.81 to 3.07) for infectious disease-related death, and 15.3 (1.26 to 186) vs 28.8 (3.75 to 221) for liver disease-related death, respectively. Conclusions Anti-HCV core antigen seropositivity independently contributes to elevated risks of all-cause and cause-specific death. Chronic HCV infection, but not past HCV infection, is a risk for death among hemodialysis patients. PMID:22001541

Modeling the number of car theft using Poisson regression

NASA Astrophysics Data System (ADS)

Zulkifli, Malina; Ling, Agnes Beh Yen; Kasim, Maznah Mat; Ismail, Noriszura

2016-10-01

Regression analysis is the most popular statistical methods used to express the relationship between the variables of response with the covariates. The aim of this paper is to evaluate the factors that influence the number of car theft using Poisson regression model. This paper will focus on the number of car thefts that occurred in districts in Peninsular Malaysia. There are two groups of factor that have been considered, namely district descriptive factors and socio and demographic factors. The result of the study showed that Bumiputera composition, Chinese composition, Other ethnic composition, foreign migration, number of residence with the age between 25 to 64, number of employed person and number of unemployed person are the most influence factors that affect the car theft cases. These information are very useful for the law enforcement department, insurance company and car owners in order to reduce and limiting the car theft cases in Peninsular Malaysia.

Predictors of the number of under-five malnourished children in Bangladesh: application of the generalized poisson regression model

PubMed Central

2013-01-01

Background Malnutrition is one of the principal causes of child mortality in developing countries including Bangladesh. According to our knowledge, most of the available studies, that addressed the issue of malnutrition among under-five children, considered the categorical (dichotomous/polychotomous) outcome variables and applied logistic regression (binary/multinomial) to find their predictors. In this study malnutrition variable (i.e. outcome) is defined as the number of under-five malnourished children in a family, which is a non-negative count variable. The purposes of the study are (i) to demonstrate the applicability of the generalized Poisson regression (GPR) model as an alternative of other statistical methods and (ii) to find some predictors of this outcome variable. Methods The data is extracted from the Bangladesh Demographic and Health Survey (BDHS) 2007. Briefly, this survey employs a nationally representative sample which is based on a two-stage stratified sample of households. A total of 4,460 under-five children is analysed using various statistical techniques namely Chi-square test and GPR model. Results The GPR model (as compared to the standard Poisson regression and negative Binomial regression) is found to be justified to study the above-mentioned outcome variable because of its under-dispersion (variance < mean) property. Our study also identify several significant predictors of the outcome variable namely mother’s education, father’s education, wealth index, sanitation status, source of drinking water, and total number of children ever born to a woman. Conclusions Consistencies of our findings in light of many other studies suggest that the GPR model is an ideal alternative of other statistical models to analyse the number of under-five malnourished children in a family. Strategies based on significant predictors may improve the nutritional status of children in Bangladesh. PMID:23297699

An INAR(1) Negative Multinomial Regression Model for Longitudinal Count Data.

ERIC Educational Resources Information Center

Bockenholt, Ulf

1999-01-01

Discusses a regression model for the analysis of longitudinal count data in a panel study by adapting an integer-valued first-order autoregressive (INAR(1)) Poisson process to represent time-dependent correlation between counts. Derives a new negative multinomial distribution by combining INAR(1) representation with a random effects approach.…

Pick Your Poisson: A Tutorial on Analyzing Counts of Student Victimization Data

ERIC Educational Resources Information Center

Huang, Francis L.; Cornell, Dewey G.

2012-01-01

School violence research is often concerned with infrequently occurring events such as counts of the number of bullying incidents or fights a student may experience. Analyzing count data using ordinary least squares regression may produce improbable predicted values, and as a result of regression assumption violations, result in higher Type I…

[Prediction and spatial distribution of recruitment trees of natural secondary forest based on geographically weighted Poisson model].

PubMed

Zhang, Ling Yu; Liu, Zhao Gang

2017-12-01

Based on the data collected from 108 permanent plots of the forest resources survey in Maoershan Experimental Forest Farm during 2004-2016, this study investigated the spatial distribution of recruitment trees in natural secondary forest by global Poisson regression and geographically weighted Poisson regression (GWPR) with four bandwidths of 2.5, 5, 10 and 15 km. The simulation effects of the 5 regressions and the factors influencing the recruitment trees in stands were analyzed, a description was given to the spatial autocorrelation of the regression residuals on global and local levels using Moran's I. The results showed that the spatial distribution of the number of natural secondary forest recruitment was significantly influenced by stands and topographic factors, especially average DBH. The GWPR model with small scale (2.5 km) had high accuracy of model fitting, a large range of model parameter estimates was generated, and the localized spatial distribution effect of the model parameters was obtained. The GWPR model at small scale (2.5 and 5 km) had produced a small range of model residuals, and the stability of the model was improved. The global spatial auto-correlation of the GWPR model residual at the small scale (2.5 km) was the lowe-st, and the local spatial auto-correlation was significantly reduced, in which an ideal spatial distribution pattern of small clusters with different observations was formed. The local model at small scale (2.5 km) was much better than the global model in the simulation effect on the spatial distribution of recruitment tree number.

Modeling urban coastal flood severity from crowd-sourced flood reports using Poisson regression and Random Forest

NASA Astrophysics Data System (ADS)

Sadler, J. M.; Goodall, J. L.; Morsy, M. M.; Spencer, K.

2018-04-01

Sea level rise has already caused more frequent and severe coastal flooding and this trend will likely continue. Flood prediction is an essential part of a coastal city's capacity to adapt to and mitigate this growing problem. Complex coastal urban hydrological systems however, do not always lend themselves easily to physically-based flood prediction approaches. This paper presents a method for using a data-driven approach to estimate flood severity in an urban coastal setting using crowd-sourced data, a non-traditional but growing data source, along with environmental observation data. Two data-driven models, Poisson regression and Random Forest regression, are trained to predict the number of flood reports per storm event as a proxy for flood severity, given extensive environmental data (i.e., rainfall, tide, groundwater table level, and wind conditions) as input. The method is demonstrated using data from Norfolk, Virginia USA from September 2010 to October 2016. Quality-controlled, crowd-sourced street flooding reports ranging from 1 to 159 per storm event for 45 storm events are used to train and evaluate the models. Random Forest performed better than Poisson regression at predicting the number of flood reports and had a lower false negative rate. From the Random Forest model, total cumulative rainfall was by far the most dominant input variable in predicting flood severity, followed by low tide and lower low tide. These methods serve as a first step toward using data-driven methods for spatially and temporally detailed coastal urban flood prediction.

77 FR 13691 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

..., ocular hypertension, retinal detachment, cataracts and corneal scaring. In most cases, their eye... Application of Multiple Regression Analysis of a Poisson Process,'' Journal of American Statistical...

Method selection and adaptation for distributed monitoring of infectious diseases for syndromic surveillance.

PubMed

Xing, Jian; Burkom, Howard; Tokars, Jerome

2011-12-01

Automated surveillance systems require statistical methods to recognize increases in visit counts that might indicate an outbreak. In prior work we presented methods to enhance the sensitivity of C2, a commonly used time series method. In this study, we compared the enhanced C2 method with five regression models. We used emergency department chief complaint data from US CDC BioSense surveillance system, aggregated by city (total of 206 hospitals, 16 cities) during 5/2008-4/2009. Data for six syndromes (asthma, gastrointestinal, nausea and vomiting, rash, respiratory, and influenza-like illness) was used and was stratified by mean count (1-19, 20-49, ≥50 per day) into 14 syndrome-count categories. We compared the sensitivity for detecting single-day artificially-added increases in syndrome counts. Four modifications of the C2 time series method, and five regression models (two linear and three Poisson), were tested. A constant alert rate of 1% was used for all methods. Among the regression models tested, we found that a Poisson model controlling for the logarithm of total visits (i.e., visits both meeting and not meeting a syndrome definition), day of week, and 14-day time period was best. Among 14 syndrome-count categories, time series and regression methods produced approximately the same sensitivity (<5% difference) in 6; in six categories, the regression method had higher sensitivity (range 6-14% improvement), and in two categories the time series method had higher sensitivity. When automated data are aggregated to the city level, a Poisson regression model that controls for total visits produces the best overall sensitivity for detecting artificially added visit counts. This improvement was achieved without increasing the alert rate, which was held constant at 1% for all methods. These findings will improve our ability to detect outbreaks in automated surveillance system data. Published by Elsevier Inc.

Handling nonnormality and variance heterogeneity for quantitative sublethal toxicity tests.

PubMed

Ritz, Christian; Van der Vliet, Leana

2009-09-01

The advantages of using regression-based techniques to derive endpoints from environmental toxicity data are clear, and slowly, this superior analytical technique is gaining acceptance. As use of regression-based analysis becomes more widespread, some of the associated nuances and potential problems come into sharper focus. Looking at data sets that cover a broad spectrum of standard test species, we noticed that some model fits to data failed to meet two key assumptions-variance homogeneity and normality-that are necessary for correct statistical analysis via regression-based techniques. Failure to meet these assumptions often is caused by reduced variance at the concentrations showing severe adverse effects. Although commonly used with linear regression analysis, transformation of the response variable only is not appropriate when fitting data using nonlinear regression techniques. Through analysis of sample data sets, including Lemna minor, Eisenia andrei (terrestrial earthworm), and algae, we show that both the so-called Box-Cox transformation and use of the Poisson distribution can help to correct variance heterogeneity and nonnormality and so allow nonlinear regression analysis to be implemented. Both the Box-Cox transformation and the Poisson distribution can be readily implemented into existing protocols for statistical analysis. By correcting for nonnormality and variance heterogeneity, these two statistical tools can be used to encourage the transition to regression-based analysis and the depreciation of less-desirable and less-flexible analytical techniques, such as linear interpolation.

Marginalized zero-inflated Poisson models with missing covariates.

PubMed

Benecha, Habtamu K; Preisser, John S; Divaris, Kimon; Herring, Amy H; Das, Kalyan

2018-05-11

Unlike zero-inflated Poisson regression, marginalized zero-inflated Poisson (MZIP) models for counts with excess zeros provide estimates with direct interpretations for the overall effects of covariates on the marginal mean. In the presence of missing covariates, MZIP and many other count data models are ordinarily fitted using complete case analysis methods due to lack of appropriate statistical methods and software. This article presents an estimation method for MZIP models with missing covariates. The method, which is applicable to other missing data problems, is illustrated and compared with complete case analysis by using simulations and dental data on the caries preventive effects of a school-based fluoride mouthrinse program. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predictors for hospitalization and outpatient visits in patients with inflammatory bowel disease: results from the Swiss Inflammatory Bowel Disease Cohort Study.

PubMed

Sulz, Michael C; Siebert, Uwe; Arvandi, Marjan; Gothe, Raffaella M; Wurm, Johannes; von Känel, Roland; Vavricka, Stephan R; Meyenberger, Christa; Sagmeister, Markus

2013-07-01

Patients with inflammatory bowel disease (IBD) have a high resource consumption, with considerable costs for the healthcare system. In a system with sparse resources, treatment is influenced not only by clinical judgement but also by resource consumption. We aimed to determine the resource consumption of IBD patients and to identify its significant predictors. Data from the prospective Swiss Inflammatory Bowel Disease Cohort Study were analysed for the resource consumption endpoints hospitalization and outpatient consultations at enrolment [1187 patients; 41.1% ulcerative colitis (UC), 58.9% Crohn's disease (CD)] and at 1-year follow-up (794 patients). Predictors of interest were chosen through an expert panel and a review of the relevant literature. Logistic regressions were used for binary endpoints, and negative binomial regressions and zero-inflated Poisson regressions were used for count data. For CD, fistula, use of biologics and disease activity were significant predictors for hospitalization days (all P-values <0.001); age, sex, steroid therapy and biologics were significant predictors for the number of outpatient visits (P=0.0368, 0.023, 0.0002, 0.0003, respectively). For UC, biologics, C-reactive protein, smoke quitters, age and sex were significantly predictive for hospitalization days (P=0.0167, 0.0003, 0.0003, 0.0076 and 0.0175 respectively); disease activity and immunosuppressive therapy predicted the number of outpatient visits (P=0.0009 and 0.0017, respectively). The results of multivariate regressions are shown in detail. Several highly significant clinical predictors for resource consumption in IBD were identified that might be considered in medical decision-making. In terms of resource consumption and its predictors, CD and UC show a different behaviour.

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

Wong, Jonathan; Xu, Beibei; Moores Cancer Center, University of California San Diego, La Jolla, California

Purpose/Objective: Palliative radiation therapy represents an important treatment option among patients with advanced cancer, although research shows decreased use among older patients. This study evaluated age-related patterns of palliative radiation use among an elderly Medicare population. Methods and Materials: We identified 63,221 patients with metastatic lung, breast, prostate, or colorectal cancer diagnosed between 2000 and 2007 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Receipt of palliative radiation therapy was extracted from Medicare claims. Multivariate Poisson regression analysis determined residual age-related disparity in the receipt of palliative radiation therapy after controlling for confounding covariates including age-related differences inmore » patient and demographic covariates, length of life, and patient preferences for aggressive cancer therapy. Results: The use of radiation decreased steadily with increasing patient age. Forty-two percent of patients aged 66 to 69 received palliative radiation therapy. Rates of palliative radiation decreased to 38%, 32%, 24%, and 14% among patients aged 70 to 74, 75 to 79, 80 to 84, and over 85, respectively. Multivariate analysis found that confounding covariates attenuated these findings, although the decreased relative rate of palliative radiation therapy among the elderly remained clinically and statistically significant. On multivariate analysis, compared to patients 66 to 69 years old, those aged 70 to 74, 75 to 79, 80 to 84, and over 85 had a 7%, 15%, 25%, and 44% decreased rate of receiving palliative radiation, respectively (all P<.0001). Conclusions: Age disparity with palliative radiation therapy exists among older cancer patients. Further research should strive to identify barriers to palliative radiation among the elderly, and extra effort should be made to give older patients the opportunity to receive this quality of life-enhancing treatment at the end of life.« less

Longitudinal Association between Periodontitis and Development of Diabetes Running title: Periodontitis and Diabetes Development.

PubMed

Joshipura, Kaumudi J; Muñoz-Torres, Francisco J; Dye, Bruce A; Leroux, Brian G; Ramírez-Vick, Margarita; Pérez, Cynthia M

2018-04-18

Clinical trials have shown very modest short-term improvements in glycemic control among participants with diabetes after periodontitis treatment. Few longitudinal studies suggest that periodontitis may be related to prediabetes/diabetes risk. We evaluated 1,206 diabetes free participants in the San Juan Overweight Adults Longitudinal Study (SOALS) and 941 with complete 3-year follow-up data were included. The National Health and Nutrition Examination Survey (NHANES) methods were used to assess periodontitis. Diabetes and prediabetes were classified using American Diabetes Association cutoffs for fasting and 2-hour post-load glucose and HbA1c. We used Poisson regression adjusting for baseline age, gender, smoking, education, family history of diabetes, physical activity, waist circumference, and alcohol intake. Over the 3-year follow-up, 69 (7.3%) of the 941 individuals developed type 2 diabetes, and 142 (34.9%) of the 407 with normal glycemia at baseline developed prediabetes. In multivariable models, greater mean pocket depth and mean attachment loss at baseline were associated with lower risk of developing prediabetes/diabetes over the follow-up (IRR=0.81; 95% CI: 0.67-0.99, and IRR=0.86; 95% CI: 0.74-0.99, respectively). Increase in periodontal attachment loss from baseline to follow-up was associated with higher prediabetes/diabetes risk (multivariate IRR=1.25; 95% CI: 1.09-1.42), and increase in pocket depth was associated with >20% fasting glucose increase (multivariate IRR=1.43; 95% CI: 1.14-1.79). The inverse associations persisted after additionally adjusting for baseline income, sugar-sweetened beverages, number of teeth, oral hygiene, glycemia, or previous periodontal therapy. There is no association between periodontitis and risk of prediabetes/diabetes in this longitudinal study. Copyright © 2018 Elsevier B.V. All rights reserved.

Using multi-year national survey cohorts for period estimates: an application of weighted discrete Poisson regression for assessing annual national mortality in US adults with and without diabetes, 2000-2006.

PubMed

Cheng, Yiling J; Gregg, Edward W; Rolka, Deborah B; Thompson, Theodore J

2016-12-15

Monitoring national mortality among persons with a disease is important to guide and evaluate progress in disease control and prevention. However, a method to estimate nationally representative annual mortality among persons with and without diabetes in the United States does not currently exist. The aim of this study is to demonstrate use of weighted discrete Poisson regression on national survey mortality follow-up data to estimate annual mortality rates among adults with diabetes. To estimate mortality among US adults with diabetes, we applied a weighted discrete time-to-event Poisson regression approach with post-stratification adjustment to national survey data. Adult participants aged 18 or older with and without diabetes in the National Health Interview Survey 1997-2004 were followed up through 2006 for mortality status. We estimated mortality among all US adults, and by self-reported diabetes status at baseline. The time-varying covariates used were age and calendar year. Mortality among all US adults was validated using direct estimates from the National Vital Statistics System (NVSS). Using our approach, annual all-cause mortality among all US adults ranged from 8.8 deaths per 1,000 person-years (95% confidence interval [CI]: 8.0, 9.6) in year 2000 to 7.9 (95% CI: 7.6, 8.3) in year 2006. By comparison, the NVSS estimates ranged from 8.6 to 7.9 (correlation = 0.94). All-cause mortality among persons with diabetes decreased from 35.7 (95% CI: 28.4, 42.9) in 2000 to 31.8 (95% CI: 28.5, 35.1) in 2006. After adjusting for age, sex, and race/ethnicity, persons with diabetes had 2.1 (95% CI: 2.01, 2.26) times the risk of death of those without diabetes. Period-specific national mortality can be estimated for people with and without a chronic condition using national surveys with mortality follow-up and a discrete time-to-event Poisson regression approach with post-stratification adjustment.

Bayesian Estimation of Multivariate Latent Regression Models: Gauss versus Laplace

ERIC Educational Resources Information Center

Culpepper, Steven Andrew; Park, Trevor

2017-01-01

A latent multivariate regression model is developed that employs a generalized asymmetric Laplace (GAL) prior distribution for regression coefficients. The model is designed for high-dimensional applications where an approximate sparsity condition is satisfied, such that many regression coefficients are near zero after accounting for all the model…

Multivariate Regression Analysis and Slaughter Livestock,

DTIC Science & Technology

AGRICULTURE, *ECONOMICS), (*MEAT, PRODUCTION), MULTIVARIATE ANALYSIS, REGRESSION ANALYSIS , ANIMALS, WEIGHT, COSTS, PREDICTIONS, STABILITY, MATHEMATICAL MODELS, STORAGE, BEEF, PORK, FOOD, STATISTICAL DATA, ACCURACY

Multivariate Autoregressive Modeling and Granger Causality Analysis of Multiple Spike Trains

PubMed Central

Krumin, Michael; Shoham, Shy

2010-01-01

Recent years have seen the emergence of microelectrode arrays and optical methods allowing simultaneous recording of spiking activity from populations of neurons in various parts of the nervous system. The analysis of multiple neural spike train data could benefit significantly from existing methods for multivariate time-series analysis which have proven to be very powerful in the modeling and analysis of continuous neural signals like EEG signals. However, those methods have not generally been well adapted to point processes. Here, we use our recent results on correlation distortions in multivariate Linear-Nonlinear-Poisson spiking neuron models to derive generalized Yule-Walker-type equations for fitting ‘‘hidden” Multivariate Autoregressive models. We use this new framework to perform Granger causality analysis in order to extract the directed information flow pattern in networks of simulated spiking neurons. We discuss the relative merits and limitations of the new method. PMID:20454705

Association of stressful life events with accelerated bone loss in older men: the Osteoporotic Fractures in Men (MrOS) Study

PubMed Central

Fink, Howard A.; Kuskowski, Michael A.; Cauley, Jane A.; Taylor, Brent C.; Schousboe, John T.; Cawthon, Peggy M.; Ensrud, Kristine E.

2015-01-01

Purpose/Introduction Prior studies suggest that stressful life events may increase adverse health outcomes, including falls and possibly fractures. The current study builds on these findings and examines whether stressful life events are associated with increased bone loss. Methods 4388 men aged ≥65 years in the Osteoporotic Fractures in Men study completed total hip bone mineral density (BMD) measures at baseline and visit 2, approximately 4.6 years later, and self-reported stressful life events data mid-way between baseline and visit 2, and at visit 2. We used linear regression to model the association of stressful life events with concurrent annualized total hip BMD loss, and log binomial regression or Poisson regression to model risk of concurrent accelerated BMD loss (>1 SD more than mean annualized change). Results 75.3% of men reported ≥1 type of stressful life event, including 43.3% with ≥2 types of stressful life events. Mean annualized BMD loss was −0.36% (SD 0.88) and 13.9% of men were categorized with accelerated BMD loss (about 5.7% or more total loss). Rate of annualized BMD loss increased with the number of types of stressful life events after adjustment for age (p<0.001), but not after multivariable adjustment (p=0.07). Multivariable-adjusted risk of accelerated BMD loss increased with the number of types of stressful life events (RR, 1.10 [95% CI, 1.04–1.16]) per increase of 1 type of stressful life event). Fracture risk was not significantly different between stressful life event-accelerated bone loss subgroups (p=0.08). Conclusions In these older men, stressful life events were associated with a small, dose-related increase in risk of concurrent accelerated hip bone loss. Low frequency of fractures limited assessment of whether rapid bone loss mediates any association of stressful life events with incident fractures. Future studies are needed to confirm these findings and to investigate the mechanism that may underlie this association. PMID:25169421

Analyzing Seasonal Variations in Suicide With Fourier Poisson Time-Series Regression: A Registry-Based Study From Norway, 1969-2007.

PubMed

Bramness, Jørgen G; Walby, Fredrik A; Morken, Gunnar; Røislien, Jo

2015-08-01

Seasonal variation in the number of suicides has long been acknowledged. It has been suggested that this seasonality has declined in recent years, but studies have generally used statistical methods incapable of confirming this. We examined all suicides occurring in Norway during 1969-2007 (more than 20,000 suicides in total) to establish whether seasonality decreased over time. Fitting of additive Fourier Poisson time-series regression models allowed for formal testing of a possible linear decrease in seasonality, or a reduction at a specific point in time, while adjusting for a possible smooth nonlinear long-term change without having to categorize time into discrete yearly units. The models were compared using Akaike's Information Criterion and analysis of variance. A model with a seasonal pattern was significantly superior to a model without one. There was a reduction in seasonality during the period. Both the model assuming a linear decrease in seasonality and the model assuming a change at a specific point in time were both superior to a model assuming constant seasonality, thus confirming by formal statistical testing that the magnitude of the seasonality in suicides has diminished. The additive Fourier Poisson time-series regression model would also be useful for studying other temporal phenomena with seasonal components. © 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.

Factors Associated with Dengue Mortality in Latin America and the Caribbean, 1995–2009: An Ecological Study

PubMed Central

Díaz-Quijano, Fredi Alexander; Waldman, Eliseu Alves

2012-01-01

In this study, we aimed to estimate the effect that environmental, demographic, and socioeconomic factors have on dengue mortality in Latin America and the Caribbean. To that end, we conducted an observational ecological study, analyzing data collected between 1995 and 2009. Dengue mortality rates were highest in the Caribbean (Spanish-speaking and non-Spanish-speaking). Multivariate analysis through Poisson regression revealed that the following factors were independently associated with dengue mortality: time since identification of endemicity (adjusted rate ratio [aRR] = 3.2 [for each 10 years]); annual rainfall (aRR = 1.5 [for each 103 L/m2]); population density (aRR = 2.1 and 3.2 for 20–120 inhabitants/km2 and > 120 inhabitants/km2, respectively); Human Development Index > 0.83 (aRR = 0.4); and circulation of the dengue 2 serotype (aRR = 1.7). These results highlight the important role that environmental, demographic, socioeconomic, and biological factors have played in increasing the severity of dengue in recent decades. PMID:22302870

Understanding prescription adherence: Pharmacy claims data from the Contraceptive CHOICE Project

PubMed Central

Pittman, Meredith E.; Secura, Gina M.; Allsworth, Jenifer E.; Homco, Juell B.; Madden, Tessa; Peipert, Jeffrey F.

2010-01-01

BACKGROUND We examined prescription adherence rates by contraceptive method among women who used oral contraceptive pills (OCP), transdermal patch, or vaginal ring. STUDY DESIGN Women in the St. Louis area were provided their choice of OCP, patch, or ring at no cost and followed for 18 months. Time between monthly refills was obtained from pharmacy data and analyzed as a marker of adherence. Risk factors for initial nonadherence were estimated using Cox proportional hazards; predictors for repeated nonadherence were analyzed using Poisson regression with robust error variance. RESULTS Overall, 619 participants filled 6,435 contraceptive prescriptions with a median of 10 refills per participant. Only 30% of women (n=187) obtained all refills on time. In the time-to-failure analysis, use of vaginal ring and increased parity were predictors of early nonadherence (p<0.05). In the multivariable analysis, use of the vaginal ring and history of abortion were risk factors for repeated nonadherence (p<0.01). CONCLUSIONS Even with financial barriers removed, pharmacy data show that many women inconsistently refill their contraception and may be at risk for unintended pregnancy. PMID:21397092

Novice drivers' risky driving behavior, risk perception, and crash risk: findings from the DRIVE study.

PubMed

Ivers, Rebecca; Senserrick, Teresa; Boufous, Soufiane; Stevenson, Mark; Chen, Huei-Yang; Woodward, Mark; Norton, Robyn

2009-09-01

We explored the risky driving behaviors and risk perceptions of a cohort of young novice drivers and sought to determine their associations with crash risk. Provisional drivers aged 17 to 24 (n = 20 822) completed a detailed questionnaire that included measures of risk perception and behaviors; 2 years following recruitment, survey data were linked to licensing and police-reported crash data. Poisson regression models that adjusted for multiple confounders were created to explore crash risk. High scores on questionnaire items for risky driving were associated with a 50% increased crash risk (adjusted relative risk = 1.51; 95% confidence interval = 1.25, 1.81). High scores for risk perception (poorer perceptions of safety) were also associated with increased crash risk in univariate and multivariate models; however, significance was not sustained after adjustment for risky driving. The overrepresentation of youths in crashes involving casualties is a significant public health issue. Risky driving behavior is strongly linked to crash risk among young drivers and overrides the importance of risk perceptions. Systemwide intervention, including licensing reform, is warranted.

Total and central obesity in elderly associated with a marker of undernutrition in early life - sitting height-to-stature ratio: A nutritional paradox.

PubMed

Silveira, Erika Aparecida; Ferreira, Carla Cristina da Conceição; Pagotto, Valéria; Santos, Annelisa Silva E Alves de Carvalho; Velasquez-Melendez, Gustavo

2017-05-06

The purpose of this study was to investigate whether sitting height-to-stature ratio (SHSR) is associated with total and central obesity in the elderly. This was a cross-sectional study with 133 noninstitutionalized elderly. High SHSR (≥ 1SD above the mean) was used as a marker of undernutrition (MU) in early life. Poisson's multiple regression was used to determine the association between variables. The prevalence of high SHSR was 21.0%, total obesity 43.6% and central obesity 50.4%. Elderly with high SHSR presented a statistically significant association with total obesity (PR 1.50; 95% CI 1.04-2.18) and central obesity (PR 1.42; 95% CI 1.03-1.95) after adjustment for sex, age, educational level and income in the multivariate analysis. The occurrence of total and central obesity in the elderly was associated with a MU in early life. This result indicates that nutritional deficiencies in childhood may increase the risk of obesity in the elderly, a nutritional paradox. © 2017 Wiley Periodicals, Inc.

[Determinants of dental services utilization by adults: a population-based study in Florianópolis, Santa Catarina State, Brazil].

PubMed

Miranda, Camila Dal-Bó Coradini; Peres, Marco Aurélio

2013-11-01

This study aimed to estimate the prevalence of dental services utilization by adults and to identify associated socioeconomic, demographic, behavioral, and self-awareness factors. A cross-sectional population-based study was conducted with adults living in the urban area of Florianópolis, Santa Catarina State, Brazil, in 2009. Associations were tested between use of dental services and predisposing, enabling, and needs-based variables. Multivariate analysis was conducted using Poisson regression with estimates of prevalence ratios and was stratified by place of last dental appointment. Prevalence of dental services utilization was 66% (95%CI: 62.9-70.7). Dental visits were 20% more frequent among women and 72% more frequent among individuals with more schooling (the latter in both public and private dental services). Individuals with private dental plans used dental services 13% more than those without. Schooling was the most important variable in predicting utilization. The study's results show the importance of monitoring associated factors in order to promote more equitable use of dental services.

Dental pain, use of dental services and oral health-related quality of life in southern Brazil.

PubMed

Cavalheiro, Charles Henrique; Abegg, Claides; Fontanive, Victor Nascimento; Davoglio, Rosane Silvia

2016-08-18

This study aimed at assessing the relationship between dental pain and the reason for using dental services and oral health quality of life in people aged 50 to 74 years in southern Brazil. A cross-sectional population-based study was conducted with 720 individuals aged 50 to 74 years, living in three health districts in the city of Porto Alegre. Dental impacts on daily life and sociodemographic data were assessed using structured interviews. The Oral Impacts on Daily Performance - OIDP instrument was used to measure oral impacts. The information was analyzed by Poisson regression with robust variance adjustment, taking into account cluster sampling. Dental pain was present in 32.5% of those reporting an oral impact on their daily activities. Dental pain most frequently affected talking (37.6%), cleaning teeth and gums (37.0%) and enjoying the companionship of people (36.5%). After adjustments to the multivariate analysis, the reason for dental visits due to dental pain was found to have a high impact on daily activities [RP 1.68 (1.11 - 2.54].

Excessive consumption of dietary supplements among professionals working in gyms in Pelotas, Rio Grande do Sul State, Brazil, 2012.

PubMed

Cava, Tatiane Araujo; Madruga, Samanta Winck; Teixeira, Gesiane Dias Trindade; Reichert, Felipe Fossati; Silva, Marcelo Cozzensa da; Rombaldi, Airton José

2017-01-01

to investigate the prevalence and factors associated with excessive consumption of dietary supplements among professionals working at gyms in Pelotas, Rio Grande do Sul State, Brazil. this is a cross-sectional study with all local fitness professionals identified in 2012; excessive consumption of dietary supplements was defined as the use of three or more types of supplements simultaneously; multivariate analysis was carried out using Poisson regression with robust variance. 497 professionals were interviewed; the prevalence of excessive consumption of dietary supplements was 10.5% (95%CI 7.9;13.5); there was association with the male sex (PR=3.2; 95%CI 1.6;6.7) and with length of time of dietary supplement consumption ≥4 years when compared to <1 year (PR=2.8; 95%CI 1.7;4.7); lower consumption was found among professionals with higher levels of education, regardless of whether they had a degree in physical education or not (p=0,007). prevalence of excessive consumption of dietary supplements can be considered high and was associated with sociodemographic variables.

Control of diabetes and fibrinogen levels as well as improvement in health care might delay low cognitive performance in societies aging progressively.

PubMed

Lopes, Daniele Almeida; Moraes, Suzana Alves de; Freitas, Isabel Cristina Martins de

2015-01-01

To know the prevalence and factors associated to low cognitive performance in a representative sample of the adult population in a society aging progressively. Cross-sectional population-based study carried out in a three-stage sampling: 81 census tracts (primary sampling unity) were randomly selected, followed by 1,672 households and 2,471 participants (weighted sample) corresponding to the second and third stages, respectively. The outcome prevalence was calculated according sociodemographic, behavioral and health related variables. Crude and adjusted prevalence ratios were estimated using Poisson regression. The prevalence of low cognitive performance was high, mainly among females, and indicated linear trends into categories of age, schooling, income, plasma fibrinogen and self-reported health status. In multivariate models, gender, diabetes, fibrinogen and self-reported health status presented positive associations, while schooling, employment and sitting time presented negative associations with the outcome. Interventions related to diabetes and fibrinogen levels control as well as improvement in health care might delay low cognitive performance in societies aging progressively as such the study population.

[Low consumption of fruit, vegetables and greens: associated factors among the elderly in a Midwest Brazilian city].

PubMed

Silveira, Erika Aparecida; Martins, Bruna Bittar; de Abreu, Laísa Ribeiro Silva; Cardoso, Camila Kellen de Souza

2015-12-01

The scope of the study was to evaluate the prevalence of daily consumption of fruit, vegetables and greens by the elderly and its association with sociodemographic, lifestyle, morbidity and hospitalization variables. The study was part of the multiple-stage sampling cross-sectional research entitled the Goiânia Elderly Project (Projeto Idosos Goiânia). 416 elderly people were interviewed in their homes. Multivariate analysis was conducted using Poisson regression to analyze statistical associations. P values of <.05 were considered statistically significant. Daily consumption of fruit, vegetables and greens was 16.6%: fruit accounted for 44%, vegetables 39.7% and greens 32.5%. Factors statistically associated with daily consumption of fruits and vegetables were female sex, age between 70 and 79, higher education level, social class A/B and C, alcohol consumption, use of sweeteners, regular physical activity during leisure time, abdominal obesity and hospitalization. Public policies to promote health should develop strategies that encourage adequate intake of fruit, vegetables and greens among the elderly, since regular consumption of same can improve quality of life and prevent/control diseases.

Brazilian abortion law: the opinion of judges and prosecutors.

PubMed

Duarte, Graciana Alves; Osis, Maria José Duarte; Faúndes, Anibal; Sousa, Maria Helena de

2010-06-01

To analyze the opinion of judges and prosecutors concerning Brazilian abortion law and situations in which the abortion should be allowed. A cross-sectional study was performed with 1,493 judges and 2,614 prosecutors in Brazil between 2005 and 2006. Participants completed a structured questionnaire approaching sociodemographic characteristics, opinions about abortion law, and circumstances in which abortion is considered lawful. Bivariate and multivariate analyses of data were carried out through Poisson regression. The majority of participants (78%) found that the circumstances in which abortion is considered lawful should be broadened, or even that abortion should not be criminalized. The highest rates of pro-abortion opinions resulted from: risk to the life of the mother (84%), anencephaly (83%), severe congenital malformation of fetus (82%), and pregnancy resulting from rape (82%). Variables related to religion were strongly associated to the opinion of participants. There is a trend in considering the need of changing the current abortion law, in the sense of widening the circumstances in which abortion is considered lawful, or even toward decriminalizing abortion, regardless of the circumstances in which it takes place.

Reproductive health preventive screening among clinic vs. over-the-counter oral contraceptive users

PubMed Central

Hopkins, Kristine; Grossman, Daniel; White, Kari; Amastae, Jon; Potter, Joseph E.

2015-01-01

Background Interest is growing in moving oral contraceptives over-the-counter (OTC), although concerns exist about whether women would continue to get preventive health screening. Study Design We recruited cohorts of US-resident women who obtained oral contraceptives from US family planning clinics (n=532) and OTC from pharmacies in Mexico (n=514) and interviewed them four times over 9 months. Based on self-reports of having a Pap smear within 3 years or ever having had a pelvic exam, clinical breast exam and testing for sexually transmitted infections (STIs), we assessed the prevalence of preventive screening using Poisson regression models. Results The prevalence of screening was high for both groups (>88% for Pap smear, pelvic exam and clinical breast exam and >71% for STI screening), while the prevalence ratios for screening were higher for clinic users, even after multivariable adjustment. Conclusions Results suggest that most women would obtain reproductive health preventive screening if oral contraceptives were available OTC, and also highlight the need to improve access to preventive screening for all low-income women. PMID:22520645

Association between educational level and access to safe abortion in a Brazilian population.

PubMed

Dias, Tábata Z; Passini, Renato; Duarte, Graciana A; Sousa, Maria H; Faúndes, Aníbal

2015-03-01

To evaluate sociodemographic factors associated with induced abortion. As part of a cross-sectional, descriptive study, 15 800 civil servants from Campinas, Brazil, were invited to complete a self-administered questionnaire about absolutely unwanted pregnancies in January 2010. Bivariate analysis and multivariate Poisson regression analysis were used to explore the associations between induced abortion and sociodemographic characteristics. Overall, 1660 questionnaires were returned. Unwanted pregnancy was reported by 296 (17.8%) respondents, of whom 165 (55.7%) resorted to abortion. Multiple regression analysis showed that college education was the only variable associated with an increased chance of abortion. Among 157 participants who answered questions about the abortion procedure, 97 (61.8%) reported that it had been performed by a physician. Following abortion, 35 (22.9%) of 153 reported that medical care was required and 26 (16.6%) of 157 reported hospitalization, principally those with a lower level of education and those whose abortion had been performed by a nonphysician. Compared with women with a college education, those with a lower education level were less likely to terminate an absolutely unwanted pregnancy and to have an abortion performed by a physician, and they were more likely to have complications. These findings confirm the social inequalities associated with abortion in Brazil. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Effect of latitude on the rate of change in incidence of Lyme disease in the United States

PubMed Central

Tuite, Ashleigh R.; Greer, Amy L.

2013-01-01

Background Tick-borne illnesses represent an important class of emerging zoonoses, with climate change projected to increase the geographic range within which tick-borne zoonoses might become endemic. We evaluated the impact of latitude on the rate of change in the incidence of Lyme disease in the United States, using publicly available data. Methods We estimated state-level year-on-year incidence rate ratios (IRRs) for Lyme disease for the period 1993 to 2007 using Poisson regression methods. We evaluated between-state heterogeneity in IRRs using a random-effects meta-analytic approach. We identified state-level characteristics associated with increasing incidence using random-effects meta-regression. Results The incidence of Lyme disease in the US increased by about 80% between 1993 and 2007 (IRR per year 1.049, 95% CI [confidence interval] 1.048 to 1.050). There was marked between-state heterogeneity in the average incidence of Lyme disease, ranging from 0.008 per 100 000 person-years in Colorado to 75 per 100 000 in Connecticut, and significant between-state heterogeneity in temporal trends (p < 0.001). In multivariable meta-regression models, increasing incidence showed a linear association with state latitude and population density. These 2 factors explained 27% of the between-state variation in IRRs. No independent association was identified for other state-level characteristics. Interpretation Lyme disease incidence increased in the US as a whole during the study period, but the changes were not uniform. Marked increases were identified in northern-most states, whereas southern states experienced stable or declining rates of Lyme disease. PMID:25077101

Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses.

PubMed

Faul, Franz; Erdfelder, Edgar; Buchner, Axel; Lang, Albert-Georg

2009-11-01

G*Power is a free power analysis program for a variety of statistical tests. We present extensions and improvements of the version introduced by Faul, Erdfelder, Lang, and Buchner (2007) in the domain of correlation and regression analyses. In the new version, we have added procedures to analyze the power of tests based on (1) single-sample tetrachoric correlations, (2) comparisons of dependent correlations, (3) bivariate linear regression, (4) multiple linear regression based on the random predictor model, (5) logistic regression, and (6) Poisson regression. We describe these new features and provide a brief introduction to their scope and handling.

Semiparametric bivariate zero-inflated Poisson models with application to studies of abundance for multiple species

USGS Publications Warehouse

Arab, Ali; Holan, Scott H.; Wikle, Christopher K.; Wildhaber, Mark L.

2012-01-01

Ecological studies involving counts of abundance, presence–absence or occupancy rates often produce data having a substantial proportion of zeros. Furthermore, these types of processes are typically multivariate and only adequately described by complex nonlinear relationships involving externally measured covariates. Ignoring these aspects of the data and implementing standard approaches can lead to models that fail to provide adequate scientific understanding of the underlying ecological processes, possibly resulting in a loss of inferential power. One method of dealing with data having excess zeros is to consider the class of univariate zero-inflated generalized linear models. However, this class of models fails to address the multivariate and nonlinear aspects associated with the data usually encountered in practice. Therefore, we propose a semiparametric bivariate zero-inflated Poisson model that takes into account both of these data attributes. The general modeling framework is hierarchical Bayes and is suitable for a broad range of applications. We demonstrate the effectiveness of our model through a motivating example on modeling catch per unit area for multiple species using data from the Missouri River Benthic Fishes Study, implemented by the United States Geological Survey.

Hierarchy of temporal responses of multivariate self-excited epidemic processes

NASA Astrophysics Data System (ADS)

Saichev, Alexander; Maillart, Thomas; Sornette, Didier

2013-04-01

Many natural and social systems are characterized by bursty dynamics, for which past events trigger future activity. These systems can be modelled by so-called self-excited Hawkes conditional Poisson processes. It is generally assumed that all events have similar triggering abilities. However, some systems exhibit heterogeneity and clusters with possibly different intra- and inter-triggering, which can be accounted for by generalization into the "multivariate" self-excited Hawkes conditional Poisson processes. We develop the general formalism of the multivariate moment generating function for the cumulative number of first-generation and of all generation events triggered by a given mother event (the "shock") as a function of the current time t. This corresponds to studying the response function of the process. A variety of different systems have been analyzed. In particular, for systems in which triggering between events of different types proceeds through a one-dimension directed or symmetric chain of influence in type space, we report a novel hierarchy of intermediate asymptotic power law decays ˜ 1/ t 1-( m+1) θ of the rate of triggered events as a function of the distance m of the events to the initial shock in the type space, where 0 < θ < 1 for the relevant long-memory processes characterizing many natural and social systems. The richness of the generated time dynamics comes from the cascades of intermediate events of possibly different kinds, unfolding via random changes of types genealogy.

Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

NASA Astrophysics Data System (ADS)

Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

2018-03-01

This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).

Correlative and multivariate analysis of increased radon concentration in underground laboratory.

PubMed

Maletić, Dimitrije M; Udovičić, Vladimir I; Banjanac, Radomir M; Joković, Dejan R; Dragić, Aleksandar L; Veselinović, Nikola B; Filipović, Jelena

2014-11-01

The results of analysis using correlative and multivariate methods, as developed for data analysis in high-energy physics and implemented in the Toolkit for Multivariate Analysis software package, of the relations of the variation of increased radon concentration with climate variables in shallow underground laboratory is presented. Multivariate regression analysis identified a number of multivariate methods which can give a good evaluation of increased radon concentrations based on climate variables. The use of the multivariate regression methods will enable the investigation of the relations of specific climate variable with increased radon concentrations by analysis of regression methods resulting in 'mapped' underlying functional behaviour of radon concentrations depending on a wide spectrum of climate variables. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quantification of Covariance in Tropical Cyclone Activity across Teleconnected Basins

NASA Astrophysics Data System (ADS)

Tolwinski-Ward, S. E.; Wang, D.

2015-12-01

Rigorous statistical quantification of natural hazard covariance across regions has important implications for risk management, and is also of fundamental scientific interest. We present a multivariate Bayesian Poisson regression model for inferring the covariance in tropical cyclone (TC) counts across multiple ocean basins and across Saffir-Simpson intensity categories. Such covariability results from the influence of large-scale modes of climate variability on local environments that can alternately suppress or enhance TC genesis and intensification, and our model also simultaneously quantifies the covariance of TC counts with various climatic modes in order to deduce the source of inter-basin TC covariability. The model explicitly treats the time-dependent uncertainty in observed maximum sustained wind data, and hence the nominal intensity category of each TC. Differences in annual TC counts as measured by different agencies are also formally addressed. The probabilistic output of the model can be probed for probabilistic answers to such questions as: - Does the relationship between different categories of TCs differ statistically by basin? - Which climatic predictors have significant relationships with TC activity in each basin? - Are the relationships between counts in different basins conditionally independent given the climatic predictors, or are there other factors at play affecting inter-basin covariability? - How can a portfolio of insured property be optimized across space to minimize risk? Although we present results of our model applied to TCs, the framework is generalizable to covariance estimation between multivariate counts of natural hazards across regions and/or across peril types.

Waist:height ratio, waist circumference and metabolic syndrome abnormalities in Colombian schooled adolescents: a multivariate analysis considering located adiposity.

PubMed

Agredo-Zúñiga, Ricardo Antonio; Aguilar-de Plata, Cecilia; Suárez-Ortegón, Milton Fabian

2015-09-14

Very few large studies in Latin America have evaluated the association between waist:height ratio (W-HtR) and cardiometabolic risk in children and adolescents. Further, multivariable analyses verifying the independence of located subcutaneous fat have not been conducted so far. The aim of this study was to evaluate the associations of W-HtR and waist circumference (WC) with metabolic syndrome abnormalities and high LDL-cholesterol levels in schooled adolescents before and after adjusting for trunk skinfolds and BMI. The sample consisted of 831 boys and 841 girls aged 10-17 years. Biochemical, blood pressure and anthropometrical variables were measured. Age- and sex-specific quartiles of W-HtR and WC were used in Poisson regression models to evaluate the associations. High WC values (highest quartile v. quartiles 1-3) were associated with high TAG levels in both sexes (prevalence ratio, boys: 2·57 (95 % CI 1·91, 3·44); girls: 1·92 (95 % CI 1·49, 2·47); P0·05). High W-HtR (highest quartile v. quartiles 1-3) was only independently associated with high TAG in female adolescents (1·99 (95 % CI 1·55, 2·56); P<0·05). In conclusion, WC showed better association with cardiometabolic risk than W-HtR in the children of this study. This observation does not support W-HtR as a relevant adiposity marker for cardiovascular and metabolic risk in adolescence.

Oral Health-Related Quality of Life in institutionalized elderly in Barcelona (Spain)

PubMed Central

Pérez, Glòria; de Lima, Kenio C.; Casals-Peidro, Elías; Borrell, Carme

2013-01-01

Objective: The objective of this study is to describe the oral health status and the factors associated with oral health-related quality of life (OHRQoL) in people aged 65 and older institutionalized in Barcelona in 2009. Study Design: Cross sectional study in 194 elderly. The dependent variable was poor OHRQoL, according to the Geriatric Oral Health Assessment Index (GOHAI). The independent variables were socio-demographic data, last dental visit, subjective and objective oral health status. Robust Poisson regression analysis was used to determine the factors associated with OHRQoL as well as the strengths of association (Prevalence Ratios with respective confidence intervals at 95%). Results: According to GOHAI, 94 women (68.1%) and 36 men (64.3%) had poor OHRQoL. The average DMFT index (number of decayed, missing and filled teeth) was 22.8, with mean 10.2 remaining teeth. According to the Community Periodontal Index only 1.9% were healthy. 33.8% of the sample (35.5% of women and 30.4% of men) presented edentulism, 54.2% needed upper dental prostheses (51.1% of women and 60.7% of men) and 64.7% needed lower ones (61.6% of women and 71.4% of men). Only 7.2% had visited a dentist in the past year (8.8% of women and 3.6% of men). After fitting several multivariate adjusted robust Poisson regression models, poor OHRQoL was found to be associated to self-reporting problems with teeth or gums, self-reporting poor opinion about teeth/gums/denture and also associated to functional edentulism, needing upper denture, but not to socio-demographic factors or time since last dental visit. Conclusions: The study population has poor objective oral health. A high percentage has poor OHRQoL associated to subjective and objective oral health conditions. Dental care is required and these services should be included in the Spanish National Health System. Key words:Oral health, homes for the aged, elderly, self-assessment, quality of life, geriatric oral health assessment index (GOHAI). PMID:23385501

Improvements in implant dentistry over the last decade: comparison of survival and complication rates in older and newer publications.

PubMed

Pjetursson, Bjarni E; Asgeirsson, Asgeir G; Zwahlen, Marcel; Sailer, Irena

2014-01-01

The objective of this systematic review was to assess and compare the survival and complication rates of implant-supported prostheses reported in studies published in the year 2000 and before, to those reported in studies published after the year 2000. Three electronic searches complemented by manual searching were conducted to identify 139 prospective and retrospective studies on implant-supported prostheses. The included studies were divided in two groups: a group of 31 older studies published in the year 2000 or before, and a group of 108 newer studies published after the year 2000. Survival and complication rates were calculated using Poisson regression models, and multivariable robust Poisson regression was used to formally compare the outcomes of older and newer studies. The 5-year survival rate of implant-supported prostheses was significantly increased in newer studies compared with older studies. The overall survival rate increased from 93.5% to 97.1%. The survival rate for cemented prostheses increased from 95.2% to 97.9%; for screw-retained reconstruction, from 77.6% to 96.8%; for implant-supported single crowns, from 92.6% to 97.2%; and for implant-supported fixed dental prostheses (FDPs), from 93.5% to 96.4%. The incidence of esthetic complications decreased in more recent studies compared with older ones, but the incidence of biologic complications was similar. The results for technical complications were inconsistent. There was a significant reduction in abutment or screw loosening by implant-supported FDPs. On the other hand, the total number of technical complications and the incidence of fracture of the veneering material was significantly increased in the newer studies. To explain the increased rate of complications, minor complications are probably reported in more detail in the newer publications. The results of the present systematic review demonstrated a positive learning curve in implant dentistry, represented in higher survival rates and lower complication rates reported in more recent clinical studies. The incidence of esthetic, biologic, and technical complications, however, is still high. Hence, it is important to identify these complications and their etiology to make implant treatment even more predictable in the future.

Correlates of current transactional sex among a sample of female exotic dancers in Baltimore, MD.

PubMed

Reuben, Jacqueline; Serio-Chapman, Chris; Welsh, Christopher; Matens, Richard; Sherman, Susan G

2011-04-01

Transactional sex work, broadly defined as the exchange of money, drugs, or goods for sexual services, occurs in a wide range of environments. There is a large body of research characterizing the risks and harms associated with street- and venue-based sex work, but there is a dearth of research characterizing the risk associated with the environment of exotic dance clubs. The current study aimed to: (1) characterize the nature of female exotic dancers' sex- and drug-related risk behaviors, (2) to examine the role of the club environment in these behaviors, and (3) to examine correlates of currently exchanging sex. From June 2008 to February 2009, we conducted a cross-sectional study among women who were aged 18 years or older and reported exotic dancing within the past 3 months (n = 98). The survey ascertained socio-demographic characteristics, personal health, medical history, sexual practices, drug use, and employment at clubs on the block. Bivariate and multivariate Poisson regression with robust variance was used to identify correlates of current sex exchange. Participants were a median of 24 years old, and were 58% white; 43% had not completed high school. Seventy-four percent reported ever having been arrested. Twenty-six percent reported having injected heroin and 29% reported having smoked crack in the past 3 months. Fifty-seven percent reported using drugs in the club in the past 3 months. Sixty-one percent had ever engaged in transactional sex, and 67% of those did so for the first time after beginning to dance. Forty-three percent reported selling any sex in the club in the past 3 months. In multiple Poisson regression, factors associated with current sex exchange included: race, ever having been arrested, and using drugs in the club. High levels of both drug use and transactional sex among this sample of exotic dancers were reported. These findings indicate that there are a number of drug- and sex-related harms faced by exotic dancers in strip clubs, implicating the environment in the promotion of HIV/STI risk-taking behaviors. Prevention and intervention programs targeting this population are needed to reduce the harms faced by exotic dancers in this environment.

Role of BMI and age in predicting pathologic vertebral fractures in newly diagnosed multiple myeloma patients: A retrospective cohort study.

PubMed

Chen, Yi-Lun; Liu, Yao-Chung; Wu, Chia-Hung; Yeh, Chiu-Mei; Chiu, Hsun-I; Lee, Gin-Yi; Lee, Yu-Ting; Hsu, Pei; Lin, Ting-Wei; Gau, Jyh-Pyng; Hsiao, Liang-Tsai; Chiou, Tzeon-Jye; Liu, Jin-Hwang; Liu, Chia-Jen

2018-04-01

Vertebral fractures affect approximately 30% of myeloma patients and lead to a poor impact on survival and life quality. In general, age and body mass index (BMI) are reported to have an important role in vertebral fractures. However, the triangle relationship among age, BMI, and vertebral fractures is still unclear in newly diagnosed multiple myeloma (NDMM) patients. This study recruited consecutive 394 patients with NDMM at Taipei Veterans General Hospital between January 1, 2005 and December 31, 2015. Risk factors for vertebral fractures in NDMM patients were collected and analyzed. The survival curves were demonstrated using Kaplan-Meier estimate. In total, 301 (76.4%) NDMM patients were enrolled in the cohort. In the median follow-up period of 18.0 months, the median survival duration in those with vertebral fractures ≥ 2 was shorter than those with vertebral fracture < 2 (59.3 vs 28.6 months; P = 0.017). In multivariate Poisson regression, BMI < 18.5 kg/m 2 declared increased vertebral fractures compared with BMI ≥ 24.0 kg/m 2 (adjusted RR, 2.79; 95% CI, 1.44-5.43). In multivariable logistic regression, BMI < 18.5 kg/m 2 was an independent risk factor for vertebral fractures ≥ 2 compared with BMI ≥ 24.0 kg/m 2 (adjusted OR, 6.05; 95% CI, 2.43-15.08). Among age stratifications, patients with both old age and low BMI were at a greater risk suffering from increased vertebral fractures, especially in patients > 75 years and BMI < 18.5 kg/m 2 (adjusted RR, 12.22; 95% CI, 3.02-49.40). This is the first study that demonstrated that age had a significant impact on vertebral fractures in NDMM patients with low BMI. Elder patients with low BMI should consider to routinely receive spinal radiographic examinations and regular follow-up. Copyright © 2017 John Wiley & Sons, Ltd.

Disease activity and transition outcomes in a childhood-onset systemic lupus erythematosus cohort.

PubMed

Son, M B; Sergeyenko, Y; Guan, H; Costenbader, K H

2016-11-01

Objective The chronicity and severity of childhood-onset systemic lupus erythematosus (cSLE) necessitate effective transition from pediatric to adult providers. We studied transition outcomes in a cSLE cohort. Methods We identified patients at an adult lupus clinic diagnosed with SLE ≤ 18 years who had been followed by a pediatric rheumatologist. Data extracted from the first three years in adult care ("post-transition period") included: sociodemographics, depression, anxiety, SLE manifestations, SLE Disease Activity Index (SLEDAI) and Systemic Lupus International Collaborating Clinics/ACR Damage Index for SLE (SLICC) scores, non-adherence, and gaps in care (no appointments in the recommended time frame). Multivariable logistic regression analyses for predictors of: (1) time between pediatric and adult providers, (2) gaps in care, (3) unscheduled utilization (emergency department visits and admissions) (4) depression and/or anxiety were performed, as was a multivariable Poisson regression analysis for number of missed appointments. Results In 50 patients, SLEDAI scores were stable (mean 5.7 ± 5.0 at start vs. 4.7 ± 4.8 at year 3, p = 0.2), but SLICC scores increased (0.46 ± 0.84, vs. 0.78 ± 1.25, p = 0.01). Depression and anxiety increased significantly (10% vs. 26%, p = 0.02). Mean time from last pediatric to first adult provider visit was almost nine months (253 ± 392 days). Nearly 75% of patients had ≥ 1 gap in care. White race, low education level and non-adherence were significantly associated with missed appointments. Conclusion Despite moderate disease activity in this cSLE transition cohort, prolonged time between pediatric and adult providers and gaps in care in the post-transition period occurred. Anxiety and depression were frequently reported. Future work should identify methods to improve transition.

Prediction of road accidents: A Bayesian hierarchical approach.

PubMed

Deublein, Markus; Schubert, Matthias; Adey, Bryan T; Köhler, Jochen; Faber, Michael H

2013-03-01

In this paper a novel methodology for the prediction of the occurrence of road accidents is presented. The methodology utilizes a combination of three statistical methods: (1) gamma-updating of the occurrence rates of injury accidents and injured road users, (2) hierarchical multivariate Poisson-lognormal regression analysis taking into account correlations amongst multiple dependent model response variables and effects of discrete accident count data e.g. over-dispersion, and (3) Bayesian inference algorithms, which are applied by means of data mining techniques supported by Bayesian Probabilistic Networks in order to represent non-linearity between risk indicating and model response variables, as well as different types of uncertainties which might be present in the development of the specific models. Prior Bayesian Probabilistic Networks are first established by means of multivariate regression analysis of the observed frequencies of the model response variables, e.g. the occurrence of an accident, and observed values of the risk indicating variables, e.g. degree of road curvature. Subsequently, parameter learning is done using updating algorithms, to determine the posterior predictive probability distributions of the model response variables, conditional on the values of the risk indicating variables. The methodology is illustrated through a case study using data of the Austrian rural motorway network. In the case study, on randomly selected road segments the methodology is used to produce a model to predict the expected number of accidents in which an injury has occurred and the expected number of light, severe and fatally injured road users. Additionally, the methodology is used for geo-referenced identification of road sections with increased occurrence probabilities of injury accident events on a road link between two Austrian cities. It is shown that the proposed methodology can be used to develop models to estimate the occurrence of road accidents for any road network provided that the required data are available. Copyright © 2012 Elsevier Ltd. All rights reserved.

Self-reported recent testing and diagnosis for sexually transmitted infections among regular ecstasy users in Australia, 2011-2012.

PubMed

Nguyen, Phuong L T; Bruno, Raimondo; Alati, Rosa; Lenton, Simon; Burns, Lucy; Dietze, Paul M

2014-03-01

Previous studies suggest that people who consume alcohol and drugs are at increased risk of sexually transmitted infections (STI). We examined the prevalence and predictors of self-reported STI testing and diagnosis among self-reported regular ecstasy users (REU). Nine hundred and fifty-five REUs from the 2011 and 2012 Ecstasy and Related Drugs Reporting System were included in the analysis. Bivariate and multivariate Poisson regression were used to identify predictors of recent STI testing, and logistic regression was used to identify predictors of recent STI diagnosis. Forty-four per cent of REUs reported having a recent STI test, and 5% reported a recent diagnosis. Of the 421 REUs who reported a recent test, 10% reported a recent STI diagnosis. In multivariate analysis, REUs were more likely to report a recent STI test if they were female versus male [risk ratio (RR) = 1.56; 95% confidence interval (CI) = 1.36-1.80], aged 25-29 years versus 16-19 years (RR = 1.34; 95% CI = 1.05-1.72), or reported ≥2 casual sex partners versus no casual partners (RR = 1.48; 95% CI = 1.01-2.14). REUs reporting cannabis use in the past six months were 0.78 times less likely to report a recent STI test (95% CI = 0.66-0.94). There were no significant predictors associated with STI diagnosis. Encouragingly, REUs who reported having multiple casual partners in the past six months were more likely to report a recent test. However, younger REUs aged 16-19 years were least likely to test, suggesting health promotion needs to be directed to this age group. Further research is required to explain the lower testing among cannabis users. © 2013 Australasian Professional Society on Alcohol and other Drugs.

A graphical method to evaluate spectral preprocessing in multivariate regression calibrations: example with Savitzky-Golay filters and partial least squares regression

USDA-ARS?s Scientific Manuscript database

In multivariate regression analysis of spectroscopy data, spectral preprocessing is often performed to reduce unwanted background information (offsets, sloped baselines) or accentuate absorption features in intrinsically overlapping bands. These procedures, also known as pretreatments, are commonly ...

Equivalence of MAXENT and Poisson point process models for species distribution modeling in ecology.

PubMed

Renner, Ian W; Warton, David I

2013-03-01

Modeling the spatial distribution of a species is a fundamental problem in ecology. A number of modeling methods have been developed, an extremely popular one being MAXENT, a maximum entropy modeling approach. In this article, we show that MAXENT is equivalent to a Poisson regression model and hence is related to a Poisson point process model, differing only in the intercept term, which is scale-dependent in MAXENT. We illustrate a number of improvements to MAXENT that follow from these relations. In particular, a point process model approach facilitates methods for choosing the appropriate spatial resolution, assessing model adequacy, and choosing the LASSO penalty parameter, all currently unavailable to MAXENT. The equivalence result represents a significant step in the unification of the species distribution modeling literature. Copyright © 2013, The International Biometric Society.

Study of non-Hodgkin's lymphoma mortality associated with industrial pollution in Spain, using Poisson models

PubMed Central

Ramis, Rebeca; Vidal, Enrique; García-Pérez, Javier; Lope, Virginia; Aragonés, Nuria; Pérez-Gómez, Beatriz; Pollán, Marina; López-Abente, Gonzalo

2009-01-01

Background Non-Hodgkin's lymphomas (NHLs) have been linked to proximity to industrial areas, but evidence regarding the health risk posed by residence near pollutant industries is very limited. The European Pollutant Emission Register (EPER) is a public register that furnishes valuable information on industries that release pollutants to air and water, along with their geographical location. This study sought to explore the relationship between NHL mortality in small areas in Spain and environmental exposure to pollutant emissions from EPER-registered industries, using three Poisson-regression-based mathematical models. Methods Observed cases were drawn from mortality registries in Spain for the period 1994–2003. Industries were grouped into the following sectors: energy; metal; mineral; organic chemicals; waste; paper; food; and use of solvents. Populations having an industry within a radius of 1, 1.5, or 2 kilometres from the municipal centroid were deemed to be exposed. Municipalities outside those radii were considered as reference populations. The relative risks (RRs) associated with proximity to pollutant industries were estimated using the following methods: Poisson Regression; mixed Poisson model with random provincial effect; and spatial autoregressive modelling (BYM model). Results Only proximity of paper industries to population centres (>2 km) could be associated with a greater risk of NHL mortality (mixed model: RR:1.24, 95% CI:1.09–1.42; BYM model: RR:1.21, 95% CI:1.01–1.45; Poisson model: RR:1.16, 95% CI:1.06–1.27). Spatial models yielded higher estimates. Conclusion The reported association between exposure to air pollution from the paper, pulp and board industry and NHL mortality is independent of the model used. Inclusion of spatial random effects terms in the risk estimate improves the study of associations between environmental exposures and mortality. The EPER could be of great utility when studying the effects of industrial pollution on the health of the population. PMID:19159450

The analysis of incontinence episodes and other count data in patients with overactive bladder by Poisson and negative binomial regression.

PubMed

Martina, R; Kay, R; van Maanen, R; Ridder, A

2015-01-01

Clinical studies in overactive bladder have traditionally used analysis of covariance or nonparametric methods to analyse the number of incontinence episodes and other count data. It is known that if the underlying distributional assumptions of a particular parametric method do not hold, an alternative parametric method may be more efficient than a nonparametric one, which makes no assumptions regarding the underlying distribution of the data. Therefore, there are advantages in using methods based on the Poisson distribution or extensions of that method, which incorporate specific features that provide a modelling framework for count data. One challenge with count data is overdispersion, but methods are available that can account for this through the introduction of random effect terms in the modelling, and it is this modelling framework that leads to the negative binomial distribution. These models can also provide clinicians with a clearer and more appropriate interpretation of treatment effects in terms of rate ratios. In this paper, the previously used parametric and non-parametric approaches are contrasted with those based on Poisson regression and various extensions in trials evaluating solifenacin and mirabegron in patients with overactive bladder. In these applications, negative binomial models are seen to fit the data well. Copyright © 2014 John Wiley & Sons, Ltd.

Validation of Statistical Models for Estimating Hospitalization Associated with Influenza and Other Respiratory Viruses

PubMed Central

Chan, King-Pan; Chan, Kwok-Hung; Wong, Wilfred Hing-Sang; Peiris, J. S. Malik; Wong, Chit-Ming

2011-01-01

Background Reliable estimates of disease burden associated with respiratory viruses are keys to deployment of preventive strategies such as vaccination and resource allocation. Such estimates are particularly needed in tropical and subtropical regions where some methods commonly used in temperate regions are not applicable. While a number of alternative approaches to assess the influenza associated disease burden have been recently reported, none of these models have been validated with virologically confirmed data. Even fewer methods have been developed for other common respiratory viruses such as respiratory syncytial virus (RSV), parainfluenza and adenovirus. Methods and Findings We had recently conducted a prospective population-based study of virologically confirmed hospitalization for acute respiratory illnesses in persons <18 years residing in Hong Kong Island. Here we used this dataset to validate two commonly used models for estimation of influenza disease burden, namely the rate difference model and Poisson regression model, and also explored the applicability of these models to estimate the disease burden of other respiratory viruses. The Poisson regression models with different link functions all yielded estimates well correlated with the virologically confirmed influenza associated hospitalization, especially in children older than two years. The disease burden estimates for RSV, parainfluenza and adenovirus were less reliable with wide confidence intervals. The rate difference model was not applicable to RSV, parainfluenza and adenovirus and grossly underestimated the true burden of influenza associated hospitalization. Conclusion The Poisson regression model generally produced satisfactory estimates in calculating the disease burden of respiratory viruses in a subtropical region such as Hong Kong. PMID:21412433

Systematic review of treatment modalities for gingival depigmentation: a random-effects poisson regression analysis.

PubMed

Lin, Yi Hung; Tu, Yu Kang; Lu, Chun Tai; Chung, Wen Chen; Huang, Chiung Fang; Huang, Mao Suan; Lu, Hsein Kun

2014-01-01

Repigmentation variably occurs with different treatment methods in patients with gingival pigmentation. A systemic review was conducted of various treatment modalities for eliminating melanin pigmentation of the gingiva, comprising bur abrasion, scalpel surgery, cryosurgery, electrosurgery, gingival grafts, and laser techniques, to compare the recurrence rates (Rrs) of these treatment procedures. Electronic databases, including PubMed, Web of Science, Google, and Medline were comprehensively searched, and manual searches were conducted for studies published from January 1951 to June 2013. After applying inclusion and exclusion criteria, the final list of articles was reviewed in depth to achieve the objectives of this review. A Poisson regression was used to analyze the outcome of depigmentation using the various treatment methods. The systematic review was based on case reports mainly. In total, 61 eligible publications met the defined criteria. The various therapeutic procedures showed variable clinical results with a wide range of Rrs. A random-effects Poisson regression showed that cryosurgery (Rr = 0.32%), electrosurgery (Rr = 0.74%), and laser depigmentation (Rr = 1.16%) yielded superior result, whereas bur abrasion yielded the highest Rr (8.89%). Within the limit of the sampling level, the present evidence-based results show that cryosurgery exhibits the optimal predictability for depigmentation of the gingiva among all procedures examined, followed by electrosurgery and laser techniques. It is possible to treat melanin pigmentation of the gingiva with various methods and prevent repigmentation. Among those treatment modalities, cryosurgery, electrosurgery, and laser surgery appear to be the best choices for treating gingival pigmentation. © 2014 Wiley Periodicals, Inc.

Disability rates for cardiovascular and psychological disorders among autoworkers by job category, facility type, and facility overtime hours.

PubMed

Landsbergis, Paul A; Janevic, Teresa; Rothenberg, Laura; Adamu, Mohammed T; Johnson, Sylvia; Mirer, Franklin E

2013-07-01

We examined the association between long work hours, assembly line work and stress-related diseases utilizing objective health and employment data from an employer's administrative databases. A North American automobile manufacturing company provided data for claims for sickness, accident and disability insurance (work absence of at least 4 days) for cardiovascular disease (CVD), hypertension and psychological disorders, employee demographics, and facility hours worked per year for 1996-2001. Age-adjusted claim rates and age-adjusted rate ratios were calculated using Poisson regression, except for comparisons between production and skilled trades workers owing to lack of age denominator data by job category. Associations between overtime hours and claim rates by facility were examined by Poisson regression and multi-level Poisson regression. Claims for hypertension, coronary heart disease, CVD, and psychological disorders were associated with facility overtime hours. We estimate that a facility with 10 more overtime hours per week than another facility would have 4.36 more claims for psychological disorders, 2.33 more claims for CVD, and 3.29 more claims for hypertension per 1,000 employees per year. Assembly plants had the highest rates of claims for most conditions. Production workers tended to have higher rates of claims than skilled trades workers. Data from an auto manufacturer's administrative databases suggest that autoworkers working long hours, and assembly-line workers relative to skilled trades workers or workers in non-assembly facilities, have a higher risk of hypertension, CVD, and psychological disorders. Occupational disease surveillance and disease prevention programs need to fully utilize such administrative data. Copyright © 2013 Wiley Periodicals, Inc.

Zero-inflated Poisson regression models for QTL mapping applied to tick-resistance in a Gyr × Holstein F2 population

PubMed Central

Silva, Fabyano Fonseca; Tunin, Karen P.; Rosa, Guilherme J.M.; da Silva, Marcos V.B.; Azevedo, Ana Luisa Souza; da Silva Verneque, Rui; Machado, Marco Antonio; Packer, Irineu Umberto

2011-01-01

Now a days, an important and interesting alternative in the control of tick-infestation in cattle is to select resistant animals, and identify the respective quantitative trait loci (QTLs) and DNA markers, for posterior use in breeding programs. The number of ticks/animal is characterized as a discrete-counting trait, which could potentially follow Poisson distribution. However, in the case of an excess of zeros, due to the occurrence of several noninfected animals, zero-inflated Poisson and generalized zero-inflated distribution (GZIP) may provide a better description of the data. Thus, the objective here was to compare through simulation, Poisson and ZIP models (simple and generalized) with classical approaches, for QTL mapping with counting phenotypes under different scenarios, and to apply these approaches to a QTL study of tick resistance in an F2 cattle (Gyr × Holstein) population. It was concluded that, when working with zero-inflated data, it is recommendable to use the generalized and simple ZIP model for analysis. On the other hand, when working with data with zeros, but not zero-inflated, the Poisson model or a data-transformation-approach, such as square-root or Box-Cox transformation, are applicable. PMID:22215960

Logistic quantile regression provides improved estimates for bounded avian counts: a case study of California Spotted Owl fledgling production

Treesearch

Brian S. Cade; Barry R. Noon; Rick D. Scherer; John J. Keane

2017-01-01

Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical...

Calibrated Multivariate Regression with Application to Neural Semantic Basis Discovery.

PubMed

Liu, Han; Wang, Lie; Zhao, Tuo

2015-08-01

We propose a calibrated multivariate regression method named CMR for fitting high dimensional multivariate regression models. Compared with existing methods, CMR calibrates regularization for each regression task with respect to its noise level so that it simultaneously attains improved finite-sample performance and tuning insensitiveness. Theoretically, we provide sufficient conditions under which CMR achieves the optimal rate of convergence in parameter estimation. Computationally, we propose an efficient smoothed proximal gradient algorithm with a worst-case numerical rate of convergence O (1/ ϵ ), where ϵ is a pre-specified accuracy of the objective function value. We conduct thorough numerical simulations to illustrate that CMR consistently outperforms other high dimensional multivariate regression methods. We also apply CMR to solve a brain activity prediction problem and find that it is as competitive as a handcrafted model created by human experts. The R package camel implementing the proposed method is available on the Comprehensive R Archive Network http://cran.r-project.org/web/packages/camel/.

Poisson, Poisson-gamma and zero-inflated regression models of motor vehicle crashes: balancing statistical fit and theory.

PubMed

Lord, Dominique; Washington, Simon P; Ivan, John N

2005-01-01

There has been considerable research conducted over the last 20 years focused on predicting motor vehicle crashes on transportation facilities. The range of statistical models commonly applied includes binomial, Poisson, Poisson-gamma (or negative binomial), zero-inflated Poisson and negative binomial models (ZIP and ZINB), and multinomial probability models. Given the range of possible modeling approaches and the host of assumptions with each modeling approach, making an intelligent choice for modeling motor vehicle crash data is difficult. There is little discussion in the literature comparing different statistical modeling approaches, identifying which statistical models are most appropriate for modeling crash data, and providing a strong justification from basic crash principles. In the recent literature, it has been suggested that the motor vehicle crash process can successfully be modeled by assuming a dual-state data-generating process, which implies that entities (e.g., intersections, road segments, pedestrian crossings, etc.) exist in one of two states-perfectly safe and unsafe. As a result, the ZIP and ZINB are two models that have been applied to account for the preponderance of "excess" zeros frequently observed in crash count data. The objective of this study is to provide defensible guidance on how to appropriate model crash data. We first examine the motor vehicle crash process using theoretical principles and a basic understanding of the crash process. It is shown that the fundamental crash process follows a Bernoulli trial with unequal probability of independent events, also known as Poisson trials. We examine the evolution of statistical models as they apply to the motor vehicle crash process, and indicate how well they statistically approximate the crash process. We also present the theory behind dual-state process count models, and note why they have become popular for modeling crash data. A simulation experiment is then conducted to demonstrate how crash data give rise to "excess" zeros frequently observed in crash data. It is shown that the Poisson and other mixed probabilistic structures are approximations assumed for modeling the motor vehicle crash process. Furthermore, it is demonstrated that under certain (fairly common) circumstances excess zeros are observed-and that these circumstances arise from low exposure and/or inappropriate selection of time/space scales and not an underlying dual state process. In conclusion, carefully selecting the time/space scales for analysis, including an improved set of explanatory variables and/or unobserved heterogeneity effects in count regression models, or applying small-area statistical methods (observations with low exposure) represent the most defensible modeling approaches for datasets with a preponderance of zeros.

Meta-analysis of haplotype-association studies: comparison of methods and empirical evaluation of the literature

PubMed Central

2011-01-01

Background Meta-analysis is a popular methodology in several fields of medical research, including genetic association studies. However, the methods used for meta-analysis of association studies that report haplotypes have not been studied in detail. In this work, methods for performing meta-analysis of haplotype association studies are summarized, compared and presented in a unified framework along with an empirical evaluation of the literature. Results We present multivariate methods that use summary-based data as well as methods that use binary and count data in a generalized linear mixed model framework (logistic regression, multinomial regression and Poisson regression). The methods presented here avoid the inflation of the type I error rate that could be the result of the traditional approach of comparing a haplotype against the remaining ones, whereas, they can be fitted using standard software. Moreover, formal global tests are presented for assessing the statistical significance of the overall association. Although the methods presented here assume that the haplotypes are directly observed, they can be easily extended to allow for such an uncertainty by weighting the haplotypes by their probability. Conclusions An empirical evaluation of the published literature and a comparison against the meta-analyses that use single nucleotide polymorphisms, suggests that the studies reporting meta-analysis of haplotypes contain approximately half of the included studies and produce significant results twice more often. We show that this excess of statistically significant results, stems from the sub-optimal method of analysis used and, in approximately half of the cases, the statistical significance is refuted if the data are properly re-analyzed. Illustrative examples of code are given in Stata and it is anticipated that the methods developed in this work will be widely applied in the meta-analysis of haplotype association studies. PMID:21247440

Geographic dimensions of heat-related mortality in seven U.S. cities.

PubMed

Hondula, David M; Davis, Robert E; Saha, Michael V; Wegner, Carleigh R; Veazey, Lindsay M

2015-04-01

Spatially targeted interventions may help protect the public when extreme heat occurs. Health outcome data are increasingly being used to map intra-urban variability in heat-health risks, but there has been little effort to compare patterns and risk factors between cities. We sought to identify places within large metropolitan areas where the mortality rate is highest on hot summer days and determine if characteristics of high-risk areas are consistent from one city to another. A Poisson regression model was adapted to quantify temperature-mortality relationships at the postal code scale based on 2.1 million records of daily all-cause mortality counts from seven U.S. cities. Multivariate spatial regression models were then used to determine the demographic and environmental variables most closely associated with intra-city variability in risk. Significant mortality increases on extreme heat days were confined to 12-44% of postal codes comprising each city. Places with greater risk had more developed land, young, elderly, and minority residents, and lower income and educational attainment, but the key explanatory variables varied from one city to another. Regression models accounted for 14-34% of the spatial variability in heat-related mortality. The results emphasize the need for public health plans for heat to be locally tailored and not assume that pre-identified vulnerability indicators are universally applicable. As known risk factors accounted for no more than one third of the spatial variability in heat-health outcomes, consideration of health outcome data is important in efforts to identify and protect residents of the places where the heat-related health risks are the highest. Copyright © 2015 Elsevier Inc. All rights reserved.

An examination of sources of sensitivity of consumer surplus estimates in travel cost models.

PubMed

Blaine, Thomas W; Lichtkoppler, Frank R; Bader, Timothy J; Hartman, Travis J; Lucente, Joseph E

2015-03-15

We examine sensitivity of estimates of recreation demand using the Travel Cost Method (TCM) to four factors. Three of the four have been routinely and widely discussed in the TCM literature: a) Poisson verses negative binomial regression; b) application of Englin correction to account for endogenous stratification; c) truncation of the data set to eliminate outliers. A fourth issue we address has not been widely modeled: the potential effect on recreation demand of the interaction between income and travel cost. We provide a straightforward comparison of all four factors, analyzing the impact of each on regression parameters and consumer surplus estimates. Truncation has a modest effect on estimates obtained from the Poisson models but a radical effect on the estimates obtained by way of the negative binomial. Inclusion of an income-travel cost interaction term generally produces a more conservative but not a statistically significantly different estimate of consumer surplus in both Poisson and negative binomial models. It also generates broader confidence intervals. Application of truncation, the Englin correction and the income-travel cost interaction produced the most conservative estimates of consumer surplus and eliminated the statistical difference between the Poisson and the negative binomial. Use of the income-travel cost interaction term reveals that for visitors who face relatively low travel costs, the relationship between income and travel demand is negative, while it is positive for those who face high travel costs. This provides an explanation of the ambiguities on the findings regarding the role of income widely observed in the TCM literature. Our results suggest that policies that reduce access to publicly owned resources inordinately impact local low income recreationists and are contrary to environmental justice. Copyright © 2014 Elsevier Ltd. All rights reserved.

Risk of Ischemic Stroke, Hemorrhagic Stroke, Bleeding, and Death in Patients Switching from Vitamin K Antagonist to Dabigatran after an Ablation.

PubMed

Pallisgaard, Jannik Langtved; Gislason, Gunnar Hilmar; Torp-Pedersen, Christian; Lee, Christina Ji-Young; Sindet-Pedersen, Caroline; Staerk, Laila; Olesen, Jonas Bjerring; Lindhardt, Tommi Bo

2016-01-01

Safety regarding switching from vitamin K antagonist (VKA) to dabigatran therapy in post-ablation patients has never been investigated and safety data for this is urgently needed. The objective of this study was to examine if switch from VKA to dabigatran increased the risk of stroke, bleeding, and death in patients after ablation for atrial fibrillation. Through the Danish nationwide registries, patients with non-valvular atrial fibrillation undergoing ablation were identified, in the period between August 22nd 2011 and December 31st 2015. The risk of ischemic stroke, hemorrhagic stroke, bleeding, and death, related to switching from VKA to dabigatran was examined using a multivariable Poisson regression model, where Incidence rate ratios (IRR) were estimated using VKA as reference. In total, 4,236 patients were included in the study cohort. The minority (n = 470, 11%) switched to dabigatran in the follow up period leaving the majority (n = 3,766, 89%) in VKA treatment. The patients in the dabigatran group were older, were more often males, and had higher CHA2DS2-VASc, and HAS-BLED scores. The incident rates of bleeding and death were almost twice as high in the dabigatran group compared with the VKA group. When adjusting for the individual components included in the CHA2DS2-VASc and HAS-BLED scores, the multivariable Poisson analyses yielded a non-significant IRR (95%CI) of 1.64 (0.72-3.75) for bleeding and of 1.41 (0.66-3.00) for death associated with the dabigatran group, compared to the VKA group. A significant increased risk of bleeding was found in the 110mg bid group with an IRR (95%CI) of 4.49(1.40-14.5). Shifting from VKA to dabigatran after ablation was associated with twice as high incidence of bleeding compared to the incidence in patients staying in VKA treatment. The only significant increased risk found in the adjusted analyses was for bleeding with 110mg bid dabigatran and not for 150mg bid. Since there was no dose-response for bleeding, the switch from VKA to dabigatran in itself was not a risk factor for bleeding.

Linear regression analysis and its application to multivariate chromatographic calibration for the quantitative analysis of two-component mixtures.

PubMed

Dinç, Erdal; Ozdemir, Abdil

2005-01-01

Multivariate chromatographic calibration technique was developed for the quantitative analysis of binary mixtures enalapril maleate (EA) and hydrochlorothiazide (HCT) in tablets in the presence of losartan potassium (LST). The mathematical algorithm of multivariate chromatographic calibration technique is based on the use of the linear regression equations constructed using relationship between concentration and peak area at the five-wavelength set. The algorithm of this mathematical calibration model having a simple mathematical content was briefly described. This approach is a powerful mathematical tool for an optimum chromatographic multivariate calibration and elimination of fluctuations coming from instrumental and experimental conditions. This multivariate chromatographic calibration contains reduction of multivariate linear regression functions to univariate data set. The validation of model was carried out by analyzing various synthetic binary mixtures and using the standard addition technique. Developed calibration technique was applied to the analysis of the real pharmaceutical tablets containing EA and HCT. The obtained results were compared with those obtained by classical HPLC method. It was observed that the proposed multivariate chromatographic calibration gives better results than classical HPLC.

Breastfeeding associated with higher lung function in African American youths with asthma.

PubMed

Oh, Sam S; Du, Randal; Zeiger, Andrew M; McGarry, Meghan E; Hu, Donglei; Thakur, Neeta; Pino-Yanes, Maria; Galanter, Joshua M; Eng, Celeste; Nishimura, Katherine Keiko; Huntsman, Scott; Farber, Harold J; Meade, Kelley; Avila, Pedro; Serebrisky, Denise; Bibbins-Domingo, Kirsten; Lenoir, Michael A; Ford, Jean G; Brigino-Buenaventura, Emerita; Rodriguez-Cintron, William; Thyne, Shannon M; Sen, Saunak; Rodriguez-Santana, Jose R; Williams, Keoki; Kumar, Rajesh; Burchard, Esteban G

2017-10-01

In the United States, Puerto Ricans and African Americans have lower prevalence of breastfeeding and worse clinical outcomes for asthma compared with other racial/ethnic groups. We hypothesize that the history of breastfeeding is associated with increased forced expiratory volume in 1 second (FEV 1 ) % predicted and reduced asthma exacerbations in Latino and African American youths with asthma. As part of the Genes-environments & Admixture in Latino Americans (GALA II) Study and the Study of African Americans, asthma, Genes & Environments (SAGE II), we conducted case-only analyses in children and adolescents aged 8-21 years with asthma from four different racial/ethnic groups: African Americans (n = 426), Mexican Americans (n = 424), mixed/other Latinos (n = 255), and Puerto Ricans (n = 629). We investigated the association between any breastfeeding in infancy and FEV 1 % predicted using multivariable linear regression; Poisson regression was used to determine the association between breastfeeding and asthma exacerbations. Prevalence of breastfeeding was lower in African Americans (59.4%) and Puerto Ricans (54.9%) compared to Mexican Americans (76.2%) and mixed/other Latinos (66.9%; p < 0.001). After adjusting for covariates, breastfeeding was associated with a 3.58% point increase in FEV 1 % predicted (p = 0.01) and a 21% reduction in asthma exacerbations (p = 0.03) in African Americans only. Breastfeeding was associated with higher FEV 1 % predicted in asthma and reduced number of asthma exacerbations in African American youths, calling attention to continued support for breastfeeding.

Testing anti-smoking messages for Air Force trainees

PubMed Central

Popova, Lucy; Linde, Brittany D.; Bursac, Zoran; Talcott, G. Wayne; Modayil, Mary V.; Little, Melissa A.; Ling, Pamela M.; Glantz, Stanton A.; Klesges, Robert C.

2015-01-01

Introduction Young adults in the military are aggressively targeted by tobacco companies and are at high risk of tobacco use. Existing anti-smoking advertisements developed for the general population might be effective in educating young adults in the military. This study evaluated the effects of different themes of existing anti-smoking advertisements on perceived harm and intentions to use cigarettes and other tobacco products among Air Force trainees. Methods In a pretest-posttest experiment, 782 Airmen were randomized to view anti-smoking advertisements in one of six conditions: anti-industry, health effects+anti-industry, sexual health, secondhand smoke, environment+anti-industry, or control. We assessed the effect of different conditions on changes in perceived harm and intentions to use cigarettes, electronic cigarettes (e-cigarettes), smokeless tobacco, hookah and cigarillos from pretest to posttest with multivariable linear regression models (perceived harm) and zero-inflated Poisson regression model (intentions). Results Anti-smoking advertisements increased perceived harm of various tobacco products and reduced intentions to use. Advertisements featuring negative effects of tobacco on health and sexual performance coupled with revealing tobacco industry manipulations had the most consistent pattern of effects on perceived harm and intentions. Conclusion Anti-smoking advertisements produced for the general public might also be effective with a young adult military population and could have spillover effects on perceptions of harm and intentions to use other tobacco products besides cigarettes. Existing anti-smoking advertising may be a cost-effective tool to educate young adults in the military. PMID:26482786

A retrospective survey of the quality of reports and their correlates among randomized controlled trials of immunotherapy for Guillain-Barré syndrome.

PubMed

Lu, Liming; Luo, Gaoquan; Xiao, Fang

2013-08-01

This study aims to assess the quality of reports and their correlates in randomized controlled trials (RCTs) of immunotherapy for Guillain-Barré syndrome (GBS). A search was performed in multiple databases of reports published between April 1992 and November 2012. Reporting quality was assessed by items of the Consolidated Standards of Reporting Trials (CONSORT) 2010 Statement. An overall quality score (OQS) and a key methodological index score (MIS) were calculated for each trial. Factors associated with OQS and MIS were then identified. A total of 19 RCTs were included in the full text. The median OQS was 7.0, with a range of 1-10. However, the quality of reporting in items of 'flow chart' and 'ancillary analyses' was poor with a positive rate of less than 40%. The median MIS was 0 with a range of 0-2. Twelve (63.2%) did not report any of the three key methodological items. Specifically, the mean OQS increased by approximately 2.73 for manuscripts published in the New England Journal of Medicine, The Lancet, Pediatrics and Neurology (95% CI: 0.35-5.12; p < 0.05). Multivariate linear regression and the Poisson regression model could not be presented as the number of included trials was too small. The reporting quality in RCTs on immunotherapy for GBS was poor, which indicated that reporting in RCTs of immunotherapy for GBS needed substantial improvement in order to meet the guideline of the CONSORT Statement.

Stop the drama Downunder: a social marketing campaign increases HIV/sexually transmitted infection knowledge and testing in Australian gay men.

PubMed

Pedrana, Alisa; Hellard, Margaret; Guy, Rebecca; El-Hayek, Carol; Gouillou, Maelenn; Asselin, Jason; Batrouney, Colin; Nguyen, Phuong; Stoovè, Mark

2012-08-01

Since 2000, notifications of HIV and other sexually transmitted infections (STIs) have increased significantly in Australian gay men. We evaluated the impact of a social marketing campaign in 2008-2009 aimed to increase health-seeking behavior and STI testing and enhance HIV/STI knowledge in gay men. A convenience sample of 295 gay men (18-66 years of age) was surveyed to evaluate the effectiveness of the campaign. Participants were asked about campaign awareness, HIV/STI knowledge, health-seeking behavior, and HIV/STI testing. We examined associations between recent STI testing and campaign awareness. Trends in HIV/STI monthly tests at 3 clinics with a high case load of gay men were also assessed. Logistic and Poisson regressions and χ tests were used. Both unaided (43%) and aided (86%) campaign awareness was high. In a multivariable logistic regression, awareness of the campaign (aided) was independently associated with having had any STI test within the past 6 months (prevalence ratio = 1.5; 95% confidence interval = 1.0-2.4. Compared with the 13 months before the campaign, clinic data showed significant increasing testing rates for HIV, syphilis, and chlamydia among HIV-negative gay men during the initial and continued campaign periods. These findings suggest that the campaign was successful in achieving its aims of increasing health-seeking behavior, STI testing, and HIV/STI knowledge among gay men in Victoria.

Introduction to the use of regression models in epidemiology.

PubMed

Bender, Ralf

2009-01-01

Regression modeling is one of the most important statistical techniques used in analytical epidemiology. By means of regression models the effect of one or several explanatory variables (e.g., exposures, subject characteristics, risk factors) on a response variable such as mortality or cancer can be investigated. From multiple regression models, adjusted effect estimates can be obtained that take the effect of potential confounders into account. Regression methods can be applied in all epidemiologic study designs so that they represent a universal tool for data analysis in epidemiology. Different kinds of regression models have been developed in dependence on the measurement scale of the response variable and the study design. The most important methods are linear regression for continuous outcomes, logistic regression for binary outcomes, Cox regression for time-to-event data, and Poisson regression for frequencies and rates. This chapter provides a nontechnical introduction to these regression models with illustrating examples from cancer research.

A quantile count model of water depth constraints on Cape Sable seaside sparrows

USGS Publications Warehouse

Cade, B.S.; Dong, Q.

2008-01-01

1. A quantile regression model for counts of breeding Cape Sable seaside sparrows Ammodramus maritimus mirabilis (L.) as a function of water depth and previous year abundance was developed based on extensive surveys, 1992-2005, in the Florida Everglades. The quantile count model extends linear quantile regression methods to discrete response variables, providing a flexible alternative to discrete parametric distributional models, e.g. Poisson, negative binomial and their zero-inflated counterparts. 2. Estimates from our multiplicative model demonstrated that negative effects of increasing water depth in breeding habitat on sparrow numbers were dependent on recent occupation history. Upper 10th percentiles of counts (one to three sparrows) decreased with increasing water depth from 0 to 30 cm when sites were not occupied in previous years. However, upper 40th percentiles of counts (one to six sparrows) decreased with increasing water depth for sites occupied in previous years. 3. Greatest decreases (-50% to -83%) in upper quantiles of sparrow counts occurred as water depths increased from 0 to 15 cm when previous year counts were 1, but a small proportion of sites (5-10%) held at least one sparrow even as water depths increased to 20 or 30 cm. 4. A zero-inflated Poisson regression model provided estimates of conditional means that also decreased with increasing water depth but rates of change were lower and decreased with increasing previous year counts compared to the quantile count model. Quantiles computed for the zero-inflated Poisson model enhanced interpretation of this model but had greater lack-of-fit for water depths > 0 cm and previous year counts 1, conditions where the negative effect of water depths were readily apparent and fitted better with the quantile count model.

The association between intimate partner domestic violence and the food security status of poor families in Brazil.

PubMed

Ribeiro-Silva, Rita de Cássia; Fiaccone, Rosemeire Leovigildo; Barreto, Maurício Lima; Santana, Mônica Leila Portela; dos Santos, Sandra Maria Chaves; da Conceição-Machado, Maria Ester Pereira; Aliaga, Marie Agnès

2016-05-01

To assess the association between physical intimate partner violence and household food security within households with schoolchildren. Cross-sectional study. Salvador, Bahia, north-eastern Brazil. The study was conducted in 1019 households with students. Violence between couples was evaluated using the Portuguese version of the revised Conflict Tactics Scales (CTS2), previously adapted and validated for use in Brazil. The Brazilian Food Insecurity Scale (BFIS) was used to identify food insecurity. We also obtained socio-economic information for each participant. We used multivariate Poisson regression to assess the associations of interest. According to the results of the BFIS, 62·5% of the households were found to experience food insecurity, including 19·5% moderate food insecurity and 6·5% severe food insecurity. The prevalence of minor physical violence was 9·6% (95% CI 7·8, 11·4%) and of severe physical violence was 4·7% (95% CI 3·4, 6·0%) among the couples. In the final multivariate model, it was found that couples reporting minor (prevalence ratio=1·23; 95% CI 1·12, 1·35) and severe (prevalence ratio=1·16; 95% CI 1·00, 1·34) physical violence were more likely to be experiencing household food insecurity, compared with those not reporting physical violence. Physical intimate partner violence was associated with food insecurity of households. The present study brings new data to the subject of the role of violence in the context of food insecurity.

Need for orthodontic treatment among Brazilian adolescents: evaluation based on public health

PubMed Central

de Freitas, Carolina Vieira; Souza, João Gabriel Silva; Mendes, Danilo Cangussu; Pordeus, Isabela Almeida; Jones, Kimberly Marie; Martins, Andréa Maria Eleutério de Barros Lima

2015-01-01

OBJECTIVE: To identify the prevalence and the severity of malocclusions and to analyze factors associated with the need for orthodontic treatment of Brazilian adolescents. METHODS: This exploratory, cross-sectional study was carried out based on secondary data from the national epidemiological survey on oral health in Brazil (2002-2003). Socio-demographic conditions, self-perception, and the existence and degree of malocclusion, using the Dental Aesthetic Index, were evaluated in 16,833 adolescent Brazilians selected by probabilistic sample by conglomerates. The dependent variable need orthodontic treatment was estimated from the severity of malocclusion. The magnitude and direction of the association in bivariate and multivariate analyzes from a Robust Poisson regression was estimated. RESULTS: The majority of the adolescents needed orthodontic treatment (53.2%). In the multivariate analysis, the prevalence of the need for orthodontic treatment was larger among females, non-whites, those that perceived a need for treatment, and those that perceived their appearance as normal, bad, or very bad. The need for orthodontic treatment was smaller among those that lived in the Northeast and Central West macro-regions compared to those living in Southeast Brazil and it was also smaller among those that perceived their chewing to be normal or their oral health to be bad or very bad. CONCLUSIONS: There was a high prevalence of orthodontic treatment need among adolescents in Brazil and this need was associated with demographic and subjective issues. The high prevalence of orthodontic needs in adolescents is a challenge to the goals of Brazil's universal public health system. PMID:25769190

Are obesity and overweight associated with gingivitis occurrence in Brazilian schoolchildren?

PubMed

Nascimento, Gustavo G; Seerig, Lenise M; Vargas-Ferreira, Fabiana; Correa, Fernanda O B; Leite, Fábio R M; Demarco, Flávio F

2013-12-01

This cross-sectional study aimed to assess the relationship between weight status and gingival inflammation in Brazilian schoolchildren aged 8- to 12-year old, when controlling for potential confounders. Overall, 1211 children aged 8- to 12-year old from public and private schools in Southern Brazil were selected by a two-stage cluster method. Questionnaires were used to assess socio-demographic data and oral hygiene habits. Oral examination evaluated presence of plaque and gingival bleeding. Anthropometric measures were collected to obtain body mass index. Multivariate Poisson regression was used for data analysis (Prevalence Ratio/95% Confidence Interval). Prevalence of gingivitis was 44.0%. Mean and median values of gingival bleeding sites were 3.10 and 2.0 respectively. Obese/overweight children totalized 34.6%. In multivariate adjusted analysis, sex (PR 0.86; 95%CI 0.75;0.98), maternal schooling (PR 1.09; 95% CI 1.01;1.18), plaque (PR 1.37; 95% CI 1.26;1.50), dental caries experience (PR 1.16; 95% CI 1.01;1.36) and bleeding during tooth brushing (PR 1.27; 95% CI 1.11;1.48) were associated with the outcome. In the sex-stratified analysis, overweight/obese boys presented a greater risk for gingivitis (PR 1.22 95% CI 1.01;1.48). Gingivitis was not associated with obesity/overweight in the total sample. Gender differences seem to influence the relationship between gingivitis and obesity/overweight; a stronger association was noted among boys than girls. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prevalence and associated factors with alcohol use disorders among adults: a population-based study in southern Brazil.

PubMed

Reisdorfer, Emilene; Büchele, Fátima; Pires, Rodrigo Otávio Moretti; Boing, Antonio Fernando

2012-09-01

The study aimed to describe the prevalence of alcohol use disorders in an adult population from Brazil and its association with demographic, socioeconomic, behavioral variables and health conditions. A population-based cross-sectional survey was conducted with adults (20 to 59 years) of a medium-sized city in Southern Brazil with a random sample of 1,720 individuals. Cluster sampling was done in two stages: census tract first and household second. Alcohol use disorders were measured using the Alcohol Use Disorders Identification Test (AUDIT) and associations were tested with selected variables by Poisson Regression. Results of multivariate analysis were expressed as prevalence ratios. The prevalence of alcohol use disorders in the population was 18.4% (95% CI: 16.6% - 20.3%), higher among men (29.9%) than in women (9.3%). The prevalence of abstinence was 30.6%; 6.8% of respondents had already caused problems to themselves or to others after drinking; and 10.3% reported that a relative, friend or doctor had already shown concern on their drinking. After multivariate analysis, an association with alcohol use disorders remained for: being male, age 20 to 29 years, being single, declaring to be light-skinned blacks and being an ex-smoker or current smoker. The prevalence of alcohol use disorders identified is high compared with other similar studies, with differences according to being male, age 20 to 29, skin color and tobacco use. These issues must be considered in formulating public health policies aimed at reducing problems related to alcohol use.

Association between split selection instability and predictive error in survival trees.

PubMed

Radespiel-Tröger, M; Gefeller, O; Rabenstein, T; Hothorn, T

2006-01-01

To evaluate split selection instability in six survival tree algorithms and its relationship with predictive error by means of a bootstrap study. We study the following algorithms: logrank statistic with multivariate p-value adjustment without pruning (LR), Kaplan-Meier distance of survival curves (KM), martingale residuals (MR), Poisson regression for censored data (PR), within-node impurity (WI), and exponential log-likelihood loss (XL). With the exception of LR, initial trees are pruned by using split-complexity, and final trees are selected by means of cross-validation. We employ a real dataset from a clinical study of patients with gallbladder stones. The predictive error is evaluated using the integrated Brier score for censored data. The relationship between split selection instability and predictive error is evaluated by means of box-percentile plots, covariate and cutpoint selection entropy, and cutpoint selection coefficients of variation, respectively, in the root node. We found a positive association between covariate selection instability and predictive error in the root node. LR yields the lowest predictive error, while KM and MR yield the highest predictive error. The predictive error of survival trees is related to split selection instability. Based on the low predictive error of LR, we recommend the use of this algorithm for the construction of survival trees. Unpruned survival trees with multivariate p-value adjustment can perform equally well compared to pruned trees. The analysis of split selection instability can be used to communicate the results of tree-based analyses to clinicians and to support the application of survival trees.

Ecological competition and the incidence of Acinetobacter baumannii bloodstream infections in a teaching hospital in Southeastern Brazil.

PubMed

Lastoria, Letícia Chamma; Caldeira, Sílvia Maria; Moreira, Rayana Gonçalves; Akazawa, Renata Tamie; Maion, Júlia Coutinho; Fortaleza, Carlos Magno Castelo Branco

2014-01-01

Recently, pathogen ecology has been recognized as an important epidemiological determinant of healthcare-associated infections (HAIs). Acinetobacter baumannii is one of the most important agents known to cause HAIs. It is widespread in healthcare settings and exhibits seasonal variations in incidence. Little is known about the impact of competition with other hospital pathogens on the incidence of A. baumannii infection. We conducted an ecological study, enrolling patients who presented with healthcare-associated bloodstream infections (HA-BSIs) from 2005 to 2010 at a 450-bed teaching hospital in Brazil. HA-BSIs were said to be present when bacteria or fungi were recovered from blood cultures collected at least three days after admission. Monthly incidence rates were calculated for all HA-BSIs (overall or caused by specific pathogens or groups of pathogens). Multivariate Poisson regression models were used to identify the impacts of the incidence of several pathogens on the incidence of A. baumannii. The overall incidence rate of HA-BSI caused by A. baumannii was 2.5 per 10,000 patient-days. In the multivariate analysis, the incidence of HA-BSI caused by A. baumannii was negatively associated with the incidence rates of HA-BSI due to Staphylococcus aureus (rate ratio [RR]=0.88; 95% confidence interval [CI]=0.80-0.97), Enterobacter spp. (RR=0.84; 95%CI=0.74-0.94) and a pool of less common gram-negative pathogens. Our results suggest that competition between pathogens influences the etiology of HA-BSIs. It would be beneficial to take these findings into account in infection control policies.

Prevalence of Anal High-Risk Human Papillomavirus Infections Among HIV-Positive and HIV-Negative Men Who Have Sex With Men in Nigeria.

PubMed

Nowak, Rebecca G; Gravitt, Patti E; He, Xin; Ketende, Sosthenes; Dauda, Wuese; Omuh, Helen; Blattner, William A; Charurat, Manhattan E

2016-04-01

Prevalence estimates of anal high-risk human papillomavirus (HR-HPV) are needed in sub-Saharan Africa where HIV is endemic. This study evaluated anal HR-HPV in Nigeria among HIV-positive and HIV-negative men who have sex with men (MSM) for future immunization recommendations. We conducted a cross-sectional study to compare the prevalence of anal HR-HPV infections between 64 HIV-negative and 90 HIV-positive MSM. Multivariate Poisson regression analyses were used to examine demographic and behavioral risk factors associated with any HR-HPV infections. The median age of the 154 participants was 25 years (interquartile range, 22-28 years; range, 16-38 years), and the median age at initiation of anal sex with another man was 16 years (interquartile range, 13-18 years; range, 7-29 years). The prevalence of anal HR-HPV was higher among HIV-positive than HIV-negative MSM (91.1% vs. 40.6%, P < 0.001). In the multivariate analysis, HIV infection (adjusted prevalence ratio [aPR], 2.02; 95% confidence interval [CI], 1.49-2.72), 10 years or more since anal sexual debut (aPR, 1.26; 95% CI, 1.07-1.49), and concurrent relationships with men (aPR, 1.32; 95% CI, 1.04-1.67) were associated with increased anal HR-HPV prevalence. Anal HR-HPV infection is high for young Nigerian MSM, and rates are amplified in those coinfected with HIV. Providing universal coverage as well as catch-up immunization for young MSM may be an effective anal cancer prevention strategy in Nigeria.

Predictors of suicide and suicide attempt in subway stations: a population-based ecological study.

PubMed

Niederkrotenthaler, Thomas; Sonneck, Gernot; Dervic, Kanita; Nader, Ingo W; Voracek, Martin; Kapusta, Nestor D; Etzersdorfer, Elmar; Mittendorfer-Rutz, Ellenor; Dorner, Thomas

2012-04-01

Suicidal behavior on the subway often involves young people and has a considerable impact on public life, but little is known about factors associated with suicides and suicide attempts in specific subway stations. Between 1979 and 2009, 185 suicides and 107 suicide attempts occurred on the subway in Vienna, Austria. Station-specific suicide and suicide attempt rates (defined as the frequency of suicidal incidents per time period) were modeled as the outcome variables in bivariate and multivariate Poisson regression models. Structural station characteristics (presence of a surveillance unit, train types used, and construction on street level versus other construction), contextual station characteristics (neighborhood to historical sites, size of the catchment area, and in operation during time period of extensive media reporting on subway suicides), and passenger-based characteristics (number of passengers getting on the trains per day, use as meeting point by drug users, and socioeconomic status of the population in the catchment area) were used as the explanatory variables. In the multivariate analyses, subway suicides increased when stations were served by the faster train type. Subway suicide attempts increased with the daily number of passengers getting on the trains and with the stations' use as meeting points by drug users. The findings indicate that there are some differences between subway suicides and suicide attempts. Completed suicides seem to vary most with train type used. Suicide attempts seem to depend mostly on passenger-based characteristics, specifically on the station's crowdedness and on its use as meeting point by drug users. Suicide-preventive interventions should concentrate on crowded stations and on stations frequented by risk groups.

Geographical variation in the incidence of childhood leukaemia in Manitoba.

PubMed

Torabi, Mahmoud; Singh, Harminder; Galloway, Katie; Israels, Sara J

2015-11-01

Identification of geographical areas and ecological factors associated with higher incidence of childhood leukaemias can direct further study for preventable factors and location of health services to manage such individuals. The aim of this study was to describe the geographical variation and the socio-demographic factors associated with childhood leukaemia in Manitoba. Information on childhood leukaemia incidence between 1992 and 2008 was obtained from the Canadian Cancer Registry and the socio-demographic characteristics for the area of residence from the 2006 Canadian Census. Bayesian spatial Poisson mixed models were used to describe the geographical variation of childhood leukaemia and to determine the association between childhood leukaemia and socio-demographic factors. The south-eastern part of the province had a higher incidence of childhood leukaemia than other parts of the province. In the age and sex-adjusted Poisson regression models, areas with higher proportions of visible minorities and immigrant residents had higher childhood leukaemia incidence rate ratios. In the saturated Poisson regression model, the childhood leukaemia rates were higher in areas with higher proportions of immigrant residents. Unemployment rates were not a significant factor in leukaemia incidence. In Manitoba, areas with higher proportions of immigrants experience higher incidence rates of childhood leukaemia. We have identified geographical areas with higher incidence, which require further study and attention. © 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Spatiotemporal hurdle models for zero-inflated count data: Exploring trends in emergency department visits.

PubMed

Neelon, Brian; Chang, Howard H; Ling, Qiang; Hastings, Nicole S

2016-12-01

Motivated by a study exploring spatiotemporal trends in emergency department use, we develop a class of two-part hurdle models for the analysis of zero-inflated areal count data. The models consist of two components-one for the probability of any emergency department use and one for the number of emergency department visits given use. Through a hierarchical structure, the models incorporate both patient- and region-level predictors, as well as spatially and temporally correlated random effects for each model component. The random effects are assigned multivariate conditionally autoregressive priors, which induce dependence between the components and provide spatial and temporal smoothing across adjacent spatial units and time periods, resulting in improved inferences. To accommodate potential overdispersion, we consider a range of parametric specifications for the positive counts, including truncated negative binomial and generalized Poisson distributions. We adopt a Bayesian inferential approach, and posterior computation is handled conveniently within standard Bayesian software. Our results indicate that the negative binomial and generalized Poisson hurdle models vastly outperform the Poisson hurdle model, demonstrating that overdispersed hurdle models provide a useful approach to analyzing zero-inflated spatiotemporal data. © The Author(s) 2014.

Factors associated with physical inactivity in transportation in Brazilian adults living in a low socioeconomic area.

PubMed

Sa, Thiago Herick; Salvador, Emanuel Péricles; Florindo, Alex Antonio

2013-08-01

Physical inactivity in transportation is negatively related to many health outcomes. However, little is known about the correlates of this condition among people living in regions of low socioeconomic level. Cross-sectional study aimed to assess factors associated with physical inactivity in transportation among adults in the Eastern Zone of São Paulo, Brazil. Home-based interviews were conducted between May 2007 and January 2008 on a probabilistic sample of the adult population (≥18 years), totaling 368 men and 522 women. Factors associated with physical inactivity in transportation (less than 10 minutes per week of walking or cycling) were assessed using multivariate Poisson regression with hierarchical selection of variables. Physical inactivity in transportation was associated with the presence of vehicles in the household in men (PR = 2.96) and women (PR = 2.42), with linear trend for both sexes (P < .001 and P = .004, respectively), even after adjusting for age, schooling level and chronic diseases (this last factor, only among women). Presence of vehicles in the household was associated positively with physical inactivity in transportation, both for men and for women. This should be taken into consideration in drawing up public policies for promoting physical activity.

Socio-demographic patterns of disability among older adult populations of low-income and middle-income countries: results from World Health Survey.

PubMed

Hosseinpoor, Ahmad Reza; Bergen, Nicole; Kostanjsek, Nenad; Kowal, Paul; Officer, Alana; Chatterji, Somnath

2016-04-01

Our objective was to quantify disability prevalence among older adults of low- and middle-income countries, and measure socio-demographic distribution of disability. World Health Survey data included 53,447 adults aged 50 or older from 43 low- and middle-income countries. Disability was a binary classification, based on a composite score derived from self-reported functional difficulties. Socio-demographic variables included sex, age, marital status, area of residence, education level, and household economic status. A multivariate Poisson regression model with robust variance was used to assess associations between disability and socio-demographic variables. Overall, 33.3 % (95 % CI 32.2-34.4 %) of older adults reported disability. Disability was 1.5 times more common in females, and was positively associated with increasing age. Divorced/separated/widowed respondents reported higher disability rates in all but one study country, and education and wealth levels were inversely associated with disability rates. Urban residence tended to be advantageous over rural. Country-level datasets showed disparate patterns. Effective approaches aimed at disability prevention and improved disability management are warranted, including the inclusion of equity considerations in monitoring and evaluation activities.

Soil-transmitted helminth infection and nutritional status among urban slum children in Kenya.

PubMed

Suchdev, Parminder S; Davis, Stephanie M; Bartoces, Monina; Ruth, Laird J; Worrell, Caitlin M; Kanyi, Henry; Odero, Kennedy; Wiegand, Ryan E; Njenga, Sammy M; Montgomery, Joel M; Fox, LeAnne M

2014-02-01

To evaluate the nutritional impact of soil-transmitted helminth (STH) infection, we conducted a cross-sectional survey of 205 pre-school (PSC) and 487 school-aged children (SAC) randomly selected from the surveillance registry of the Centers for Disease Control and Prevention of the Kibera slum in Kenya. Hemoglobin, iron deficiency (ID), vitamin A deficiency (VAD), inflammation, malaria, anthropometry, and STH ova were measured. Poisson regression models evaluated associations between STH and malnutrition outcomes and controlled for confounders. Approximately 40% of PSC and SAC had STH infection, primarily Ascaris and Trichuris; 2.9% of PSC and 1.1% of SAC had high-intensity infection. Malnutrition prevalence among PSC and SAC was anemia (38.3% and 14.0%, respectively), ID (23.0% and 5.0%, respectively), VAD (16.9% and 4.5%, respectively), and stunting (29.7% and 16.9%, respectively). In multivariate analysis, STH in PSC was associated with VAD (prevalence ratio [PR] = 2.2, 95% confidence interval = 1.1-4.6) and ID (PR = 3.3, 95% confidence interval = 1.6-6.6) but not anemia or stunting. No associations were significant in SAC. Integrated deworming and micronutrient supplementation strategies should be evaluated in this population.

Association between Periodontal Condition and Nutritional Status of Brazilian Adolescents: A Population-based Study.

PubMed

Cavalcanti, Alessandro L; Ramos, Ianny A; Cardoso, Andreia M R; Fernandes, Liege Helena F; Aragão, Amanda S; Santos, Fábio G; Aguiar, Yêska P C; Carvalho, Danielle F; Medeiros, Carla C M; De S C Soares, Renata; Castro, Ricardo D

2016-12-01

Obesity is a serious problem of public health and affects all socio-economic groups, irrespective of age, sex or ethnicity. The aim of this study was to evaluate the association between periodontal condition and nutritional status of adolescents. This was a cross-sectional study using a probability cluster sampling, and the sample was defined by statistical criterion, consisting of 559 students aged 15-19 yr enrolled in public schools of adolescents of Campina Grande, PB, Brazil in 2012. Socioeconomic characteristics were analyzed, as well as self-reported general and oral health, anthropometric data and periodontal condition (CPI and OHI-S). Descriptive and analytical analysis from bivariate and multivariate Poisson regression analysis with 5% significance level was performed. Of the 559 adolescents, 18.6% were overweight and 98.4% had some form of periodontal changes such as: bleeding (34.3%), calculus (38.8%), shallow pocket (22.9%) and deep pocket (2.3%). There was association between presence of periodontal changes with obesity ( P <0.05; CI 95%: 0.99 [0.98 - 0.99]). The association between presence of periodontal changes and obesity status in adolescents was indicated.

Association between Periodontal Condition and Nutritional Status of Brazilian Adolescents: A Population-based Study

PubMed Central

CAVALCANTI, Alessandro L.; RAMOS, Ianny A.; CARDOSO, Andreia M. R.; FERNANDES, Liege Helena F.; ARAGÃO, Amanda S.; SANTOS, Fábio G.; AGUIAR, Yêska P. C.; CARVALHO, Danielle F.; MEDEIROS, Carla C. M.; De S. C. SOARES, Renata; CASTRO, Ricardo D.

2016-01-01

Background: Obesity is a serious problem of public health and affects all socio-economic groups, irrespective of age, sex or ethnicity. The aim of this study was to evaluate the association between periodontal condition and nutritional status of adolescents. Methods: This was a cross-sectional study using a probability cluster sampling, and the sample was defined by statistical criterion, consisting of 559 students aged 15–19 yr enrolled in public schools of adolescents of Campina Grande, PB, Brazil in 2012. Socioeconomic characteristics were analyzed, as well as self-reported general and oral health, anthropometric data and periodontal condition (CPI and OHI-S). Descriptive and analytical analysis from bivariate and multivariate Poisson regression analysis with 5% significance level was performed. Results: Of the 559 adolescents, 18.6% were overweight and 98.4% had some form of periodontal changes such as: bleeding (34.3%), calculus (38.8%), shallow pocket (22.9%) and deep pocket (2.3%). There was association between presence of periodontal changes with obesity (P<0.05; CI 95%: 0.99 [0.98 – 0.99]). Conclusion: The association between presence of periodontal changes and obesity status in adolescents was indicated. PMID:28053924

Influence of passive smoking on learning in elementary school.

PubMed

Jorge, Juliana Gomes; Botelho, Clóvis; Silva, Ageo Mário Cândido; Moi, Gisele Pedroso

2016-01-01

To analyze the association between household smoking and the development of learning in elementary schoolchildren. Cross-sectional study with 785 students from the 2nd to the 5th year of elementary school. Students were evaluated by the School Literacy Screening Protocol to identify the presence of learning disabilities. Mothers/guardians were interviewed at home through a validated questionnaire. Descriptive and bivariate analysis, as well as multivariate Poisson regression, were performed. In the final model, the variables associated with learning difficulties were current smoking at the household in the presence of the child (PR=6.10, 95% CI: 4.56 to 8.16), maternal passive smoking during pregnancy (PR=1.46, 95% CI: 1.07 to 2.01), students attending the 2nd and 3rd years of Elementary School (PR=1.44, 95% CI: 1.10 to 1.90), and being children of mothers with only elementary level education (PR=1.36, 95% CI: 1.04 to 1.79). The study demonstrated an association between passive exposure to tobacco smoke and learning difficulties at school. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

A longitudinal analysis of shooter games and their relationship with conduct disorder and cself-reported delinquency.

PubMed

Smith, Sven; Ferguson, Chris; Beaver, Kevin

Despite several decades of research, little scholarly consensus has emerged regarding the role of violent video games in the development of youth psychopathology or crime. The current study employed the Avon Longitudinal Study of Parents and Children longitudinal dataset to examine the impact of the shooter game genre ownership in childhood on later adolescent conduct disorder and criminal behavior. Multivariate Poisson regressions with the robust estimator correlation matrix were performed comparing effects of independent and confounding variables. Results revealed that early childhood mental health symptoms at age seven related to ADHD, depression and early conduct disorder predicted criminal behavior at age fifteen. Male gender also predicted criminal behavior at age fifteen. However, exposure to shooter games did not predict adolescent conduct disorder or criminal behavior. We have found support that suggests that the role of violent video games in the development of youth psychopathology or crime is very little if any. Lack of a relationship between exposure to shooter games and later conduct and criminal behavior problems may be understood within the context of the Catalyst Model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of malocclusion on the quality of life of children aged 8 to 10 years.

PubMed

Dutra, Sônia Rodrigues; Pretti, Henrique; Martins, Milene Torres; Bendo, Cristiane Baccin; Vale, Miriam Pimenta

2018-01-01

The aim of the present cross-sectional study was to assess the impact of malocclusion on the quality of life of children aged 8 to 10 years attending public elementary schools in Belo Horizonte, State of Minas Gerais, Brazil. The Brazilian version of the Child Perceptions Questionnaire 8-10 (CPQ8-10) was used to evaluate oral health-related quality of life. The children were examined for the diagnosis of malocclusion using the Dental Aesthetic Index (DAI). The data were analyzed by bivariate and multivariate descriptive statistics using Poisson regression at a 5% significance level. A total of 270 children participated in the study. Children with normal occlusion or mild malocclusion (DAI ≤ 25) were 56% less likely (95%CI: 0.258-0.758; p= 0.003) to have their quality of life affected compared with children diagnosed with extremely severe malocclusion (DAI ≥ 36). Children with a maxillary anterior overjet ≥ 3 mm had higher CPQ8-10 mean scores (19.4; SD = 17.1) than those with an overjet < 3 mm (13.6; SD = 11.7; p= 0.038). Extremely severe malocclusion and pronounced maxillary anterior overjet were associated with a negative impact on quality of life.

A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control.

PubMed

Jacques, Antoine; Laurent, Marion; Ribière-Chabert, Magali; Saussac, Mathilde; Bougeard, Stéphanie; Budge, Giles E; Hendrikx, Pascal; Chauzat, Marie-Pierre

2017-01-01

Reports of honey bee population decline has spurred many national efforts to understand the extent of the problem and to identify causative or associated factors. However, our collective understanding of the factors has been hampered by a lack of joined up trans-national effort. Moreover, the impacts of beekeeper knowledge and beekeeping management practices have often been overlooked, despite honey bees being a managed pollinator. Here, we established a standardised active monitoring network for 5 798 apiaries over two consecutive years to quantify honey bee colony mortality across 17 European countries. Our data demonstrate that overwinter losses ranged between 2% and 32%, and that high summer losses were likely to follow high winter losses. Multivariate Poisson regression models revealed that hobbyist beekeepers with small apiaries and little experience in beekeeping had double the winter mortality rate when compared to professional beekeepers. Furthermore, honey bees kept by professional beekeepers never showed signs of disease, unlike apiaries from hobbyist beekeepers that had symptoms of bacterial infection and heavy Varroa infestation. Our data highlight beekeeper background and apicultural practices as major drivers of honey bee colony losses. The benefits of conducting trans-national monitoring schemes and improving beekeeper training are discussed.

[Occupation-, transportation- and leisure-related physical activity: gender inequalities in Santander, Colombia].

PubMed

Hormiga-Sánchez, Claudia M; Alzate-Posada, Martha L; Borrell, Carme; Palència, Laia; Rodríguez-Villamizar, Laura A; Otero-Wandurraga, Johanna A

2016-04-01

Objectives To estimate the prevalence of occupation-, transportation- and leisure-related physical activity, its compliance with recommendations, and to explore its association with demographic and socioeconomic variables in men and women of the Department of Santander (Colombia). Methods The sample consisted of 2421 people between 15 and 64 years of age, participants in the Risk Factors for Chronic Diseases of Santander cross-sectional study, developed in 2010. The Global Physical Activity Questionnaire was used for data collection. Age-adjusted prevalence ratios were calculated and multivariate analysis models were built by sex using robust Poisson regression. Results The prevalence of occupational and leisure physical activity and compliance with recommendations were lower in women. Sexual division of labor and a low socioeconomic level negatively influenced physical activity in women, limiting the possibility of practice of those principally engaged in unpaid work at home. Young or single men and those living in higher socioeconomic areas were more likely to practice physical activity in leisure time and meet recommendations. Conclusion Physical activity surveillance and related public policies should take into account the inequalities between the practice of men and women related to their socioeconomic conditions and the sexual division of labor.

THE DELINKING OF SEX AND MARRIAGE: PATHWAYS TO FERTILITY AMONG YOUNG FILIPINO WOMEN.

PubMed

Gipson, Jessica D; Hicks, Andrew L

2017-01-01

Partnership and fertility patterns of young Filipinos have changed dramatically from previous generations, with a widening gap between sexual initiation and marriage, and concurrent increases in teenage pregnancy and unwanted fertility. Further understanding of young adults' social contexts and partnership patterns are needed to inform reproductive health programmes and policies affecting young Filipinos. Multivariate Poisson regression models were conducted with longitudinal and inter-generational data from the Cebu Longitudinal Health and Nutrition Survey (1998-2009) to examine the predictors of young women's fertility. Age at first sex, and number and duration of partnerships each independently and significantly predicted women's fertility by 2009 after controlling for contextual influences. Young women with more conservative attitudes towards dating, sex and marriage, and who perceived their mothers to have more conservative attitudes, had higher fertility than their peers, as did young women with mothers who reported more adolescent sexual behaviours. In contrast, fertility was lower among daughters who had higher levels of communication with their mothers. Given high levels of unintended fertility and teenage pregnancy in the Philippines, the findings indicate that the interval between sexual initiation and first and subsequent partnerships may be ideal intervention points for reproductive health services for young Filipinos.

Impact of temperature on mortality in Hubei, China: a multi-county time series analysis

NASA Astrophysics Data System (ADS)

Zhang, Yunquan; Yu, Chuanhua; Bao, Junzhe; Li, Xudong

2017-03-01

We examined the impact of extreme temperatures on mortality in 12 counties across Hubei Province, central China, during 2009-2012. Quasi-Poisson generalized linear regression combined with distributed lag non-linear model was first applied to estimate county-specific relationship between temperature and mortality. A multivariable meta-analysis was then used to pool the estimates of county-specific mortality effects of extreme cold temperature (1st percentile) and hot temperature (99th percentile). An inverse J-shaped relationship was observed between temperature and mortality at the provincial level. Heat effect occurred immediately and persisted for 2-3 days, whereas cold effect was 1-2 days delayed and much longer lasting. Higher mortality risks were observed among females, the elderly aged over 75 years, persons dying outside the hospital and those with high education attainment, especially for cold effects. Our data revealed some slight differences in heat- and cold- related mortality effects on urban and rural residents. These findings may have important implications for developing locally-based preventive and intervention strategies to reduce temperature-related mortality, especially for those susceptible subpopulations. Also, urbanization should be considered as a potential influence factor when evaluating temperature-mortality association in future researches.

When healthcare workers get sick: exploring sickness absenteeism in British Columbia, Canada.

PubMed

Gorman, Erin; Yu, Shicheng; Alamgir, Hasanat

2010-01-01

To determine the demographic and work characteristics of healthcare workers who were more likely to take sickness absences from work in British Columbia, Canada. Payroll data were analyzed for three health regions. Sickness absence rates were determined per person-year and then compared across demographic and work characteristics using multivariate Poisson regression models. The direct costs to the employer due to sickness absences were also estimated. Female, older, full-time workers, long-term care workers and those with a lower hourly wage were more likely to take sickness absences and had similar trends with respect to the costs due to sickness absence. For occupations, licensed practical nurses, care aides and facility support workers had higher rates of sickness absence. Registered nurses, and those workers paid high hourly wages were associated with highest sickness related costs. It is important to understand the demographic and work characteristics of those workers who are more likely to take sickness absences in order to make sure that they are not experiencing additional hazards at work or facing detrimental workplace conditions. Policy makers need to establish healthy, safe and in turn more productive workplaces. Further research is needed on how interventions can reduce sickness absence.

Health-risk behaviors in young adolescents in the child welfare system.

PubMed

Leslie, Laurel K; James, Sigrid; Monn, Amy; Kauten, Milena C; Zhang, Jinjin; Aarons, Gregory

2010-07-01

To examine rates and patterns of health-risk behavior (e.g., sexuality, depression/suicidality, substance use, delinquency) among a national probability sample of youth active to the child welfare/child protective services system. Recent federal legislation, P.L. 110-351, encourages child welfare systems, Medicaid, and pediatric experts to collaborate to ensure youth entering foster care receive comprehensive health examinations. Analysis of baseline caregiver, caseworker, and child interviews, and assessment data for a subsample (n = 993) of youth, aged 11-15 years, from the National Survey of Child and Adolescent Well-Being, a national probability sample of children and adolescents undergoing investigation for abuse or neglect. Almost half of the sample (46.3%) endorsed at least one health-risk behavior. On Poisson multivariate regression modeling, factors related to higher rates of health-risk behaviors included older age, female gender, abuse history, deviant peers, limited caregiver monitoring, and poor school engagement. Given the heightened vulnerability of this population, early screening for health-risk behaviors must be prioritized. Further research should explore specific subpopulations at risk for health-risk behaviors and possible interventions to change these youths' trajectories. Copyright (c) 2010 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Does attitude matter in computer use in Australian general practice? A zero-inflated Poisson regression analysis.

PubMed

Khan, Asaduzzaman; Western, Mark

The purpose of this study was to explore factors that facilitate or hinder effective use of computers in Australian general medical practice. This study is based on data extracted from a national telephone survey of 480 general practitioners (GPs) across Australia. Clinical functions performed by GPs using computers were examined using a zero-inflated Poisson (ZIP) regression modelling. About 17% of GPs were not using computer for any clinical function, while 18% reported using computers for all clinical functions. The ZIP model showed that computer anxiety was negatively associated with effective computer use, while practitioners' belief about usefulness of computers was positively associated with effective computer use. Being a female GP or working in partnership or group practice increased the odds of effectively using computers for clinical functions. To fully capitalise on the benefits of computer technology, GPs need to be convinced that this technology is useful and can make a difference.

Simple, Efficient Estimators of Treatment Effects in Randomized Trials Using Generalized Linear Models to Leverage Baseline Variables

PubMed Central

Rosenblum, Michael; van der Laan, Mark J.

2010-01-01

Models, such as logistic regression and Poisson regression models, are often used to estimate treatment effects in randomized trials. These models leverage information in variables collected before randomization, in order to obtain more precise estimates of treatment effects. However, there is the danger that model misspecification will lead to bias. We show that certain easy to compute, model-based estimators are asymptotically unbiased even when the working model used is arbitrarily misspecified. Furthermore, these estimators are locally efficient. As a special case of our main result, we consider a simple Poisson working model containing only main terms; in this case, we prove the maximum likelihood estimate of the coefficient corresponding to the treatment variable is an asymptotically unbiased estimator of the marginal log rate ratio, even when the working model is arbitrarily misspecified. This is the log-linear analog of ANCOVA for linear models. Our results demonstrate one application of targeted maximum likelihood estimation. PMID:20628636

Alternatives for using multivariate regression to adjust prospective payment rates

PubMed Central

Sheingold, Steven H.

1990-01-01

Multivariate regression analysis has been used in structuring three of the adjustments to Medicare's prospective payment rates. Because the indirect-teaching adjustment, the disproportionate-share adjustment, and the adjustment for large cities are responsible for distributing approximately $3 billion in payments each year, the specification of regression models for these adjustments is of critical importance. In this article, the application of regression for adjusting Medicare's prospective rates is discussed, and the implications that differing specifications could have for these adjustments are demonstrated. PMID:10113271

Electricity Consumption in the Industrial Sector of Jordan: Application of Multivariate Linear Regression and Adaptive Neuro-Fuzzy Techniques

NASA Astrophysics Data System (ADS)

Samhouri, M.; Al-Ghandoor, A.; Fouad, R. H.

2009-08-01

In this study two techniques, for modeling electricity consumption of the Jordanian industrial sector, are presented: (i) multivariate linear regression and (ii) neuro-fuzzy models. Electricity consumption is modeled as function of different variables such as number of establishments, number of employees, electricity tariff, prevailing fuel prices, production outputs, capacity utilizations, and structural effects. It was found that industrial production and capacity utilization are the most important variables that have significant effect on future electrical power demand. The results showed that both the multivariate linear regression and neuro-fuzzy models are generally comparable and can be used adequately to simulate industrial electricity consumption. However, comparison that is based on the square root average squared error of data suggests that the neuro-fuzzy model performs slightly better for future prediction of electricity consumption than the multivariate linear regression model. Such results are in full agreement with similar work, using different methods, for other countries.

Detecting isotopic ratio outliers

NASA Astrophysics Data System (ADS)

Bayne, C. K.; Smith, D. H.

An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers.

Applied Statistics: From Bivariate through Multivariate Techniques [with CD-ROM

ERIC Educational Resources Information Center

Warner, Rebecca M.

2007-01-01

This book provides a clear introduction to widely used topics in bivariate and multivariate statistics, including multiple regression, discriminant analysis, MANOVA, factor analysis, and binary logistic regression. The approach is applied and does not require formal mathematics; equations are accompanied by verbal explanations. Students are asked…

Generation of Plausible Hurricane Tracks for Preparedness Exercises

DTIC Science & Technology

2017-04-25

wind extents are simulated by Poisson regression and temporal filtering . The un-optimized MATLAB code runs in less than a minute and is integrated into...of real hurricanes. After wind radii have been simulated for the entire track, median filtering , attenuation over land, and smoothing clean up the wind

Inhalant Use among Indiana School Children, 1991-2004

ERIC Educational Resources Information Center

Ding, Kele; Torabi, Mohammad R.; Perera, Bilesha; Jun, Mi Kyung; Jones-McKyer, E. Lisako

2007-01-01

Objective: To examine the prevalence and trend of inhalant use among Indiana public school students. Methods: The Alcohol, Tobacco, and Other Drug Use among Indiana Children and Adolescents surveys conducted annually between 1991 and 2004 were reanalyzed using 2-way moving average, Poisson regression, and ANOVA tests. Results: The prevalence had…

Effect of Contact Damage on the Strength of Ceramic Materials.

DTIC Science & Technology

1982-10-01

variables that are important to erosion, and a multivariate , linear regression analysis is used to fit the data to the dimensional analysis. The...of Equations 7 and 8 by a multivariable regression analysis (room tem- perature data) Exponent Regression Standard error Computed coefficient of...1980) 593. WEAVER, Proc. Brit. Ceram. Soc. 22 (1973) 125. 39. P. W. BRIDGMAN, "Dimensional Analaysis ", (Yale 18. R. W. RICE, S. W. FREIMAN and P. F

Seasonally adjusted birth frequencies follow the Poisson distribution.

PubMed

Barra, Mathias; Lindstrøm, Jonas C; Adams, Samantha S; Augestad, Liv A

2015-12-15

Variations in birth frequencies have an impact on activity planning in maternity wards. Previous studies of this phenomenon have commonly included elective births. A Danish study of spontaneous births found that birth frequencies were well modelled by a Poisson process. Somewhat unexpectedly, there were also weekly variations in the frequency of spontaneous births. Another study claimed that birth frequencies follow the Benford distribution. Our objective was to test these results. We analysed 50,017 spontaneous births at Akershus University Hospital in the period 1999-2014. To investigate the Poisson distribution of these births, we plotted their variance over a sliding average. We specified various Poisson regression models, with the number of births on a given day as the outcome variable. The explanatory variables included various combinations of years, months, days of the week and the digit sum of the date. The relationship between the variance and the average fits well with an underlying Poisson process. A Benford distribution was disproved by a goodness-of-fit test (p < 0.01). The fundamental model with year and month as explanatory variables is significantly improved (p < 0.001) by adding day of the week as an explanatory variable. Altogether 7.5% more children are born on Tuesdays than on Sundays. The digit sum of the date is non-significant as an explanatory variable (p = 0.23), nor does it increase the explained variance. INERPRETATION: Spontaneous births are well modelled by a time-dependent Poisson process when monthly and day-of-the-week variation is included. The frequency is highest in summer towards June and July, Friday and Tuesday stand out as particularly busy days, and the activity level is at its lowest during weekends.

Marginal regression models for clustered count data based on zero-inflated Conway-Maxwell-Poisson distribution with applications.

PubMed

Choo-Wosoba, Hyoyoung; Levy, Steven M; Datta, Somnath

2016-06-01

Community water fluoridation is an important public health measure to prevent dental caries, but it continues to be somewhat controversial. The Iowa Fluoride Study (IFS) is a longitudinal study on a cohort of Iowa children that began in 1991. The main purposes of this study (http://www.dentistry.uiowa.edu/preventive-fluoride-study) were to quantify fluoride exposures from both dietary and nondietary sources and to associate longitudinal fluoride exposures with dental fluorosis (spots on teeth) and dental caries (cavities). We analyze a subset of the IFS data by a marginal regression model with a zero-inflated version of the Conway-Maxwell-Poisson distribution for count data exhibiting excessive zeros and a wide range of dispersion patterns. In general, we introduce two estimation methods for fitting a ZICMP marginal regression model. Finite sample behaviors of the estimators and the resulting confidence intervals are studied using extensive simulation studies. We apply our methodologies to the dental caries data. Our novel modeling incorporating zero inflation, clustering, and overdispersion sheds some new light on the effect of community water fluoridation and other factors. We also include a second application of our methodology to a genomic (next-generation sequencing) dataset that exhibits underdispersion. © 2015, The International Biometric Society.

Local polynomial estimation of heteroscedasticity in a multivariate linear regression model and its applications in economics.

PubMed

Su, Liyun; Zhao, Yanyong; Yan, Tianshun; Li, Fenglan

2012-01-01

Multivariate local polynomial fitting is applied to the multivariate linear heteroscedastic regression model. Firstly, the local polynomial fitting is applied to estimate heteroscedastic function, then the coefficients of regression model are obtained by using generalized least squares method. One noteworthy feature of our approach is that we avoid the testing for heteroscedasticity by improving the traditional two-stage method. Due to non-parametric technique of local polynomial estimation, it is unnecessary to know the form of heteroscedastic function. Therefore, we can improve the estimation precision, when the heteroscedastic function is unknown. Furthermore, we verify that the regression coefficients is asymptotic normal based on numerical simulations and normal Q-Q plots of residuals. Finally, the simulation results and the local polynomial estimation of real data indicate that our approach is surely effective in finite-sample situations.

Modeling Tetanus Neonatorum case using the regression of negative binomial and zero-inflated negative binomial

NASA Astrophysics Data System (ADS)

Amaliana, Luthfatul; Sa'adah, Umu; Wayan Surya Wardhani, Ni

2017-12-01

Tetanus Neonatorum is an infectious disease that can be prevented by immunization. The number of Tetanus Neonatorum cases in East Java Province is the highest in Indonesia until 2015. Tetanus Neonatorum data contain over dispersion and big enough proportion of zero-inflation. Negative Binomial (NB) regression is an alternative method when over dispersion happens in Poisson regression. However, the data containing over dispersion and zero-inflation are more appropriately analyzed by using Zero-Inflated Negative Binomial (ZINB) regression. The purpose of this study are: (1) to model Tetanus Neonatorum cases in East Java Province with 71.05 percent proportion of zero-inflation by using NB and ZINB regression, (2) to obtain the best model. The result of this study indicates that ZINB is better than NB regression with smaller AIC.

The association of C-reactive protein with subclinical cardiovascular disease in HIV-infected and HIV-uninfected women.

PubMed

Moran, Caitlin A; Sheth, Anandi N; Mehta, C Christina; Hanna, David B; Gustafson, Deborah R; Plankey, Michael W; Mack, Wendy J; Tien, Phyllis C; French, Audrey L; Golub, Elizabeth T; Quyyumi, Arshed; Kaplan, Robert C; Ofotokun, Ighovwerha

2018-05-15

HIV is a cardiovascular disease (CVD) risk factor. However, CVD risk is often underestimated in HIV-infected women. C-reactive protein (CRP) may improve CVD prediction in this population. We examined the association of baseline plasma CRP with subclinical CVD in women with and without HIV. Retrospective cohort study. A total of 572 HIV-infected and 211 HIV-uninfected women enrolled in the Women's Interagency HIV Study underwent serial high-resolution B-mode carotid artery ultrasonography between 2004 and 2013 to assess carotid intima-media thickness (CIMT) and focal carotid artery plaques. We used multivariable linear and logistic regression models to assess the association of baseline high (≥3 mg/l) high-sensitivity (hs) CRP with baseline CIMT and focal plaques, and used multivariable linear and Poisson regression models for the associations of high hsCRP with CIMT change and focal plaque progression. We stratified our analyses by HIV status. Median (interquartile range) hsCRP was 2.2 mg/l (0.8-5.3) in HIV-infected, and 3.2 mg/l (0.9-7.7) in HIV-uninfected, women (P = 0.005). There was no statistically significant association of hsCRP with baseline CIMT [adjusted mean difference -3.5 μm (95% confidence interval:-19.0 to 12.1)] or focal plaques [adjusted odds ratio: 1.31 (0.67-2.67)], and no statistically significant association of hsCRP with CIMT change [adjusted mean difference 11.4 μm (-2.3 to 25.1)]. However, hsCRP at least 3 mg/l was positively associated with focal plaque progression in HIV-uninfected [adjusted rate ratio: 5.97 (1.46-24.43)], but not in HIV-infected [adjusted rate ratio: 0.81 (0.47-1.42)] women (P = 0.042 for interaction). In our cohort of women with similar CVD risk factors, higher baseline hsCRP is positively associated with carotid plaque progression in HIV-uninfected, but not HIV-infected, women, suggesting that subclinical CVD pathogenesis may be different HIV-infected women.

Pregnancy Intentions and Safer Pregnancy Knowledge Among Female Sex Workers in Port Elizabeth, South Africa.

PubMed

Rao, Amrita; Baral, Stefan; Phaswana-Mafuya, Nancy; Lambert, Andrew; Kose, Zamakayise; Mcingana, Mfezi; Holland, Claire; Ketende, Sosthenes; Schwartz, Sheree

2016-07-01

To assess the association between human immunodeficiency virus (HIV) and pregnancy intentions and safer conception knowledge among female sex workers in Port Elizabeth, South Africa. This cross-sectional study recruited female sex workers in Port Elizabeth using respondent-driven sampling and completed an interviewer-administered questionnaire alongside HIV testing and counseling. In this secondary analysis, robust Poisson regression was used to model prevalence ratios for positive fertility intentions in this cross-sectional study. Knowledge of safer conception methods by HIV status was compared using Fisher exact tests. Overall 391 women were represented in the analyses. More than 50% had a prior HIV diagnosis, and an additional 12% were diagnosed with HIV during the study. Approximately half (n=185) of the women reported future pregnancy intentions. In univariate analysis, a prior HIV diagnosis was negatively associated with pregnancy intentions as compared with HIV-negative women (prevalence ratio 0.68, 95% confidence interval 0.55-0.85). Only parity remained independently associated with future pregnancy intentions in multivariate regression after controlling for HIV status, age, race, relationship status, and years selling sex. Knowledge of safer conception methods such as timed sex without a condom, preexposure prophylaxis, or self-insemination was low and similar between those with and without future pregnancy plans. Pregnancy intentions did not significantly vary according to HIV status. Fertility intentions were high, however, and knowledge of safer conception methods low, suggesting a need to provide female sex workers with advice around options to conceive safely in the context of high HIV prevalence.

Socioeconomic, hygienic, and sanitation factors in reducing diarrhea in the Amazon

PubMed Central

Imada, Katiuscia Shirota; de Araújo, Thiago Santos; Muniz, Pascoal Torres; de Pádua, Valter Lúcio

2016-01-01

ABSTRACT OBJECTIVE To analyze the contributions of the socioeconomic, hygienic, and sanitation improvements in reducing the prevalence of diarrhea in a city of the Amazon. METHODS In this population-based cross-sectional study, we analyzed data from surveys conducted in the city of Jordão, Acre. In 2005 and 2012, these surveys evaluated, respectively, 466 and 826 children under five years old. Questionnaires were applied on the socioeconomic conditions, construction of houses, food and hygienic habits, and environmental sanitation. We applied Pearson’s Chi-squared test and Poisson regression to verify the relationship between origin of water, construction of homes, age of introduction of cow’s milk in the diet, place of birth and the prevalence of diarrhea. RESULTS The prevalence of diarrhea was reduced from 45.1% to 35.4%. We identified higher probability of diarrhea in children who did not use water from the public network, in those receiving cow’s milk in the first month after birth, and in those living in houses made of paxiúba. Children born at home presented lower risk of diarrhea when compared to those who were born in hospital, with this difference reversing for the 2012 survey. CONCLUSIONS Sanitation conditions improved with the increase of bathrooms with toilets, implementation of the Programa de Saúde da Família (PSF – Family Health Program), and water treatment in the city. The multivariate regression model identified a statistically significant association between use of water from the public network, construction of houses, late introduction of cow’s milk, and access to health service with occurrence of diarrhea. PMID:28099660

Testing antismoking messages for Air Force trainees.

PubMed

Popova, Lucy; Linde, Brittany D; Bursac, Zoran; Talcott, G Wayne; Modayil, Mary V; Little, Melissa A; Ling, Pamela M; Glantz, Stanton A; Klesges, Robert C

2016-11-01

Young adults in the military are aggressively targeted by tobacco companies and are at high risk of tobacco use. Existing antismoking advertisements developed for the general population might be effective in educating young adults in the military. This study evaluated the effects of different themes of existing antismoking advertisements on perceived harm and intentions to use cigarettes and other tobacco products among Air Force trainees. In a pretest-post-test experiment, 782 Airmen were randomised to view antismoking advertisements in 1 of 6 conditions: anti-industry, health effects+anti-industry, sexual health, secondhand smoke, environment+anti-industry or control. We assessed the effect of different conditions on changes in perceived harm and intentions to use cigarettes, electronic cigarettes, smokeless tobacco, hookah and cigarillos from pretest to post-test with multivariable linear regression models (perceived harm) and zero-inflated Poisson regression model (intentions). Antismoking advertisements increased perceived harm of various tobacco products and reduced intentions to use. Advertisements featuring negative effects of tobacco on health and sexual performance coupled with revealing tobacco industry manipulations had the most consistent pattern of effects on perceived harm and intentions. Antismoking advertisements produced for the general public might also be effective with a young adult military population and could have spillover effects on perceptions of harm and intentions to use other tobacco products besides cigarettes. Existing antismoking advertising may be a cost-effective tool to educate young adults in the military. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Mortality among subjects with chronic obstructive pulmonary disease or asthma at two respiratory disease clinics in Ontario

PubMed Central

Finkelstein, Murray M; Chapman, Kenneth R; McIvor, R Andrew; Sears, Malcolm R

2011-01-01

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and asthma are common; however, mortality rates among individuals with these diseases are not well studied in North America. OBJECTIVE: To investigate mortality rates and risk factors for premature death among subjects with COPD. METHODS: Subjects were identified from the lung function testing databases of two academic respiratory disease clinics in Hamilton and Toronto, Ontario. Mortality was ascertained by linkage to the Ontario mortality registry between 1992 and 2002, inclusive. Standardized mortality ratios were computed. Poisson regression of standardized mortality ratios and proportional hazards regression were performed to examine the multivariate effect of risk factors on the standardized mortality ratios and mortality hazards. RESULTS: Compared with the Ontario population, all-cause mortality was approximately doubled among subjects with COPD, but was lower than expected among subjects with asthma. The risk of mortality in patients with COPD was related to cigarette smoking, to the presence of comorbid conditons of ischemic heart disease and diabetes, and to Global initiative for chronic Obstructive Lung Disease severity scores. Individuals living closer to traffic sources showed an elevated risk of death compared with those who lived further away from traffic sources. CONCLUSIONS: Mortality rates among subjects diagnosed with COPD were substantially elevated. There were several deaths attributed to asthma among subjects in the present study; however, overall, patients with asthma demonstrated lower mortality rates than the general population. Subjects with COPD need to be managed with attention devoted to both their respiratory disorders and related comorbidities. PMID:22187688

Syndromic surveillance for evaluating the occurrence of healthcare-associated infections in equine hospitals.

PubMed

Ruple-Czerniak, A A; Aceto, H W; Bender, J B; Paradis, M R; Shaw, S P; Van Metre, D C; Weese, J S; Wilson, D A; Wilson, J; Morley, P S

2014-07-01

Methods that can be used to estimate rates of healthcare-associated infections and other nosocomial events have not been well established for use in equine hospitals. Traditional laboratory-based surveillance is expensive and cannot be applied in all of these settings. To evaluate the use of a syndromic surveillance system for estimating rates of occurrence of healthcare-associated infections among hospitalised equine cases. Multicentre, prospective longitudinal study. This study included weaned equids (n = 297) that were admitted for gastrointestinal disorders at one of 5 participating veterinary referral hospitals during a 12-week period in 2006. A survey form was completed by the primary clinician to summarise basic case information, procedures and treatments the horse received, and whether one or more of 7 predefined nosocomial syndromes were recognised at any point during hospitalisation. Adjusted rates of nosocomial events were estimated using Poisson regression. Risk factors associated with the risk of developing a nosocomial event were analysed using multivariable logistic regression. Among the study population, 95 nosocomial events were reported to have occurred in 65 horses. Controlling for differences among hospitals, 19.7% (95% confidence interval, 14.5-26.7) of the study population was reported to have had at least one nosocomial event recognised during hospitalisation. The most commonly reported nosocomial syndromes that were unrelated to the reason for hospitalisation were surgical site inflammation and i.v. catheter site inflammation. Syndromic surveillance systems can be standardised successfully for use across multiple hospitals without interfering with established organisational structures, in order to provide useful estimates of rates related to healthcare-associated infections. © 2013 EVJ Ltd.

Paramedic-Initiated Home Care Referrals and Use of Home Care and Emergency Medical Services.

PubMed

Verma, Amol A; Klich, John; Thurston, Adam; Scantlebury, Jordan; Kiss, Alex; Seddon, Gayle; Sinha, Samir K

2018-01-01

We examined the association between paramedic-initiated home care referrals and utilization of home care, 9-1-1, and Emergency Department (ED) services. This was a retrospective cohort study of individuals who received a paramedic-initiated home care referral after a 9-1-1 call between January 1, 2011 and December 31, 2012 in Toronto, Ontario, Canada. Home care, 9-1-1, and ED utilization were compared in the 6 months before and after home care referral. Nonparametric longitudinal regression was performed to assess changes in hours of home care service use and zero-inflated Poisson regression was performed to assess changes in the number of 9-1-1 calls and ambulance transports to ED. During the 24-month study period, 2,382 individuals received a paramedic-initiated home care referral. After excluding individuals who died, were hospitalized, or were admitted to a nursing home, the final study cohort was 1,851. The proportion of the study population receiving home care services increased from 18.2% to 42.5% after referral, representing 450 additional people receiving services. In longitudinal regression analysis, there was an increase of 17.4 hours in total services per person in the six months after referral (95% CI: 1.7-33.1, p = 0.03). The mean number of 9-1-1 calls per person was 1.44 (SD 9.58) before home care referral and 1.20 (SD 7.04) after home care referral in the overall study cohort. This represented a 10% reduction in 9-1-1 calls (95% CI: 7-13%, p < 0.001) in Poisson regression analysis. The mean number of ambulance transports to ED per person was 0.91 (SD 8.90) before home care referral and 0.79 (SD 6.27) after home care referral, representing a 7% reduction (95% CI: 3-11%, p < 0.001) in Poisson regression analysis. When only the participants with complete paramedic and home care records were included in the analysis, the reductions in 9-1-1 calls and ambulance transports to ED were attenuated but remained statistically significant. Paramedic-initiated home care referrals in Toronto were associated with improved access to and use of home care services and may have been associated with reduced 9-1-1 calls and ambulance transports to ED.

Variable Selection in Logistic Regression.

DTIC Science & Technology

1987-06-01

23 %. AUTIOR(.) S. CONTRACT OR GRANT NUMBE Rf.i %Z. D. Bai, P. R. Krishnaiah and . C. Zhao F49620-85- C-0008 " PERFORMING ORGANIZATION NAME AND AOORESS...d I7 IOK-TK- d 7 -I0 7’ VARIABLE SELECTION IN LOGISTIC REGRESSION Z. D. Bai, P. R. Krishnaiah and L. C. Zhao Center for Multivariate Analysis...University of Pittsburgh Center for Multivariate Analysis University of Pittsburgh Y !I VARIABLE SELECTION IN LOGISTIC REGRESSION Z- 0. Bai, P. R. Krishnaiah

Accident prediction model for public highway-rail grade crossings.

PubMed

Lu, Pan; Tolliver, Denver

2016-05-01

Considerable research has focused on roadway accident frequency analysis, but relatively little research has examined safety evaluation at highway-rail grade crossings. Highway-rail grade crossings are critical spatial locations of utmost importance for transportation safety because traffic crashes at highway-rail grade crossings are often catastrophic with serious consequences. The Poisson regression model has been employed to analyze vehicle accident frequency as a good starting point for many years. The most commonly applied variations of Poisson including negative binomial, and zero-inflated Poisson. These models are used to deal with common crash data issues such as over-dispersion (sample variance is larger than the sample mean) and preponderance of zeros (low sample mean and small sample size). On rare occasions traffic crash data have been shown to be under-dispersed (sample variance is smaller than the sample mean) and traditional distributions such as Poisson or negative binomial cannot handle under-dispersion well. The objective of this study is to investigate and compare various alternate highway-rail grade crossing accident frequency models that can handle the under-dispersion issue. The contributions of the paper are two-fold: (1) application of probability models to deal with under-dispersion issues and (2) obtain insights regarding to vehicle crashes at public highway-rail grade crossings. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical modeling of dental unit water bacterial test kit performance.

PubMed

Cohen, Mark E; Harte, Jennifer A; Stone, Mark E; O'Connor, Karen H; Coen, Michael L; Cullum, Malford E

2007-01-01

While it is important to monitor dental water quality, it is unclear whether in-office test kits provide bacterial counts comparable to the gold standard method (R2A). Studies were conducted on specimens with known bacterial concentrations, and from dental units, to evaluate test kit accuracy across a range of bacterial types and loads. Colony forming units (CFU) were counted for samples from each source, using R2A and two types of test kits, and conformity to Poisson distribution expectations was evaluated. Poisson regression was used to test for effects of source and device, and to estimate rate ratios for kits relative to R2A. For all devices, distributions were Poisson for low CFU/mL when only beige-pigmented bacteria were considered. For higher counts, R2A remained Poisson, but kits exhibited over-dispersion. Both kits undercounted relative to R2A, but the degree of undercounting was reasonably stable. Kits did not grow pink-pigmented bacteria from dental-unit water identified as Methylobacterium rhodesianum. Only one of the test kits provided results with adequate reliability at higher bacterial concentrations. Undercount bias could be estimated for this device and used to adjust test kit results. Insensitivity to methylobacteria spp. is problematic.

Comparing lagged linear correlation, lagged regression, Granger causality, and vector autoregression for uncovering associations in EHR data.

PubMed

Levine, Matthew E; Albers, David J; Hripcsak, George

2016-01-01

Time series analysis methods have been shown to reveal clinical and biological associations in data collected in the electronic health record. We wish to develop reliable high-throughput methods for identifying adverse drug effects that are easy to implement and produce readily interpretable results. To move toward this goal, we used univariate and multivariate lagged regression models to investigate associations between twenty pairs of drug orders and laboratory measurements. Multivariate lagged regression models exhibited higher sensitivity and specificity than univariate lagged regression in the 20 examples, and incorporating autoregressive terms for labs and drugs produced more robust signals in cases of known associations among the 20 example pairings. Moreover, including inpatient admission terms in the model attenuated the signals for some cases of unlikely associations, demonstrating how multivariate lagged regression models' explicit handling of context-based variables can provide a simple way to probe for health-care processes that confound analyses of EHR data.

Terminal Duct Lobular Unit Involution of the Normal Breast: Implications for Breast Cancer Etiology

PubMed Central

Pfeiffer, Ruth M.; Patel, Deesha A.; Linville, Laura; Brinton, Louise A.; Gierach, Gretchen L.; Yang, Xiaohong R.; Papathomas, Daphne; Visscher, Daniel; Mies, Carolyn; Degnim, Amy C.; Anderson, William F.; Hewitt, Stephen; Khodr, Zeina G.; Clare, Susan E.; Storniolo, Anna Maria; Sherman, Mark E.

2014-01-01

Background Greater degrees of terminal duct lobular unit (TDLU) involution have been linked to lower breast cancer risk; however, factors that influence this process are poorly characterized. Methods To study this question, we developed three reproducible measures that are inversely associated with TDLU involution: TDLU counts, median TDLU span, and median acini counts/TDLU. We determined factors associated with TDLU involution using normal breast tissues from 1938 participants (1369 premenopausal and 569 postmenopausal) ages 18 to 75 years in the Susan G. Komen Tissue Bank at the Indiana University Simon Cancer Center. Multivariable zero-inflated Poisson models were used to estimate relative risks (RRs) and 95% confidence intervals (95% CIs) for factors associated with TDLU counts, and multivariable ordinal logistic regression models were used to estimate odds ratios (ORs) and 95% CIs for factors associated with categories of median TDLU span and acini counts/TDLU. Results All TDLU measures started declining in the third age decade (all measures, two-sided P trend ≤ .001); and all metrics were statistically significantly lower among postmenopausal women. Nulliparous women demonstrated lower TDLU counts compared with uniparous women (among premenopausal women, RR = 0.79, 95% CI = 0.73 to 0.85; among postmenopausal, RR = 0.67, 95% CI = 0.56 to 0.79); however, rates of age-related TDLU decline were faster among parous women. Other factors were related to specific measures of TDLU involution. Conclusion Morphometric analysis of TDLU involution warrants further evaluation to understand the pathogenesis of breast cancer and assessing its role as a progression marker for women with benign biopsies or as an intermediate endpoint in prevention studies. PMID:25274491

Back Pain Prevalence and Its Associated Factors in Brazilian Athletes from Public High Schools: A Cross-Sectional Study.

PubMed

Noll, Matias; de Avelar, Ivan Silveira; Lehnen, Georgia Cristina; Vieira, Marcus Fraga

2016-01-01

Most studies on the prevalence of back pain have evaluated it in developed countries (Human Development Index--HDI > 0.808), and their conclusions may not hold for developing countries. The aim of this study was to identify the prevalence of back pain in representative Brazilian athletes from public high schools. This cross-sectional study was performed during the state phase of the 2015 Jogos dos Institutos Federais (JIF), or Federal Institutes Games, in Brazil (HDI = 0.744), and it enrolled 251 athletes, 173 males and 78 females (14-20 years old). The dependent variable was back pain, and the independent variables were demographic, socioeconomic, psychosocial, hereditary, exercise-level, anthropometric, strength, behavioral, and postural factors. The prevalence ratio (PR) was calculated using multivariable analysis according to the Poisson regression model (α = 0.05). The prevalence of back pain in the three months prior to the study was 43.7% (n = 104), and 26% of the athletes reported feeling back pain only once. Multivariable analysis showed that back pain was associated with demographic (sex), psychosocial (loneliness and loss of sleep in the previous year), hereditary (ethnicity, parental back pain), strength (lumbar and hand forces), anthropometric (body mass index), behavioral (sleeping time per night, reading and studying in bed, smoking habits in the previous month), and postural (sitting posture while writing, while on a bench, and while using a computer) variables. Participants who recorded higher levels of lumbar and manual forces reported a lower prevalence of back pain (PR < 0.79), whereas feeling lonely in the previous year, obesity, and ethnicity exhibited the highest prevalence ratio (PR > 1.30). In conclusion, there is no association between exercise levels and back pain but there is an association between back pain and non-exercise related variables.

Physical activity and unplanned illness-related work absenteeism: Data from an employee wellness program.

PubMed

Losina, Elena; Yang, Heidi Y; Deshpande, Bhushan R; Katz, Jeffrey N; Collins, Jamie E

2017-01-01

Illness-related absenteeism is a major threat to work productivity. Our objective was to assess the relationship between physical activity and unplanned illness-related absenteeism from work. We implemented physical activity program for sedentary non-clinician employees of a tertiary medical center. Financial rewards were available for reaching accelerometer-measured ambulatory physical activity goals over a 24-week period. We categorized participants into three groups based on mean levels of physical activity: low (0-74 min/week), medium (75-149 min/week) and meeting CDC guidelines (≥150 min/week). We built a multivariable Poisson regression model to evaluate the relationship between physical activity and rates of unplanned illness-related absenteeism. The sample consisted of 292 employees who participated in the program. Their mean age was 38 years (SD 11), 83% were female, and 38% were obese. Over the 24 intervention weeks, participants engaged in a mean of 90 min/week (SD 74) of physical activity and missed a mean of 14 hours of work (SD 38) due to illness. Unplanned absenteeism due to illness was associated with physical activity. As compared to the group meeting CDC guidelines, in multivariable analyses those in the medium physical activity group had a 2.4 (95% CI 1.3-4.5) fold higher rate of illness-related absenteeism and those in the lowest physical activity group had a 3.5 (95% CI 1.7-7.2) fold higher rate of illness-related absenteeism. Less physical activity was associated with more illness-related absenteeism. Workforce-based interventions to increase physical activity may thus be a promising vehicle to reduce unplanned illness-related absenteeism.

Medication Nonadherence is Associated with Increased Subsequent Acute Care Utilization among Medicaid Beneficiaries with Systemic Lupus Erythematosus

PubMed Central

Feldman, Candace H.; Yazdany, Jinoos; Guan, Hongshu; Solomon, Daniel H.; Costenbader, Karen H.

2015-01-01

Objective We examined whether nonadherence to hydroxychloroquine (HCQ) or immunosuppressive medications (IS) was associated with higher subsequent acute care utilization among Medicaid beneficiaries with systemic lupus erythematosus (SLE). Methods We utilized U.S. Medicaid data from 2000–2006 to identify adults 18–64 years with SLE who were new users of HCQ or IS. We defined the index date as receipt of HCQ or IS without use in the prior six months. We measured adherence using the medication possession ratio (MPR), the proportion of days covered by total days supply dispensed, for one-year post-index date. Our outcomes were all-cause and SLE-related emergency department (ED) visits and hospitalizations in the subsequent year. We used multivariable Poisson regression models to examine the association between nonadherence (MPR<80%) and acute care utilization adjusting for sociodemographics and comorbidities. Results We identified 9,600 HCQ new users and 3,829 IS new users with SLE. The mean MPR for HCQ was 47.8% (SD 30.3) and for IS, 42.7% (SD 30.7). 79% of HCQ users and 83% of IS users were nonadherent (MPR<80%). In multivariable models, among HCQ users, the incidence rate ratio (IRR) of ED visits was 1.55 (95% CI 1.43–1.69) and the IRR of hospitalizations was 1.37 (95% CI 1.25–1.50), comparing nonadherers to adherers. For IS users, the IRR of ED visits was 1.64 (95% CI 1.42–1.89) and of hospitalizations was 1.67 (95% CI 1.41–1.96) for nonadherers versus adherers. Conclusion In this cohort, nonadherence to HCQ and IS was common and was associated with significantly higher subsequent acute care utilization. PMID:26097166

Factors predictive of increased influenza and pneumococcal vaccination coverage in long-term care facilities: the CMS-CDC standing orders program Project.

PubMed

Bardenheier, Barbara H; Shefer, Abigail; McKibben, Linda; Roberts, Henry; Rhew, David; Bratzler, Dale

2005-01-01

Between 1999 and 2002, a multistate demonstration project was conducted in long-term care facilities (LTCFs) to encourage implementation of standing orders programs (SOP) as evidence-based vaccine delivery strategies to increase influenza and pneumococcal vaccination coverage in LTCFs. Examine predictors of increase in influenza and pneumococcal vaccination coverage in LTCFs. Intervention study. Self-administered surveys of LTCFs merged with data from OSCAR (On-line Survey Certification and Reporting System) and immunization coverage was abstracted from residents' medical charts in LTCFs. Twenty LTCFs were sampled from 9 intervention and 5 control states in the 2000 to 2001 influenza season for baseline and during the 2001 to 2002 influenza season for postintervention. Each state's quality improvement organization (QIO) promoted the use of standing orders for immunizations as well as other strategies to increase immunization coverage among LTCF residents. Multivariate analysis included Poisson regression to determine independent predictors of at least a 10 percentage-point increase in facility influenza and pneumococcal vaccination coverage. Forty-two (20%) and 59 (28%) of the facilities had at least a 10 percentage-point increase in influenza and pneumococcal immunizations, respectively. In the multivariate analysis, predictors associated with increase in influenza vaccination coverage included adoption of requirement in written immunization protocol to document refusals, less-demanding consent requirements, lower baseline influenza coverage, and small facility size. Factors associated with increase in pneumococcal vaccination coverage included adoption of recording pneumococcal immunizations in a consistent place, affiliation with a multifacility chain, and provision of resource materials. To improve the health of LTCF residents, strategies should be considered that increase immunization coverage, including written protocol for immunizations and documentation of refusals, documenting vaccination status in a consistent place in medical records, and minimal consent requirements for vaccinations.

Estimated incidence of erythema migrans in five regions of France and ecological correlations with environmental characteristics.

PubMed

Mariet, Anne-Sophie; Retel, Olivier; Avocat, Hélène; Serre, Anne; Schapman, Lucie; Schmitt, Marielle; Charron, Martine; Monnet, Elisabeth

2013-09-01

While several studies conducted on Lyme borreliosis (LB) risk in the United States showed an association with environmental characteristics, most of European studies considered solely the effect of climate characteristics. The aims of this study were to estimate incidence of erythema migrans (EM) in five regions of France and to analyze associations with several environmental characteristics of the place of residence. LB surveillance networks of general practitioners (GPs) were set up for a period of 2 years in five regions of France. Participating GPs reported all patients with EM during the study period. Data were pooled according to a standardized EM case definition. For each area with a participating GP, age-standardized incidence rates and ratios were estimated. Associations with altitude, indicators of landscape composition, and indicators of landscape configuration were tested with multivariate Poisson regression. Standardized estimated incidence rates of EM per 10(5) person-years were 8.8 [95% confidence interval (CI)=7.9-9.7] in Aquitaine, 40.0 (95% CI 36.4-43.6) in Limousin, 76.0 (95% CI 72.9-79.1) in the three participating départements of Rhône-Alpes, 46.1 (95% CI 43.0-49.2) in Franche-Comté, and 87.7 (95% CI 84.6-90.8) in Alsace. In multivariate analysis, age-adjusted incidence rates increased with the altitude (p<0.0001) and decreased with forest patch density (p<0.0001). The marked variations in EM risk among the five regions were partly related to differences in landscape and environmental characteristics. The latter may point out potential risk areas and provide information for targeting preventive actions.

Elevated cancer risk in Holocaust survivors residing in Israel: A retrospective cohort study.

PubMed

Ben David, Ran; Biderman, Aya; Sherf, Michael; Zamstein, Omri; Dreiher, Jacob

2018-05-01

The purpose of this study was to examine the incidence of malignant diseases among Holocaust survivors in Israel compared with European and American immigrants who did not experience the Holocaust. Study subjects included Holocaust survivors born in European countries under Nazi occupation before 1945, who immigrated to Israel after 1945 and were alive as of the year 2000. Living survivors were identified based on recognition criteria in accordance with the Holocaust Survivor Benefits Law. The comparison group consisted of Clalit enrollees who were born before 1945 in European countries not under Nazi occupation and were alive in 2000 or were born in any European country or America, immigrated to Israel before 1939 and were alive in 2000. The incidence of malignant diseases was compared in univariate and Poisson regression models analyses, controlling for age, smoking, obesity, diabetes and place of residence. The study included 294,543 Holocaust survivors, and the mean age at the beginning of follow-up was 74 ± 8.7 years; 43% males. In multivariable analyses, the rate ratio (RR) values for males and females were 1.9 and 1.3 for colon cancer, 1.9 and 1.4 for lung cancer, 1.6 and 1.4 for bladder cancer and 1.2 and 1.3 for melanoma, respectively. For prostate cancer in males, the RR was 1.4, while for breast cancer in females, it was 1.2. The incidence of malignant diseases among Holocaust survivors residing in Israel was higher than that among non-Holocaust survivors. These associations remained statistically significant in a multivariable analysis and were stronger for males. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessing Timely Presentation to Care Among People Diagnosed with HIV During Hospital Admission: A Population-Based Study in Ontario, Canada.

PubMed

Kendall, Claire E; Shoemaker, Esther S; Raboud, Janet; Mark, Amy E; Bayoumi, Ahmed M; Burchell, Ann N; Loutfy, Mona; Rourke, Sean B; Liddy, Clare E; Rosenes, Ron; Rogers, Timothy; Antoniou, Tony

2018-03-13

Timely presentation to care for people newly diagnosed with HIV is critical to optimize health outcomes and reduce onward HIV transmission. Studies describing presentation to care following diagnosis during a hospital admission are lacking. We sought to assess the timeliness of presentation to care and to identify factors associated with delayed presentation. We conducted a population-level study using health administrative databases. Participants were all individuals older than 16 and newly diagnosed with HIV during hospital admission in Ontario, Canada, between April 1, 2007 and March 31, 2015. We used modified Poisson regression models to derive relative risk ratios for the association between sociodemographic and clinical variables and the presentation to out-patient HIV care by 90 days following hospital discharge. Among 372 patients who received a primary HIV diagnosis in hospital, 83.6% presented to care by 90 days. Following multivariable analysis, we did not find associations between patient sociodemographic or clinical characteristics and presentation to care by 90 days. In a secondary analysis of 483 patients diagnosed during hospitalization but for whom HIV was not recorded as the principal reason for admission, 73.1% presented to care by 90 days. Following multivariable adjustment, we found immigrants from countries with generalized HIV epidemics (RR 1.265, 95% CI 1.133-1.413) were more likely to present to care, whereas timely presentation was less likely for people with a mental health diagnosis (RR 0.817, 95% CI 0.742-0.898) and women (RR 0.748, 95% CI 0.559-1.001). Future work should evaluate mechanisms to facilitate presentation to care among these populations.

Impact of malocclusion and dentofacial anomalies on the prevalence and severity of dental caries among adolescents.

PubMed

Feldens, Carlos Alberto; Dos Santos Dullius, Angela Isabel; Kramer, Paulo Floriani; Scapini, Annarosa; Busato, Adair Luiz Stefanello; Vargas-Ferreira, Fabiana

2015-11-01

To investigate the association between malocclusion/dentofacial anomalies and dental caries among adolescents. A cross-sectional study was conducted with 509 adolescents aged 11 to 14 years enrolled at public schools in the city of Osório in southern Brazil. Parents/caregivers answered a structured questionnaire on demographic and socioeconomic variables. A trained examiner recorded the presence of malocclusion (Dental Aesthetic Index [DAI]), traumatic dental injury, and dental caries. Data analysis involved the chi-square, Mann-Whitney, and Kruskal-Wallis tests. Poisson regression with robust variance was used for the multivariable analysis. A total of 44.8% of the adolescents had dental caries (mean DFMT  =  1.33 ± 1.84). The DAI index ranged from 15 to 77 (mean  =  29.0 ± 7.9); 43.6% of the sample had severe malocclusion and 11.6% had traumatic dental injury. The prevalence and severity of dental caries were significantly greater among adolescents with severe malocclusion. The multivariate analysis demonstrated that adolescents with severe or handicapping malocclusion had a 31% greater probability of having dental caries (prevalence ratio: 1.31; 95% CI: 1.02-1.67), independently of demographic, socioeconomic, or clinical aspects. The orthodontic characteristics associated with the occurrence and severity of caries were maxillary irregularity ≥3 mm (P  =  .021) and abnormal molar relationship (P  =  .021). Handicapping malocclusion, maxillary irregularity, and abnormal molar relationship were associated with the occurrence and severity of dental caries. The findings suggest that the prevention and treatment of these conditions can contribute to a reduction in dental caries among adolescents.

Secular trends and factors associated with overweight among Brazilian preschool children: PNSN-1989, PNDS-1996, and 2006/07.

PubMed

Silveira, Jonas Augusto C; Colugnati, Fernando Antônio B; Cocetti, Monize; Taddei, José Augusto A C

2014-01-01

to describe the secular trends in overweight among preschool children in the years 1989, 1996, and 2006, and to identify risk factors associated with this condition in 2006. anthropometric data from three surveys (1989, 1996, and 2006) with a representative sample of the population were analyzed. Overweight was defined as the weight-for-height Z-score. The multivariable models of overweight association with risk factors were generated by Poisson regression, and the estimates were shown as prevalence ratios with their respective 95% confidence intervals (PR [95% CI]). throughout the 17-year period studied, the relative prevalence of overweight in preschoolers increased by 160% in Brazil, representing an increase of 9.4% per year. Based on data from the National Survey on Demography and Health of Women and Children - 2006/07, four multivariable models were created (macro-environmental, maternal, individual, and final model) assuming hierarchy among the risk factors. In the final model, only the following remained associated with overweight: regions South/Southeast (1.55 [1.17 to 2.06]), middle-class (1.35 [1.02 to 1.77]), maternal obesity (1.66 [1.22 to 2.27]), birth weight ≥ 3.9kg (1.87 [1.31 to 2.67]), and being an only child or having only one sibling (1.81 [1.31 to 2.49]). the prevalence of overweight among preschool children in Brazil has increased dramatically over the past 17 years, and it was higher in the 1996-2006 period. Future strategies for prevention and control of overweight in public health should focus or intensify actions in communities that are characterized by the presence of the risks identified in the present study. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

The paradox of public holidays: Hospital-treated self-harm and associated factors.

PubMed

Griffin, Eve; Dillon, Christina B; O'Regan, Grace; Corcoran, Paul; Perry, Ivan J; Arensman, Ella

2017-08-15

Recent research on the patterns of self-harm around public holidays is lacking. This study used national data to examine the patterns of hospital-treated self-harm during public holidays, and to examine associated factors. Data on self-harm presentations to all emergency departments were obtained from the National Self-Harm Registry Ireland. The association between self-harm presentations and public holidays was examined using univariate and multivariate Poisson regression analyses. A total of 104,371 presentations of self-harm were recorded between 2007 and 2015. The mean number of self-harm presentations was 32 on public holidays. St. Patrick's Day had the highest number of presentations compared to all other public holidays, with a daily mean of 44 presentations. Across all years, self-harm presentations during public holidays had a 24% increased risk of involving alcohol consumption compared to all other days and this effect was most pronounced during the Christmas period. The association with alcohol remained significant at a multivariate level. Presentations on public holidays were more likely to attend out of normal working hours. An increase in male presentations involving self-cutting was observed on public holidays and there was an over-representation of males presenting for the first time. It is likely that extent of alcohol involvement in self-harm presentations reported here is an underestimate, as it was dependent on the information being recorded by the attending clinician. Public holidays are associated with an elevated number of self-harm presentations to hospital, with presentations to hospital involving alcohol significantly increased on these days. Hospital resources should be targeted to address increases during public holidays, including during out-of-hours. Involvement of alcohol may delay delivery of care to these patients in emergency settings. Copyright © 2017 Elsevier B.V. All rights reserved.

Physical activity and unplanned illness-related work absenteeism: Data from an employee wellness program

PubMed Central

Yang, Heidi Y.; Katz, Jeffrey N.; Collins, Jamie E.

2017-01-01

Background Illness-related absenteeism is a major threat to work productivity. Our objective was to assess the relationship between physical activity and unplanned illness-related absenteeism from work. Methods We implemented physical activity program for sedentary non-clinician employees of a tertiary medical center. Financial rewards were available for reaching accelerometer-measured ambulatory physical activity goals over a 24-week period. We categorized participants into three groups based on mean levels of physical activity: low (0–74 min/week), medium (75–149 min/week) and meeting CDC guidelines (≥150 min/week). We built a multivariable Poisson regression model to evaluate the relationship between physical activity and rates of unplanned illness-related absenteeism. Results The sample consisted of 292 employees who participated in the program. Their mean age was 38 years (SD 11), 83% were female, and 38% were obese. Over the 24 intervention weeks, participants engaged in a mean of 90 min/week (SD 74) of physical activity and missed a mean of 14 hours of work (SD 38) due to illness. Unplanned absenteeism due to illness was associated with physical activity. As compared to the group meeting CDC guidelines, in multivariable analyses those in the medium physical activity group had a 2.4 (95% CI 1.3–4.5) fold higher rate of illness-related absenteeism and those in the lowest physical activity group had a 3.5 (95% CI 1.7–7.2) fold higher rate of illness-related absenteeism. Discussion Less physical activity was associated with more illness-related absenteeism. Workforce-based interventions to increase physical activity may thus be a promising vehicle to reduce unplanned illness-related absenteeism. PMID:28472084

Prevalence of anal high-risk human papillomavirus infections among HIV-positive and HIV-negative men who have sex with men (MSM) in Nigeria

PubMed Central

Nowak, Rebecca G.; Gravitt, Patti E.; He, Xin; Ketende, Sosthenes; Anom, Wuese; Omuh, Helen; Blattner, William A.; Charurat, Manhattan E.

2016-01-01

Background Prevalence estimates of anal high-risk human papillomavirus (HR-HPV) are needed in sub-Saharan Africa where HIV is endemic. This study evaluated anal HR-HPV in Nigeria among HIV-positive and HIV-negative men who have sex with men (MSM) for future immunization recommendations. Methods We conducted a cross-sectional study to compare the prevalence of anal HR-HPV infections between 64 HIV-negative and 90 HIV-positive MSM. Multivariate Poisson regression analyses were used to examine demographic and behavioral risk factors associated with any HR-HPV infections. Results The median age of the 154 participants was 25 years (interquartile range [IQR]: 22-28, range: 16-38) and the median age at initiation of anal sex with another man was 16 years (IQR: 13-18, range: 7-29). The prevalence of anal HR-HPV was higher among HIV-positive than HIV-negative MSM (91.1% vs. 40.6%, p<0.001). In the multivariate analysis, HIV infection (adjusted prevalence ratio [aPR]: 2.02, 95% CI: 1.49-2.72), ten years or more since anal sexual debut (aPR: 1.26, 95% CI: 1.07-1.49), and concurrent relationships with men (aPR: 1.32, 95% CI: 1.04-1.67) were associated with increased anal HR-HPV prevalence. Conclusions Anal HR-HPV infection is high for young Nigerian MSM and rates are amplified in those co-infected with HIV. Providing universal coverage as well as catchup immunization for young MSM may be an effective anal cancer prevention strategy in Nigeria. PMID:26967301

Cigarette smoking and quit attempts among injection drug users in Tijuana, Mexico.

PubMed

Shin, Sanghyuk S; Moreno, Patricia Gonzalez; Rao, Smriti; Garfein, Richard S; Novotny, Thomas E; Strathdee, Steffanie A

2013-12-01

Injection drug use and cigarette smoking are major global health concerns. Limited data exist regarding cigarette smoking behavior and quit attempts among injection drug users (IDUs) in low- and middle-income countries to inform the development of cigarette smoking interventions. We conducted a cross-sectional study to describe cigarette smoking behavior and quit attempts among IDUs in Tijuana, Mexico. IDUs were recruited through community outreach and administered in-person interviews. Multivariable Poisson regression models were constructed to determine prevalence ratios (PRs) for quit attempts. Of the 670 participants interviewed, 601 (89.7%) were current smokers. Of these, median number of cigarettes smoked daily was 10; 190 (31.6%) contemplated quitting smoking in the next 6 months; 132 (22.0%) had previously quit for ≥1 year; and 124 (20.6%) had made a recent quit attempt (lasting ≥1 day during the previous 6 months). In multivariable analysis, recent quit attempts were positively associated with average monthly income (≥3,500 pesos [US$280] vs. <1,500 pesos [US$120]; PR = 2.30; 95% CI = 1.57-3.36), smoking marijuana (PR = 1.38; 95% CI = 1.01-2.90), and smoking heroin (PR = 1.85; 95% CI = 1.23-2.78), and they were negatively associated with number of cigarettes smoked daily (PR = 0.96; 95% CI = 0.94-0.98). One out of 5 IDUs attempted to quit cigarette smoking during the previous 6 months. Additional research is needed to improve the understanding of the association between drug use patterns and cigarette smoking quit attempts, including the higher rate of quit attempts observed among IDUs who smoke marijuana or heroin compared with IDUs who do not smoke these substances.

Experiences with urine drug testing by police among people who inject drugs in Bangkok, Thailand.

PubMed

Hayashi, Kanna; Ti, Lianping; Buxton, Jane A; Kaplan, Karyn; Suwannawong, Paisan; Wood, Evan; Kerr, Thomas

2014-03-01

Thailand has relied on drug law enforcement in an effort to curb illicit drug use. While anecdotal reports suggest that Thai police frequently use urine toxicology to identify drug users, little is known about the prevalence or impacts of this practice among people who inject drugs (IDU). Therefore, we sought to examine experiences with urine drug testing by police among IDU in Bangkok. Data were derived from a community-recruited sample of IDU in Bangkok participating in the Mitsampan Community Research Project between July and October 2011. We assessed the prevalence and correlates of being subjected to urine toxicology testing by police using multivariate Poisson regression. In total, 438 IDU participated in this study, with 293 (66.9%) participants reporting having been tested for illicit drugs by police. In multivariate analyses, reports of drug testing by police were independently and positively associated with younger age (adjusted prevalence ratio [APR]: 1.28), a history of methamphetamine injection (APR: 1.22), a history of incarceration (APR: 1.21), having been in compulsory drug detention (APR: 1.43), avoiding healthcare (APR: 1.15), and HIV seropositivity (APR: 1.19), and negatively associated with access to voluntary drug treatment (APR: 0.82) (all p<0.05). A high proportion of IDU in Bangkok were subjected to drug testing by police. Young people and methamphetamine injectors were more likely to have been tested. The findings indicate that drug testing by police is associated with the compulsory drug detention system and may be interfering with IDU's access to healthcare and voluntary drug treatment. These findings raise concern about the widespread practice of drug testing by police and its associated impacts. Copyright © 2013 Elsevier B.V. All rights reserved.

Costs of treatment and complications of adult type 1 diabetes.

PubMed

Franciosi, M; Lucisano, G; Amoretti, R; Capani, F; Bruttomesso, D; Di Bartolo, P; Girelli, A; Leonetti, F; Morviducci, L; Vitacolonna, E; Nicolucci, A

2013-07-01

Costs associated with diabetes represent a large burden for patients and the health-care system. However, few studies examined the costs for diabetes treatment in adults with type 1 diabetes (T1DM). This analysis was aimed to assess the costs of treatment associated with T1DM among adults in Italy from the national health-care system perspective. Data were collected using a questionnaire assessing resource consumption retrospectively (drugs, visits, diagnostics, hospitalisations and self-monitoring of blood glucose (SMBG)). One-year costs were calculated for the 12 months preceding the survey. Cost estimation, referred to 2006, was carried out using univariate and multivariate Poisson regression models. Fifty-eight centres enrolled 1193 patients (49.5% women; aged between 18 and 55 years, average diabetes duration was 16.1 ± 9.8 years). The average annual cost for an adult patient with TDM1 was € 2450 (95% confidence interval (CI): 2358-2544). Insulin therapy and SMBG accounted together for 71.2% of total costs (35.6% and 35.6%, respectively); the remainder was shared by hospitalisations (18%), visits (4.0%), diagnostics (3.9%) and other drugs (2.9%). Univariate analyses showed that the presence of complications was associated with excess of costs, mainly related to the hospitalisation and drugs. Multivariate analyses confirmed these results showing that the presence of micro-vascular plus macrovascular complications doubles the cost of treatment. Strategies of care for T1DM that can improve disease management and prevent or delay the onset of complications could represent the most important tool to reduce costs in the long term while improving clinical outcomes and quality of life. Copyright © 2012 Elsevier B.V. All rights reserved.

Rates and risk factors of injury in CrossFitTM: a prospective cohort study.

PubMed

Moran, Sebastian; Booker, Harry; Staines, Jacob; Williams, Sean

2017-09-01

CrossFitTM is a strength and conditioning program that has gained widespread popularity since its inception approximately 15 years ago. However, at present little is known about the level of injury risk associated with this form of training. Movement competency, assessed using the Functional Movement ScreenTM (FMS), has been identified as a risk factor for injury in numerous athletic populations, but its role in CrossFit participants is currently unclear. The aim of this study was to evaluate the level of injury risk associated with CrossFit training, and examine the influence of a number of potential risk factors (including movement competency). A cohort of 117 CrossFit participants were followed prospectively for 12 weeks. Participants' characteristics, previous injury history and training experience were recorded at baseline, and an FMS assessment was conducted. The overall injury incidence rate was 2.10 per 1000 training hours (90% confidence limits: 1.32-3.33). A multivariate Poisson regression model identified males (rate ratio [RR]: 4.44 ×/÷ 3.30, very likely harmful) and those with previous injuries (RR: 2.35 ×/÷ 2.37, likely harmful) as having a higher injury risk. Inferences relating to FMS variables were unclear in the multivariate model, although number of asymmetries was a clear risk factor in a univariate model (RR per two additional asymmetries: 2.62 ×/÷ 1.53, likely harmful). The injury incidence rate associated with CrossFit training was low, and comparable to other forms of recreational fitness activities. Previous injury and gender were identified as risk factors for injury, whilst the role of movement competency in this setting warrants further investigation.

[Sunburn in young people: population-based study in Southern Brazil].

PubMed

Haack, Ricardo Lanzetta; Horta, Bernardo Lessa; Cesar, Juraci Almeida

2008-02-01

To assess the prevalence and risk factors for sunburn in young people. Population-based cross-sectional study using a multiple-stage sampling carried out with people living in the urban area of Pelotas, Southern Brazil, between October and December 2005. Data was collected from interviews with 1.604 subjects using a standardized pre-coded questionnaire about their family and another questionnaire applied to those aged between ten and 29 years for assessing the occurrence of sunburn episodes. Sunburn was defined as skin burning after sun exposure. Chi-square test with Yates' correction was used to compare proportions and Poisson regression with design effect control and robust adjustment of variance was applied in the multivariate analysis. Of those aged between 10 and 29 years, 1,412 reported sun exposure in the last summer. Losses and refusals were 5.5%. A total of 48.7% of the interviewees reported sunburn in the last year. The following variables were associated with sunburn in the multivariate analysis: white skin (PR=1.41; 95% CI: 1.12;1.79); higher skin sensitivity to sun exposure (PR=1.84; 95% CI: 1.64;2.06); age between 15 and 19 years (PR=1.30; 95% CI: 1.12;1.50); belonging to the higher quartile of income (PR=1.20; 95% CI: 1.01;1.42); and irregular use of sunscreens (PR=1.23; 95% CI: 1.08;1.42). The prevalence of sunburn in the population studied was high mainly among white young people with higher skin sensitivity, higher income and who used sunscreens irregularly. Sun exposure during safe times and with adequate protection should be promoted.

Higher risk of venous thrombosis associated with drospirenone-containing oral contraceptives: a population-based cohort study

PubMed Central

Gronich, Naomi; Lavi, Idit; Rennert, Gad

2011-01-01

Background: Combined oral contraceptives are a common method of contraception, but they carry a risk of venous and arterial thrombosis. We assessed whether use of drospirenone was associated with an increase in thrombotic risk relative to third-generation combined oral contraceptives. Methods: Using computerized records of the largest health care provider in Israel, we identified all women aged 12 to 50 years for whom combined oral contraceptives had been dispensed between Jan. 1, 2002, and Dec. 31, 2008. We followed the cohort until 2009. We used Poisson regression models to estimate the crude and adjusted rate ratios for risk factors for venous thrombotic events (specifically deep vein thrombosis and pulmonary embolism) and arterial thromboic events (specifically transient ischemic attack and cerebrovascular accident). We performed multivariable analyses to compare types of contraceptives, with adjustment for the various risk factors. Results: We identified a total of 1017 (0.24%) venous and arterial thrombotic events among 431 223 use episodes during 819 749 woman-years of follow-up (6.33 venous events and 6.10 arterial events per 10 000 woman-years). In a multivariable model, use of drospirenone carried an increased risk of venous thrombotic events, relative to both third-generation combined oral contraceptives (rate ratio [RR] 1.43, 95% confidence interval [CI] 1.15–1.78) and second-generation combined oral contraceptives (RR 1.65, 95% CI 1.02–2.65). There was no increase in the risk of arterial thrombosis with drospirenone. Interpretation: Use of drospirenone-containing oral contraceptives was associated with an increased risk of deep vein thrombosis and pulmonary embolism, but not transient ischemic attack or cerebrovascular attack, relative to second- and third-generation combined oral contraceptives. PMID:22065352

The Effectiveness of an Electronic Security Management System in a Privately Owned Apartment Complex

ERIC Educational Resources Information Center

Greenberg, David F.; Roush, Jeffrey B.

2009-01-01

Poisson and negative binomial regression methods are used to analyze the monthly time series data to determine the effects of introducing an integrated security management system including closed-circuit television (CCTV), door alarm monitoring, proximity card access, and emergency call boxes to a large privately-owned complex of apartment…

Hospitalizations for primary care-sensitive conditions in Pelotas, Brazil: 1998 to 2012.

PubMed

Costa, Juvenal Soares Dias da; Teixeira, Ana Maria Ferreira Borges; Moraes, Mauricio; Strauch, Eliane Schneider; Silveira, Denise Silva da; Carret, Maria Laura Vidal; Fantinel, Everton

2017-01-01

To verify the hospitalization trend for primary care sensitive-conditions in Pelotas, Rio Grande do Sul, Brazil from 1998 to 2012. An ecological study compared hospitalizations rates of the city of Pelotas with the rest of state of Rio Grande do Sul. Analysis was conducted using direct standardization of rates, coefficients were stratified by sex and the Poisson regression was used. Hospitalizations for sensitive conditions decreased in Pelotas and Rio Grande do Sul. In Pelotas, a 63.8% decrease was detected in the period observed, and there was a 43.1% decrease in the state of Rio Grande do Sul. Poisson regression coefficients showed a decrease of 7% in Pelotas and of 4% in the rest of Rio Grande do Sul each year. During the study period, several changes were introduced in the Brazilian Unified Health System ("Sistema Único de Saúde") that may have influenced the results, including changes in administration, health funding, and a complete reworking of primary care through the creation of the Family Health Strategy program ("Estratégia Saúde da Família").

The Use of Illegal Drugs and Infectious Contagious Diseases: Knowledge and Intervention among Dockworkers

PubMed Central

Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; da Silva, Mara Regina Santos; de Farias, Francisca Lucélia Ribeiro; de Almeida, Marlise Capa Verde

2016-01-01

This study’s objective was to analyze the use of illegal drugs by dockworkers and provide risk communication regarding the use of illegal drugs and test for infectious contagious diseases among dockworkers. This cross-sectional study including an intervention addressed to 232 dockworkers, who were individually interviewed, as well as communication of risk with testing for infectious contagious diseases for 93 dockworkers from a city in the interior of Rio Grande do Sul, Brazil. Poisson regression analysis was used. Twenty-nine workers reported the use of illegal drugs. Poisson regression indicated that being a wharfage worker, smoker, having a high income, and heavier workload increases the prevalence of the use of illegal drugs. During risk communication, two workers were diagnosed with hepatitis B (2.2%), three (3.2%) with hepatitis C, two (2.2%) with syphilis. None of the workers, though, had HIV. This study provides evidence that can motivate further research on the topic and also lead to treatment of individuals to improve work safety, productivity, and the health of workers. PMID:26771625

Modeling both of the number of pausibacillary and multibacillary leprosy patients by using bivariate poisson regression

NASA Astrophysics Data System (ADS)

Winahju, W. S.; Mukarromah, A.; Putri, S.

2015-03-01

Leprosy is a chronic infectious disease caused by bacteria of leprosy (Mycobacterium leprae). Leprosy has become an important thing in Indonesia because its morbidity is quite high. Based on WHO data in 2014, in 2012 Indonesia has the highest number of new leprosy patients after India and Brazil with a contribution of 18.994 people (8.7% of the world). This number makes Indonesia automatically placed as the country with the highest number of leprosy morbidity of ASEAN countries. The province that most contributes to the number of leprosy patients in Indonesia is East Java. There are two kind of leprosy. They consist of pausibacillary and multibacillary. The morbidity of multibacillary leprosy is higher than pausibacillary leprosy. This paper will discuss modeling both of the number of multibacillary and pausibacillary leprosy patients as responses variables. These responses are count variables, so modeling will be conducted by using bivariate poisson regression method. Unit experiment used is in East Java, and predictors involved are: environment, demography, and poverty. The model uses data in 2012, and the result indicates that all predictors influence significantly.

Statistical guides to estimating the number of undiscovered mineral deposits: an example with porphyry copper deposits

USGS Publications Warehouse

Singer, Donald A.; Menzie, W.D.; Cheng, Qiuming; Bonham-Carter, G. F.

2005-01-01

Estimating numbers of undiscovered mineral deposits is a fundamental part of assessing mineral resources. Some statistical tools can act as guides to low variance, unbiased estimates of the number of deposits. The primary guide is that the estimates must be consistent with the grade and tonnage models. Another statistical guide is the deposit density (i.e., the number of deposits per unit area of permissive rock in well-explored control areas). Preliminary estimates and confidence limits of the number of undiscovered deposits in a tract of given area may be calculated using linear regression and refined using frequency distributions with appropriate parameters. A Poisson distribution leads to estimates having lower relative variances than the regression estimates and implies a random distribution of deposits. Coefficients of variation are used to compare uncertainties of negative binomial, Poisson, or MARK3 empirical distributions that have the same expected number of deposits as the deposit density. Statistical guides presented here allow simple yet robust estimation of the number of undiscovered deposits in permissive terranes. 

The Use of Illegal Drugs and Infectious Contagious Diseases: Knowledge and Intervention among Dockworkers.

PubMed

Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; da Silva, Mara Regina Santos; de Farias, Francisca Lucélia Ribeiro; de Almeida, Marlise Capa Verde

2016-01-12

This study's objective was to analyze the use of illegal drugs by dockworkers and provide risk communication regarding the use of illegal drugs and test for infectious contagious diseases among dockworkers. This cross-sectional study including an intervention addressed to 232 dockworkers, who were individually interviewed, as well as communication of risk with testing for infectious contagious diseases for 93 dockworkers from a city in the interior of Rio Grande do Sul, Brazil. Poisson regression analysis was used. Twenty-nine workers reported the use of illegal drugs. Poisson regression indicated that being a wharfage worker, smoker, having a high income, and heavier workload increases the prevalence of the use of illegal drugs. During risk communication, two workers were diagnosed with hepatitis B (2.2%), three (3.2%) with hepatitis C, two (2.2%) with syphilis. None of the workers, though, had HIV. This study provides evidence that can motivate further research on the topic and also lead to treatment of individuals to improve work safety, productivity, and the health of workers.

Modeling Stochastic Variability in the Numbers of Surviving Salmonella enterica, Enterohemorrhagic Escherichia coli, and Listeria monocytogenes Cells at the Single-Cell Level in a Desiccated Environment

PubMed Central

Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso

2016-01-01

ABSTRACT Despite effective inactivation procedures, small numbers of bacterial cells may still remain in food samples. The risk that bacteria will survive these procedures has not been estimated precisely because deterministic models cannot be used to describe the uncertain behavior of bacterial populations. We used the Poisson distribution as a representative probability distribution to estimate the variability in bacterial numbers during the inactivation process. Strains of four serotypes of Salmonella enterica, three serotypes of enterohemorrhagic Escherichia coli, and one serotype of Listeria monocytogenes were evaluated for survival. We prepared bacterial cell numbers following a Poisson distribution (indicated by the parameter λ, which was equal to 2) and plated the cells in 96-well microplates, which were stored in a desiccated environment at 10% to 20% relative humidity and at 5, 15, and 25°C. The survival or death of the bacterial cells in each well was confirmed by adding tryptic soy broth as an enrichment culture. Changes in the Poisson distribution parameter during the inactivation process, which represent the variability in the numbers of surviving bacteria, were described by nonlinear regression with an exponential function based on a Weibull distribution. We also examined random changes in the number of surviving bacteria using a random number generator and computer simulations to determine whether the number of surviving bacteria followed a Poisson distribution during the bacterial death process by use of the Poisson process. For small initial cell numbers, more than 80% of the simulated distributions (λ = 2 or 10) followed a Poisson distribution. The results demonstrate that variability in the number of surviving bacteria can be described as a Poisson distribution by use of the model developed by use of the Poisson process. IMPORTANCE We developed a model to enable the quantitative assessment of bacterial survivors of inactivation procedures because the presence of even one bacterium can cause foodborne disease. The results demonstrate that the variability in the numbers of surviving bacteria was described as a Poisson distribution by use of the model developed by use of the Poisson process. Description of the number of surviving bacteria as a probability distribution rather than as the point estimates used in a deterministic approach can provide a more realistic estimation of risk. The probability model should be useful for estimating the quantitative risk of bacterial survival during inactivation. PMID:27940547

Modeling Stochastic Variability in the Numbers of Surviving Salmonella enterica, Enterohemorrhagic Escherichia coli, and Listeria monocytogenes Cells at the Single-Cell Level in a Desiccated Environment.

PubMed

Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso; Koseki, Shigenobu

2017-02-15

Despite effective inactivation procedures, small numbers of bacterial cells may still remain in food samples. The risk that bacteria will survive these procedures has not been estimated precisely because deterministic models cannot be used to describe the uncertain behavior of bacterial populations. We used the Poisson distribution as a representative probability distribution to estimate the variability in bacterial numbers during the inactivation process. Strains of four serotypes of Salmonella enterica, three serotypes of enterohemorrhagic Escherichia coli, and one serotype of Listeria monocytogenes were evaluated for survival. We prepared bacterial cell numbers following a Poisson distribution (indicated by the parameter λ, which was equal to 2) and plated the cells in 96-well microplates, which were stored in a desiccated environment at 10% to 20% relative humidity and at 5, 15, and 25°C. The survival or death of the bacterial cells in each well was confirmed by adding tryptic soy broth as an enrichment culture. Changes in the Poisson distribution parameter during the inactivation process, which represent the variability in the numbers of surviving bacteria, were described by nonlinear regression with an exponential function based on a Weibull distribution. We also examined random changes in the number of surviving bacteria using a random number generator and computer simulations to determine whether the number of surviving bacteria followed a Poisson distribution during the bacterial death process by use of the Poisson process. For small initial cell numbers, more than 80% of the simulated distributions (λ = 2 or 10) followed a Poisson distribution. The results demonstrate that variability in the number of surviving bacteria can be described as a Poisson distribution by use of the model developed by use of the Poisson process. We developed a model to enable the quantitative assessment of bacterial survivors of inactivation procedures because the presence of even one bacterium can cause foodborne disease. The results demonstrate that the variability in the numbers of surviving bacteria was described as a Poisson distribution by use of the model developed by use of the Poisson process. Description of the number of surviving bacteria as a probability distribution rather than as the point estimates used in a deterministic approach can provide a more realistic estimation of risk. The probability model should be useful for estimating the quantitative risk of bacterial survival during inactivation. Copyright © 2017 Koyama et al.

A matrix-based method of moments for fitting the multivariate random effects model for meta-analysis and meta-regression

PubMed Central

Jackson, Dan; White, Ian R; Riley, Richard D

2013-01-01

Multivariate meta-analysis is becoming more commonly used. Methods for fitting the multivariate random effects model include maximum likelihood, restricted maximum likelihood, Bayesian estimation and multivariate generalisations of the standard univariate method of moments. Here, we provide a new multivariate method of moments for estimating the between-study covariance matrix with the properties that (1) it allows for either complete or incomplete outcomes and (2) it allows for covariates through meta-regression. Further, for complete data, it is invariant to linear transformations. Our method reduces to the usual univariate method of moments, proposed by DerSimonian and Laird, in a single dimension. We illustrate our method and compare it with some of the alternatives using a simulation study and a real example. PMID:23401213

SMURC: High-Dimension Small-Sample Multivariate Regression With Covariance Estimation.

PubMed

Bayar, Belhassen; Bouaynaya, Nidhal; Shterenberg, Roman

2017-03-01

We consider a high-dimension low sample-size multivariate regression problem that accounts for correlation of the response variables. The system is underdetermined as there are more parameters than samples. We show that the maximum likelihood approach with covariance estimation is senseless because the likelihood diverges. We subsequently propose a normalization of the likelihood function that guarantees convergence. We call this method small-sample multivariate regression with covariance (SMURC) estimation. We derive an optimization problem and its convex approximation to compute SMURC. Simulation results show that the proposed algorithm outperforms the regularized likelihood estimator with known covariance matrix and the sparse conditional Gaussian graphical model. We also apply SMURC to the inference of the wing-muscle gene network of the Drosophila melanogaster (fruit fly).

Isolated and synergistic effects of PM10 and average temperature on cardiovascular and respiratory mortality.

PubMed

Pinheiro, Samya de Lara Lins de Araujo; Saldiva, Paulo Hilário Nascimento; Schwartz, Joel; Zanobetti, Antonella

2014-12-01

OBJECTIVE To analyze the effect of air pollution and temperature on mortality due to cardiovascular and respiratory diseases. METHODS We evaluated the isolated and synergistic effects of temperature and particulate matter with aerodynamic diameter < 10 µm (PM10) on the mortality of individuals > 40 years old due to cardiovascular disease and that of individuals > 60 years old due to respiratory diseases in Sao Paulo, SP, Southeastern Brazil, between 1998 and 2008. Three methodologies were used to evaluate the isolated association: time-series analysis using Poisson regression model, bidirectional case-crossover analysis matched by period, and case-crossover analysis matched by the confounding factor, i.e., average temperature or pollutant concentration. The graphical representation of the response surface, generated by the interaction term between these factors added to the Poisson regression model, was interpreted to evaluate the synergistic effect of the risk factors. RESULTS No differences were observed between the results of the case-crossover and time-series analyses. The percentage change in the relative risk of cardiovascular and respiratory mortality was 0.85% (0.45;1.25) and 1.60% (0.74;2.46), respectively, due to an increase of 10 μg/m3 in the PM10 concentration. The pattern of correlation of the temperature with cardiovascular mortality was U-shaped and that with respiratory mortality was J-shaped, indicating an increased relative risk at high temperatures. The values for the interaction term indicated a higher relative risk for cardiovascular and respiratory mortalities at low temperatures and high temperatures, respectively, when the pollution levels reached approximately 60 μg/m3. CONCLUSIONS The positive association standardized in the Poisson regression model for pollutant concentration is not confounded by temperature, and the effect of temperature is not confounded by the pollutant levels in the time-series analysis. The simultaneous exposure to different levels of environmental factors can create synergistic effects that are as disturbing as those caused by extreme concentrations.

The Use of a Poisson Regression to Evaluate Antihistamines and Fatal Aircraft Mishaps in Instrument Meteorological Conditions.

PubMed

Gildea, Kevin M; Hileman, Christy R; Rogers, Paul; Salazar, Guillermo J; Paskoff, Lawrence N

2018-04-01

Research indicates that first-generation antihistamine usage may impair pilot performance by increasing the likelihood of vestibular illusions, spatial disorientation, and/or cognitive impairment. Second- and third-generation antihistamines generally have fewer impairing side effects and are approved for pilot use. We hypothesized that toxicological findings positive for second- and third-generation antihistamines are less likely to be associated with pilots involved in fatal mishaps than first-generation antihistamines. The evaluated population consisted of 1475 U.S. civil pilots fatally injured between September 30, 2008, and October 1, 2014. Mishap factors evaluated included year, weather conditions, airman rating, recent airman flight time, quarter of year, and time of day. Due to the low prevalence of positive antihistamine findings, a count-based model was selected, which can account for rare outcomes. The means and variances were close for both regression models supporting the assumption that the data follow a Poisson distribution; first-generation antihistamine mishap airmen (N = 582, M = 0.17, S2 = 0.17) with second- and third-generation antihistamine mishap airmen (N = 116, M = 0.20, S2 = 0.18). The data indicate fewer airmen with second- and third-generation antihistamines than first-generation antihistamines in their system are fatally injured while flying in IMC conditions. Whether the lower incidence is a factor of greater usage of first-generation antihistamines versus second- and third-generation antihistamines by the pilot population or fewer deleterious side effects with second- and third-generation antihistamines is unclear. These results engender cautious optimism, but additional research is necessary to determine why these differences exist.Gildea KM, Hileman CR, Rogers P, Salazar GJ, Paskoff LN. The use of a Poisson regression to evaluate antihistamines and fatal aircraft mishaps in instrument meteorological conditions. Aerosp Med Hum Perform. 2018; 89(4):389-395.

Fine particulate air pollution and all-cause mortality within the Harvard Six-Cities Study: variations in risk by period of exposure.

PubMed

Villeneuve, Paul J; Goldberg, Mark S; Krewski, Daniel; Burnett, Richard T; Chen, Yue

2002-11-01

We used Poisson regression methods to examine the relation between temporal changes in the levels of fine particulate air pollution (PM(2.5)) and the risk of mortality among participants of the Harvard Six Cities longitudinal study. Our analyses were based on 1430 deaths that occurred between 1974 and 1991 in a cohort that accumulated 105,714 person-years of follow-up. For each city, indices of PM(2.5) were derived using daily samples. Individual level data were collected on several risk factors including: smoking, education, body mass index (BMI), and occupational exposure to dusts. Time-dependent indices of PM(2.5) were created across 13 calendar periods (< 1979, 1979, 1980, em leader, 1989, >/= 1990) to explore whether recent or chronic exposures were more important predictors of mortality. The relative risk (RR) of mortality calculated using Poisson regression based on average city-specific exposures that remained constant during follow-up was 1.31 [95% confidence interval (CI) = 1.12-1.52] per 18.6 microg/m(3) of PM(2.5). This result was similar to the risk calculated using the Cox model (RR = 1.26, 95% CI = 1.08-1.46). The RR of mortality was attenuated when the Poisson regression model included a time-dependent estimate of exposure (RR = 1.19, 95% CI = 1.04-1.36). There was little variation in RR across time-dependent indices of PM(2.5). The attenuated risk of mortality that was observed with a time-dependent index of PM(2.5) is due to the combined influence of city-specific variations in mortality rates and decreasing levels of air pollution that occurred during follow-up. The RR of mortality associated with PM(2.5) did not depend on when exposure occurred in relation to death, possibly because of little variation between the time-dependent city-specific exposure indices.

Nonparametric Inference of Doubly Stochastic Poisson Process Data via the Kernel Method

PubMed Central

Zhang, Tingting; Kou, S. C.

2010-01-01

Doubly stochastic Poisson processes, also known as the Cox processes, frequently occur in various scientific fields. In this article, motivated primarily by analyzing Cox process data in biophysics, we propose a nonparametric kernel-based inference method. We conduct a detailed study, including an asymptotic analysis, of the proposed method, and provide guidelines for its practical use, introducing a fast and stable regression method for bandwidth selection. We apply our method to real photon arrival data from recent single-molecule biophysical experiments, investigating proteins' conformational dynamics. Our result shows that conformational fluctuation is widely present in protein systems, and that the fluctuation covers a broad range of time scales, highlighting the dynamic and complex nature of proteins' structure. PMID:21258615

Nonparametric Inference of Doubly Stochastic Poisson Process Data via the Kernel Method.

PubMed

Zhang, Tingting; Kou, S C

2010-01-01

Doubly stochastic Poisson processes, also known as the Cox processes, frequently occur in various scientific fields. In this article, motivated primarily by analyzing Cox process data in biophysics, we propose a nonparametric kernel-based inference method. We conduct a detailed study, including an asymptotic analysis, of the proposed method, and provide guidelines for its practical use, introducing a fast and stable regression method for bandwidth selection. We apply our method to real photon arrival data from recent single-molecule biophysical experiments, investigating proteins' conformational dynamics. Our result shows that conformational fluctuation is widely present in protein systems, and that the fluctuation covers a broad range of time scales, highlighting the dynamic and complex nature of proteins' structure.

Log-normal frailty models fitted as Poisson generalized linear mixed models.

PubMed

Hirsch, Katharina; Wienke, Andreas; Kuss, Oliver

2016-12-01

The equivalence of a survival model with a piecewise constant baseline hazard function and a Poisson regression model has been known since decades. As shown in recent studies, this equivalence carries over to clustered survival data: A frailty model with a log-normal frailty term can be interpreted and estimated as a generalized linear mixed model with a binary response, a Poisson likelihood, and a specific offset. Proceeding this way, statistical theory and software for generalized linear mixed models are readily available for fitting frailty models. This gain in flexibility comes at the small price of (1) having to fix the number of pieces for the baseline hazard in advance and (2) having to "explode" the data set by the number of pieces. In this paper we extend the simulations of former studies by using a more realistic baseline hazard (Gompertz) and by comparing the model under consideration with competing models. Furthermore, the SAS macro %PCFrailty is introduced to apply the Poisson generalized linear mixed approach to frailty models. The simulations show good results for the shared frailty model. Our new %PCFrailty macro provides proper estimates, especially in case of 4 events per piece. The suggested Poisson generalized linear mixed approach for log-normal frailty models based on the %PCFrailty macro provides several advantages in the analysis of clustered survival data with respect to more flexible modelling of fixed and random effects, exact (in the sense of non-approximate) maximum likelihood estimation, and standard errors and different types of confidence intervals for all variance parameters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Racial/Ethnic Disparities in Nursing Home Quality of Life Deficiencies, 2001 to 2011

PubMed Central

Campbell, Lauren J.; Cai, Xueya; Gao, Shan; Li, Yue

2016-01-01

Objectives: Racial/ethnic disparities in nursing homes (NHs) are associated with lower quality of care, and state Medicaid payment policies may influence NH quality. However, no studies analyzing disparities in NH quality of life (QoL) exist. Therefore, this study aims to estimate associations at the NH level between average number of QoL deficiencies and concentrations of racial/ethnic minority residents, and to identify effects of state Medicaid payment policies on racial/ethnic disparities. Method: Multivariable Poisson regression with NH random effects was used to determine the association between NH minority concentration in 2000 to 2010 and average number of QoL deficiencies in 2001 to 2011 at the NH level, and the effect of state NH payment policies on QoL deficiencies and racial/ethnic disparities in QoL deficiencies across NH minority concentrations. Results: Racial/ethnic disparities in QoL between high and low minority concentration NHs decrease over time, but are not eliminated. Case mix payment was associated with an increased disparity between high and low minority concentration NHs in QoL deficiencies. Discussion: NH managers and policy makers should consider initiatives targeting minority residents or low-performing NHs with higher minority concentrations for improvement to reduce disparities and address QoL deficiencies. PMID:27819015

Hand Hygiene Program Decreases School Absenteeism Due to Upper Respiratory Infections.

PubMed

Azor-Martinez, Ernestina; Cobos-Carrascosa, Elena; Seijas-Vazquez, Maria Luisa; Fernández-Sánchez, Carmen; Strizzi, Jenna M; Torres-Alegre, Pilar; Santisteban-Martínez, Joaquin; Gimenez-Sanchez, Francisco

2016-12-01

We assessed the effectiveness of a handwashing program using hand sanitizer to prevent school absenteeism due to upper respiratory infections (URIs). This was a randomized, controlled, and open study on a sample of 1341 children 4-12 years old, attending 5 state schools in Almería (Spain), with an 8-month follow-up. The experimental group (EG) washed their hands with soap and water, together with using hand sanitizer, and the control group followed their usual handwashing procedures. Absenteeism rates due to URIs were compared between the 2 groups through a multivariate Poisson regression analysis. The percent of days missed in both groups were compared with a z test. Overall, 1271 cases of school absenteeism due to URIs were registered. Schoolchildren from the EG had a 38% lower risk of absenteeism due to URIs, incidence rate ratio: 0.62, 95% confidence interval: 0.55-0.70, and a decrease in absenteeism of 0.45 episodes/child/academic year, p < .001. Pupils missed 2734 school days due to URIs and the percentage of days absent was significantly lower in the EG, p < .001. Use of hand sanitizer plus handwashing with soap accompanied by educational support is an effective measure to reduce absenteeism due to URIs. © 2016, American School Health Association.

Doctor-certified sickness absence in first and second trimesters of pregnancy among native and immigrant women in Norway.

PubMed

Brekke, Idunn; Berg, John E; Sletner, Line; Jenum, Anne Karen

2013-03-01

The authors sought to estimate differences in doctor-certified sickness absence during pregnancy among immigrant and native women. Population-based cohort study of pregnant women attending three Child Health Clinics in Groruddalen, Oslo, and their offspring. Questionnaire data were collected at gestational weeks 10-20 and 28. The participation rate was 74%. A multivariate Poisson regression was used to analyse differences in sickness absence in pregnancy between immigrant and native women. A total of 573 women who were employed prior to their pregnancies were included, 51% were immigrants. After adjusting for age, years of education, marital status, number of children, occupation, part-time/full-time work, health status, severe pregnancy-induced emesis and language proficiency, the immigrant/native differences in number of weeks with sickness absence decreased from 2.0 to 1.2 weeks. Part-time/full-time work, health status, severe pregnancy-induced emesis and language proficiency were significant predictors of sickness absence. Immigrant women had higher sickness absence than native women during pregnancy. The difference in average number of weeks between native and immigrant women was partly explained by poorer health status prior to pregnancy, severe pregnancy-induced emesis and poorer proficiency in the Norwegian language among the immigrant women.

Cauda equina syndrome: an analysis of incidence rates and risk factors among a closed North American military population.

PubMed

Schoenfeld, Andrew J; Bader, Julia O

2012-09-01

This investigation attempted to determine the incidence of cauda equine syndrome (CES) within a closed North American population from 2001 to 2010. This study also aimed to define risk factors influential in its development. A search was performed using the Defense Medical Epidemiology Database and the ICD-9 code for CES (344.6). Demographic information including sex, race, military rank, branch of service, and age was obtained for the entire military population, as well as those diagnosed with CES. Incidence rates were calculated for the population as a whole, as well as for risk factors of interest. Multivariate Poisson regression analysis was utilized to identify significant risks while controlling for other factors in the model. Between 2001 and 2010, the incidence of CES in the military was 7 per 100,000 person-years. Female sex was found to have the highest incidence rate at 0.15 per 1000 person-years. Female sex, whites, individuals classified as other race, senior military rank, and age 30 and older were found to be significant risks for the development of CES. The results are in keeping with the findings of previous works, however, our cohort represents the largest number of patients with CES to be presented in the literature. Published by Elsevier B.V.

A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control

PubMed Central

Jacques, Antoine; Laurent, Marion; Ribière-Chabert, Magali; Saussac, Mathilde; Bougeard, Stéphanie; Budge, Giles E.; Hendrikx, Pascal; Chauzat, Marie-Pierre

2017-01-01

Reports of honey bee population decline has spurred many national efforts to understand the extent of the problem and to identify causative or associated factors. However, our collective understanding of the factors has been hampered by a lack of joined up trans-national effort. Moreover, the impacts of beekeeper knowledge and beekeeping management practices have often been overlooked, despite honey bees being a managed pollinator. Here, we established a standardised active monitoring network for 5 798 apiaries over two consecutive years to quantify honey bee colony mortality across 17 European countries. Our data demonstrate that overwinter losses ranged between 2% and 32%, and that high summer losses were likely to follow high winter losses. Multivariate Poisson regression models revealed that hobbyist beekeepers with small apiaries and little experience in beekeeping had double the winter mortality rate when compared to professional beekeepers. Furthermore, honey bees kept by professional beekeepers never showed signs of disease, unlike apiaries from hobbyist beekeepers that had symptoms of bacterial infection and heavy Varroa infestation. Our data highlight beekeeper background and apicultural practices as major drivers of honey bee colony losses. The benefits of conducting trans-national monitoring schemes and improving beekeeper training are discussed. PMID:28278255

Lack of Effectiveness of Neutropenic Diet and Social Restrictions as Anti-Infective Measures in Children With Acute Myeloid Leukemia: An Analysis of the AML-BFM 2004 Trial

PubMed Central

Tramsen, Lars; Salzmann-Manrique, Emilia; Bochennek, Konrad; Klingebiel, Thomas; Reinhardt, Dirk; Creutzig, Ursula; Sung, Lillian

2016-01-01

Purpose Although nonpharmacologic anti-infective measures are widely used in children treated for acute myeloid leukemia (AML), there is little evidence of their effectiveness. Patients and Methods We analyzed infectious complications in children during intensive treatment of AML according to the AML-BFM 2004 trial and surveyed sites on institutional standards regarding recommended restrictions of social contacts (six items), pets (five items), and food (eight items). A scoring system was developed with a restriction score for each item. Multivariable Poisson regression adjusted for sex, age, weight group, risk stratification, and prophylactic antibiotics was used to estimate the impact of the restrictions on the incidence ratios of fever of unknown origin, bacteremia, pneumonia, and gastroenteritis. Results Data on recommendations of nonpharmacologic anti-infective measures and infectious complications were available in 339 patients treated in 37 institutions. Analyses did not demonstrate a significant benefit of any of the restrictions regarding food, social contacts, and pets on the risk of fever, bacteremia, pneumonia, and gastroenteritis. In contrast, age, weight group, risk stratification, and nonabsorbable antibiotics had some influence on infections complications. Conclusion The lack of effectiveness of dietary restrictions and restrictions regarding social contacts and pets should result in reconsideration of anti-infective policies. PMID:27269945

Lack of Effectiveness of Neutropenic Diet and Social Restrictions as Anti-Infective Measures in Children With Acute Myeloid Leukemia: An Analysis of the AML-BFM 2004 Trial.

PubMed

Tramsen, Lars; Salzmann-Manrique, Emilia; Bochennek, Konrad; Klingebiel, Thomas; Reinhardt, Dirk; Creutzig, Ursula; Sung, Lillian; Lehrnbecher, Thomas

2016-08-10

Although nonpharmacologic anti-infective measures are widely used in children treated for acute myeloid leukemia (AML), there is little evidence of their effectiveness. We analyzed infectious complications in children during intensive treatment of AML according to the AML-BFM 2004 trial and surveyed sites on institutional standards regarding recommended restrictions of social contacts (six items), pets (five items), and food (eight items). A scoring system was developed with a restriction score for each item. Multivariable Poisson regression adjusted for sex, age, weight group, risk stratification, and prophylactic antibiotics was used to estimate the impact of the restrictions on the incidence ratios of fever of unknown origin, bacteremia, pneumonia, and gastroenteritis. Data on recommendations of nonpharmacologic anti-infective measures and infectious complications were available in 339 patients treated in 37 institutions. Analyses did not demonstrate a significant benefit of any of the restrictions regarding food, social contacts, and pets on the risk of fever, bacteremia, pneumonia, and gastroenteritis. In contrast, age, weight group, risk stratification, and nonabsorbable antibiotics had some influence on infections complications. The lack of effectiveness of dietary restrictions and restrictions regarding social contacts and pets should result in reconsideration of anti-infective policies. © 2016 by American Society of Clinical Oncology.

Scholarships for scientific initiation encourage post-graduation degree.

PubMed

Pinto, Gabriela S; Nascimento, Gustavo G; Mendes, Matheus S; Ogliari, Fabrício A; Demarco, Flávio F; Correa, Marcos B

2014-01-01

This study aimed to evaluate the factors associated with the decision to attend an academic post-graduation program by dental students. A cross-sectional study was conducted in 2012, last-year undergraduate students from Dental Schools of Southern Brazil. A closed questionnaire was applied including questions grouped in three different blocks: pre-graduate, undergraduate period and future perspectives. The outcome was the decision to pursuit an academic post-graduation degree. Associations were tested using chi-squared test and chi-squared test for linear trends when appropriate. Multivariate Poisson regression was also performed. The sample was composed by 671 students (response rate of 69.9%, n=467). In relation to future perspectives, 68% of the interviewed students intended to attend a post-graduation program, but only 17.5% would choose a program with academic and research post-graduation program (Master and PhD programs). In the final model, students from public universities (PR 2.08, 95%CI 1.41-3.08) and students that received scientific initiation scholarship (PR 1.93 95%CI 1.14-3.27) presented a twice greater prevalence to seek academic post-graduate programs. Students with higher family incomes showed a lower prevalence to seek these programs (PR 0.50, 95%IC 0.28-0.90). Scholarships seem to encourage undergraduate students to pursue stricto sensu post-graduation.

Is obesity associated to dental caries in Brazilian schoolchildren?

PubMed

Fernández, María Raquel; Goettems, Marília Leão; Demarco, Flávio Fernando; Corrêa, Marcos Britto

2017-11-06

This cross-sectional study aimed to determine the association between dental caries and weight status, and between dental caries and physical activity in Brazilian schoolchildren aged 8 to 12 years. A multi-stage sample of children enrolled in 20 private and public schools in 2010 in Pelotas, Southern Brazil, were invited to participate in the study. Socioeconomic data were collected from parents, and data regarding children characteristics were collected from children using a questionnaire and anthropometric measures. The Body Mass Index was obtained, and children were classified as overweight/obese considering age and sex. Dental examinations were performed to assess the presence of gingival inflammation, dental caries prevalence (DMFT≥1) and dental caries experience (mean DMFT). Multivariate Poisson Regression was used to assess factors associated with dental caries prevalence and experience. A total of 1,210 children were included in the study. Dental caries prevalence was 32.4% (95% CI 29.7-35.2), while the mean DMFT was 0.64 (± SD 1.00). Children who practiced less than 300 minutes per week of physical activity and overweigh/obese children had lower prevalence of dental caries, while children with obesity or overweight presented lower dental caries experience. Obesity/overweight and physical activity level presented an inverse relationship with dental caries. Longitudinal studies investigating the complexity of this relationship are required.

THE DELINKING OF SEX AND MARRIAGE: PATHWAYS TO FERTILITY AMONG YOUNG FILIPINO WOMEN

PubMed Central

GIPSON, JESSICA D.; HICKS, ANDREW L.

2017-01-01

Summary Partnership and fertility patterns of young Filipinos have changed dramatically from previous generations, with a widening gap between sexual initiation and marriage, and concurrent increases in teenage pregnancy and unwanted fertility. Further understanding of young adults’ social contexts and partnership patterns are needed to inform reproductive health programmes and policies affecting young Filipinos. Multivariate Poisson regression models were conducted with longitudinal and inter-generational data from the Cebu Longitudinal Health and Nutrition Survey (1998–2009) to examine the predictors of young women’s fertility. Age at first sex, and number and duration of partnerships each independently and significantly predicted women’s fertility by 2009 after controlling for contextual influences. Young women with more conservative attitudes towards dating, sex and marriage, and who perceived their mothers to have more conservative attitudes, had higher fertility than their peers, as did young women with mothers who reported more adolescent sexual behaviours. In contrast, fertility was lower among daughters who had higher levels of communication with their mothers. Given high levels of unintended fertility and teenage pregnancy in the Philippines, the findings indicate that the interval between sexual initiation and first and subsequent partnerships may be ideal intervention points for reproductive health services for young Filipinos. PMID:26811216

Sexual minority population density and incidence of lung, colorectal and female breast cancer in California.

PubMed

Boehmer, Ulrike; Miao, Xiaopeng; Maxwell, Nancy I; Ozonoff, Al

2014-03-26

Risk factors for breast, colorectal, and lung cancer are known to be more common among lesbian, gay, and bisexual (LGB) individuals, suggesting they may be more likely to develop these cancers. Our objective was to determine differences in cancer incidence by sexual orientation, using sexual orientation data aggregated at the county level. Data on cancer incidence were obtained from the California Cancer Registry and data on sexual orientation were obtained from the California Health Interview Survey, from which a measure of age-specific LGB population density by county was calculated. Using multivariable Poisson regression models, the association between the age-race-stratified incident rate of breast, lung and colorectal cancer in each county and LGB population density was examined, with race, age group and poverty as covariates. Among men, bisexual population density was associated with lower incidence of lung cancer and with higher incidence of colorectal cancer. Among women, lesbian population density was associated with lower incidence of lung and colorectal cancer and with higher incidence of breast cancer; bisexual population density was associated with higher incidence of lung and colorectal cancer and with lower incidence of breast cancer. These study findings clearly document links between county-level LGB population density and cancer incidence, illuminating an important public health disparity.

Certification in infection control matters: Impact of infection control department characteristics and policies on rates of multidrug-resistant infections

PubMed Central

Pogorzelska, Monika; Stone, PatriciaW.; Larson, Elaine L.

2012-01-01

Background The study objective is to describe infection control policies aimed at multidrug-resistant organisms (MDRO) in California hospitals and assess the relationship among these policies, structural characteristics, and rates of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) bloodstream infections and Clostridium difficile infections. Methods Data on infection control policies, structural characteristics, and MDRO rates were collected through a 2010 survey of California infection control departments. Bivariate and multivariable Poisson and negative binomial regressions were conducted. Results One hundred eighty hospitals provided data (response rate, 54%). Targeted MRSA screening upon admission was reported by the majority of hospitals (87%). The majority of hospitals implemented contact precautions for confirmed MDRO and C difficile patients; presumptive isolation/contact precautions for patients with pending screens were less frequently implemented. Few infection control policies were associated with lower MDRO rates. Hospitals with a certified infection control director had significantly lower rates of MRSA bloodstream infections (P < .05). Conclusion Although most California hospitals are involved in activities to decrease MDRO, there is variation in specific activities utilized with the most focus placed on MRSA. This study highlights the importance of certification and its significant impact on infection rates. Additional research is needed to confirm these findings. PMID:22381222

Breakdown in the organ donation process and its effect on organ availability.

PubMed

Razdan, Manik; Degenholtz, Howard B; Kahn, Jeremy M; Driessen, Julia

2015-01-01

Background. This study examines the effect of breakdown in the organ donation process on the availability of transplantable organs. A process breakdown is defined as a deviation from the organ donation protocol that may jeopardize organ recovery. Methods. A retrospective analysis of donation-eligible decedents was conducted using data from an independent organ procurement organization. Adjusted effect of process breakdown on organs transplanted from an eligible decedent was examined using multivariable zero-inflated Poisson regression. Results. An eligible decedent is four times more likely to become an organ donor when there is no process breakdown (adjusted OR: 4.01; 95% CI: 1.6838, 9.6414; P < 0.01) even after controlling for the decedent's age, gender, race, and whether or not a decedent had joined the state donor registry. However once the eligible decedent becomes a donor, whether or not there was a process breakdown does not affect the number of transplantable organs yielded. Overall, for every process breakdown occurring in the care of an eligible decedent, one less organ is available for transplant. Decedent's age is a strong predictor of likelihood of donation and the number of organs transplanted from a donor. Conclusion. Eliminating breakdowns in the donation process can potentially increase the number of organs available for transplant but some organs will still be lost.

Inpatient Trauma Mortality after Implementation of the Affordable Care Act in Illinois

PubMed Central

Dresden, Scott M.; Powell, Emilie S.; Feinglass, Joe

2018-01-01

Introduction Illinois hospitals have experienced a marked decrease in the number of uninsured patients after implementation of the Affordable Care Act (ACA). However, the full impact of health insurance expansion on trauma mortality is still unknown. The objective of this study was to determine the impact of ACA insurance expansion on trauma patients hospitalized in Illinois. Methods We performed a retrospective cohort study of 87,001 trauma inpatients from third quarter 2010 through second quarter 2015, which spans the implementation of the ACA in Illinois. We examined the effects of insurance expansion on trauma mortality using multivariable Poisson regression. Results There was no significant difference in mortality comparing the post-ACA period to the pre-ACA period incident rate ratio (IRR)=1.05 (95% confidence interval [CI] [0.93–1.17]). However, mortality was significantly higher among the uninsured in the post-ACA period when compared with the pre-ACA uninsured population IRR=1.46 (95% CI [1.14–1.88]). Conclusion While the ACA has reduced the number of uninsured trauma patients in Illinois, we found no significant decrease in inpatient trauma mortality. However, the group that remains uninsured after ACA implementation appears to be particularly vulnerable. This group should be studied in order to reduce disparate outcomes after trauma. PMID:29560058

Association of physical inactivity with hypertension and low educational level in people living with HIV / AIDS.

PubMed

Silveira, Erika Aparecida; Santos, Annelisa Silva E Alves de Carvalho; Falco, Marianne de Oliveira; Cardoso, Rodrigo de Castro; Vitorino, Priscila Valverde de Oliveira

2018-08-01

The aim of this study was to determine the prevalence of physical inactivity and whether it is associated with sociodemographic, lifestyle, clinical, anthropometric, and body composition variables in people living with HIV/AIDS (PLWHA). This study makes use of data from a cohort of 288 adults aged ≥19 years, conducted between October 2009 and July 2011. The variables studied were sex, age, education, income, skin color, tobacco use, alcohol intake, body mass index, body fat percentage, waist circumference, and waist-hip ratio, length of HIV/AIDS diagnosis, use of antiretroviral therapy and length of its use, CD4, hypertension (HT) and diabetes mellitus. Physical inactivity was defined as a score below 600 metabolic equivalent minutes/week according to the International Physical Activity Questionnaire - Short Version. Poisson multiple regression was applied in the multivariate analysis with a significance level of 5%. The prevalence of physical inactivity was 44.1%. Education of ≤4 years of study (prevalence ratio [PR]: 1.71) and HT (PR: 1.49) were associated with physical inactivity. Physical inactivity was highly prevalent in PLWHA and associated with low educational level and HT. We highlight the simultaneous association between two cardiometabolic risk factors, HT and physical inactivity.

Perceived Discrimination and Health among Immigrants in Europe According to National Integration Policies.

PubMed

Borrell, Carme; Palència, Laia; Bartoll, Xavier; Ikram, Umar; Malmusi, Davide

2015-08-31

Discrimination harms immigrants' health. The objective of this study was to analyze the association between perceived discrimination and health outcomes among first and second generation immigrants from low-income countries living in Europe, while accounting for sex and the national policy on immigration. Cross-sectional study including immigrants from low-income countries aged ≥15 years in 18 European countries (European Social Survey, 2012) (sample of 1271 men and 1335 women). The dependent variables were self-reported health, symptoms of depression, and limitation of activity. The independent variables were perceived group discrimination, immigrant background and national immigrant integration policy. We tested for association between perceived group discrimination and health outcomes by fitting robust Poisson regression models. We only observed significant associations between perceived group discrimination and health outcomes in first generation immigrants. For example, depression was associated with discrimination among both men and women (Prevalence Ratio-, 1.55 (95% CI: 1.16-2.07) and 1.47 (95% CI: 1.15-1.89) in the multivariate model, respectively), and mainly in countries with assimilationist immigrant integration policies. Perceived group discrimination is associated with poor health outcomes in first generation immigrants from low-income countries who live in European countries, but not among their descendants. These associations are more important in assimilationist countries.

Low back pain and associated presenteeism among hospital nursing staff.

PubMed

d'Errico, Angelo; Viotti, Sara; Baratti, Alberto; Mottura, Bianca; Barocelli, Anna Pia; Tagna, Marina; Sgambelluri, Barbara; Battaglino, Paolo; Converso, Daniela

2013-01-01

In spite of the high prevalence of low back pain (LBP) and presenteeism previously observed among nurses, no study has assessed the risk of presenteeism specifically due to LBP in nursing staff. Therefore, aim of the present study was to assess prevalence and risk factors of presenteeism due to LBP among hospital nursing personnel. 174 female nurses underwent a clinical interview and filled in a questionnaire on sociodemographics, LBP symptoms and associated sickness absence, mental symptoms, burnout and on exposure to workplace organizational, psychosocial and ergonomic factors; 111 subjects affected by LBP were included in the analysis. The effect of sociodemographic and workplace characteristics on presenteeism was examined through multivariate Poisson robust regression models. Prevalence of presenteeism due to LBP was 58%, with wide differences between registered nurses and nursing aides (p=0.001). Only a few workplace factors were significantly associated with presenteeism, including frequent stooping, which decreased the risk of presenteeism, and good working climate and procedural justice, which increased it. Presenteeism due to LBP was very high among registered nurses and was influenced only by workplace, but not by sociodemographic characteristics. Presenteeism due to LBP among registered nurses should be closely monitored, and effort should be made to reduce it to prevent future work disability associated with LBP.

Dental caries experience in Australian Army recruits 2002-2003.

PubMed

Hopcraft, M; Morgan, M V

2005-03-01

Recent data have suggested that the trend of decreasing caries experience in Australian children is slowing with increasing dmft and DMFT scores seen in children. However, there are limited data on dental caries experience in young Australian adults. A cross-sectional study of 973 Australian Army recruits was conducted between November 2002 and March 2003. A clinical examination with bitewing radiographs was conducted and a questionnaire was used to elicit socio-demographic information. Mean DMFT scores were 2.43, 3.44, 5.48, 7.02 and 10.77 for subjects aged 17-20, 21-25, 26-30, 31-35 and 36-51 years respectively. Subjects with a lifetime exposure to fluoridated drinking water had a mean DMFT of 2.80 while subjects with no exposure to fluoridated drinking water had a mean DMFT of 3.91. Multivariate Poisson regression found that age, level of educationand lifetime exposure to fluoridated drinking water had a statistically significant effect on caries experience. It appears that there has been a continual decline in caries experience and prevalence in young Australian adults between 1996 and 2002-2003. Lifetime exposure to fluoridated drinking water conferred an appreciable benefit for subjects in this study compared with subjects with no exposure to fluoridated drinking water.

STI Screening Uptake and Knowledge of STI Symptoms among Female Sex Workers Participating in a Community Randomized Trial in Peru

PubMed Central

Kohler, Pamela K.; Campos, Pablo E.; Garcia, Patricia J.; Carcamo, Cesar P.; Buendia, Clara; Hughes, James P.; Mejia, Carolina; Garnett, Geoff P.; King, K.

2016-01-01

This study aims to evaluate condom use, STI screening, and knowledge of STI symptoms among female sex workers (FSW) in Peru associated with sex work venue and a community randomized trial of STI control. One component of the Peru PREVEN intervention conducted mobile-team outreach to FSW to reduce STIs and increase condom use and access to government clinics for STI screening and evaluation. Prevalence ratios were calculated using multivariate Poisson regression models with robust standard errors, clustering by city. As-treated analyses were conducted to assess outcomes associated with reported exposure to the intervention. Care-seeking was more frequent in intervention communities, but differences were not statistically significant. FSW reporting exposure to the intervention had significantly higher likelihood of condom use, STI screening at public health clinics, and symptom recognition compared to those not exposed. Compared with street or bar-based FSW, brothel-based FSW reported significantly higher rates of condom use with last client, recent screening exams for STIs and HIV testing. Brothel-based FSW also more often reported knowledge of STIs and recognition of STI symptoms in women and in men. Interventions to promote STI-detection and prevention among FSW in Peru should consider structural or regulatory factors related to sex work venue. PMID:25941053

Recall of anti-tobacco advertisements and effects on quitting behavior: results from the California smokers cohort.

PubMed

Leas, Eric C; Myers, Mark G; Strong, David R; Hofstetter, C Richard; Al-Delaimy, Wael K

2015-02-01

We assessed whether an anti-tobacco television advertisement called "Stages," which depicted a woman giving a brief emotional narrative of her experiences with tobacco use, would be recalled more often and have a greater effect on smoking cessation than 3 other advertisements with different intended themes. Our data were derived from a sample of 2596 California adult smokers. We used multivariable log-binomial and modified Poisson regression models to calculate respondents' probability of quitting as a result of advertisement recall. More respondents recalled the "Stages" ad (58.5%) than the 3 other ads (23.1%, 23.4%, and 25.6%; P<.001). Respondents who recalled "Stages" at baseline had a higher probability than those who did not recall the ad of making a quit attempt between baseline and follow-up (adjusted risk ratio [RR]=1.18; 95% confidence interval [CI]=1.03, 1.34) and a higher probability of being in a period of smoking abstinence for at least a month at follow-up (adjusted RR=1.55; 95% CI=1.02, 2.37). Anti-tobacco television advertisements that depict visceral and personal messages may be recalled by a larger percentage of smokers and may have a greater impact on smoking cessation than other types of advertisements.

Self-perceived oral health influences tooth brushing in preschool children.

PubMed

Agostini, Bernardo Antonio; Machry, Rômulo Vaz; Teixeira, Carlos Roberto da Silva; Piovesan, Chaiana; Oliveira, Marta Dutra Machado; Bresolin, Carmela Rampazzo; Ardenghi, Thiago Machado

2014-01-01

This study assessed the influence of socioeconomic and clinical factors, as well as parent's perception of child's oral health on the toothbrushing frequency of 0-5-year-old children. The study was carried out in Santa Maria, RS, Brazil, during the National Children's Vaccination Day, and 478 children aged 0-5 years were included. Data were collected by clinical examinations and a structured questionnaire, conducted by 15 calibrated examiners and 30 supports. A questionnaire was filled out by the parents with information about several socioeconomic indicators, perception of child's oral health and frequency of tooth brushing. The main outcome was collected by the question: "How many times a day do you brush your child's teeth?". Multivariable Poisson regression model taking into account the cluster sample was performed to assess the association between the predictors and outcome. Children whose parents related worse perception of child's oral health showed less tooth brushing frequency (PR 1.23; 1.06 - 1.43). Young children brush their teeth less than the older ones (PR 0.90; 0.84 - 0.96); and lack of visit to a dentist was predictor for less tooth brushing frequency (PR 1.29; 1.05 - 1.59). Parent's perception of child oral health influence children's healthy behaviors, supporting the evidence that psychosocial factors are strong predictors of children's oral health.

Multivariate regression model for predicting lumber grade volumes of northern red oak sawlogs

Treesearch

Daniel A. Yaussy; Robert L. Brisbin

1983-01-01

A multivariate regression model was developed to predict green board-foot yields for the seven common factory lumber grades processed from northern red oak (Quercus rubra L.) factory grade logs. The model uses the standard log measurements of grade, scaling diameter, length, and percent defect. It was validated with an independent data set. The model...

Predictive and mechanistic multivariate linear regression models for reaction development

PubMed Central

Santiago, Celine B.; Guo, Jing-Yao

2018-01-01

Multivariate Linear Regression (MLR) models utilizing computationally-derived and empirically-derived physical organic molecular descriptors are described in this review. Several reports demonstrating the effectiveness of this methodological approach towards reaction optimization and mechanistic interrogation are discussed. A detailed protocol to access quantitative and predictive MLR models is provided as a guide for model development and parameter analysis. PMID:29719711

Multivariate regression model for predicting yields of grade lumber from yellow birch sawlogs

Treesearch

Andrew F. Howard; Daniel A. Yaussy

1986-01-01

A multivariate regression model was developed to predict green board-foot yields for the common grades of factory lumber processed from yellow birch factory-grade logs. The model incorporates the standard log measurements of scaling diameter, length, proportion of scalable defects, and the assigned USDA Forest Service log grade. Differences in yields between band and...

G/SPLINES: A hybrid of Friedman's Multivariate Adaptive Regression Splines (MARS) algorithm with Holland's genetic algorithm

NASA Technical Reports Server (NTRS)

Rogers, David

1991-01-01

G/SPLINES are a hybrid of Friedman's Multivariable Adaptive Regression Splines (MARS) algorithm with Holland's Genetic Algorithm. In this hybrid, the incremental search is replaced by a genetic search. The G/SPLINE algorithm exhibits performance comparable to that of the MARS algorithm, requires fewer least squares computations, and allows significantly larger problems to be considered.

Validation of cross-sectional time series and multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents using doubly labeled water

USDA-ARS?s Scientific Manuscript database

Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant cha...

Analytical framework for reconstructing heterogeneous environmental variables from mammal community structure.

PubMed

Louys, Julien; Meloro, Carlo; Elton, Sarah; Ditchfield, Peter; Bishop, Laura C

2015-01-01

We test the performance of two models that use mammalian communities to reconstruct multivariate palaeoenvironments. While both models exploit the correlation between mammal communities (defined in terms of functional groups) and arboreal heterogeneity, the first uses a multiple multivariate regression of community structure and arboreal heterogeneity, while the second uses a linear regression of the principal components of each ecospace. The success of these methods means the palaeoenvironment of a particular locality can be reconstructed in terms of the proportions of heavy, moderate, light, and absent tree canopy cover. The linear regression is less biased, and more precisely and accurately reconstructs heavy tree canopy cover than the multiple multivariate model. However, the multiple multivariate model performs better than the linear regression for all other canopy cover categories. Both models consistently perform better than randomly generated reconstructions. We apply both models to the palaeocommunity of the Upper Laetolil Beds, Tanzania. Our reconstructions indicate that there was very little heavy tree cover at this site (likely less than 10%), with the palaeo-landscape instead comprising a mixture of light and absent tree cover. These reconstructions help resolve the previous conflicting palaeoecological reconstructions made for this site. Copyright © 2014 Elsevier Ltd. All rights reserved.

Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

NASA Astrophysics Data System (ADS)

Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

2016-03-01

From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states.

Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

PubMed Central

Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

2016-01-01

From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states. PMID:26996254

Regression Models For Multivariate Count Data

PubMed Central

Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

2016-01-01

Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data. PMID:28348500

Regression Models For Multivariate Count Data.

PubMed

Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

2017-01-01

Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data.

Occurrence of Conotruncal Heart Birth Defects in Texas: A Comparison of Urban/Rural Classifications

ERIC Educational Resources Information Center

Langlois, Peter H.; Jandle, Leigh; Scheuerle, Angela; Horel, Scott A.; Carozza, Susan E.

2010-01-01

Purpose: (1) Determine if there is an association between 3 conotruncal heart birth defects and urban/rural residence of mother. (2) Compare results using different methods of measuring urban/rural status. Methods: Data were taken from the Texas Birth Defects Registry, 1999-2003. Poisson regression was used to compare crude and adjusted birth…

Stagnation in Mortality Decline among Elders in the Netherlands

ERIC Educational Resources Information Center

Janssen, Fanny; Nusselder, Wilma J.; Looman, Caspar W. N.; Mackenbach, Johan P.; Kunst, Anton E.

2003-01-01

Purpose: This study assesses whether the stagnation of old-age (80+) mortality decline observed in The Netherlands in the 1980s continued in the 1990s and determines which factors contributed to this stagnation. Emphasis is on the role of smoking. Design and Methods: Poisson regression analysis with linear splines was applied to total and…

Dynamic spatiotemporal analysis of indigenous dengue fever at street-level in Guangzhou city, China

PubMed Central

Xia, Yao; Zhang, Yingtao; Huang, Xiaodong; Huang, Jiawei; Nie, Enqiong; Jing, Qinlong; Wang, Guoling; Yang, Zhicong; Hu, Wenbiao

2018-01-01

Background This study aimed to investigate the spatiotemporal clustering and socio-environmental factors associated with dengue fever (DF) incidence rates at street level in Guangzhou city, China. Methods Spatiotemporal scan technique was applied to identify the high risk region of DF. Multiple regression model was used to identify the socio-environmental factors associated with DF infection. A Poisson regression model was employed to examine the spatiotemporal patterns in the spread of DF. Results Spatial clusters of DF were primarily concentrated at the southwest part of Guangzhou city. Age group (65+ years) (Odd Ratio (OR) = 1.49, 95% Confidence Interval (CI) = 1.13 to 2.03), floating population (OR = 1.09, 95% CI = 1.05 to 1.15), low-education (OR = 1.08, 95% CI = 1.01 to 1.16) and non-agriculture (OR = 1.07, 95% CI = 1.03 to 1.11) were associated with DF transmission. Poisson regression results indicated that changes in DF incidence rates were significantly associated with longitude (β = -5.08, P<0.01) and latitude (β = -1.99, P<0.01). Conclusions The study demonstrated that social-environmental factors may play an important role in DF transmission in Guangzhou. As geographic range of notified DF has significantly expanded over recent years, an early warning systems based on spatiotemporal model with socio-environmental is urgently needed to improve the effectiveness and efficiency of dengue control and prevention. PMID:29561835

Dynamic spatiotemporal analysis of indigenous dengue fever at street-level in Guangzhou city, China.

PubMed

Liu, Kangkang; Zhu, Yanshan; Xia, Yao; Zhang, Yingtao; Huang, Xiaodong; Huang, Jiawei; Nie, Enqiong; Jing, Qinlong; Wang, Guoling; Yang, Zhicong; Hu, Wenbiao; Lu, Jiahai

2018-03-01

This study aimed to investigate the spatiotemporal clustering and socio-environmental factors associated with dengue fever (DF) incidence rates at street level in Guangzhou city, China. Spatiotemporal scan technique was applied to identify the high risk region of DF. Multiple regression model was used to identify the socio-environmental factors associated with DF infection. A Poisson regression model was employed to examine the spatiotemporal patterns in the spread of DF. Spatial clusters of DF were primarily concentrated at the southwest part of Guangzhou city. Age group (65+ years) (Odd Ratio (OR) = 1.49, 95% Confidence Interval (CI) = 1.13 to 2.03), floating population (OR = 1.09, 95% CI = 1.05 to 1.15), low-education (OR = 1.08, 95% CI = 1.01 to 1.16) and non-agriculture (OR = 1.07, 95% CI = 1.03 to 1.11) were associated with DF transmission. Poisson regression results indicated that changes in DF incidence rates were significantly associated with longitude (β = -5.08, P<0.01) and latitude (β = -1.99, P<0.01). The study demonstrated that social-environmental factors may play an important role in DF transmission in Guangzhou. As geographic range of notified DF has significantly expanded over recent years, an early warning systems based on spatiotemporal model with socio-environmental is urgently needed to improve the effectiveness and efficiency of dengue control and prevention.

Remote Sensing-Driven Climatic/Environmental Variables for Modelling Malaria Transmission in Sub-Saharan Africa.

PubMed

Ebhuoma, Osadolor; Gebreslasie, Michael

2016-06-14

Malaria is a serious public health threat in Sub-Saharan Africa (SSA), and its transmission risk varies geographically. Modelling its geographic characteristics is essential for identifying the spatial and temporal risk of malaria transmission. Remote sensing (RS) has been serving as an important tool in providing and assessing a variety of potential climatic/environmental malaria transmission variables in diverse areas. This review focuses on the utilization of RS-driven climatic/environmental variables in determining malaria transmission in SSA. A systematic search on Google Scholar and the Institute for Scientific Information (ISI) Web of Knowledge(SM) databases (PubMed, Web of Science and ScienceDirect) was carried out. We identified thirty-five peer-reviewed articles that studied the relationship between remotely-sensed climatic variable(s) and malaria epidemiological data in the SSA sub-regions. The relationship between malaria disease and different climatic/environmental proxies was examined using different statistical methods. Across the SSA sub-region, the normalized difference vegetation index (NDVI) derived from either the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) or Moderate-resolution Imaging Spectrometer (MODIS) satellite sensors was most frequently returned as a statistically-significant variable to model both spatial and temporal malaria transmission. Furthermore, generalized linear models (linear regression, logistic regression and Poisson regression) were the most frequently-employed methods of statistical analysis in determining malaria transmission predictors in East, Southern and West Africa. By contrast, multivariate analysis was used in Central Africa. We stress that the utilization of RS in determining reliable malaria transmission predictors and climatic/environmental monitoring variables would require a tailored approach that will have cognizance of the geographical/climatic setting, the stage of malaria elimination continuum, the characteristics of the RS variables and the analytical approach, which in turn, would support the channeling of intervention resources sustainably.

Remote Sensing-Driven Climatic/Environmental Variables for Modelling Malaria Transmission in Sub-Saharan Africa

PubMed Central

Ebhuoma, Osadolor; Gebreslasie, Michael

2016-01-01

Malaria is a serious public health threat in Sub-Saharan Africa (SSA), and its transmission risk varies geographically. Modelling its geographic characteristics is essential for identifying the spatial and temporal risk of malaria transmission. Remote sensing (RS) has been serving as an important tool in providing and assessing a variety of potential climatic/environmental malaria transmission variables in diverse areas. This review focuses on the utilization of RS-driven climatic/environmental variables in determining malaria transmission in SSA. A systematic search on Google Scholar and the Institute for Scientific Information (ISI) Web of KnowledgeSM databases (PubMed, Web of Science and ScienceDirect) was carried out. We identified thirty-five peer-reviewed articles that studied the relationship between remotely-sensed climatic variable(s) and malaria epidemiological data in the SSA sub-regions. The relationship between malaria disease and different climatic/environmental proxies was examined using different statistical methods. Across the SSA sub-region, the normalized difference vegetation index (NDVI) derived from either the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) or Moderate-resolution Imaging Spectrometer (MODIS) satellite sensors was most frequently returned as a statistically-significant variable to model both spatial and temporal malaria transmission. Furthermore, generalized linear models (linear regression, logistic regression and Poisson regression) were the most frequently-employed methods of statistical analysis in determining malaria transmission predictors in East, Southern and West Africa. By contrast, multivariate analysis was used in Central Africa. We stress that the utilization of RS in determining reliable malaria transmission predictors and climatic/environmental monitoring variables would require a tailored approach that will have cognizance of the geographical/climatic setting, the stage of malaria elimination continuum, the characteristics of the RS variables and the analytical approach, which in turn, would support the channeling of intervention resources sustainably. PMID:27314369

Effects of Clostridium difficile infection in patients with alcoholic hepatitis.

PubMed

Sundaram, Vinay; May, Folasade P; Manne, Vignan; Saab, Sammy

2014-10-01

Infection increases mortality in patients with alcoholic hepatitis (AH). Little is known about the association between Clostridium difficile infection (CDI) and AH. We examined the prevalence and effects of CDI in patients with AH, compared with those of other infections. We performed a cross-sectional analysis using data collected from the Nationwide Inpatient Sample, from 2008 through 2011. International Classification of Diseases, 9th revision, Clinical Modification codes were used to identify patients with AH. We used multivariable logistic regression to determine risk factors that affect mortality, negative binomial regression to evaluate the effects of CDI on predicted length of stay (LOS), and Poisson regression to determine the effects of CDI on predicted hospital charges. Chi-square and Wilcoxon rank-sum analyses were used to compare mortality, LOS, and hospital charges associated with CDI with those associated with urinary tract infection (UTI) and spontaneous bacterial peritonitis (SBP). Of 10,939 patients with AH, 177 had CDI (1.62%). Patients with AH and CDI had increased odds of inpatient mortality (adjusted odds ratio, 1.75; P = .04), a longer predicted LOS (10.63 vs 5.75 d; P < .001), and greater predicted hospital charges ($36,924.30 vs $29,136.58; P < .001), compared with those without CDI. Compared with UTI, CDI was associated with similar mortality but greater LOS (9 vs 6 d; P < .001) and hospital charges ($45,607 vs $32,087; P < .001). SBP was associated with higher mortality than CDI (17.3% vs 10.1%; P = .045), but similar LOS and hospital charges. In patients with AH, CDI is associated with greater mortality and health care use. These effects appear similar to those for UTI and SBP. We propose further studies to determine the cost effectiveness of screening for CDI among patients with AH. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Measures of clustering and heterogeneity in multilevel Poisson regression analyses of rates/count data

PubMed Central

Austin, Peter C.; Stryhn, Henrik; Leckie, George; Merlo, Juan

2017-01-01

Multilevel data occur frequently in many research areas like health services research and epidemiology. A suitable way to analyze such data is through the use of multilevel regression models. These models incorporate cluster‐specific random effects that allow one to partition the total variation in the outcome into between‐cluster variation and between‐individual variation. The magnitude of the effect of clustering provides a measure of the general contextual effect. When outcomes are binary or time‐to‐event in nature, the general contextual effect can be quantified by measures of heterogeneity like the median odds ratio or the median hazard ratio, respectively, which can be calculated from a multilevel regression model. Outcomes that are integer counts denoting the number of times that an event occurred are common in epidemiological and medical research. The median (incidence) rate ratio in multilevel Poisson regression for counts that corresponds to the median odds ratio or median hazard ratio for binary or time‐to‐event outcomes respectively is relatively unknown and is rarely used. The median rate ratio is the median relative change in the rate of the occurrence of the event when comparing identical subjects from 2 randomly selected different clusters that are ordered by rate. We also describe how the variance partition coefficient, which denotes the proportion of the variation in the outcome that is attributable to between‐cluster differences, can be computed with count outcomes. We illustrate the application and interpretation of these measures in a case study analyzing the rate of hospital readmission in patients discharged from hospital with a diagnosis of heart failure. PMID:29114926

Spatiotemporal analysis of the relationship between socioeconomic factors and stroke in the Portuguese mainland population under 65 years old.

PubMed

Oliveira, André; Cabral, António J R; Mendes, Jorge M; Martins, Maria R O; Cabral, Pedro

2015-11-04

Stroke risk has been shown to display varying patterns of geographic distribution amongst countries but also between regions of the same country. Traditionally a disease of older persons, a global 25% increase in incidence instead was noticed between 1990 and 2010 in persons aged 20-≤64 years, particularly in low- and medium-income countries. Understanding spatial disparities in the association between socioeconomic factors and stroke is critical to target public health initiatives aiming to mitigate or prevent this disease, including in younger persons. We aimed to identify socioeconomic determinants of geographic disparities of stroke risk in people <65 years old, in municipalities of mainland Portugal, and the spatiotemporal variation of the association between these determinants and stroke risk during two study periods (1992-1996 and 2002-2006). Poisson and negative binomial global regression models were used to explore determinants of disease risk. Geographically weighted regression (GWR) represents a distinctive approach, allowing estimation of local regression coefficients. Models for both study periods were identified. Significant variables included education attainment, work hours per week and unemployment. Local Poisson GWR models achieved the best fit and evidenced spatially varying regression coefficients. Spatiotemporal inequalities were observed in significant variables, with dissimilarities between men and women. This study contributes to a better understanding of the relationship between stroke and socioeconomic factors in the population <65 years of age, one age group seldom analysed separately. It can thus help to improve the targeting of public health initiatives, even more in a context of economic crisis.

Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

Treesearch

Michael S. Balshi; A. David McGuire; Paul Duffy; Mike Flannigan; John Walsh; Jerry Melillo

2009-01-01

We developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5o (latitude x longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was...

Improving Prediction Accuracy for WSN Data Reduction by Applying Multivariate Spatio-Temporal Correlation

PubMed Central

Carvalho, Carlos; Gomes, Danielo G.; Agoulmine, Nazim; de Souza, José Neuman

2011-01-01

This paper proposes a method based on multivariate spatial and temporal correlation to improve prediction accuracy in data reduction for Wireless Sensor Networks (WSN). Prediction of data not sent to the sink node is a technique used to save energy in WSNs by reducing the amount of data traffic. However, it may not be very accurate. Simulations were made involving simple linear regression and multiple linear regression functions to assess the performance of the proposed method. The results show a higher correlation between gathered inputs when compared to time, which is an independent variable widely used for prediction and forecasting. Prediction accuracy is lower when simple linear regression is used, whereas multiple linear regression is the most accurate one. In addition to that, our proposal outperforms some current solutions by about 50% in humidity prediction and 21% in light prediction. To the best of our knowledge, we believe that we are probably the first to address prediction based on multivariate correlation for WSN data reduction. PMID:22346626

Characterizing multivariate decoding models based on correlated EEG spectral features

PubMed Central

McFarland, Dennis J.

2013-01-01

Objective Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Methods Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). Results The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Conclusions Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. Significance While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. PMID:23466267

Mechanics of fiber reinforced materials

NASA Astrophysics Data System (ADS)

Sun, Huiyu

This dissertation is dedicated to mechanics of fiber reinforced materials and the woven reinforcement and composed of four parts of research: analytical characterization of the interfaces in laminated composites; micromechanics of braided composites; shear deformation, and Poisson's ratios of woven fabric reinforcements. A new approach to evaluate the mechanical characteristics of interfaces between composite laminae based on a modified laminate theory is proposed. By including an interface as a special lamina termed the "bonding-layer" in the analysis, the mechanical properties of the interfaces are obtained. A numerical illustration is given. For micro-mechanical properties of three-dimensionally braided composite materials, a new method via homogenization theory and incompatible multivariable FEM is developed. Results from the hybrid stress element approach compare more favorably with the experimental data than other existing numerical methods widely used. To evaluate the shearing properties for woven fabrics, a new mechanical model is proposed during the initial slip region. Analytical results show that this model provides better agreement with the experiments for both the initial shear modulus and the slipping angle than the existing models. Finally, another mechanical model for a woven fabric made of extensible yarns is employed to calculate the fabric Poisson's ratios. Theoretical results are compared with the available experimental data. A thorough examination on the influences of various mechanical properties of yarns and structural parameters of fabrics on the Poisson's ratios of a woven fabric is given at the end.

Multivariate Boosting for Integrative Analysis of High-Dimensional Cancer Genomic Data

PubMed Central

Xiong, Lie; Kuan, Pei-Fen; Tian, Jianan; Keles, Sunduz; Wang, Sijian

2015-01-01

In this paper, we propose a novel multivariate component-wise boosting method for fitting multivariate response regression models under the high-dimension, low sample size setting. Our method is motivated by modeling the association among different biological molecules based on multiple types of high-dimensional genomic data. Particularly, we are interested in two applications: studying the influence of DNA copy number alterations on RNA transcript levels and investigating the association between DNA methylation and gene expression. For this purpose, we model the dependence of the RNA expression levels on DNA copy number alterations and the dependence of gene expression on DNA methylation through multivariate regression models and utilize boosting-type method to handle the high dimensionality as well as model the possible nonlinear associations. The performance of the proposed method is demonstrated through simulation studies. Finally, our multivariate boosting method is applied to two breast cancer studies. PMID:26609213

Quantitative monitoring of sucrose, reducing sugar and total sugar dynamics for phenotyping of water-deficit stress tolerance in rice through spectroscopy and chemometrics

NASA Astrophysics Data System (ADS)

Das, Bappa; Sahoo, Rabi N.; Pargal, Sourabh; Krishna, Gopal; Verma, Rakesh; Chinnusamy, Viswanathan; Sehgal, Vinay K.; Gupta, Vinod K.; Dash, Sushanta K.; Swain, Padmini

2018-03-01

In the present investigation, the changes in sucrose, reducing and total sugar content due to water-deficit stress in rice leaves were modeled using visible, near infrared (VNIR) and shortwave infrared (SWIR) spectroscopy. The objectives of the study were to identify the best vegetation indices and suitable multivariate technique based on precise analysis of hyperspectral data (350 to 2500 nm) and sucrose, reducing sugar and total sugar content measured at different stress levels from 16 different rice genotypes. Spectral data analysis was done to identify suitable spectral indices and models for sucrose estimation. Novel spectral indices in near infrared (NIR) range viz. ratio spectral index (RSI) and normalised difference spectral indices (NDSI) sensitive to sucrose, reducing sugar and total sugar content were identified which were subsequently calibrated and validated. The RSI and NDSI models had R2 values of 0.65, 0.71 and 0.67; RPD values of 1.68, 1.95 and 1.66 for sucrose, reducing sugar and total sugar, respectively for validation dataset. Different multivariate spectral models such as artificial neural network (ANN), multivariate adaptive regression splines (MARS), multiple linear regression (MLR), partial least square regression (PLSR), random forest regression (RFR) and support vector machine regression (SVMR) were also evaluated. The best performing multivariate models for sucrose, reducing sugars and total sugars were found to be, MARS, ANN and MARS, respectively with respect to RPD values of 2.08, 2.44, and 1.93. Results indicated that VNIR and SWIR spectroscopy combined with multivariate calibration can be used as a reliable alternative to conventional methods for measurement of sucrose, reducing sugars and total sugars of rice under water-deficit stress as this technique is fast, economic, and noninvasive.

Finding structure in data using multivariate tree boosting

PubMed Central

Miller, Patrick J.; Lubke, Gitta H.; McArtor, Daniel B.; Bergeman, C. S.

2016-01-01

Technology and collaboration enable dramatic increases in the size of psychological and psychiatric data collections, but finding structure in these large data sets with many collected variables is challenging. Decision tree ensembles such as random forests (Strobl, Malley, & Tutz, 2009) are a useful tool for finding structure, but are difficult to interpret with multiple outcome variables which are often of interest in psychology. To find and interpret structure in data sets with multiple outcomes and many predictors (possibly exceeding the sample size), we introduce a multivariate extension to a decision tree ensemble method called gradient boosted regression trees (Friedman, 2001). Our extension, multivariate tree boosting, is a method for nonparametric regression that is useful for identifying important predictors, detecting predictors with nonlinear effects and interactions without specification of such effects, and for identifying predictors that cause two or more outcome variables to covary. We provide the R package ‘mvtboost’ to estimate, tune, and interpret the resulting model, which extends the implementation of univariate boosting in the R package ‘gbm’ (Ridgeway et al., 2015) to continuous, multivariate outcomes. To illustrate the approach, we analyze predictors of psychological well-being (Ryff & Keyes, 1995). Simulations verify that our approach identifies predictors with nonlinear effects and achieves high prediction accuracy, exceeding or matching the performance of (penalized) multivariate multiple regression and multivariate decision trees over a wide range of conditions. PMID:27918183

Evaluation of Shiryaev-Roberts procedure for on-line environmental radiation monitoring.

PubMed

Watson, Mara M; Seliman, Ayman F; Bliznyuk, Valery N; DeVol, Timothy A

2018-04-30

Water can become contaminated as a result of a leak from a nuclear facility, such as a waste facility, or from clandestine nuclear activity. Low-level on-line radiation monitoring is needed to detect these events in real time. A Bayesian control chart method, Shiryaev-Roberts (SR) procedure, was compared with classical methods, 3-σ and cumulative sum (CUSUM), for quantifying an accumulating signal from an extractive scintillating resin flow-cell detection system. Solutions containing 0.10-5.0 Bq/L of 99 Tc, as T99cO 4 - were pumped through a flow cell packed with extractive scintillating resin used in conjunction with a Beta-RAM Model 5 HPLC detector. While T99cO 4 - accumulated on the resin, time series data were collected. Control chart methods were applied to the data using statistical algorithms developed in MATLAB. SR charts were constructed using Poisson (Poisson SR) and Gaussian (Gaussian SR) probability distributions of count data to estimate the likelihood ratio. Poisson and Gaussian SR charts required less volume of radioactive solution at a fixed concentration to exceed the control limit in most cases than 3-σ and CUSUM control charts, particularly solutions with lower activity. SR is thus the ideal control chart for low-level on-line radiation monitoring. Once the control limit was exceeded, activity concentrations were estimated from the SR control chart using the control chart slope on a semi-logarithmic plot. A linear regression fit was applied to averaged slope data for five activity concentration groupings for Poisson and Gaussian SR control charts. A correlation coefficient (R 2 ) of 0.77 for Poisson SR and 0.90 for Gaussian SR suggest this method will adequately estimate activity concentration for an unknown solution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Association of Fitness With Incident Dyslipidemias Over 25 Years in the Coronary Artery Risk Development in Young Adults Study.

PubMed

Sarzynski, Mark A; Schuna, John M; Carnethon, Mercedes R; Jacobs, David R; Lewis, Cora E; Quesenberry, Charles P; Sidney, Stephen; Schreiner, Pamela J; Sternfeld, Barbara

2015-11-01

Few studies have examined the longitudinal associations of fitness or changes in fitness on the risk of developing dyslipidemias. This study examined the associations of (1) baseline fitness with 25-year dyslipidemia incidence and (2) 20-year fitness change on dyslipidemia development in middle age in the Coronary Artery Risk Development in Young Adults Study (CARDIA). Multivariable Cox proportional hazards regression models were used to test the association of baseline fitness (1985-1986) with dyslipidemia incidence over 25 years (2010-2011) in CARDIA (N=4,898). Modified Poisson regression models were used to examine the association of 20-year change in fitness with dyslipidemia incidence between Years 20 and 25 (n=2,487). Data were analyzed in June 2014 and February 2015. In adjusted models, the risk of incident low high-density lipoprotein cholesterol (HDL-C); high triglycerides; and high low-density lipoprotein cholesterol (LDL-C) was significantly lower, by 9%, 16%, and 14%, respectively, for each 2.0-minute increase in baseline treadmill endurance. After additional adjustment for baseline trait level, the associations remained significant for incident high triglycerides and high LDL-C in the total population and for incident high triglycerides in both men and women. In race-stratified models, these associations appeared to be limited to whites. In adjusted models, change in fitness did not predict 5-year incidence of dyslipidemias, whereas baseline fitness significantly predicted 5-year incidence of high triglycerides. Our findings demonstrate the importance of cardiorespiratory fitness in young adulthood as a risk factor for developing dyslipidemias, particularly high triglycerides, during the transition to middle age. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Association of Fitness With Incident Dyslipidemias Over 25 Years in the Coronary Artery Risk Development in Young Adults Study

PubMed Central

Sarzynski, Mark A.; Schuna, John M.; Carnethon, Mercedes R.; Jacobs, David R.; Lewis, Cora E.; Quesenberry, Charles P.; Sidney, Stephen; Schreiner, Pamela J.; Sternfeld, Barbara

2015-01-01

Introduction Few studies have examined the longitudinal associations of fitness or changes in fitness on the risk of developing dyslipidemias. This study examined the associations of: (1) baseline fitness with 25-year dyslipidemia incidence; and (2) 20-year fitness change on dyslipidemia development in middle age in the Coronary Artery Risk Development in young Adults (CARDIA) study. Methods Multivariable Cox proportional hazards regression models were used to test the association of baseline fitness (1985–1986) with dyslipidemia incidence over 25 years (2010–2011) in CARDIA (N=4,898). Modified Poisson regression models were used to examine the association of 20-year change in fitness with dyslipidemia incidence between Years 20 and 25 (n=2,487). Data were analyzed in June 2014 and February 2015. Results In adjusted models, the risk of incident low high-density lipoprotein cholesterol (HDL-C), high triglycerides, and high low-density lipoprotein cholesterol (LDL-C) was significantly lower, by 9%, 16%, and 14%, respectively, for each 2.0-minute increase in baseline treadmill endurance. After additional adjustment for baseline trait level, the associations remained significant for incident high triglycerides and high LDL-C in the total population and for incident high triglycerides in both men and women. In race-stratified models, these associations appeared to be limited to whites. In adjusted models, change in fitness did not predict 5-year incidence of dyslipidemias, whereas baseline fitness significantly predicted 5-year incidence of high triglycerides. Conclusions Our findings demonstrate the importance of cardiorespiratory fitness in young adulthood as a risk factor for developing dyslipidemias, particularly high triglycerides, during the transition to middle age. PMID:26165197

From macro to micro: the health of Swedish lone mothers during changing economic and social circumstances.

PubMed

Fritzell, Sara; Ringbäck Weitoft, Gunilla; Fritzell, Johan; Burström, Bo

2007-12-01

The deep recession in Sweden in the early 1990s led to high unemployment levels. In addition, policy changes and reductions in welfare benefits increased costs of living. These changes may have affected lone mothers to a greater extent than other groups. How have these changes in the social context and policy context impacted on the health of lone mothers in comparison with couple mothers in Sweden between 1983 and 2001? Survey data on 19,192 mothers over the period of 1983-2001 were used to study changes in individual economic and social circumstances and self-rated health (SRH) with multivariate logistic regression. In addition, all-cause mortality, cause-specific mortality and severe morbidity were studied using registers for the whole population. Three cohorts of mothers aged 20-54 years (starting 1985, 1990 and 1996) were formed. Age-adjusted risk ratios were calculated using Poisson regression. The employment rate among lone mothers declined from 1983 to 2001. At the same time, prevalence of self-reported financial problems and exposure to violence increased. Lone mothers reported worse SRH and had higher risks of hospitalisation and mortality than couple mothers in all time periods. Despite changes in social context and policy context causing an increase of health detrimental exposures, and deteriorated levels of SRH 1980-2001 for lone mothers, there was no evidence of increased differentials over time between lone and couple mothers in less than good SRH, hospitalisation or mortality. Three alternative explanations are discussed: the Swedish welfare state still acts as a buffer for ill health; latency makes the follow-up time too short; and finally, the lack of increased differentials is due to methodological reasons.

The Impact of Trauma Exposure and Post-Traumatic Stress Disorder on Healthcare Utilization Among Primary Care Patients

PubMed Central

Kartha, Anand; Brower, Victoria; Saitz, Richard; Samet, Jeffrey H.; Keane, Terence M.; Liebschutz, Jane

2009-01-01

Background Trauma exposure and post-traumatic stress disorder (PTSD) increase healthcare utilization in veterans, but their impact on utilization in other populations is uncertain. Objectives To examine the association of trauma exposure and PTSD with healthcare utilization, in civilian primary care patients. Research Design Cross-sectional study. Subjects English speaking patients at an academic, urban primary care clinic. Measures Trauma exposure and current PTSD diagnoses were obtained from the Composite International Diagnostic Interview. Outcomes were nonmental health outpatient and emergency department visits, hospitalizations, and mental health outpatient visits in the prior year from an electronic medical record. Analyses included bivariate unadjusted and multivariable Poisson regressions adjusted for age, gender, income, substance dependence, depression, and comorbidities. Results Among 592 subjects, 80% had ≥1 trauma exposure and 22% had current PTSD. In adjusted regressions, subjects with trauma exposure had more mental health visits [incidence rate ratio (IRR), 3.9; 95% confidence interval (CI), 1.1–14.1] but no other increased utilization. After adjusting for PTSD, this effect of trauma exposure was attenuated (IRR, 3.2; 95% CI, 0.9–11.7). Subjects with PTSD had more hospitalizations (IRR, 2.2; 95% CI, 1.4–3.7), more hospital nights (IRR, 2.6; 95% CI, 1.4–5.0), and more mental health visits (IRR, 2.2; 95% CI, 1.1–4.1) but no increase in outpatient and emergency department visits. Conclusions PTSD is associated with more hospitalizations, longer hospitalizations, and greater mental healthcare utilization in urban primary care patients. Although trauma exposure is independently associated with greater mental healthcare utilization, PTSD mediates a portion of this association. PMID:18362818

Use of administrative records to assess pneumococcal conjugate vaccine impact on pediatric meningitis and pneumonia hospitalizations in Rwanda.

PubMed

Gatera, Maurice; Uwimana, Jeannine; Manzi, Emmanuel; Ngabo, Fidele; Nwaigwe, Friday; Gessner, Bradford D; Moïsi, Jennifer C

2016-10-17

Ongoing surveillance is critical to assessing pneumococcal conjugate vaccine (PCV) impact over time. However, robust prospective studies are difficult to implement in resource-poor settings. We evaluated retrospective use of routinely collected data to estimate PCV impact in Rwanda. We collected data from admission registers at five district hospitals on children age <5yearsadmitted for suspected meningitis and pneumonia during 2002-2012. We obtained clinical and laboratory data on meningitis from sentinel surveillance at the national reference hospital in Kigali. We developed multivariable logistic regression models to estimate PCV effectiveness (VE) against severe pneumonia and probable bacterial meningitis and Poisson models to estimate absolute rate reductions. Haemophilus influenzae type b vaccine was introduced in January 2002, PCV7 in April 2009 and PCV13 in August 2011. At the district hospitals, the severe pneumonia and suspected meningitis hospitalization rates decreased by 70/100,000 and 11/100,000 children for 2012 compared to baseline, respectively. VE against severe pneumonia calculated from logistic regression was 54% (95% CI 42-63%). In Kigali, from 2002 to 2012, annual suspected meningitis cases decreased from 170 pre-PCV7 to 40 post-PCV13 and confirmed pneumococcal meningitis cases from 7 to 0. VE against probable bacterial meningitis was 42% (95% CI -4% to 68%). In a resource-poor African setting, analysis of district hospital admission logbooks and routine sentinel surveillance data produced results consistent with more sophisticated impact studies conducted elsewhere. Our findings support applying this methodology in other settings and confirm the benefits of PCV in Rwanda. Copyright © 2016 Elsevier Ltd. All rights reserved.

Breast cancer diagnosis and mortality by tumor stage and migration background in a nationwide cohort study in Sweden.

PubMed

Abdoli, Gholamreza; Bottai, Matteo; Sandelin, Kerstin; Moradi, Tahereh

2017-02-01

Survival in breast cancer patients has steadily increased over the years, but with considerable disparities between individuals with different migration background and social position. We explored differences in diagnosis and all-cause mortality in breast cancer patients by stage of disease at the time of diagnosis and by country of birth, while considering the effect of comorbidity, regional and socio-demographic factors. We used Swedish national registers to follow a cohort of 35,268 patients (4232 foreign-born) with breast cancer between 2004 and 2009 in Sweden. We estimated relative risk ratio (RRR) for diagnosis, hazard ratio (HR) for all-cause mortality and relative excess rate (RER) for breast cancer mortality using multinomial logistic regression models, multivariable Cox proportional hazard, and Poisson regression, respectively. We observed 4178 deaths due to any causes. Among them 418 women were born abroad. Foreign-born patients were on average 3 years younger at the time of breast cancer diagnosis and had higher risk of stage II tumors compared with Sweden-born women (RRR = 1.09, 95% CI 1.00-1.19). Risk of dying was 20% higher in foreign-born compared with Sweden-born breast cancer patients, if the tumor was diagnosed at stages III-IV after adjustment for age at diagnosis, education, county of residence and Charlson's comorbidity index (HR = 1.20, 95% CI 0.95-1.51 and RER = 1.21, 95% CI 0.95-1.55). The worse prognosis in foreign-born patients with advanced tumors compared with Sweden-born patients is not explained by educational level or comorbidity. The reasons behind the observed disparities should be further studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prenatal Exposure to Butylbenzyl Phthalate and Early Eczema in an Urban Cohort

PubMed Central

Whyatt, Robin M.; Perzanowski, Matthew S.; Calafat, Antonia M.; Perera, Frederica P.; Goldstein, Inge F.; Chen, Qixuan; Rundle, Andrew G.; Miller, Rachel L.

2012-01-01

Background: Recent cross-sectional studies suggest a link between butylbenzyl phthalate (BBzP) in house dust and childhood eczema. Objectives: We aimed to evaluate whether concentrations of monobenzyl phthalate (MBzP), the main BBzP metabolite in urine, during pregnancy are associated prospectively with eczema in young children, and whether this association varies by the child’s sensitization to indoor allergens or serological evidence of any allergies. Methods: MBzP was measured in spot urine samples during the third trimester of pregnancy from 407 African-American and Dominican women residing in New York City in 1999–2006. Repeated questionnaires asked mothers whether their doctor ever said their child had eczema. Child blood samples at 24, 36, and 60 months of age were analyzed for total, anti-cockroach, dust mite, and mouse IgE. Relative risks (RR) were estimated with multivariable modified Poisson regression. Analyses included a multinomial logistic regression model for early- and late-onset eczema versus no eczema through 60 months of age. Results: MBzP was detected in > 99% of samples (geometric mean = 13.6; interquartile range: 5.7–31.1 ng/mL). By 24 months, 30% of children developed eczema, with the proportion higher among African Americans (48%) than among Dominicans (21%) (p < 0.001). An interquartile range increase in log MBzP concentration was associated positively with early-onset eczema (RR = 1.52 for eczema by 24 months; 95% confidence interval: 1.21, 1.91, p = 0.0003, n = 113 reporting eczema/376 total sample), adjusting for urine specific gravity, sex, and race/ethnicity. MBzP was not associated with allergic sensitization, nor did seroatopy modify consistently the MBzP and eczema association. Conclusions: Prenatal exposure to BBzP may influence the risk of developing eczema in early childhood. PMID:22732598

Features associated with hematologic abnormalities and their impact in patients with systemic lupus erythematosus: Data from a multiethnic Latin American cohort.

PubMed

González-Naranjo, Luis A; Betancur, Octavio Martínez; Alarcón, Graciela S; Ugarte-Gil, Manuel F; Jaramillo-Arroyave, Daniel; Wojdyla, Daniel; Pons-Estel, Guillermo J; Rondón-Herrera, Federico; Vásquez-Duque, Gloria M; Quintana-López, Gerardo; Da Silva, Nilzio A; Tavares Brenol, João C; Reyes-Llerena, Gil; Pascual-Ramos, Virginia; Amigo, Mary C; Massardo, Loreto; Alfaro-Lozano, José; Segami, María I; Esteva-Spinetti, María H; Iglesias-Gamarra, Antonio; Pons-Estel, Bernardo A

2016-06-01

To examine hematological manifestations' correlates and their impact on damage accrual and mortality in SLE patients from the multiethnic, Latin American, GLADEL cohort. In patients with recent SLE diagnosis (≤2 years), the association between follow-up hematological manifestations (per ACR criteria) and socio-demographic and clinical variables was examined by univariable and multivariable logistic regressions; their impact on damage accrual and mortality was examined by Poisson and Cox proportional-hazards regression analyses, respectively. Of 1437 patients, 948 (66.0%) developed ≥1 hematological manifestation [5.5% hemolytic anemia (AHA), 16.3% thrombocytopenia, and 56.4% lymphopenia] over 4.3 (3.3) follow-up years. Younger age, Mestizo ethnicity, hematologic disorder (at/or before SLE diagnosis), and first damage recorded were associated with hematological manifestations while antimalarials were negatively associated. AHA (at/or before SLE diagnosis), anti-Sm, and anti-RNP antibodies were associated with subsequent AHA occurrence while musculoskeletal involvement was negatively associated. Thrombocytopenia (at/or before SLE diagnosis), AHA, anti-phospholipid antibodies (aPLs), anti-SSA/Ro, anti-SSB/La antibodies, and first damage recorded were associated with later thrombocytopenia occurrence. Lymphopenia (at/or before SLE diagnosis), younger age at diagnosis, Mestizo ethnicity, having medical insurance, and first damage recorded were associated with subsequent lymphopenia occurrence while antimalarials and azathioprine treatment were negatively associated. AHA was associated with damage accrual and mortality after adjusting for variables known to affect these outcomes. Mestizo ethnicity and early hematological manifestations are risk factors for their subsequent occurrence while antimalarials have a protective effect. The associations between AHA and aPLs and thrombocytopenia were corroborated. AHA contributes independently to damage accrual and diminished survival. Copyright © 2016 Elsevier Inc. All rights reserved.

Mental Health Services Utilization and Expenditures Among Children Enrolled in Employer-Sponsored Health Plans.

PubMed

Walter, Angela Wangari; Yuan, Yiyang; Cabral, Howard J

2017-05-01

Mental illness in children increases the risk of developing mental health disorders in adulthood, and reduces physical and emotional well-being across the life course. The Mental Health Parity and Addiction Equity Act (MHPAEA, 2008) aimed to improve access to mental health treatment by requiring employer-sponsored health plans to include insurance coverage for behavioral health services. Investigators used IBM Watson/Truven Analytics MarketScan claims data (2007-2013) to examine: (1) the distribution of mental illness; (2) trends in utilization and out-of-pocket expenditures; and (3) the overall effect of the MHPAEA on mental health services utilization and out-of-pocket expenditures among privately-insured children aged 3 to 17 with mental health disorders. Multivariate Poisson regression and linear regression modeling techniques were used. Mental health services use for outpatient behavioral health therapy (BHT) was higher in the years after the implementation of the MHPAEA (2010-2013). Specifically, before the MHPAEA implementation, the annual total visits for BHT provided by mental health physicians were 17.1% lower and 2.5% lower for BHT by mental health professionals, compared to years when MHPAEA was in effect. Children covered by consumer-driven and high-deductible plans had significantly higher out-of-pocket expenditures for BHT compared to those enrolled PPOs. Our findings demonstrate increased mental health services use and higher out-of-pocket costs per outpatient visit after implementation of the MHPAEA. As consumer-driven and high-deductible health plans continue to grow, enrollees need to be cognizant of the impact of health insurance benefit designs on health services offered in these plans. Copyright © 2017 by the American Academy of Pediatrics.

Demographic and Prescribing Patterns of Chinese Herbal Products for Individualized Therapy for Ischemic Heart Disease in Taiwan: Population-Based Study

PubMed Central

Hu, Wen-Long; Chen, Hsuan-Ju; Li, Tsai-Chung; Tsai, Pei-Yuan; Chen, Hsin-Ping; Huang, Meng-Hsuan; Su, Fang-Yen

2015-01-01

Objective Combinations of Chinese herbal products (CHPs) are widely used for ischemic heart disease (IHD) in Taiwan. We analyzed the usage and frequency of CHPs prescribed for patients with IHD. Methods A nationwide population-based cross-sectional study was conducted, 53531 patients from a random sample of one million in the National Health Insurance Research Database (NHIRD) from 2000 to 2010 were enrolled. Descriptive statistics, the multiple logistic regression method and Poisson regression analysis were employed to estimate the adjusted odds ratios (aORs) and adjusted risk ratios (aRRs) for utilization of CHPs. Results The mean age of traditional Chinese medicine (TCM) nonusers was significantly higher than that of TCM users. Zhi-Gan-Cao-Tang (24.85%) was the most commonly prescribed formula CHPs, followed by Xue-Fu-Zhu-Yu-Tang (16.53%) and Sheng-Mai-San (16.00%). The most commonly prescribed single CHPs were Dan Shen (29.30%), Yu Jin (7.44%), and Ge Gen (6.03%). After multivariate adjustment, patients with IHD younger than 29 years had 2.62 times higher odds to use TCM than those 60 years or older. Residents living in Central Taiwan, having hyperlipidemia or cardiac dysrhythmias also have higher odds to use TCM. On the contrary, those who were males, who had diabetes mellitus (DM), hypertension, stroke, myocardial infarction (MI) were less likely to use TCM. Conclusions Zhi-Gan-Cao-Tang and Dan Shen are the most commonly prescribed CHPs for IHD in Taiwan. Our results should be taken into account by physicians when devising individualized therapy for IHD. Further large-scale, randomized clinical trials are warranted in order to determine the effectiveness and safety of these herbal medicines. PMID:26322893

Nut intake and 5-year changes in body weight and obesity risk in adults: results from the EPIC-PANACEA study.

PubMed

Freisling, Heinz; Noh, Hwayoung; Slimani, Nadia; Chajès, Véronique; May, Anne M; Peeters, Petra H; Weiderpass, Elisabete; Cross, Amanda J; Skeie, Guri; Jenab, Mazda; Mancini, Francesca R; Boutron-Ruault, Marie-Christine; Fagherazzi, Guy; Katzke, Verena A; Kühn, Tilman; Steffen, Annika; Boeing, Heiner; Tjønneland, Anne; Kyrø, Cecilie; Hansen, Camilla P; Overvad, Kim; Duell, Eric J; Redondo-Sánchez, Daniel; Amiano, Pilar; Navarro, Carmen; Barricarte, Aurelio; Perez-Cornago, Aurora; Tsilidis, Konstantinos K; Aune, Dagfinn; Ward, Heather; Trichopoulou, Antonia; Naska, Androniki; Orfanos, Philippos; Masala, Giovanna; Agnoli, Claudia; Berrino, Franco; Tumino, Rosario; Sacerdote, Carlotta; Mattiello, Amalia; Bueno-de-Mesquita, H Bas; Ericson, Ulrika; Sonestedt, Emily; Winkvist, Anna; Braaten, Tonje; Romieu, Isabelle; Sabaté, Joan

2017-07-21

There is inconsistent evidence regarding the relationship between higher intake of nuts, being an energy-dense food, and weight gain. We investigated the relationship between nut intake and changes in weight over 5 years. This study includes 373,293 men and women, 25-70 years old, recruited between 1992 and 2000 from 10 European countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Habitual intake of nuts including peanuts, together defined as nut intake, was estimated from country-specific validated dietary questionnaires. Body weight was measured at recruitment and self-reported 5 years later. The association between nut intake and body weight change was estimated using multilevel mixed linear regression models with center/country as random effect and nut intake and relevant confounders as fixed effects. The relative risk (RR) of becoming overweight or obese after 5 years was investigated using multivariate Poisson regressions stratified according to baseline body mass index (BMI). On average, study participants gained 2.1 kg (SD 5.0 kg) over 5 years. Compared to non-consumers, subjects in the highest quartile of nut intake had less weight gain over 5 years (-0.07 kg; 95% CI -0.12 to -0.02) (P trend = 0.025) and had 5% lower risk of becoming overweight (RR 0.95; 95% CI 0.92-0.98) or obese (RR 0.95; 95% CI 0.90-0.99) (both P trend <0.008). Higher intake of nuts is associated with reduced weight gain and a lower risk of becoming overweight or obese.

Improvements in Colorectal Cancer Incidence Not Experienced by Nonmetropolitan Women: A Population-Based Study From Utah.

PubMed

Fowler, Brynn; Samadder, N Jewel; Kepka, Deanna; Ding, Qian; Pappas, Lisa; Kirchhoff, Anne C

2018-03-01

Little is known about disparities in colorectal cancer (CRC) incidence and mortality by community-level factors such as metropolitan status. This analysis utilized data from the Surveillance, Epidemiology, and End Results (SEER) program from Utah. We included patients diagnosed with CRC from 1991 to 2010. To determine whether associations existed between metropolitan/nonmetropolitan county of residence and CRC incidence, Poisson regression models were used. CRC mortality was assessed using multivariable Cox regression models. CRC incidence rates did not differ between metropolitan and nonmetropolitan counties by gender (males: 46.2 per 100,000 vs 45.1 per 100,000, P = .87; females: 34.4 per 100,000 vs 36.1 per 100,000, P = .70). However, CRC incidence between the years of 2006 and 2010 in nonmetropolitan counties was significantly higher in females (metropolitan: 30.4 vs nonmetropolitan: 37.0 per 100,000, P = .002). As compared to metropolitan counties, the incidence of unstaged CRC in nonmetropolitan counties was significantly higher in both males (1.7 vs 2.8 per 100,000, P = .003) and females (1.4 vs 1.6 per 100,000, P = .002). Among patients who were diagnosed between 2006 and 2010, metropolitan counties were found to have significantly increased survival among males and females, but nonmetropolitan counties showed increased survival only for males. While we observed a decreasing incidence of CRC among men and women in Utah, this effect was not seen in women in nonmetropolitan areas nor among those with unstaged disease. Further studies should evaluate factors that may account for these differences. This analysis can inform interventions with a focus on women in nonmetropolitan areas. © 2017 National Rural Health Association.

Coronary angiography and myocardial revascularization following the first acute myocardial infarction in Norway during 2001-2009: Analyzing time trends and educational inequalities using data from the CVDNOR project.

PubMed

Sulo, Enxhela; Nygård, Ottar; Vollset, Stein Emil; Igland, Jannicke; Sulo, Gerhard; Ebbing, Marta; Egeland, Grace M; Hawkins, Nathaniel M; Tell, Grethe S

2016-06-01

We analyzed trends in the utilization of coronary angiography and revascularization - including percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) - related to the first AMI and explored potential educational inequalities in such procedures. All first AMI patients aged 35-89, hospitalized during 2001-2009 were retrieved from 'The Cardiovascular Disease in Norway' project. Information on education was obtained from The Norwegian Education Database. Gender and age group-specific trends in coronary procedures were analyzed using Joinpoint regression. Educational inequalities were explored using multivariable Poisson regression and reported as incidence rate ratios (IRR). A total of 104 836 patients (37.3% women) were included. Revascularization rates increased on average 9.0% and 15.4% per year among younger (35-64years) and older (65-89years) men. Corresponding increases among women were 5.6% and 16.6%. Compared to patients with primary education only, those with secondary and tertiary education had 8% (IRR=1.08, 95% CI; 1.06-1.10) and 12% (IRR=1.12, 95% CI; 1.09-1.14) higher revascularization rates. Educational inequalities were entirely driven by educational differences in receiving coronary angiography (IRR=1.10, 95% CI; 1.08-1.11 for secondary versus primary and IRR=1.14, 95% CI; 1.12-1.16 for tertiary versus primary education level.) Among diagnosed patients, no educational differences were observed in coronary revascularization rates. Revascularization rates increased whereas educational differences in revascularization decreased among AMI patients in Norway during 2001-2009. Lower coronary revascularization rates among patients with low education were explained by educational differences in receiving coronary angiography. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Perceived Treatment Status of Fluctuations in Parkinson Disease Impacts Suicidality.

PubMed

Hinkle, Jared T; Perepezko, Kate; Mari, Zoltan; Marsh, Laura; Pontone, Gregory M

2018-01-31

On/off motor fluctuations in Parkinson disease (PD) can be associated with extreme mood fluctuations and severe dysphoria. The impact of these affective symptoms may be overlooked in the treatment of motor fluctuations. Our goal was to examine the relationship between motor fluctuations, their treatment status, and suicidality in PD participants. We analyzed data from the Methods of Optimal Depression Detection in Parkinson's Disease (MOOD-PD) study of 223 individuals with PD. Suicidality was measured using items from four depression scales: Hamilton Depression Rating Scale (HAM-D-17); Montgomery-Åsberg Depression Rating Scale (MADRS); Inventory for Depressive Symptomatology (IDS-C); and the self-rated Beck Depression Inventory (BDI). Multivariable Poisson regression analyses tested whether self-reported motor fluctuations and their treatment status were associated with suicidality while controlling for recognized risk factors. Thirty-seven participants (16.6%) self-reported suicidality and 89 (39.5%) self-reported motor fluctuations, of whom 21 (23.6%) perceived their fluctuations as untreated. Participants reporting untreated motor fluctuations more frequently had a current depressive disorder (p < 0.001) and endorsed suicidality (p = 0.006) than participants with treated or no fluctuations. They also had significantly higher total scores on the HAM-D-17, MADRS, IDS-C, and BDI depression scales (p < 0.001 for each). Regression analyses showed significant associations between untreated motor fluctuations and higher scores on suicide questions extracted from the HAM-D-17, MADRS, and IDS-C (p < 0.01 for each). PD patients with untreated motor fluctuations are at increased risk for suicidal thoughts and should be monitored for mood changes as treatment is adapted. Copyright © 2018 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Is Heart Rate Variability Better Than Routine Vital Signs for Prehospital Identification of Major Hemorrhage

DTIC Science & Technology

2015-01-01

different PRBC transfusion volumes. We performed multivariate regression analysis using HRV metrics and routine vital signs to test the hypothesis that...study sponsors did not have any role in the study design, data collection, analysis and interpretation of data, report writing, or the decision to...primary outcome was hemorrhagic injury plus different PRBC transfusion volumes. We performed multivariate regression analysis using HRV metrics and

Rates of Femicide in Women of Different Races, Ethnicities, and Places of Birth: Massachusetts, 1993-2007

ERIC Educational Resources Information Center

Azziz-Baumgartner, Eduardo; McKeown, Loreta; Melvin, Patrice; Dang, Quynh; Reed, Joan

2011-01-01

To describe the epidemiology of intimate partner violence (IPV) homicide in Massachusetts, an IPV mortality data set developed by the Massachusetts Department of Public Health was analyzed. The rates of death were estimated by dividing the number of decedents over the aged-matched population and Poisson regression was used to estimate the…

Growth Curve Models for Zero-Inflated Count Data: An Application to Smoking Behavior

ERIC Educational Resources Information Center

Liu, Hui; Powers, Daniel A.

2007-01-01

This article applies growth curve models to longitudinal count data characterized by an excess of zero counts. We discuss a zero-inflated Poisson regression model for longitudinal data in which the impact of covariates on the initial counts and the rate of change in counts over time is the focus of inference. Basic growth curve models using a…

Relations Between Residential Proximity to EPA-Designated Toxic Release Sites and Diffuse Large B-Cell Lymphoma Incidence.

PubMed

Bulka, Catherine; Nastoupil, Loretta J; Koff, Jean L; Bernal-Mizrachi, Leon; Ward, Kevin C; Williams, Jessica N; Bayakly, A Rana; Switchenko, Jeffrey M; Waller, Lance A; Flowers, Christopher R

2016-10-01

Examining the spatial patterns of diffuse large B-cell lymphoma (DLBCL) incidence and residential proximity to toxic release locations may provide insight regarding environmental and sociodemographic risk factors. We linked and geocoded cancer incidence data for the period 1999-2008 from the Georgia Comprehensive Cancer Registry with population data from the US Census and the Environmental Protection Agency's Toxics Release Inventory. We conducted cluster analyses and constructed Poisson regression models to assess DLBCL incidence as a function of mean distance to the toxic release sites. In total, 3851 incident DLBCL cases occurred among adults residing in Georgia between 1999 and 2008. Significant focal clustering was observed around 57% of ethylene oxide sites, 5% of benzene sites, 9% of tetrachloroethylene sites, 7% of styrene sites, 10% of formaldehyde sites, 5% of trichloroethylene sites, and 10% of all release sites. Mean distance to sites was significantly associated with DLBCL risk for all chemicals. Proximity to Toxics Release Inventory sites can be linked to increased DLBCL risk as assessed through focal clustering and Poisson regression, and confirmatory studies using geospatial mapping can aid in further specifying risk factors for DLBCL.

Prediction of Short-Distance Aerial Movement of Phakopsora pachyrhizi Urediniospores Using Machine Learning.

PubMed

Wen, L; Bowen, C R; Hartman, G L

2017-10-01

Dispersal of urediniospores by wind is the primary means of spread for Phakopsora pachyrhizi, the cause of soybean rust. Our research focused on the short-distance movement of urediniospores from within the soybean canopy and up to 61 m from field-grown rust-infected soybean plants. Environmental variables were used to develop and compare models including the least absolute shrinkage and selection operator regression, zero-inflated Poisson/regular Poisson regression, random forest, and neural network to describe deposition of urediniospores collected in passive and active traps. All four models identified distance of trap from source, humidity, temperature, wind direction, and wind speed as the five most important variables influencing short-distance movement of urediniospores. The random forest model provided the best predictions, explaining 76.1 and 86.8% of the total variation in the passive- and active-trap datasets, respectively. The prediction accuracy based on the correlation coefficient (r) between predicted values and the true values were 0.83 (P < 0.0001) and 0.94 (P < 0.0001) for the passive and active trap datasets, respectively. Overall, multiple machine learning techniques identified the most important variables to make the most accurate predictions of movement of P. pachyrhizi urediniospores short-distance.

Predictors for the Number of Warning Information Sources During Tornadoes.

PubMed

Cong, Zhen; Luo, Jianjun; Liang, Daan; Nejat, Ali

2017-04-01

People may receive tornado warnings from multiple information sources, but little is known about factors that affect the number of warning information sources (WISs). This study examined predictors for the number of WISs with a telephone survey on randomly sampled residents in Tuscaloosa, Alabama, and Joplin, Missouri, approximately 1 year after both cities were struck by violent tornadoes (EF4 and EF5) in 2011. The survey included 1006 finished interviews and the working sample included 903 respondents. Poisson regression and Zero-Inflated Poisson regression showed that older age and having an emergency plan predicted more WISs in both cities. Education, marital status, and gender affected the possibilities of receiving warnings and the number of WISs either in Joplin or in Tuscaloosa. The findings suggest that social disparity affects the access to warnings not only with respect to the likelihood of receiving any warnings but also with respect to the number of WISs. In addition, historical and social contexts are important for examining predictors for the number of WISs. We recommend that the number of WISs should be regarded as an important measure to evaluate access to warnings in addition to the likelihood of receiving warnings. (Disaster Med Public Health Preparedness. 2017;11:168-172).

Association between large strongyle genera in larval cultures--using rare-event poisson regression.

PubMed

Cao, X; Vidyashankar, A N; Nielsen, M K

2013-09-01

Decades of intensive anthelmintic treatment has caused equine large strongyles to become quite rare, while the cyathostomins have developed resistance to several drug classes. The larval culture has been associated with low to moderate negative predictive values for detecting Strongylus vulgaris infection. It is unknown whether detection of other large strongyle species can be statistically associated with presence of S. vulgaris. This remains a statistical challenge because of the rare occurrence of large strongyle species. This study used a modified Poisson regression to analyse a dataset for associations between S. vulgaris infection and simultaneous occurrence of Strongylus edentatus and Triodontophorus spp. In 663 horses on 42 Danish farms, the individual prevalences of S. vulgaris, S. edentatus and Triodontophorus spp. were 12%, 3% and 12%, respectively. Both S. edentatus and Triodontophorus spp. were significantly associated with S. vulgaris infection with relative risks above 1. Further, S. edentatus was associated with use of selective therapy on the farms, as well as negatively associated with anthelmintic treatment carried out within 6 months prior to the study. The findings illustrate that occurrence of S. vulgaris in larval cultures can be interpreted as indicative of other large strongyles being likely to be present.

A Time Series Analysis: Weather Factors, Human Migration and Malaria Cases in Endemic Area of Purworejo, Indonesia, 2005–2014

PubMed Central

REJEKI, Dwi Sarwani Sri; NURHAYATI, Nunung; AJI, Budi; MURHANDARWATI, E. Elsa Herdiana; KUSNANTO, Hari

2018-01-01

Background: Climatic and weather factors become important determinants of vector-borne diseases transmission like malaria. This study aimed to prove relationships between weather factors with considering human migration and previous case findings and malaria cases in endemic areas in Purworejo during 2005–2014. Methods: This study employed ecological time series analysis by using monthly data. The independent variables were the maximum temperature, minimum temperature, maximum humidity, minimum humidity, precipitation, human migration, and previous malaria cases, while the dependent variable was positive malaria cases. Three models of count data regression analysis i.e. Poisson model, quasi-Poisson model, and negative binomial model were applied to measure the relationship. The least Akaike Information Criteria (AIC) value was also performed to find the best model. Negative binomial regression analysis was considered as the best model. Results: The model showed that humidity (lag 2), precipitation (lag 3), precipitation (lag 12), migration (lag1) and previous malaria cases (lag 12) had a significant relationship with malaria cases. Conclusion: Weather, migration and previous malaria cases factors need to be considered as prominent indicators for the increase of malaria case projection. PMID:29900134

Is there continued evidence for an association between abacavir usage and myocardial infarction risk in individuals with HIV? A cohort collaboration.

PubMed

Sabin, Caroline A; Reiss, Peter; Ryom, Lene; Phillips, Andrew N; Weber, Rainer; Law, Matthew; Fontas, Eric; Mocroft, Amanda; de Wit, Stephane; Smith, Colette; Dabis, Francois; d'Arminio Monforte, Antonella; El-Sadr, Wafaa; Lundgren, Jens D

2016-03-31

In March 2008, the D:A:D study published results demonstrating an increased risk of myocardial infarction (MI) for patients on abacavir (ABC). We describe changes to the use of ABC since this date, and investigate changes to the association between ABC and MI with subsequent follow-up. A total of 49,717 D:A:D participants were followed from study entry until the first of an MI, death, 1 February 2013 or 6 months after last visit. Associations between a person's 10-year cardiovascular disease (CVD) risk and the likelihood of initiating or discontinuing ABC were assessed using multivariable logistic/Poisson regression. Poisson regression was used to assess the association between current ABC use and MI risk, adjusting for potential confounders, and a test of interaction was performed to assess whether the association had changed in the post-March 2008 period. Use of ABC increased from 10 % of the cohort in 2000 to 20 % in 2008, before stabilising at 18-19 %. Increases in use pre-March 2008, and subsequent decreases, were greatest in those at moderate and high CVD risk. Post-March 2008, those on ABC at moderate/high CVD risk were more likely to discontinue ABC than those at low/unknown CVD risk, regardless of viral load (≤1,000 copies/ml: relative rate 1.49 [95 % confidence interval 1.34-1.65]; >1,000 copies/ml: 1.23 [1.02-1.48]); no such associations were seen pre-March 2008. There was some evidence that antiretroviral therapy (ART)-naïve persons at moderate/high CVD risk post-March 2008 were less likely to initiate ABC than those at low/unknown CVD risk (odds ratio 0.74 [0.48-1.13]). By 1 February 2013, 941 MI events had occurred in 367,559 person-years. Current ABC use was associated with a 98 % increase in MI rate (RR 1.98 [1.72-2.29]) with no difference in the pre- (1.97 [1.68-2.33]) or post- (1.97 [1.43-2.72]) March 2008 periods (interaction P = 0.74). Despite a reduction in the channelling of ABC for patients at higher CVD risk since 2008, we continue to observe an association between ABC use and MI risk. Whilst confounding cannot be fully ruled out, this further diminishes channelling bias as an explanation for our findings.

Are all quantitative postmarketing signal detection methods equal? Performance characteristics of logistic regression and Multi-item Gamma Poisson Shrinker.

PubMed

Berlin, Conny; Blanch, Carles; Lewis, David J; Maladorno, Dionigi D; Michel, Christiane; Petrin, Michael; Sarp, Severine; Close, Philippe

2012-06-01

The detection of safety signals with medicines is an essential activity to protect public health. Despite widespread acceptance, it is unclear whether recently applied statistical algorithms provide enhanced performance characteristics when compared with traditional systems. Novartis has adopted a novel system for automated signal detection on the basis of disproportionality methods within a safety data mining application (Empirica™ Signal System [ESS]). ESS uses two algorithms for routine analyses: empirical Bayes Multi-item Gamma Poisson Shrinker and logistic regression (LR). A model was developed comprising 14 medicines, categorized as "new" or "established." A standard was prepared on the basis of safety findings selected from traditional sources. ESS results were compared with the standard to calculate the positive predictive value (PPV), specificity, and sensitivity. PPVs of the lower one-sided 5% and 0.05% confidence limits of the Bayes geometric mean (EB05) and of the LR odds ratio (LR0005) almost coincided for all the drug-event combinations studied. There was no obvious difference comparing the PPV of the leading Medical Dictionary for Regulatory Activities (MedDRA) terms to the PPV for all terms. The PPV of narrow MedDRA query searches was higher than that for broad searches. The widely used threshold value of EB05 = 2.0 or LR0005 = 2.0 together with more than three spontaneous reports of the drug-event combination produced balanced results for PPV, sensitivity, and specificity. Consequently, performance characteristics were best for leading terms with narrow MedDRA query searches irrespective of applying Multi-item Gamma Poisson Shrinker or LR at a threshold value of 2.0. This research formed the basis for the configuration of ESS for signal detection at Novartis. Copyright © 2011 John Wiley & Sons, Ltd.

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.

Use of ACE-inhibitors and falls in patients with Parkinson's disease.

PubMed

Laudisio, Alice; Lo Monaco, Maria Rita; Silveri, Maria Caterina; Bentivoglio, Anna Rita; Vetrano, Davide L; Pisciotta, Maria Stella; Brandi, Vincenzo; Bernabei, Roberto; Zuccalà, Giuseppe

2017-05-01

Falls represent a major concern in patients with Parkinson's disease (PD); however, currently acknowledged treatments for PD are not effective in reducing the risk of falling. The aim was to assess the association of use of ACE-inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) with falls among patients with PD. We analysed data of 194 elderly with PD attending a geriatric Day Hospital. Self-reported history of falls that occurred over the last year, as well as use of drugs, including ACEIs and angiotensin II receptor blockers (ARBs) were recorded. The association of the occurrence of any falls with use of ACEIs, and ARBs was assessed by logistic regression analysis. The association between the number of falls and use of ACEIs, and ARBs was assessed according to Poisson regression. In logistic regression, after adjusting for potential confounders, use of ACEIs was associated with a reduced probability of falling over the last year (OR=0.15, 95% CI=0.03-0.81; P=0.028). This association did not vary with blood pressure levels (P for the interaction term=0.528). Also, using Poisson regression, use of ACEIs predicted a reduced number of falls among participants who fell (PR=0.31; 95% CI=0.10-0.94; P=0.039). No association was found between use of ARBs and falls. Our results indicate that use of ACEIs might be independently associated with reduced probability, and a reduced number of falls among patients with PD. Dedicated studies are needed to define the single agents and dosages that might most effectively reduce the risk of falling in clinical practice. Copyright © 2017 Elsevier B.V. All rights reserved.

Trends in Mortality After Primary Cytoreductive Surgery for Ovarian Cancer: A Systematic Review and Metaregression of Randomized Clinical Trials and Observational Studies.

PubMed

Di Donato, Violante; Kontopantelis, Evangelos; Aletti, Giovanni; Casorelli, Assunta; Piacenti, Ilaria; Bogani, Giorgio; Lecce, Francesca; Benedetti Panici, Pierluigi

2017-06-01

Primary cytoreductive surgery (PDS) followed by platinum-based chemotherapy is the cornerstone of treatment and the absence of residual tumor after PDS is universally considered the most important prognostic factor. The aim of the present analysis was to evaluate trend and predictors of 30-day mortality in patients undergoing primary cytoreduction for ovarian cancer. Literature was searched for records reporting 30-day mortality after PDS. All cohorts were rated for quality. Simple and multiple Poisson regression models were used to quantify the association between 30-day mortality and the following: overall or severe complications, proportion of patients with stage IV disease, median age, year of publication, and weighted surgical complexity index. Using the multiple regression model, we calculated the risk of perioperative mortality at different levels for statistically significant covariates of interest. Simple regression identified median age and proportion of patients with stage IV disease as statistically significant predictors of 30-day mortality. When included in the multiple Poisson regression model, both remained statistically significant, with an incidence rate ratio of 1.087 for median age and 1.017 for stage IV disease. Disease stage was a strong predictor, with the risk estimated to increase from 2.8% (95% confidence interval 2.02-3.66) for stage III to 16.1% (95% confidence interval 6.18-25.93) for stage IV, for a cohort with a median age of 65 years. Metaregression demonstrated that increased age and advanced clinical stage were independently associated with an increased risk of mortality, and the combined effects of both factors greatly increased the risk.

Characterizing multivariate decoding models based on correlated EEG spectral features.

PubMed

McFarland, Dennis J

2013-07-01

Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

SPReM: Sparse Projection Regression Model For High-dimensional Linear Regression *

PubMed Central

Sun, Qiang; Zhu, Hongtu; Liu, Yufeng; Ibrahim, Joseph G.

2014-01-01

The aim of this paper is to develop a sparse projection regression modeling (SPReM) framework to perform multivariate regression modeling with a large number of responses and a multivariate covariate of interest. We propose two novel heritability ratios to simultaneously perform dimension reduction, response selection, estimation, and testing, while explicitly accounting for correlations among multivariate responses. Our SPReM is devised to specifically address the low statistical power issue of many standard statistical approaches, such as the Hotelling’s T2 test statistic or a mass univariate analysis, for high-dimensional data. We formulate the estimation problem of SPREM as a novel sparse unit rank projection (SURP) problem and propose a fast optimization algorithm for SURP. Furthermore, we extend SURP to the sparse multi-rank projection (SMURP) by adopting a sequential SURP approximation. Theoretically, we have systematically investigated the convergence properties of SURP and the convergence rate of SURP estimates. Our simulation results and real data analysis have shown that SPReM out-performs other state-of-the-art methods. PMID:26527844

Using a Modification of the Capture-Recapture Model To Estimate the Need for Substance Abuse Treatment.

ERIC Educational Resources Information Center

Maxwell, Jane Carlisle; Pullum, Thomas W.

2001-01-01

Applied the capture-recapture model, through a Poisson regression to a time series of data for admissions to treatment from 1987 to 1996 to estimate the number of heroin addicts in Texas who are "at-risk" for treatment. The entire data set produced estimates that were lower and more plausible than those produced by drawing samples,…

Predicting Hospital Admissions With Poisson Regression Analysis

DTIC Science & Technology

2009-06-01

East and Four West. Four East is where bariatric , general, neurologic, otolaryngology (ENT), ophthalmologic, orthopedic, and plastic surgery ...where care is provided for cardiovascular, thoracic, and vascular surgery patients. Figure 1 shows a bar graph for each unit, giving the proportion of...provided at NMCSD, or a study could be conducted on the amount of time that patients generally wait for elective surgeries . There is also the

Population heterogeneity in the salience of multiple risk factors for adolescent delinquency.

PubMed

Lanza, Stephanie T; Cooper, Brittany R; Bray, Bethany C

2014-03-01

To present mixture regression analysis as an alternative to more standard regression analysis for predicting adolescent delinquency. We demonstrate how mixture regression analysis allows for the identification of population subgroups defined by the salience of multiple risk factors. We identified population subgroups (i.e., latent classes) of individuals based on their coefficients in a regression model predicting adolescent delinquency from eight previously established risk indices drawn from the community, school, family, peer, and individual levels. The study included N = 37,763 10th-grade adolescents who participated in the Communities That Care Youth Survey. Standard, zero-inflated, and mixture Poisson and negative binomial regression models were considered. Standard and mixture negative binomial regression models were selected as optimal. The five-class regression model was interpreted based on the class-specific regression coefficients, indicating that risk factors had varying salience across classes of adolescents. Standard regression showed that all risk factors were significantly associated with delinquency. Mixture regression provided more nuanced information, suggesting a unique set of risk factors that were salient for different subgroups of adolescents. Implications for the design of subgroup-specific interventions are discussed. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Antenatal Corticosteroids for the Prevention of Respiratory Distress Syndrome in Premature Twins.

PubMed

Viteri, Oscar A; Blackwell, Sean C; Chauhan, Suneet P; Refuerzo, Jerrie S; Pedroza, Claudia; Salazar, Ximena C; Sibai, Baha M

2016-09-01

To estimate whether antenatal corticosteroids before 34 weeks of gestation are associated with reduced incidence of respiratory distress syndrome (RDS) and composite neonatal morbidity in preterm twins. This was a secondary analysis of a multicenter randomized trial for the prevention of preterm birth in multiple gestations. All liveborn, nonanomalous twins delivered between 24 0/7 and 36 6/7 weeks of gestation were included. Neonatal outcomes were compared between women who received antenatal corticosteroids and those who did not. The primary outcome was the incidence of RDS. The secondary outcome was the incidence of serious composite neonatal morbidity. Multivariable log Poisson regression with correlation adjustment between twins born to the same mother was performed for confounder control. Adjusted relative risks (RRs) are reported for study outcomes. Based on a post hoc power analysis, this study was powered to detect an RR less than 0.63 for RDS and greater than 1.43 for composite neonatal morbidity outcomes. A total of 432 women (850 neonates) were included. Only 300 (35%) neonates were born to women receiving antenatal corticosteroids. After multivariable regression, antenatal corticosteroids were not associated with a reduced incidence of RDS (81 [27%] compared with 92 [17%] neonates, adjusted RR 1.28, 95% confidence interval [CI] 0.97-1.71) or composite neonatal morbidity (87 [29%] compared with 108 [20%] neonates, adjusted RR 1.21, 95% CI 0.93-1.56). However, antenatal corticosteroids were associated with increased rates of neonatal intensive care unit admissions (235 [78%] compared with 322 [59%] neonates, adjusted RR 1.22, 95% CI 1.09-1.36) and mechanical ventilation (70 [23%] compared with 66 [12%] neonates, adjusted RR 1.52, 95% CI 1.12-2.09). Focusing analysis to newborns delivered before 34 weeks of gestation (n=311), 161 (52%) received antenatal corticosteroids. Similarly, no differences in the rate of RDS (66 [41%] compared with 68 [45%] neonates, adjusted RR 1.01, 95% CI 0.76-1.34) or composite neonatal morbidity (72 [45%] compared with 81 [54%] neonates, adjusted RR 0.95, 95% CI 0.74-1.22) were noted. In this cohort of preterm twins, antenatal corticosteroid administration was not associated with a reduced incidence of RDS and composite neonatal morbidity.

Modeling motor vehicle crashes using Poisson-gamma models: examining the effects of low sample mean values and small sample size on the estimation of the fixed dispersion parameter.

PubMed

Lord, Dominique

2006-07-01

There has been considerable research conducted on the development of statistical models for predicting crashes on highway facilities. Despite numerous advancements made for improving the estimation tools of statistical models, the most common probabilistic structure used for modeling motor vehicle crashes remains the traditional Poisson and Poisson-gamma (or Negative Binomial) distribution; when crash data exhibit over-dispersion, the Poisson-gamma model is usually the model of choice most favored by transportation safety modelers. Crash data collected for safety studies often have the unusual attributes of being characterized by low sample mean values. Studies have shown that the goodness-of-fit of statistical models produced from such datasets can be significantly affected. This issue has been defined as the "low mean problem" (LMP). Despite recent developments on methods to circumvent the LMP and test the goodness-of-fit of models developed using such datasets, no work has so far examined how the LMP affects the fixed dispersion parameter of Poisson-gamma models used for modeling motor vehicle crashes. The dispersion parameter plays an important role in many types of safety studies and should, therefore, be reliably estimated. The primary objective of this research project was to verify whether the LMP affects the estimation of the dispersion parameter and, if it is, to determine the magnitude of the problem. The secondary objective consisted of determining the effects of an unreliably estimated dispersion parameter on common analyses performed in highway safety studies. To accomplish the objectives of the study, a series of Poisson-gamma distributions were simulated using different values describing the mean, the dispersion parameter, and the sample size. Three estimators commonly used by transportation safety modelers for estimating the dispersion parameter of Poisson-gamma models were evaluated: the method of moments, the weighted regression, and the maximum likelihood method. In an attempt to complement the outcome of the simulation study, Poisson-gamma models were fitted to crash data collected in Toronto, Ont. characterized by a low sample mean and small sample size. The study shows that a low sample mean combined with a small sample size can seriously affect the estimation of the dispersion parameter, no matter which estimator is used within the estimation process. The probability the dispersion parameter becomes unreliably estimated increases significantly as the sample mean and sample size decrease. Consequently, the results show that an unreliably estimated dispersion parameter can significantly undermine empirical Bayes (EB) estimates as well as the estimation of confidence intervals for the gamma mean and predicted response. The paper ends with recommendations about minimizing the likelihood of producing Poisson-gamma models with an unreliable dispersion parameter for modeling motor vehicle crashes.

EXTENDING MULTIVARIATE DISTANCE MATRIX REGRESSION WITH AN EFFECT SIZE MEASURE AND THE ASYMPTOTIC NULL DISTRIBUTION OF THE TEST STATISTIC

PubMed Central

McArtor, Daniel B.; Lubke, Gitta H.; Bergeman, C. S.

2017-01-01

Person-centered methods are useful for studying individual differences in terms of (dis)similarities between response profiles on multivariate outcomes. Multivariate distance matrix regression (MDMR) tests the significance of associations of response profile (dis)similarities and a set of predictors using permutation tests. This paper extends MDMR by deriving and empirically validating the asymptotic null distribution of its test statistic, and by proposing an effect size for individual outcome variables, which is shown to recover true associations. These extensions alleviate the computational burden of permutation tests currently used in MDMR and render more informative results, thus making MDMR accessible to new research domains. PMID:27738957

Extending multivariate distance matrix regression with an effect size measure and the asymptotic null distribution of the test statistic.

PubMed

McArtor, Daniel B; Lubke, Gitta H; Bergeman, C S

2017-12-01

Person-centered methods are useful for studying individual differences in terms of (dis)similarities between response profiles on multivariate outcomes. Multivariate distance matrix regression (MDMR) tests the significance of associations of response profile (dis)similarities and a set of predictors using permutation tests. This paper extends MDMR by deriving and empirically validating the asymptotic null distribution of its test statistic, and by proposing an effect size for individual outcome variables, which is shown to recover true associations. These extensions alleviate the computational burden of permutation tests currently used in MDMR and render more informative results, thus making MDMR accessible to new research domains.

Computational Aspects of N-Mixture Models

PubMed Central

Dennis, Emily B; Morgan, Byron JT; Ridout, Martin S

2015-01-01

The N-mixture model is widely used to estimate the abundance of a population in the presence of unknown detection probability from only a set of counts subject to spatial and temporal replication (Royle, 2004, Biometrics 60, 105–115). We explain and exploit the equivalence of N-mixture and multivariate Poisson and negative-binomial models, which provides powerful new approaches for fitting these models. We show that particularly when detection probability and the number of sampling occasions are small, infinite estimates of abundance can arise. We propose a sample covariance as a diagnostic for this event, and demonstrate its good performance in the Poisson case. Infinite estimates may be missed in practice, due to numerical optimization procedures terminating at arbitrarily large values. It is shown that the use of a bound, K, for an infinite summation in the N-mixture likelihood can result in underestimation of abundance, so that default values of K in computer packages should be avoided. Instead we propose a simple automatic way to choose K. The methods are illustrated by analysis of data on Hermann's tortoise Testudo hermanni. PMID:25314629

A multi-Poisson dynamic mixture model to cluster developmental patterns of gene expression by RNA-seq.

PubMed

Ye, Meixia; Wang, Zhong; Wang, Yaqun; Wu, Rongling

2015-03-01

Dynamic changes of gene expression reflect an intrinsic mechanism of how an organism responds to developmental and environmental signals. With the increasing availability of expression data across a time-space scale by RNA-seq, the classification of genes as per their biological function using RNA-seq data has become one of the most significant challenges in contemporary biology. Here we develop a clustering mixture model to discover distinct groups of genes expressed during a period of organ development. By integrating the density function of multivariate Poisson distribution, the model accommodates the discrete property of read counts characteristic of RNA-seq data. The temporal dependence of gene expression is modeled by the first-order autoregressive process. The model is implemented with the Expectation-Maximization algorithm and model selection to determine the optimal number of gene clusters and obtain the estimates of Poisson parameters that describe the pattern of time-dependent expression of genes from each cluster. The model has been demonstrated by analyzing a real data from an experiment aimed to link the pattern of gene expression to catkin development in white poplar. The usefulness of the model has been validated through computer simulation. The model provides a valuable tool for clustering RNA-seq data, facilitating our global view of expression dynamics and understanding of gene regulation mechanisms. © The Author 2014. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

A prospective cohort study of postoperative complications in the management of perforated peptic ulcer.

PubMed

Sharma, Smita S; Mamtani, Manju R; Sharma, Mamta S; Kulkarni, Hemant

2006-06-16

With dwindling rates of postoperative mortality in perforated peptic ulcer that is attributable to H2-receptor blocker usage, there is a need to shift the focus towards the prevention of postoperative morbidity. Further, the simultaneous contribution of several putative clinical predictors to this postoperative morbidity is not fully appreciated. Our objective was to assess the predictors of the risk, rate and number of postoperative complications in surgically treated patients of perforated peptic ulcer. In a prospective cohort study of 96 subjects presenting as perforated peptic ulcer and treated using Graham's omentoplatsy patch or gastrojejunostomy (with total truncal vagotomy), we assessed the association of clinical predictors with three domains of postoperative complications: the risk of developing a complication, the rate of developing the first complication and the risk of developing higher number of complications. We used multiple regression methods - logistic regression, Cox proportional hazards regression and Poisson regression, respectively - to examine the association of the predictors with these three domains. We observed that the risk of developing a postoperative complication was significantly influenced by the presence of a concomitant medical illness [odds ratio (OR) = 8.9, p = 0.001], abdominal distension (3.8, 0.048) and a need of blood transfusion (OR = 8.2, p = 0.027). Using Poisson regression, it was observed that the risk for a higher number of complications was influenced by the same three factors [relative risk (RR) = 2.6, p = 0.015; RR = 4.6, p < 0.001; and RR = 2.4, p = 0.002; respectively]. However, the rate of development of complications was influenced by a history suggestive of shock [relative hazards (RH) = 3.4, p = 0.002] and A- blood group (RH = 4.7, p = 0.04). Abdominal distension, presence of a concomitant medical illness and a history suggestive of shock at the time of admission warrant a closer and alacritous postoperative management in patients of perforated peptic ulcer.

Perceived Discrimination and Health among Immigrants in Europe According to National Integration Policies

PubMed Central

Borrell, Carme; Palència, Laia; Bartoll, Xavier; Ikram, Umar; Malmusi, Davide

2015-01-01

Background: Discrimination harms immigrants’ health. The objective of this study was to analyze the association between perceived discrimination and health outcomes among first and second generation immigrants from low-income countries living in Europe, while accounting for sex and the national policy on immigration. Methods: Cross-sectional study including immigrants from low-income countries aged ≥15 years in 18 European countries (European Social Survey, 2012) (sample of 1271 men and 1335 women). The dependent variables were self-reported health, symptoms of depression, and limitation of activity. The independent variables were perceived group discrimination, immigrant background and national immigrant integration policy. We tested for association between perceived group discrimination and health outcomes by fitting robust Poisson regression models. Results: We only observed significant associations between perceived group discrimination and health outcomes in first generation immigrants. For example, depression was associated with discrimination among both men and women (Prevalence Ratio-, 1.55 (95% CI: 1.16–2.07) and 1.47 (95% CI: 1.15–1.89) in the multivariate model, respectively), and mainly in countries with assimilationist immigrant integration policies. Conclusion: Perceived group discrimination is associated with poor health outcomes in first generation immigrants from low-income countries who live in European countries, but not among their descendants. These associations are more important in assimilationist countries. PMID:26334284

Access to a Loaded Gun Without Adult Permission and School-Based Bullying.

PubMed

Simckes, Maayan S; Simonetti, Joseph A; Moreno, Megan A; Rivara, Frederick P; Oudekerk, Barbara A; Rowhani-Rahbar, Ali

2017-09-01

Gun access and bullying are risk factors for sustaining or perpetrating violence among adolescents. Our knowledge of gun access among bullied students is limited. We used data on students, aged 12-18 years, from the 2011 and 2013 School Crime Supplement to the National Crime Victimization Survey to assess the association between self-reported bullying victimization (traditional and cyber) and access to a loaded gun without adult permission. Prevalence ratios (PRs) and confidence intervals (CIs) were obtained from multivariable Poisson regression using the Taylor series after controlling for student age, sex, family income, public/private school, and race. Of 10,704 participants, 4.2% (95% CI: 3.8%-4.6%) reported gun access. Compared with nonbullied students, those who reported traditional bullying (PR = 2.2; 95% CI: 1.7-2.4), cyberbullying (PR = 2.8; 95% CI: 1.6-4.9), and both (PR = 5.9; 95% CI: 4.6-7.7) were more likely to also report gun access. Adolescents who experience bullying, particularly those who report both traditional bullying and cyberbullying, are more likely to report access to a loaded gun without adult permission. These findings highlight the importance of developing interventions focused on these modifiable risk factors for preventing self-directed or interpersonal violence among youth. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Agreement between two cutoff points for physical activity and associated factors in young individuals☆

PubMed Central

Coledam, Diogo Henrique Constantino; Ferraiol, Philippe Fanelli; Pires, Raymundo; Ribeiro, Edinéia Aparecida Gomes; Ferreira, Marco Antonio Cabral; de Oliveira, Arli Ramos

2014-01-01

Objective: To analyze the agreement between two cutoff points for physical activity (300 and 420 minutes/week) and associated factors in youth. Methods: The study enrolled 738 adolescents of Londrina city, Paraná, Southern Brazil. The following variables were collected by a self report questionnaire: presence of moderate to vigorous physical activity, gender, age, father and mother education level, with whom the adolescent lives, number of siblings, physical activity perception, participation in Physical Education classes, facilities available to physical activity practice and sedentary behavior. Prevalence of physical activity between criterions were compared using McNemar test and the agreement was analysed by Kappa index. Multivariate analysis was performed using Poisson regression with robust variance adjustment was applied. Results: The prevalence for physical activity was significantly different: 22,3% for 300 minutes/week and 12,8% for 420 minutes/week (p<0,05), but the agreement was strong (k=0,82, p<0,001). The variables gender, father education, physical activity perception and sedentary behavior were associated to physical activity in both analyzed criteria. Participation in Physical Education class and facilities available to physical activity practice were associated to physical activity only with 300 minutes/week cutoff point. Conclusion: Caution is suggested regarding cutoffs use for physical activity in epidemiological studies, considering they can result in differences in prevalence of physical activity and its associated factors. PMID:25479852

Health Departments’ Engagement in Emergency Preparedness Activities: The Influence of Health Informatics Capacity

PubMed Central

Shah, Gulzar H.; Newell, Bobbie; Whitworth, Ruth E.

2016-01-01

Background: Local health departments (LHDs) operate in a complex and dynamic public health landscape, with changing demands on their emergency response capacities. Informatics capacities might play an instrumental role in aiding LHDs emergency preparedness. This study aimed to explore the extent to which LHDs’ informatics capacities are associated with their activity level in emergency preparedness and to identify which health informatics capacities are associated with improved emergency preparedness. Methods: We used the 2013 National Profile of LHDs study to perform Poisson regression of emergency preparedness activities. Results: Only 38.3% of LHDs participated in full-scale exercises or drills for an emergency in the 12 months period prior to the survey, but a much larger proportion provided emergency preparedness training to staff (84.3%), and/or participated in tabletop exercises (76.4%). Our multivariable analysis showed that after adjusting for several resource-related LHD characteristics, LHDs with more of the 6 information systems still tend to have slightly more preparedness activities. In addition, having a designated emergency preparedness coordinator, and having one or more emergency preparedness staff were among the most significant factors associated with LHDs performing more emergency preparedness activities. Conclusion: LHDs might want to utilize better health information systems and information technology tools to improve their activity level in emergency preparedness, through improved information dissemination, and evidence collection. PMID:27694648

Trends in presentation, management and survival of patients with de novo metastatic breast cancer in a Southeast Asian setting.

PubMed

Bhoo-Pathy, Nirmala; Verkooijen, Helena Marieke; Tan, Ern-Yu; Miao, Hui; Taib, Nur Aishah Mohd; Brand, Judith S; Dent, Rebecca A; See, Mee-Hoong; Subramaniam, ShriDevi; Chan, Patrick; Lee, Soo-Chin; Hartman, Mikael; Yip, Cheng-Har

2015-11-05

Up to 25% of breast cancer patients in Asia present with de novo metastatic disease. We examined the survival trends of Asian patients with metastatic breast cancer over fifteen years. The impact of changes in patient's demography, tumor characteristics, tumor burden, and treatment on survival trend were examined. Patients with de novo metastatic breast cancer from three hospitals in Malaysia and Singapore (N = 856) were grouped by year of diagnosis: 1996-2000, 2001-2005 and 2006-2010. Step-wise multivariable Poisson regression was used to estimate the contribution of above-mentioned factors on the survival trend. Proportions of patients presenting with metastatic breast cancer were 10% in 1996-2000, 7% in 2001-2005, and 9% in 2006-2010. Patients in 2006-2010 were significantly older, appeared to have higher disease burden, and received more chemotherapy, endocrine therapy, and surgery of primary tumor. The three-year relative survival in the above periods were 20·6% (95% CI: 13·9%-28·2%), 28·8% (95% CI: 23·4%-34·2%), and 33·6% (95% CI: 28·8%-38·5%), respectively. Adjustment for treatment considerably attenuated the relative excess risk of mortality in recent years, compared to other factors. Substantial improvements in survival were observed in patients with de novo metastatic breast cancer in this study.

Ergonomic and socioeconomic risk factors for hospital workers' compensation injury claims.

PubMed

Boyer, Jon; Galizzi, Monica; Cifuentes, Manuel; d'Errico, Angelo; Gore, Rebecca; Punnett, Laura; Slatin, Craig

2009-07-01

Hospital workers are a diverse population with high rates of musculoskeletal disorders (MSDs). The risk of MSD leading to workers' compensation (WC) claims is likely to show a gradient by socioeconomic status (SES) that may be partly explained by working conditions. A single community hospital provided workforce demographics and WC claim records for 2003-2005. An ergonomic job exposure matrix (JEM) was developed for these healthcare jobs from direct observation of physical workload and extraction of physical and psychosocial job requirements from the O*NET online database. Occupational exposures and SES categories were assigned to workers through their O*NET job titles. Univariate and multivariate Poisson regression analyses were performed to estimate the propensity to file an injury claim in relation to individual factors, occupational exposures, and SES. The jobs with the highest injury rates were nurses, semi-professionals, and semi-skilled. Increased physical work and psychological demands along with low job tenure were associated with an increase in risk, while risk decreased with psychosocial rewards and supervisor support. Both occupational and individual factors mediated the relationship between SES and rate of injury claims. Physical and organizational features of these hospital jobs along with low job tenure predicted WC injury claim risk and explained a substantial proportion of the effects of SES. Further studies that include lifestyle risk factors and control for prior injuries and co-morbidities are warranted to strengthen the current study findings.

[Risk factors associated among anemia in pregnancy women of network public health of a capital of Brazil Northeastern].

PubMed

De Oliveira, Alane Cabral Menezes; De Barros, Amanda Maria Rocha; Ferreira, Raphaela Costa

2015-11-01

To evaluate the factors associated with anemia among pregnant women receiving public health care in a capital city in Northeastern Brazil. This was a cross-sectional study conducted on a sample of 428 patients obtained on the basis of the estimated prevalence of anemia during pregnancy (50%), a 95% confidence interval (95%CI), an error of 5% and a sample loss of 20%. Pregnant women who lived in the city and were served by the municipal public health network were considered to be eligible for the study. Socioeconomic, lifestyle, clinical and anthropometric data and dietary iron intake were obtained, and capillary hemoglobin was determined. Anemia was identified as a hemoglobin level <11 g/dL, and its association with risk factors was tested using multivariate Poisson regression analysis, with the results expressed as the Prevalence Ratio (PR) and 95%CI. The prevalence of anemia was 28.3% and was higher among women with more members in the household (PR=1.49; 95%CI 1.01-2.22; p=0.046) and those living with food insecurity (PR=1.43; 95%CI 1.00-2.04; p=0.047). The prevalence of anemia among pregnant women receiving care from the public health system of the city is a moderate public health problem, requiring the planning of effective measures for its control.

Dental caries and social factors: impact on quality of life in Brazilian children.

PubMed

Martins, Milene Torres; Sardenberg, Fernanda; Vale, Míriam Pimenta; Paiva, Saul Martins; Pordeus, Isabela Almeida

2015-01-01

The objective of this study was to evaluate the impact of dental caries and social determinants in the Oral Health Related Quality of Life (OHRQoL) of children in Belo Horizonte, Brazil. This is a population-based cross-sectional study with a representative sample of 1,204 children aged 8 to 10 years randomly selected from 19 public and private schools. The children were clinically examined at school by two trained and calibrated examiners (Kappa = 0.78 - 1.00). The Decayed, Missing and Filled Teeth Index (DMF-T and dmf-t) was used for the diagnosis of dental caries. The social factors were determined by parents'/caregivers' schooling, household income, number of people in the household, type of school, and by the Social Vulnerability Index. The Brazilian version of the Child Perceptions Questionnaire for ages 8 to 10 years was used to assess the impact on quality of life. A total of 278 (23.1%) out of 1,204 children had at least one cavitated carious lesion and 47.0% presented a negative impact on OHRQoL. In the final multivariate Poisson's regression model, household income and presence of untreated dental caries were statistically associated with a negative impact on OHRQoL (p < 0.001).Children with dental caries and from low-income families had a higher negative impact on OHRQoL.

Self-management practices among primary care patients with musculoskeletal pain and depression.

PubMed

Damush, Teresa M; Wu, Jingwei; Bair, Matthew J; Sutherland, Jason M; Kroenke, Kurt

2008-08-01

The objective of this study was to assess the effect of clinical depression on pain self-management practices. We employed a cross-sectional analysis of baseline data from the Stepped Care for Affective disorders and Musculoskeletal Pain (SCAMP) study. Participants included 250 patients with pain and comorbid depression and 250 patients with pain only and were enrolled from urban university and VA primary care clinics. Musculoskeletal pain was defined as low back, hip or knee pain present >or=3 months and with at least a moderate, Brief Pain Inventory severity score >or=5. Depression was defined as a PHQ-9 score >or=10. We used multiple logistic and Poisson regression to assess the relationship between individual and combined effects of depression and pain severity on two core pain self-management skills: exercise duration and cognitive strategies. Depressed patients exercised less per week than did nondepressed patients but showed a trend towards more frequent use of cognitive strategies. On multivariable analysis, depression severity substantially decreased the use of exercise as a pain self-management strategy. In contrast, depression and pain severity interacted to increase the use of cognitive strategies. Depression and pain severity have differential effects on self-management practices. Understanding the differences between preferential strategies of pain patients with and without depression may be useful in tailoring pain self-management programs.

The effect of short-term alcohol restriction on risk of alcohol-related injury: A state wide population-based study.

PubMed

Liang, Wenbin; Gilmore, William; Chikritzhs, Tanya

2016-02-01

Alcohol consumption and related harms are largely determined by both demand and supply of alcohol. Across Western Australia, under state licensing laws, there are state-wide alcohol sales restrictions imposed on Good Friday and Christmas Day each year. This study aimed to evaluate the effect of the Good Friday and Christmas Day state-wide alcohol restrictions on the risk of alcohol-related injuries presenting at emergency departments. This is a population-based cohort study using ED injury presentation data for the period 1st January 2002 to 1st January 2015. Risk of injury during the alcohol-related time of day affected by the alcohol restrictions (intervention periods, including Good Friday and Christmas Day) were compared to the same time of day over a number of control days. Multivariable Poisson regression model was used to perform the analysis. The crude injury risk was considerably lower during the alcohol restriction periods compared to control periods in both metropolitan and non-metropolitan areas. The protective effect observed on the days of the alcohol restrictions remained significant, and largely unchanged, when potential confounding effects were controlled for. The significant reduction in alcohol-related injury presentations observed for public holiday periods with alcohol restrictions were likely caused by the alcohol restriction policy and its direct effect on alcohol supply. Copyright © 2015 Elsevier B.V. All rights reserved.

Health risks caused by short term exposure to ultrafine particles generated by residential wood combustion: a case study of Temuco, Chile.

PubMed

Díaz-Robles, Luis A; Fu, Joshua S; Vergara-Fernández, Alberto; Etcharren, Pablo; Schiappacasse, Luis N; Reed, Gregory D; Silva, María P

2014-05-01

Temuco is one of the most highly wood smoke polluted cities in Chile; however, there is scarce evidence of respiratory morbidity due to fine particulate matter. We aimed to estimate the relationship between daily concentration of ultrafine particles (UFP), with an aerodynamic diameter ≤ 0.1 μm, and outpatient visits for respiratory illness at medical care centers of Temuco, Chile, from August the 20th, 2009 to June the 30th, 2011. The Air Pollution Health Effects European Approach (APHEA2) protocol was followed, and a multivariate semi-parametric Poisson regression model was fitted with GAM techniques using R-Project statistical package; controlling for trend, seasonality, and confounders. The daily UFP were measured by a MOUDI NR-110 sampler. We found that results of the statistical analyses show significant associations between UFP and respiratory outpatient visits, with the elderly (population ≥ 65 years), being the group that presented the greatest risk. An interquartile increase of 4.73 μg/m(3) in UFP (lag 5 days) was associated with respiratory outpatient visits with a relative risk (RR) of 1.1458 [95% CI (1.0497-1.2507)] for the elderly. These results show novel findings regarding the relevance of daily UFP concentrations and health risk, especially for susceptible population in a wood smoke polluted city. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of patterns and knowledge of benefits and warnings of fish consumption between parents and children.

PubMed

Herdt-Losavio, Michele L; Lin, Shao; Chen, Ming; Luo, Ming; Tang, Jianzhong; Hwang, Syni-An

2014-07-01

We examined generational differences in fish consumption and knowledge of benefits/warnings of fish consumption among parents and children. This cross-sectional study gathered self-administered questionnaire data, including demographics, fish consumption behavior (including specific fish species) and knowledge of fish consumption warnings and benefits. Fish were later grouped into four categories by potential mercury contamination. Descriptive statistics were conducted for all variables comparing all adults and children. Benefit/risk knowledge variables were also descriptively analyzed among parent-child pairs only. Multivariate Poisson regression was conducted on pairs to assess risk factors for children eating higher mercury fish. 421 adults and 207 children (171 adult-child pairs) participated (family response rate: 71%). Slightly more adults (97.6%) ate fish in the last year than children (92.3%); however, there was no difference between consumption of fish by category of potential mercury contamination. Both adults (44%) and children (45%) ate high-mercury fish. In 71% of parent-child pairs, both the parent and the child knew of benefits of consuming fish; only 31% knew of warnings. Parental consumption of high or moderately-high-mercury fish was related to the child's consumption of fish in the same category. Parents and children need additional education to make better choices about fish consumption. Education should target the family and include specifics about benefits and risks.

Metformin Use and Severe Dengue in Diabetic Adults.

PubMed

Htun, Htet Lin; Yeo, Tsin Wen; Tam, Clarence C; Pang, Junxiong; Leo, Yee Sin; Lye, David C

2018-02-20

Diabetes mellitus is a risk factor for severe dengue in adults, but few studies have examined the association between metformin use and disease severity in dengue. In addition to its effect on glucose control, metformin has been associated with pleiotropic properties in preclinical studies. Using a cohort of laboratory-confirmed adult (≥21 years) dengue patients with diabetes mellitus admitted to Tan Tock Seng Hospital, we conducted a retrospective cohort study involving 131 (58.7%) metformin users and 92 (41.3%) non-users. Dengue severity was categorized as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) in World Health Organization (WHO) 1997 criteria and severe dengue (SD) in WHO 2009 criteria. Multivariable Poisson regression with robust error variance was used to estimate risk ratio (RR). Compared with non-use, metformin use was associated with a decreased risk of developing severe dengue (adjusted risk ratio [aRR] = 0.60, 95% confidence interval [CI]: 0.37-0.98, P = 0.04). Additionally, there was an inverse dose-response relationship (aRR = 0.69, 95% CI: 0.49-0.98, P = 0.04) with dengue severity as classified by WHO 2009 criteria. Use of metformin, however, was not associated with dengue severity based on WHO 1997 criteria; and no dose-response relationship was noted. Our results suggest metformin use could attenuate disease severity in dengue-infected diabetes mellitus individuals.

Prevalence of STI/HIV Counseling Services Received by Teen Males, 1995 to 2002

PubMed Central

Marcell, Arik V.; Bell, David L.; Lindberg, Laura Duberstein; Takruri, Adel

2009-01-01

Purpose To examine whether improvements have been made in the delivery of STI/HIV counseling services to teen males. Methods Analysis was performed using the 1995 National Survey of Adolescent Males (N=1729, response rate=75%) and the 2002 National Survey of Family Growth (N=1121, response rate=78%), two nationally representative surveys of 15–19 year old males. Main outcome measure included discussion about STIs/HIV with a doctor/nurse. Weighted bivariate and multivariate Poisson regression analyses examined the association of outcome measures and survey year among males engaging in various types of sexual behaviors (e.g., varying partner numbers, higher risk sex) unadjusted and adjusted for sociodemographic and health care access factors. Results In 2002, STI/HIV counseling receipt in the past year was reported by one-third of males who reported 3 or more female partners, anal sex with female partners, or oral/anal sex with male partners. Only 26% of males reporting high-risk sex (e.g., sex with prostitute, person with HIV or often/always high with sex) reported STI/HIV counseling receipt. Overall, no improvements were found between 1995 and 2002 in STI/HIV counseling, even after controlling for sociodemographic and health care access factors. Conclusions Mechanisms are needed to raise the importance of STI/HIV counseling services among sexually active male teens as well as to improve health care providers’ delivery of these services. PMID:20472212

Hospitalizations for ambulatory care sensitive conditions and quality of primary care: their relation with socioeconomic and health care variables in the Madrid regional health service (Spain).

PubMed

Magán, Purificación; Alberquilla, Angel; Otero, Angel; Ribera, José Manuel

2011-01-01

Hospitalizations for ambulatory care sensitive conditions (ACSH) have been proposed as an indirect indicator of the effectiveness and quality of care provided by primary health care. To investigate the association of ACSH rates with population socioeconomic factors and with characteristics of primary health care. Cross-sectional, ecologic study. Using hospital discharge data, ACSH were selected from the list of conditions validated for Spain. All 34 health districts in the Region of Madrid, Spain. Individuals aged 65 years or older residing in the region of Madrid between 2001 and 2003, inclusive. Age- and gender-adjusted ACSH rates in each health district. The adjusted ACSH rate per 1000 population was 35.37 in men and 20.45 in women. In the Poisson regression analysis, an inverse relation was seen between ACSH rates and the socioeconomic variables. Physician workload was the only health care variable with a statistically significant relation (rate ratio of 1.066 [95% CI; 1.041-1.091]). These results were similar in the analyses disaggregated by gender. In the multivariate analyses that included health care variables, none of the health care variables were statistically significant. ACSH may be more closely related with socioeconomic variables than with characteristics of primary care activity. Therefore, other factors outside the health system must be considered to improve health outcomes in the population.

Work conditions and morbidity among coal miners in Guachetá, Colombia: The miners' perspective.

PubMed

Jiménez-Forero, Claudia P; Zabala, Ivonne T; Idrovo, Álvaro J

2015-08-01

Investigations in Colombia about work and health conditions in coal mining are scarce and few have focused on the perception of the exposed population and their behaviors in response to inherent risks. To determine the association between work conditions and the perception of morbidity among coal miners in Guachetá, Cundinamarca. A cross-sectional study was performed with 154 workers selected randomly from the total registered with the municipality. Information about social and demographic characteristics and work and health conditions in the mines was gathered. The prevalence was estimated for respiratory, musculoskeletal and auditory disorders. The associations between certain work conditions, and events with a prevalence over 30% were explored using bivariate and multivariate analyses with Poisson regressions with robust variance. Workers were mostly men. Ages ranged from 18 to 77 years. Most frequently reported health problems were: back pain (46.1 %), pain in an upper limb (40.3%), pain in a lower limb (34.4 %), and respiratory (17.5 %) and auditory problems (13.6 %). Significant differences in perception were found depending on time on the job and underground or ground work conditions. The most recognized risks were those associated with musculoskeletal disorders since they were closer in time to the work performed (time discount). Some actions to identify psychological traits are proposed in order to improve risk perception among coal miners.

Severe liver disease related to chronic hepatitis C virus infection in treatment-naive patients: epidemiological characteristics and associated factors at first expert centre visit, France, 2000 to 2007 and 2010 to 2014

PubMed Central

Sanna, Alice; Le Strat, Yann; Roudot-Thoraval, Françoise; Deuffic Burban, Sylvie; Carrieri, Patrizia; Delarocque-Astagneau, Elisabeth; Larsen, Christine

2017-01-01

Given recent profound improvements in the effectiveness of antiviral treatment for chronic Hepatitis C virus (HCV) infection, we aimed to describe the characteristics of patients referred to hepatology expert centres in France from 2000 to 2007 and from 2010 to 2014, and to identify factors associated with severe liver disease at their first visit for evaluation. We analysed data from two sources covering all of France: the former hepatitis C surveillance network, which included patients between 2000 and 2007, and the ANRS CO22 HEPATHER multi-centre cohort, which included patients between 2012 and 2014. Severe liver disease (SLD) was defined as the presence of either cirrhosis (histological, biochemical or clinical) or hepatocellular carcinoma. Multivariable Poisson regression models were used to identify the factors associated with SLD in complete-case analysis and after multiple imputation. Overall, 16,851 patients were included in the analysis and SLD was diagnosed in 11.6%. SLD at first visit was significantly associated with known risk factors (male sex, history of excessive alcohol intake, HCV genotype 3), late referral to hepatologists after diagnosis and HCV diagnosis at an older age. Providing earlier specialised care and treatment may be an important target for public health action. PMID:28797326

Quadrivalent human papillomavirus vaccine uptake in adolescent boys and maternal utilization of preventive care and history of sexually transmitted infections.

PubMed

Hechter, Rulin C; Chao, Chun; Sy, Lina S; Ackerson, Bradley K; Slezak, Jeff M; Sidell, Margo A; Jacobsen, Steven J

2013-09-01

We examined whether maternal utilization of preventive care and history of sexually transmitted infections (STIs) predicted quadrivalent human papillomavirus vaccine (HPV4) uptake among adolescent boys 1 year following the recommendation for permissive use of HPV4 for males. We linked maternal information with electronic health records of 254 489 boys aged 9 to 17 years who enrolled in Kaiser Permanente Southern California health plan from October 21, 2009, through December 21, 2010. We used multivariable Poisson regression with robust error variance to examine whether HPV4 initiation was associated with maternal uptake of influenza vaccine, Papanicolaou (Pap) screening, and history of STIs. We identified a modest but statistically significant association between initiation of HPV4 series and maternal receipt of influenza vaccine (rate ratio [RR] = 1.16; 95% confidence interval [CI] = 1.07, 1.26) and Pap screening (RR = 1.13; 95% CI = 1.01, 1.26). Boys whose mothers had a history of genital warts were more likely to initiate HPV4 (RR = 1.47; 95% CI = 0.93, 2.34), although the association did not reach statistical significance (P = .1). Maternal utilization of preventive care and history of genital warts may influence HPV4 uptake among adolescent boys. The important role of maternal health characteristics and health behaviors needs be considered in intervention efforts to increase vaccine uptake among boys.

Increase in upper extremity fractures in young male soccer players in the Netherlands, 1998-2009.

PubMed

de Putter, C E; van Beeck, E F; Burdorf, A; Borsboom, G J J M; Toet, H; Hovius, S E R; Selles, R W

2015-08-01

Young male soccer players have been identified as a target group for injury prevention, but studies addressing trends and determinants of injuries within this group are scarce. The goal of this study was to analyze age-specific trends in hospital-treated upper extremity fractures (UEF) among boys playing soccer in the Netherlands and to explore associated soccer-related factors. Data were obtained from a national database for the period 1998-2009. Rates were expressed as the annual number of UEF per 1000 soccer players. Poisson's regression was used to explore the association of UEF with the number of artificial turf fields and the number of injuries by physical contact. UEF rates increased significantly by 19.4% in boys 5-10 years, 73.2% in boys 11-14 years, and 38.8% in boys 15-18 years old. The number of injuries by physical contact showed a significant univariate association with UEF in boys 15-18 years old. The number of artificial turf fields showed a significant univariate association with UEF in all age groups, and remained significant for boys aged 15-18 years in a multivariate model. This study showed an increase of UEF rates in boys playing soccer, and an independent association between artificial turf fields and UEF in the oldest boys. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Anticonvulsants and suicide attempts in bipolar I disorders.

PubMed

Bellivier, F; Belzeaux, R; Scott, J; Courtet, P; Golmard, J-L; Azorin, J-M

2017-05-01

To identify risk factors for suicide attempts (SA) in individuals commencing treatment for a manic or mixed episode. A total of 3390 manic or mixed cases with bipolar disorder (BD) type I recruited from 14 European countries were included in a prospective, 2-year observational study. Poisson regression models were used to identify individual and treatment factors associated with new SA events. Two multivariate models were built, stratified for the presence or absence of prior SA. A total of 302 SA were recorded prospectively; the peak incidence was 0-12 weeks after commencing treatment. In cases with a prior history of SA, risk of SA repetition was associated with younger age of first manic episode (P = 0.03), rapid cycling (P < 0.001), history of alcohol and/or substance use disorder (P < 0.001), number of psychotropic drugs prescribed (P < 0.001) and initiation of an anticonvulsant at study entry (P < 0.001). In cases with no previous SA, the first SA event was associated with rapid cycling (P = 0.02), lifetime history of alcohol use disorder (P = 0.02) and initiation of an anticonvulsant at study entry (P = 0.002). The introduction of anticonvulsants for a recent-onset manic or mixed episode may be associated with an increased risk of SA. Further BD studies must determine whether this link is causal. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prevalence of facial trauma and associated factors in victims of road traffic accidents.

PubMed

Nóbrega, Lorena Marques; Cavalcante, Gigliana M S; Lima, Monalyza M S M; Madruga, Renata C R; Ramos-Jorge, Maria Letícia; d'Avila, Sérgio

2014-11-01

The aim of this study was to determine the prevalence of facial trauma among victims of road traffic accidents and investigate factors associated with it. A cross-sectional study was carried out using the medical and dental charts of 2570 victims of road traffic accidents with bodily and/or facial injuries between 2008 and 2011. Sociodemographic variables of the victims and characteristics of the accidents and injuries were evaluated. Statistical analyses included the χ(2) test as well as the Poisson univariate and multivariate regression analyses for the determination of the final hierarchical model. The prevalence of facial injuries was 16.4%. Most of the victims were male. Among the victims with facial injuries, 44.3% had polytrauma to the face. The prevalence of facial injuries was high among accidents that occurred at night (Prevalence Ratio (PR), 1.42; 95% confidence interval [CI], 1.10-1.84; P = .007) and victims up to 9 years of age (PR, 2.31; 95% CI, 1.03-5.17; P = .041). Moreover, the prevalence of facial injuries was lower among victims of motorcycle accidents than victims of automobile accidents (PR, 0.59; 95% CI, 0.44-0.89; P = .001). The prevalence of facial injuries was high in this study and was significantly associated with the place of residence, time of day, age group, and type of accident. Copyright © 2014 Elsevier Inc. All rights reserved.

Weight gain in the first two years of life, asthma and atopy: the SCAALA cohort study.

PubMed

Matos, Sheila M A; Jesus, Sandra R; Saldiva, Silvia R D M; Prado, Matildes S; D'Innocenzo, Silvana; Assis, Ana M O; Rodrigues, Laura C; Alcantara-Neves, Neuza M; Cruz, Alvaro A; Simões, Silvia de Magalhães; Fiaccone, Rosemeire L; Barreto, Maurício L

2014-11-01

To evaluate the association between weight gain in the first two years of life and the occurrence of wheezing, asthma, serum IgE, skin reactivity and pulmonary function. Cohort study. The metropolitan region of Salvador, Bahia, Brazil. The association was studied between 1997 and 2005 in 669 children up to 11 years of age. Data were collected on asthma and risk factors, both current factors and those present in the first years of life. Weight gain was considered fast when the Z-score was >0·67. Poisson regression was used in the multivariate statistical analysis. Wheezing was reported in 25·6 % of the children. Weight gain was considered fast (Z-score >0·67) in 29·6 % of the children and slow (Z-score <-0·67) in 13·9 %. Children in the slow weight gain group had 36 % fewer symptoms of asthma (prevalence ratio = 0·65; 95 % CI 0·42, 0·99). Slower weight gain in the early years of life may constitute a protective factor against symptoms of asthma. The relevance of this finding for public health is not yet certain, since it is known that children with slow and fast weight gain may be more likely to develop adverse health consequences related to both these situations.

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil.

PubMed

Matos, Sheila M A; Jesus, Sandra R; Saldiva, Silvia R D M; Prado, Matildes S; D'Innocenzo, Silvana; Assis, Ana M O; Rodrigues, Laura C; Alcantara-Neves, Neuza M; Cruz, Álvaro A; Simões, Silvia de Magalhães; Barreto, Maurício L

2011-07-01

To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. Cross-sectional study nested in a cohort. The metropolitan region of Salvador, Bahia, Brazil. The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted. Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing. These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.

Firearm Ownership, Storage Practices, and Suicide Risk Factors in Washington State, 2013-2016.

PubMed

Morgan, Erin Renee; Gomez, Anthony; Rowhani-Rahbar, Ali

2018-05-17

To characterize firearm ownership and storage practices in Washington State and assess their relationship with suicide risk factors. Using Washington State Behavioral Risk Factor Surveillance System data for 2013 to 2016, we conducted survey-weighted multivariable Poisson regression models to obtain prevalence ratios (PRs) and confidence intervals (CIs). Of 34 884 adult respondents, 34.3% (95% CI = 33.7%, 35.0%) reported a firearm in their household, among whom 36.6% (95% CI = 35.4%, 37.7%) stored their firearm locked and unloaded. There were no differences in mental health indicators by firearm ownership or storage practice status. Binge and chronic alcohol use were somewhat more prevalent among adults from firearm-owning households (PR = 1.2; 95% CI = 1.1, 1.3; PR = 1.2; 95% CI = 1.1, 1.4, respectively) and among those living in households not practicing safe storage (PR = 1.4; 95% CI = 1.2, 1.7; PR = 1.9; 1.5, 2.3, respectively). Variability in mental health does not explain the substantial increased suicide risk among individuals in firearm-owning households. Greater prevalence of alcohol misuse among adults in firearm-owning households not practicing safe storage highlights the need for suicide prevention interventions. (Am J Public Health. Published online ahead of print May 17, 2018: e1-e7. doi:10.2105/AJPH.2018.304403).

Socioeconomic position, health behaviors, and racial disparities in cause-specific infant mortality in Michigan, USA

PubMed Central

El-Sayed, Abdulrahman M.; Finkton, Darryl W.; Paczkowski, Magdalena; Keyes, Katherine M.; Galea, Sandro

2015-01-01

Objectives Studies about racial disparities in infant mortality suggest that racial differences in socioeconomic position (SEP) and maternal risk behaviors explain some, but not all, excess infant mortality among Blacks relative to non-Hispanic Whites. We examined the contribution of these to disparities in specific causes of infant mortality. Methods We analyzed data about 2,087,191 mother–child dyads in Michigan between 1989 and 2005. First, we calculated crude Black–White infant mortality ratios independently and by specific cause of death. Second, we fit multivariable Poisson regression models of infant mortality, overall and by cause, adjusting for SEP and maternal risk behaviors. Third, Crude Black–White mortality ratios were compared to adjusted predicted probability ratios, overall and by specific cause. Results SEP and maternal risk behaviors explained nearly a third of the disparity in infant mortality overall, and over 25% of disparities in several specific causes including homicide, accident, sudden infant death syndrome, and respiratory distress syndrome. However, SEP and maternal risk behaviors had little influence on disparities in other specific causes, such as septicemia and congenital anomalies. Conclusions These findings help focus policy attention toward disparities in those specific causes of infant mortality most amenable to social and behavioral intervention, as well as research attention to disparities in specific causes unexplained by SEP and behavioral differences. PMID:25849882

Socioeconomic position, health behaviors, and racial disparities in cause-specific infant mortality in Michigan, USA.

PubMed

El-Sayed, Abdulrahman M; Finkton, Darryl W; Paczkowski, Magdalena; Keyes, Katherine M; Galea, Sandro

2015-07-01

Studies about racial disparities in infant mortality suggest that racial differences in socioeconomic position (SEP) and maternal risk behaviors explain some, but not all, excess infant mortality among Blacks relative to non-Hispanic Whites. We examined the contribution of these to disparities in specific causes of infant mortality. We analyzed data about 2,087,191 mother-child dyads in Michigan between 1989 and 2005. First, we calculated crude Black-White infant mortality ratios independently and by specific cause of death. Second, we fit multivariable Poisson regression models of infant mortality, overall and by cause, adjusting for SEP and maternal risk behaviors. Third, Crude Black-White mortality ratios were compared to adjusted predicted probability ratios, overall and by specific cause. SEP and maternal risk behaviors explained nearly a third of the disparity in infant mortality overall, and over 25% of disparities in several specific causes including homicide, accident, sudden infant death syndrome, and respiratory distress syndrome. However, SEP and maternal risk behaviors had little influence on disparities in other specific causes, such as septicemia and congenital anomalies. These findings help focus policy attention toward disparities in those specific causes of infant mortality most amenable to social and behavioral intervention, as well as research attention to disparities in specific causes unexplained by SEP and behavioral differences. Copyright © 2015. Published by Elsevier Inc.

Recall of Anti-Tobacco Advertisements and Effects on Quitting Behavior: Results From the California Smokers Cohort

PubMed Central

Leas, Eric C.; Myers, Mark G.; Strong, David R.; Hofstetter, C. Richard

2015-01-01

Objectives. We assessed whether an anti-tobacco television advertisement called “Stages,” which depicted a woman giving a brief emotional narrative of her experiences with tobacco use, would be recalled more often and have a greater effect on smoking cessation than 3 other advertisements with different intended themes. Methods. Our data were derived from a sample of 2596 California adult smokers. We used multivariable log-binomial and modified Poisson regression models to calculate respondents’ probability of quitting as a result of advertisement recall. Results. More respondents recalled the “Stages” ad (58.5%) than the 3 other ads (23.1%, 23.4%, and 25.6%; P < .001). Respondents who recalled “Stages” at baseline had a higher probability than those who did not recall the ad of making a quit attempt between baseline and follow-up (adjusted risk ratio [RR] = 1.18; 95% confidence interval [CI] = 1.03, 1.34) and a higher probability of being in a period of smoking abstinence for at least a month at follow-up (adjusted RR = 1.55; 95% CI = 1.02, 2.37). Conclusions. Anti-tobacco television advertisements that depict visceral and personal messages may be recalled by a larger percentage of smokers and may have a greater impact on smoking cessation than other types of advertisements. PMID:25521871

Retailer compliance with tobacco control laws in New York City before and after raising the minimum legal purchase age to 21.

PubMed

Silver, Diana; Macinko, James; Giorgio, Margaret; Bae, Jin Yung; Jimenez, Geronimo

2016-11-01

New York City (NYC) is the first large city to increase the legal minimum age for possessing tobacco products from 18 to 21 (Tobacco 21) and establish a minimum price law to reduce smoking rates among youth. However, retailer compliance with these regulations is unknown. Youthful investigators purchased cigarettes pre and post-Tobacco 21 implementation in 92 NYC neighbourhoods. Investigators recorded whether their ID was checked, the pack's purchase price, and observed compliance with additional regulations. Multivariable OLS and Poisson regression models assess pre and post Tobacco 21 compliance with ID checks and purchase prices, controlling for retailer type, location and compliance with other laws. Retailer compliance with ID checks declined from 71% to 62% (p<0.004) between periods, and holding constant other factors, compliance with ID checks and sales at legal prices declined significantly after the laws changed. Compared to chain stores, independent retailers had significantly lower compliance rates (p<0.01). Several aspects of tobacco control appear to have deteriorated in NYC. Greater attention to monitoring retailer compliance with all tobacco regulations will be important for Tobacco 21 laws to be effective in reducing youth access to tobacco products. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Risk of epilepsy in surgical patients undergoing general or neuraxial anaesthesia.

PubMed

Chang, H C; Liao, C C; Chang, C C; Huang, S Y; Yeh, C C; Hu, C J; Cherng, Y G; Chen, T L

2018-03-01

Limited information is available on the risks of epilepsy after surgery in patients receiving general or neuraxial anaesthesia. Using Taiwan's National Health Insurance Research Database, we identified 1,478,977 patients aged ≥ 20 years who underwent surgery (required general or neuraxial anaesthesia with hospitalisation for more than one day) between 2004 and 2011. We selected 235,066 patients with general anaesthesia and 235,066 patients with neuraxial anaesthesia using a frequency-matching procedure for age and sex. We did not study those with co-existing epilepsy-related risk factors. The adjusted rate ratios (RRs) and 95% confidence intervals (CIs) of newly diagnosed epilepsy 1 year after surgery associated with general anaesthesia were analysed in the multivariate Poisson regression model. The one-year incidence of postoperative epilepsy for patients with general anaesthesia and neuraxial anaesthesia were 0.41 and 0.32 per 1000 persons, respectively, and the corresponding RR was 1.27 (95%CI 1.15-1.41). The association between general anaesthesia and postoperative epilepsy was significant in men (RR = 1.22; 95%CI 1.06-1.40), women (RR = 1.33; 95%CI 1.15-1.55) and 20-39-year-old patients. The risk of postoperative epilepsy increased in patients with general anaesthesia who had co-existing medical conditions and postoperative complications. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Logistic models--an odd(s) kind of regression.

PubMed

Jupiter, Daniel C

2013-01-01

The logistic regression model bears some similarity to the multivariable linear regression with which we are familiar. However, the differences are great enough to warrant a discussion of the need for and interpretation of logistic regression. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Retro-regression--another important multivariate regression improvement.

PubMed

Randić, M

2001-01-01

We review the serious problem associated with instabilities of the coefficients of regression equations, referred to as the MRA (multivariate regression analysis) "nightmare of the first kind". This is manifested when in a stepwise regression a descriptor is included or excluded from a regression. The consequence is an unpredictable change of the coefficients of the descriptors that remain in the regression equation. We follow with consideration of an even more serious problem, referred to as the MRA "nightmare of the second kind", arising when optimal descriptors are selected from a large pool of descriptors. This process typically causes at different steps of the stepwise regression a replacement of several previously used descriptors by new ones. We describe a procedure that resolves these difficulties. The approach is illustrated on boiling points of nonanes which are considered (1) by using an ordered connectivity basis; (2) by using an ordering resulting from application of greedy algorithm; and (3) by using an ordering derived from an exhaustive search for optimal descriptors. A novel variant of multiple regression analysis, called retro-regression (RR), is outlined showing how it resolves the ambiguities associated with both "nightmares" of the first and the second kind of MRA.

Spirituality and Resilience Among Mexican American IPV Survivors.

PubMed

de la Rosa, Iván A; Barnett-Queen, Timothy; Messick, Madeline; Gurrola, Maria

2016-12-01

Women with abusive partners use a variety of coping strategies. This study examined the correlation between spirituality, resilience, and intimate partner violence using a cross-sectional survey of 54 Mexican American women living along the U.S.-Mexico border. The meaning-making coping model provides the conceptual framework to explore how spirituality is used as a copying strategy. Multiple ordinary least squares (OLS) regression results indicate women who score higher on spirituality also report greater resilient characteristics. Poisson regression analyses revealed that an increase in level of spirituality is associated with lower number of types of abuse experienced. Clinical, programmatic, and research implications are discussed. © The Author(s) 2015.

Social stressors and alcohol use among immigrant sexual and gender minority Latinos in a nontraditional settlement state.

PubMed

Gilbert, Paul A; Perreira, Krista; Eng, Eugenia; Rhodes, Scott D

2014-09-01

We sought to quantify the association of social stressors with alcohol use among immigrant sexual and gender minority Latinos in North Carolina (n = 190). We modeled any drinking in past year using logistic regression and heavy episodic drinking in past 30 days using Poisson regression. Despite a large proportion of abstainers, there were indications of hazardous drinking. Among current drinkers, 63% reported at least one heavy drinking episode in past 30 days. Ethnic discrimination increased, and social support decreased, odds of any drinking in past year. Social support moderated the associations of English use and ethnic discrimination with heavy episodic drinking.

Linear Multivariable Regression Models for Prediction of Eddy Dissipation Rate from Available Meteorological Data

NASA Technical Reports Server (NTRS)

MCKissick, Burnell T. (Technical Monitor); Plassman, Gerald E.; Mall, Gerald H.; Quagliano, John R.

2005-01-01

Linear multivariable regression models for predicting day and night Eddy Dissipation Rate (EDR) from available meteorological data sources are defined and validated. Model definition is based on a combination of 1997-2000 Dallas/Fort Worth (DFW) data sources, EDR from Aircraft Vortex Spacing System (AVOSS) deployment data, and regression variables primarily from corresponding Automated Surface Observation System (ASOS) data. Model validation is accomplished through EDR predictions on a similar combination of 1994-1995 Memphis (MEM) AVOSS and ASOS data. Model forms include an intercept plus a single term of fixed optimal power for each of these regression variables; 30-minute forward averaged mean and variance of near-surface wind speed and temperature, variance of wind direction, and a discrete cloud cover metric. Distinct day and night models, regressing on EDR and the natural log of EDR respectively, yield best performance and avoid model discontinuity over day/night data boundaries.

Assessing Principal Component Regression Prediction of Neurochemicals Detected with Fast-Scan Cyclic Voltammetry

PubMed Central

2011-01-01

Principal component regression is a multivariate data analysis approach routinely used to predict neurochemical concentrations from in vivo fast-scan cyclic voltammetry measurements. This mathematical procedure can rapidly be employed with present day computer programming languages. Here, we evaluate several methods that can be used to evaluate and improve multivariate concentration determination. The cyclic voltammetric representation of the calculated regression vector is shown to be a valuable tool in determining whether the calculated multivariate model is chemically appropriate. The use of Cook’s distance successfully identified outliers contained within in vivo fast-scan cyclic voltammetry training sets. This work also presents the first direct interpretation of a residual color plot and demonstrated the effect of peak shifts on predicted dopamine concentrations. Finally, separate analyses of smaller increments of a single continuous measurement could not be concatenated without substantial error in the predicted neurochemical concentrations due to electrode drift. Taken together, these tools allow for the construction of more robust multivariate calibration models and provide the first approach to assess the predictive ability of a procedure that is inherently impossible to validate because of the lack of in vivo standards. PMID:21966586

Parameter estimation of multivariate multiple regression model using bayesian with non-informative Jeffreys’ prior distribution

NASA Astrophysics Data System (ADS)

Saputro, D. R. S.; Amalia, F.; Widyaningsih, P.; Affan, R. C.

2018-05-01

Bayesian method is a method that can be used to estimate the parameters of multivariate multiple regression model. Bayesian method has two distributions, there are prior and posterior distributions. Posterior distribution is influenced by the selection of prior distribution. Jeffreys’ prior distribution is a kind of Non-informative prior distribution. This prior is used when the information about parameter not available. Non-informative Jeffreys’ prior distribution is combined with the sample information resulting the posterior distribution. Posterior distribution is used to estimate the parameter. The purposes of this research is to estimate the parameters of multivariate regression model using Bayesian method with Non-informative Jeffreys’ prior distribution. Based on the results and discussion, parameter estimation of β and Σ which were obtained from expected value of random variable of marginal posterior distribution function. The marginal posterior distributions for β and Σ are multivariate normal and inverse Wishart. However, in calculation of the expected value involving integral of a function which difficult to determine the value. Therefore, approach is needed by generating of random samples according to the posterior distribution characteristics of each parameter using Markov chain Monte Carlo (MCMC) Gibbs sampling algorithm.

Field applications of stand-off sensing using visible/NIR multivariate optical computing

NASA Astrophysics Data System (ADS)

Eastwood, DeLyle; Soyemi, Olusola O.; Karunamuni, Jeevanandra; Zhang, Lixia; Li, Hongli; Myrick, Michael L.

2001-02-01

12 A novel multivariate visible/NIR optical computing approach applicable to standoff sensing will be demonstrated with porphyrin mixtures as examples. The ultimate goal is to develop environmental or counter-terrorism sensors for chemicals such as organophosphorus (OP) pesticides or chemical warfare simulants in the near infrared spectral region. The mathematical operation that characterizes prediction of properties via regression from optical spectra is a calculation of inner products between the spectrum and the pre-determined regression vector. The result is scaled appropriately and offset to correspond to the basis from which the regression vector is derived. The process involves collecting spectroscopic data and synthesizing a multivariate vector using a pattern recognition method. Then, an interference coating is designed that reproduces the pattern of the multivariate vector in its transmission or reflection spectrum, and appropriate interference filters are fabricated. High and low refractive index materials such as Nb2O5 and SiO2 are excellent choices for the visible and near infrared regions. The proof of concept has now been established for this system in the visible and will later be extended to chemicals such as OP compounds in the near and mid-infrared.

Assessing principal component regression prediction of neurochemicals detected with fast-scan cyclic voltammetry.

PubMed

Keithley, Richard B; Wightman, R Mark

2011-06-07

Principal component regression is a multivariate data analysis approach routinely used to predict neurochemical concentrations from in vivo fast-scan cyclic voltammetry measurements. This mathematical procedure can rapidly be employed with present day computer programming languages. Here, we evaluate several methods that can be used to evaluate and improve multivariate concentration determination. The cyclic voltammetric representation of the calculated regression vector is shown to be a valuable tool in determining whether the calculated multivariate model is chemically appropriate. The use of Cook's distance successfully identified outliers contained within in vivo fast-scan cyclic voltammetry training sets. This work also presents the first direct interpretation of a residual color plot and demonstrated the effect of peak shifts on predicted dopamine concentrations. Finally, separate analyses of smaller increments of a single continuous measurement could not be concatenated without substantial error in the predicted neurochemical concentrations due to electrode drift. Taken together, these tools allow for the construction of more robust multivariate calibration models and provide the first approach to assess the predictive ability of a procedure that is inherently impossible to validate because of the lack of in vivo standards.

A refined method for multivariate meta-analysis and meta-regression.

PubMed

Jackson, Daniel; Riley, Richard D

2014-02-20

Making inferences about the average treatment effect using the random effects model for meta-analysis is problematic in the common situation where there is a small number of studies. This is because estimates of the between-study variance are not precise enough to accurately apply the conventional methods for testing and deriving a confidence interval for the average effect. We have found that a refined method for univariate meta-analysis, which applies a scaling factor to the estimated effects' standard error, provides more accurate inference. We explain how to extend this method to the multivariate scenario and show that our proposal for refined multivariate meta-analysis and meta-regression can provide more accurate inferences than the more conventional approach. We explain how our proposed approach can be implemented using standard output from multivariate meta-analysis software packages and apply our methodology to two real examples. Copyright © 2013 John Wiley & Sons, Ltd.

Newer classification and regression tree techniques: Bagging and Random Forests for ecological prediction

Treesearch

Anantha M. Prasad; Louis R. Iverson; Andy Liaw; Andy Liaw

2006-01-01

We evaluated four statistical models - Regression Tree Analysis (RTA), Bagging Trees (BT), Random Forests (RF), and Multivariate Adaptive Regression Splines (MARS) - for predictive vegetation mapping under current and future climate scenarios according to the Canadian Climate Centre global circulation model.

Angiogenic Signaling in Living Breast Tumor Models

DTIC Science & Technology

2007-06-01

Poisson distributed random noise is added in an amount relative to the desired signal to noise ratio. We fit the data using a regressive fitting...AD_________________ Award Number: W81XWH-05-1-0396 TITLE: Angiogenic Signaling in Living Breast...CONTRACT NUMBER Angiogenic Signaling in Living Breast Tumor Models 5b. GRANT NUMBER W81XWH-05-1-0396 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

The Role of Depressive Symptoms, Family Invalidation and Behavioral Impulsivity in the Occurrence and Repetition of Non-Suicidal Self-Injury in Chinese Adolescents: A 2-Year Follow-Up Study

ERIC Educational Resources Information Center

You, Jianing; Leung, Freedom

2012-01-01

This study used zero-inflated poisson regression analysis to examine the role of depressive symptoms, family invalidation, and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury among Chinese community adolescents over a 2-year period. Participants, 4782 high school students, were assessed twice during the…

Long-term sickness absence during pregnancy and the gender balance of workplaces.

PubMed

Melsom, Anne M

2014-11-01

This study addresses how the gender composition of workplaces affects pregnant women's sickness absence. It also assesses whether an observed association may be explaine by differential selection to female- or male-dominated workplaces. The analyses are based on Norwegian registry data from 2003-2011. Using Poisson regressions with detailed control for occupational categories, I examine whether the number of absence days are associated with the proportion of females at the workplace. I address possible selection effects by Poisson regressions with fixed individual effects using only within-individual variation on women with two or more pregnancies during the time window. The analyses indicate a positive and significant relationship between the female proportion in workplaces and sickness absence rates during pregnancy. Analyses limited to within-individual variation also show positive and significant effects of similar strength, indicating that the observed relationship is not due to differential selection of absence-prone pregnant workers to female-dominated workplaces. The proportion of female individuals at workplaces is positively associated with sickness absence rates during pregnancy this association is not likely explained by occupational nor individual characteristics the results are consistent with absence culture theory and more lenient norms concerning sickness absence during pregnancy at female-dominated workplaces. © 2014 the Nordic Societies of Public Health.

Anonymous birth law saves babies--optimization, sustainability and public awareness.

PubMed

Grylli, Chryssa; Brockington, Ian; Fiala, Christian; Huscsava, Mercedes; Waldhoer, Thomas; Klier, Claudia M

2016-04-01

The aims of this study are to assess the impact of Austria's anonymous birth law from the time relevant statistical records are available and to evaluate the use of hatches versus anonymous hospital delivery. This study is a complete census of police-reported neonaticides (1975-2012) as well as anonymous births including baby hatches in Austria during 2002-2012. The time trends of neonaticide rates, anonymous births and baby hatches were analysed by means of Poisson and logistic regression model. Predicted and observed rates were derived and compared using a Bayesian Poisson regression model. Predicted numbers of neonaticides for the period of the active awareness campaign, 2002-2004, were more than three times larger than the observed number (p = 0.0067). Of the 365 women who benefitted from this legislation, only 11.5% chose to put their babies in a baby hatch. Since the law was introduced, a significant decreasing tendency of numbers of anonymous births (p = 047) was observed, while there was significant increase of neonaticide rates (p = 0.0001). The implementation of the anonymous delivery law is associated with a decrease in the number of police-reported neonaticides. The subsequent significantly decreasing numbers of anonymous births with an accompanying increase of neonaticides represents additional evidence for the effectiveness of the measure.

Spatial distribution of psychotic disorders in an urban area of France: an ecological study.

PubMed

Pignon, Baptiste; Schürhoff, Franck; Baudin, Grégoire; Ferchiou, Aziz; Richard, Jean-Romain; Saba, Ghassen; Leboyer, Marion; Kirkbride, James B; Szöke, Andrei

2016-05-18

Previous analyses of neighbourhood variations of non-affective psychotic disorders (NAPD) have focused mainly on incidence. However, prevalence studies provide important insights on factors associated with disease evolution as well as for healthcare resource allocation. This study aimed to investigate the distribution of prevalent NAPD cases in an urban area in France. The number of cases in each neighbourhood was modelled as a function of potential confounders and ecological variables, namely: migrant density, economic deprivation and social fragmentation. This was modelled using statistical models of increasing complexity: frequentist models (using Poisson and negative binomial regressions), and several Bayesian models. For each model, assumptions validity were checked and compared as to how this fitted to the data, in order to test for possible spatial variation in prevalence. Data showed significant overdispersion (invalidating the Poisson regression model) and residual autocorrelation (suggesting the need to use Bayesian models). The best Bayesian model was Leroux's model (i.e. a model with both strong correlation between neighbouring areas and weaker correlation between areas further apart), with economic deprivation as an explanatory variable (OR = 1.13, 95% CI [1.02-1.25]). In comparison with frequentist methods, the Bayesian model showed a better fit. The number of cases showed non-random spatial distribution and was linked to economic deprivation.

Zero-Inflated Poisson Modeling of Fall Risk Factors in Community-Dwelling Older Adults.

PubMed

Jung, Dukyoo; Kang, Younhee; Kim, Mi Young; Ma, Rye-Won; Bhandari, Pratibha

2016-02-01

The aim of this study was to identify risk factors for falls among community-dwelling older adults. The study used a cross-sectional descriptive design. Self-report questionnaires were used to collect data from 658 community-dwelling older adults and were analyzed using logistic and zero-inflated Poisson (ZIP) regression. Perceived health status was a significant factor in the count model, and fall efficacy emerged as a significant predictor in the logistic models. The findings suggest that fall efficacy is important for predicting not only faller and nonfaller status but also fall counts in older adults who may or may not have experienced a previous fall. The fall predictors identified in this study--perceived health status and fall efficacy--indicate the need for fall-prevention programs tailored to address both the physical and psychological issues unique to older adults. © The Author(s) 2014.

Functional Relationships and Regression Analysis.

ERIC Educational Resources Information Center

Preece, Peter F. W.

1978-01-01

Using a degenerate multivariate normal model for the distribution of organismic variables, the form of least-squares regression analysis required to estimate a linear functional relationship between variables is derived. It is suggested that the two conventional regression lines may be considered to describe functional, not merely statistical,…

Do parental education and income matter? A nationwide register-based study on HPV vaccine uptake in the school-based immunisation programme in Norway

PubMed Central

Feiring, Berit; Laake, Ida; Molden, Tor; Cappelen, Inger; Håberg, Siri E; Magnus, Per; Steingrímsdóttir, Ólöf Anna; Strand, Bjørn Heine; Stålcrantz, Jeanette; Trogstad, Lill

2015-01-01

Objective Vaccine against human papillomavirus (HPV) has been offered free of charge to all 12-year-old girls in Norway since 2009. Nevertheless, the uptake of HPV vaccine is lower than for other childhood vaccines. The aim of this study was to examine whether parental education and income are associated with initiation and completion of HPV vaccination. Design Nationwide register-based study. Setting Publicly funded childhood immunisation programme in Norway. Participants 91 405 girls born between 1997 and 1999 and registered in the Norwegian Central Population Registry were offered HPV vaccine during the first 3 programme years. Of these, 84 139 had complete information on all variables and were included in the study. Measurements Information on HPV-vaccination status was obtained from the Norwegian Immunisation Registry. Data on socioeconomic factors were extracted from Statistics Norway. Risk differences (RDs) and CIs were estimated with Poisson regression. Results In the study sample, 78.3% received at least one dose of HPV vaccine and 73.6% received all three doses. High maternal education was significantly associated with lower probability of initiating HPV vaccination (multivariable RD=−5.5% (95% CI −7.0% to −4.0%) for highest compared with lowest education level). In contrast, high maternal income was significantly associated with higher probability of initiating vaccination (multivariable RD=10.1% (95% CI 9.0% to 11.3%) for highest compared with lowest quintile). Paternal education and income showed similar, but weaker, associations. The negative association between education and initiation was only seen for incomes below the median value. Conclusions In spite of the presumably equal access to HPV vaccine in Norway, we found socioeconomic disparities in vaccine uptake. More studies are needed to explain the underlying factors responsible for the observed socioeconomic differences. Insight into these factors is necessary to target information and increase vaccination coverage to ultimately reduce HPV-related disease across socioeconomic barriers. PMID:25991445

Contemporary Trends in Radiation Oncology Resident Research

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

Verma, Vivek; Burt, Lindsay; Gimotty, Phyllis A.

Purpose: To test the hypothesis that recent resident research productivity might be different than a decade ago, and to provide contemporary information about resident scholarly activity. Methods and Materials: We compiled a list of radiation oncology residents from the 2 most recent graduating classes (June 2014 and 2015) using the Association of Residents in Radiation Oncology annual directories. We queried the PubMed database for each resident's first-authored publications from postgraduate years (PGY) 2 through 5, plus a 3-month period after residency completion. We abstracted corresponding historical data for 2002 to 2007 from the benchmark publication by Morgan and colleagues (Int Jmore » Radiat Oncol Biol Phys 2009;74:1567-1572). We tested the null hypothesis that these 2 samples had the same distribution for number of publications using the Wilcoxon rank-sum test. We explored the association of demographic factors and publication number using multivariable zero-inflated Poisson regression. Results: There were 334 residents publishing 659 eligible first-author publications during residency (range 0-17; interquartile range 0-3; mean 2.0; median 1). The contemporary and historical distributions were significantly different (P<.001); contemporary publication rates were higher. Publications accrued late in residency (27% in PGY-4, 59% in PGY-5), and most were original research (75%). In the historical cohort, half of all articles were published in 3 journals; in contrast, the top half of contemporary publications were spread over 10 journals—most commonly International Journal of Radiation Oncology • Biology • Physics (17%), Practical Radiation Oncology (7%), and Radiation Oncology (4%). Male gender, non-PhD status, and larger residency size were associated with higher number of publications in the multivariable analysis. Conclusion: We observed an increase in first-author publications during training compared with historical data from the mid-2000s. These contemporary figures may be useful to medical students considering radiation oncology, current residents, training programs, and prospective employers.« less

[Prescription of systemic cold and cough drugs to children 0-13 years old. An unresolved problem].

PubMed

Cano Garcinuño, A; Casares Alonso, I; Rodríguez Barbero, J; Pérez García, I; Blanco Quirós, A

2013-01-01

Upper respiratory tract infections are the most common cause of paediatric consultation, generating a high volume of prescriptions of drugs with unfavourable risk-benefit ratio. The aim of this study is to describe the prescription of systemic cough and cold medicines to children under 14 years of age in Castilla y León and analyse its variability. A count was made of the prescriptions for the R05 therapeutic subgroup (antitussives and mucolytics) and the R01B pharmacological therapeutic subgroup (nasal decongestants for systemic use), prescribed for children under the age of 14 in the Public Health System between 2005-2010. The number of prescriptions was analysed as crude and age-adjusted rates, as well as a a multivariate analysis (Poisson regression) of the variability associated with health area, the urban/rural environment, age, and year of prescription. There were 806,785 prescriptions for systemic cough and cold drugs given to an exposed population of 1,580,229 person-years. Prescription rates (per 100 person-years) were 20.7 (antitussives), 7.0 (sympathomimetic) and 23.4 (mucolytics). These drugs were employed more often in children <4 years. The prescription of mucolytics and sympathomimetics was highest at age of 1 year (rates=41.9 and 18.7, respectively) and of antitussives at 3 years (35.7). Multivariate analysis showed that in rural areas the prescription was higher than in urban areas, and that there were also significant differences between health areas. Between 2005 and 2010 there was a high prescription of systemic cough and cold medicines, especially in children under 2 years old, and often outside the recommended conditions of use, and there was a high geographic variabilty. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier España. All rights reserved.

Back Pain Prevalence and Its Associated Factors in Brazilian Athletes from Public High Schools: A Cross-Sectional Study

PubMed Central

Noll, Matias; de Avelar, Ivan Silveira; Lehnen, Georgia Cristina; Vieira, Marcus Fraga

2016-01-01

Most studies on the prevalence of back pain have evaluated it in developed countries (Human Development Index—HDI > 0.808), and their conclusions may not hold for developing countries. The aim of this study was to identify the prevalence of back pain in representative Brazilian athletes from public high schools. This cross-sectional study was performed during the state phase of the 2015 Jogos dos Institutos Federais (JIF), or Federal Institutes Games, in Brazil (HDI = 0.744), and it enrolled 251 athletes, 173 males and 78 females (14–20 years old). The dependent variable was back pain, and the independent variables were demographic, socioeconomic, psychosocial, hereditary, exercise-level, anthropometric, strength, behavioral, and postural factors. The prevalence ratio (PR) was calculated using multivariable analysis according to the Poisson regression model (α = 0.05). The prevalence of back pain in the three months prior to the study was 43.7% (n = 104), and 26% of the athletes reported feeling back pain only once. Multivariable analysis showed that back pain was associated with demographic (sex), psychosocial (loneliness and loss of sleep in the previous year), hereditary (ethnicity, parental back pain), strength (lumbar and hand forces), anthropometric (body mass index), behavioral (sleeping time per night, reading and studying in bed, smoking habits in the previous month), and postural (sitting posture while writing, while on a bench, and while using a computer) variables. Participants who recorded higher levels of lumbar and manual forces reported a lower prevalence of back pain (PR < 0.79), whereas feeling lonely in the previous year, obesity, and ethnicity exhibited the highest prevalence ratio (PR > 1.30). In conclusion, there is no association between exercise levels and back pain but there is an association between back pain and non-exercise related variables. PMID:26938456

Dangerous student car drop-off behaviors and child pedestrian-motor vehicle collisions: An observational study.

PubMed

Rothman, Linda; Howard, Andrew; Buliung, Ron; Macarthur, Colin; Macpherson, Alison

2016-07-03

The objective of this study was to examine the association between dangerous student car drop-off behaviors and historical child pedestrian-motor vehicle collisions (PMVCs) near elementary schools in Toronto, Canada. Police-reported child PMVCs during school travel times from 2000 to 2011 were mapped within 200 m of 118 elementary schools. Observers measured dangerous student morning car drop-off behaviors and number of children walking to school during one day in 2011. A composite score of school social disadvantage was obtained from the Toronto District School Board. Built environment and traffic features were mapped and included as covariates. A multivariate Poisson regression was used to model the rates of PMVC/number of children walking and dangerous student car drop-off behaviors, adjusting for the built environment and social disadvantage. There were 45 child PMVCs, with 29 (64%) sustaining minor injuries resulting in emergency department visits. The mean collision rate was 2.9/10,000 children walking/year (SD = 6.7). Dangerous drop-off behaviors were observed in 104 schools (88%). In the multivariate analysis, each additional dangerous drop-off behavior was associated with a 45% increase in collision rates (incident rate ratio [IRR] = 1.45, 95% confidence interval [CI], 1.02, 2.07). Higher speed roads (IRR = 1.27, 95% CI, 1.13, 1.44) and social disadvantage (IRR = 2.99, 95% CI, 1.03, 8.68) were associated with higher collision rates. Dangerous student car drop-off behaviors were associated with historical nonfatal child PMVC rates during school travel times near schools. Some caution must be taken in interpreting these results due small number of events and limitations in the data collection, because collision data were collected historically over a 12-year period, whereas driving behavior was only observed on a single day in 2011. Targeted multifaceted intervention approaches related to the built environment, enforcement, and education could address dangerous drop-off behaviors near schools to reduce child PMVCs and promote safe walking to school.

Factors associated with consistent condom use and STIs among foreign female entertainment workers: results from a cross-sectional survey in Singapore.

PubMed

Lim, Raymond Boon Tar; Wong, Mee Lian; Cheung, Olive N Y; Tham, Dede Kam Tyng; Tai, Bee Choo; Chan, Roy

2017-03-01

We assessed the prevalence of consistent condom use and laboratory-confirmed STIs among foreign female entertainment workers (FEWs) who engaged in paid or casual sex in Singapore and the factors associated with these characteristics. A cross-sectional survey, using time-location sampling, was conducted on 220 FEWs (115 Vietnamese and 105 Thai) in 2015. For multivariable analysis, we used a mixed-effects Poisson regression model with backward stepwise approach to account for clustering by venue and to obtain the adjusted prevalence ratios (aPRs) of factors associated with consistent condom use and STI positivity, respectively. Consistent condom use with paid or casual partners in the past month was 39.6% and 36.2% for vaginal and oral sex, respectively. The prevalence of STI (cervical chlamydia, cervical gonorrhoea or pharyngeal gonorrhoea) positivity was 13.6%. In multivariable analysis, consistent condom use for both vaginal and oral sex increased with high self-perceived risk of getting STI/HIV (vaginal: aPR 2.09; 95% CI 1.26 to 3.46; oral: aPR 2.41; 95% CI 1.23 to 4.69) and condom negotiation (vaginal: aPR 3.74; 95% CI 2.07 to 6.75; oral: aPR 2.81; 95% CI 1.51 to 5.26). STI positivity decreased with consistent condom use for vaginal sex (aPR 0.22; 95% CI 0.07 to 0.75) and increased with number of sexual partners (aPR 1.43; 95% CI 1.07 to 1.92). In addition to advocating for policy decisions to provide a safer work environment, behavioural interventions on condom negotiation skills and condom use and biomedical interventions on STI/HIV testing and treatment interventions are needed among the FEWs in Singapore. NCT02780986; pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Critical determinants of the epilepsy treatment gap: a cross-national analysis in resource-limited settings

PubMed Central

Meyer, Ana-Claire L.; Dua, Tarun; Boscardin, John; Escarce, José J.; Saxena, Shekhar; Birbeck, Gretchen L.

2013-01-01

Purpose Epilepsy is one of the most common serious neurological disorders worldwide. Our objective was to determine which economic, healthcare, neurology and epilepsy specific resources were associated with untreated epilepsy in resource-constrained settings. Methods A systematic review of the literature identified community-based studies in resource-constrained settings that calculated the epilepsy treatment gap, the proportion with untreated epilepsy, from prevalent active epilepsy cases. Economic, healthcare, neurology and epilepsy specific resources were taken from existing datasets. Poisson regression models with jackknifed standard errors were used to create bivariate and multivariate models comparing the association between treatment status and economic and health resource indicators. Relative risks were reported. Key Findings Forty-seven studies of 8285 individuals from 24 countries met inclusion criteria. Bivariate analysis demonstrated that individuals residing in rural locations had significantly higher risks of untreated epilepsy [Relative Risk(RR)=1.63; 95% confidence interval(CI):1.26,2.11]. Significantly lower risks of untreated epilepsy were observed for higher physician density [RR=0.65, 95% CI:0.55,0.78], presence of a lay [RR=0.74, 95%CI:0.60,0.91] or professional association for epilepsy [RR=0.73, 95%CI:0.59,0.91], or post-graduate neurology training program [RR=0.67, 95%CI:0.55, 0.82]. In multivariate models, higher physician density maintained significant effects [RR=0.67; 95%CI:0.52,0.88]. Significance Even among resource-limited regions, people with epilepsy in countries with fewer economic, healthcare, neurology and epilepsy specific resources are more likely to have untreated epilepsy. Community-based epilepsy care programs have improved access to treatment but in order to decrease the epilepsy treatment gap, poverty and inequalities of healthcare, neurological and epilepsy resources must be dealt with at the local, national, and global levels. PMID:23106784

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.

Predictors of low back pain in nursing home workers after implementation of a safe resident handling programme.

PubMed

Gold, Judith E; Punnett, Laura; Gore, Rebecca J

2017-06-01

Healthcare workers have high rates of low back pain (LBP) related to handling patients. A large chain of nursing homes experienced reduced biomechanical load, compensation claims and costs following implementation of a safe resident handling programme (SRHP). The aim of this study was to examine whether LBP similarly declined and whether it was associated with relevant self-reported occupational exposures or personal health factors. Worker surveys were conducted on multiple occasions beginning with the week of first SRHP introduction (baseline). In each survey, the outcome was LBP during the prior 3 months with at least mild severity during the past week. Robust Poisson multivariable regression models were constructed to examine correlates of LBP cross-sectionally at 2 years (F3) and longitudinally at 5-6 years (F5) post-SRHP implementation among workers also in at least one prior survey. LBP prevalence declined minimally between baseline and F3. The prevalence was 37% at F3 and cumulative incidence to F5 was 22%. LBP prevalence at F3 was positively associated with combined physical exposures, psychological job demands and prior back injury, while frequent lift device usage and 'intense' aerobic exercise frequency were protective. At F5, the multivariable model included frequent lift usage at F3 (relative risk (RR) 0.39 (0.18 to 0.84)) and F5 work-family imbalance (RR=1.82 (1.12 to 2.98)). In this observational study, resident lifting device usage predicted reduced LBP in nursing home workers. Other physical and psychosocial demands of nursing home work also contributed, while frequent intense aerobic exercise appeared to reduce LBP risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Sex-for-Crack exchanges: associations with risky sexual and drug use niches in an urban Canadian city

PubMed Central

2013-01-01

Background While crack cocaine has been associated with elevated sexual risks and transmission of HIV/STIs, particularly in the context of street-based sex work, few empirical studies have examined correlates of direct sex-for-crack exchanges. This study longitudinally examined the correlates of sex-for-crack exchanges and associated effects on sexual risk outcomes among street-based female sex workers (SW) who use drugs in Vancouver, Canada. Methods Data were drawn from a prospective cohort of street-based SWs (2006–2008), restricted to those who smoke crack cocaine. Multivariable generalized estimating equations (GEE) were employed to examine the correlates of exchanging sex for crack. A confounding model using GEE quasi-Poisson regression modeled the independent effect of exchanging sex for crack on number of clients/week. Results Of 206 SWs, 101 (49%) reported sex-for-crack exchanges over 18 months of follow-up. In multivariable GEE analyses, sharing a crack pipe with a client (aOR = 1.98; 95%CI: 1.27-3.08) and smoking crack in a group of strangers (e.g., in an alley or crackhouse) (aOR = 1.70; 95% CI: 1.13-2.58) were independently correlated with sex-for-crack exchanges. In our confounding model, exchanging sex for crack (aIRR = 1.34; 95% CI: 1.07-1.69) remained significantly associated with servicing a greater number (>10) of clients/week. Conclusions These findings reveal elevated sexual- and drug- risk patterns among those who exchange sex for crack. The physical and social environment featured prominently in our results as a driver of sex-for-crack exchanges, highlighting the need for gender-sensitive multilevel approaches to harm reduction, STI and HIV prevention that address SWs’ environment, individual level factors, and the interplay between them. PMID:24238367

The Gutenberg health study: associations between occupational and private stress factors and work-privacy conflict.

PubMed

Garthus-Niegel, Susan; Hegewald, Janice; Seidler, Andreas; Nübling, Matthias; Espinola-Klein, Christine; Liebers, Falk; Wild, Philipp S; Latza, Ute; Letzel, Stephan

2016-02-29

Work-privacy conflict (WPC) is no longer a rarity but constitutes a societal problem. The objectives of the present study were (1) to investigate the distribution and prevalence of WPC among the employed participants in the Gutenberg Health Study at baseline and (2) to study the dependence of WPC on a broad range of private life and occupational characteristics as well as on psychosocial working conditions. This analysis is based on a representative, population-based sample of 3,709 employees participating in the Gutenberg Health Study. Descriptive and bivariable analyses were carried out separately for women and men. Distribution and prevalence of WPC were examined according to socio-demographic and occupational characteristics as well as psychosocial working conditions. Further, stepwise selection of Poisson log-linear regression models were performed to determine which socio-demographic and occupational characteristics were most associated with the outcome variable WPC and to obtain adjusted prevalence ratios from the final model. The multivariable analyses were conducted both separately for women and men and with all subjects together in one analysis. There was a high prevalence of WPC in the present study (27.4 % of the men and 23.0 % of the women reported a high or very high WPC). A variety of factors was associated with WPC, e.g. full-time employment, depression and many of the psychosocial risk factors at work. Also, the multivariable results showed that women were of higher risk for a WPC. By affecting the individual work life, home life, and the general well-being and health, WPC may lead to detrimental effects in employees, their families, employers, and society as a whole. Therefore, the high prevalence of WPC in our sample should be of concern. Among women, the risk for suffering from WPC was even higher, most likely due to multiple burdens.

Short-term Natural History of High-Risk Human Papillomavirus Infection in Mid-Adult Women Sampled Monthly (Short title: Short-term HPV Natural History in Mid-Adult Women)

PubMed Central

Fu, Tsung-chieh (Jane); Xi, Long Fu; Hulbert, Ayaka; Hughes, James P.; Feng, Qinghua; Schwartz, Stephen M.; Hawes, Stephen E.; Koutsky, Laura A.; Winer, Rachel L.

2015-01-01

Characterizing short-term HPV detection patterns and viral load may inform HPV natural history in mid-adult women. From 2011–2012, we recruited women aged 30–50 years. Women submitted monthly self-collected vaginal samples for high-risk HPV DNA testing for 6 months. Positive samples were tested for type-specific HPV DNA load by real-time PCR. HPV type-adjusted linear and Poisson regression assessed factors associated with 1) viral load at initial HPV detection and 2) repeat type-specific HPV detection. One-hundred thirty-nine women (36% of 387 women with ≥4 samples) contributed 243 type-specific HR HPV infections during the study; 54% of infections were prevalent and 46% were incident. Incident (versus prevalent) detection and past pregnancy were associated with lower viral load, whereas current smoking was associated with higher viral load. In multivariate analysis, current smoking was associated with a 40% (95%CI:5%–87%) increase in the proportion of samples that were repeatedly positive for the same HPV type, whereas incident (versus prevalent) detection status and past pregnancy were each associated with a reduction in the proportion of samples repeatedly positive (55%,95%CI:38%–67% and 26%,95%CI:10%–39%, respectively). In a separate multivariate model, each log10 increase in viral load was associated with a 10% (95%CI:4%–16%) increase in the proportion of samples repeatedly positive. Factors associated with repeat HPV detection were similar to those observed in longer-term studies, suggesting that short-term repeat detection may relate to long-term persistence. The negative associations between incident HPV detection and both viral load and repeat detection suggest that reactivation or intermittent persistence was more common than new acquisition. PMID:25976733

The role of the assistant during robot-assisted partial nephrectomy: does experience matter?

PubMed

Potretzke, Aaron M; Knight, Brent A; Brockman, John A; Vetter, Joel; Figenshau, Robert S; Bhayani, Sam B; Benway, Brian M

2016-06-01

The objective of this study was to evaluate surgical outcomes with respect to the experience level of the bedside assistant during robot-assisted partial nephrectomy. A retrospective review was conducted of a prospectively maintained database of 414 consecutive robot-assisted laparoscopic partial nephrectomies performed by experienced robotic surgeons at our institution from April 2011 to September 2014. A senior-level assistant was defined as a resident in his or her post-graduate year (PGY) 4 or 5, or a fellow. Junior-level assistants were considered to be PGY-2, PGY-3, or a nurse first assistant. Multivariate analyses were performed using linear, Poisson, and logistic regression models. There were 115 junior-level cases and 299 senior-level cases. On univariate analysis, the experience level of the assistant had no impact on operative time (168 for junior level vs. 163 min for senior level, p = 0.656). Likewise, there were no differences between the junior- and senior-level groups with regard to warm ischemia time (21.3 vs. 20.9 min, p = 0.843), negative margin status (111/115 (96.5 %) vs. 280/299 (93.6 %), p = 0.340), or postoperative complications (17/115 (14.8 %) vs. 35/299 (11.7 %), p = 0.408). After multivariate analysis, operative time was associated with increased body mass index and tumor size (both p < 0.001), but not with resident experience level (p = 0.051). Estimated blood loss and postoperative complications were also not associated with the PGY of the assistant (p = 0.488 and p = 0.916, respectively). Despite common concern, the PGY status of a physician trainee serving as the bedside assistant does not appear to influence the outcomes of robot-assisted partial nephrectomy at a high-volume center.

Contemporary Trends in Radiation Oncology Resident Research.

PubMed

Verma, Vivek; Burt, Lindsay; Gimotty, Phyllis A; Ojerholm, Eric

2016-11-15

To test the hypothesis that recent resident research productivity might be different than a decade ago, and to provide contemporary information about resident scholarly activity. We compiled a list of radiation oncology residents from the 2 most recent graduating classes (June 2014 and 2015) using the Association of Residents in Radiation Oncology annual directories. We queried the PubMed database for each resident's first-authored publications from postgraduate years (PGY) 2 through 5, plus a 3-month period after residency completion. We abstracted corresponding historical data for 2002 to 2007 from the benchmark publication by Morgan and colleagues (Int J Radiat Oncol Biol Phys 2009;74:1567-1572). We tested the null hypothesis that these 2 samples had the same distribution for number of publications using the Wilcoxon rank-sum test. We explored the association of demographic factors and publication number using multivariable zero-inflated Poisson regression. There were 334 residents publishing 659 eligible first-author publications during residency (range 0-17; interquartile range 0-3; mean 2.0; median 1). The contemporary and historical distributions were significantly different (P<.001); contemporary publication rates were higher. Publications accrued late in residency (27% in PGY-4, 59% in PGY-5), and most were original research (75%). In the historical cohort, half of all articles were published in 3 journals; in contrast, the top half of contemporary publications were spread over 10 journals-most commonly International Journal of Radiation Oncology • Biology • Physics (17%), Practical Radiation Oncology (7%), and Radiation Oncology (4%). Male gender, non-PhD status, and larger residency size were associated with higher number of publications in the multivariable analysis. We observed an increase in first-author publications during training compared with historical data from the mid-2000s. These contemporary figures may be useful to medical students considering radiation oncology, current residents, training programs, and prospective employers. Copyright © 2016 Elsevier Inc. All rights reserved.

Association of socio-demographic factors, sick-leave and health care patterns with the risk of being granted a disability pension among psychiatric outpatients with depression.

PubMed

Mittendorfer-Rutz, Ellenor; Härkänen, Tommi; Tiihonen, Jari; Haukka, Jari

2014-01-01

Depression ranges among the leading causes of early exit from the labor market worldwide. We aimed to investigate the associations of socio-demographic factors, sickness absence, health care and prescription patterns with the risk of being granted a disability pension in psychiatric outpatients with depression. All non-retired patients aged 18-60 years and living in Sweden 31.12.2005 with at least one psychiatric outpatient care visit due to a depressive episode during 2006 (N = 18,034): were followed from 01.01.2007 to 31.12.2010 with regard to granting of all-cause and diagnosis-specific disability pension. Uni- and multivariate Rate Ratios (RR) and 95% Confidence Intervals (CI) were estimated for the various risk markers by Poisson Regression. During the four years of follow-up, 3044 patients (16.8%) were granted a disability pension, the majority due to mental disorders (2558, 84%). In the multivariate analyses, being female, below 25 or above 45 years of age, with low educational level, living alone, residing outside big cities and being born outside Europe were predictive of a granted disability pension. Frequent in- and outpatient care due to mental disorders, prescription of antidepressants and long sickness absence spells were also associated with an increased risk of disability pension (range of RRs 1.10 to 5.26). Somatic health care was only predictive of disability pension due to somatic disorders. The risk of being granted a disability pension remained at the same level as at the start of follow-up for about 1.5 years, when it started to decrease and to level off at about 20% of the risk at the end of follow-up. Identified risk markers should be considered when monitoring individuals with depression and when designing intervention programs.

Association of Socio-Demographic Factors, Sick-Leave and Health Care Patterns with the Risk of Being Granted a Disability Pension among Psychiatric Outpatients with Depression

PubMed Central

Mittendorfer-Rutz, Ellenor; Härkänen, Tommi; Tiihonen, Jari; Haukka, Jari

2014-01-01

Background Depression ranges among the leading causes of early exit from the labor market worldwide. We aimed to investigate the associations of socio-demographic factors, sickness absence, health care and prescription patterns with the risk of being granted a disability pension in psychiatric outpatients with depression. Methods All non-retired patients aged 18–60 years and living in Sweden 31.12.2005 with at least one psychiatric outpatient care visit due to a depressive episode during 2006 (N = 18034): were followed from 01.01.2007 to 31.12.2010 with regard to granting of all-cause and diagnosis-specific disability pension. Uni- and multivariate Rate Ratios (RR) and 95% Confidence Intervals (CI) were estimated for the various risk markers by Poisson Regression. Results During the four years of follow-up, 3044 patients (16.8%) were granted a disability pension, the majority due to mental disorders (2558, 84%). In the multivariate analyses, being female, below 25 or above 45 years of age, with low educational level, living alone, residing outside big cities and being born outside Europe were predictive of a granted disability pension. Frequent in- and outpatient care due to mental disorders, prescription of antidepressants and long sickness absence spells were also associated with an increased risk of disability pension (range of RRs 1.10 to 5.26). Somatic health care was only predictive of disability pension due to somatic disorders. The risk of being granted a disability pension remained at the same level as at the start of follow-up for about 1.5 years, when it started to decrease and to level off at about 20% of the risk at the end of follow-up. Conclusions Identified risk markers should be considered when monitoring individuals with depression and when designing intervention programs. PMID:24963812

Relative and absolute risks of all-cause and cause-specific deaths attributable to atrial fibrillation in middle-aged and elderly community dwellers.

PubMed

Ohsawa, Masaki; Okamura, Tomonori; Ogasawara, Kuniaki; Ogawa, Akira; Fujioka, Tomoaki; Tanno, Kozo; Yonekura, Yuki; Omama, Shinichi; Turin, Tanvir Chowdhury; Itai, Kazuyoshi; Ishibashi, Yasuhiro; Morino, Yoshihiro; Itoh, Tomonori; Miyamatsu, Naomi; Onoda, Toshiyuki; Kuribayashi, Toru; Makita, Shinji; Yoshida, Yuki; Nakamura, Motoyuki; Tanaka, Fumitaka; Ohta, Mutsuko; Sakata, Kiyomi; Okayama, Akira

2015-04-01

The relative and absolute risks of outcomes other than all-cause death (ACD) attributable to atrial fibrillation (AF) stratified age have not been sufficiently investigated. A prospective study of 23,634 community dwellers aged 40 years or older without organic cardiovascular disease (AF=335, non-AF=23,299) was conducted. Multivariate-adjusted rates, rate ratios (RRs) and excess deaths (EDs) for ACD, cardiovascular death (CVD) and non-cardiovascular death (non-CVD), and sex- and age-adjusted RR and ED in middle-aged (40 to 69) and elderly (70 years or older) for ACD, CVD, non-CVD, sudden cardiac death (SCD), stroke-related death (Str-D), neoplasm-related death (NPD), and infection-related death (IFD) attributable to AF were estimated using Poisson regression. Multivariate-adjusted analysis revealed that AF significantly increased the risk of ACD (RR [95% confidence interval]:1.70 [1.23-2.95]) and CVD (3.86 [2.38-6.27]), but not non-CVD. Age-stratified analysis revealed that AF increased the risk of Str-D in middle-aged (14.5 [4.77-44.3]) and elderly individuals (4.92 [1.91-12.7]), SCD in elderly individuals (3.21 [1.37-7.51]), and might increase the risk of IFD in elderly individuals (2.02 [0.80-4.65], p=0.098). The RR of CVD was higher in middle-aged versus elderly individuals (RRs, 6.19 vs. 3.57) but the absolute risk difference was larger in elderly individuals (EDs: 7.6 vs. 3.0 per 1000 person-years). Larger absolute risk differences for ACD and CVD attributable to AF among elderly people indicate that the absolute burden of AF is higher in elderly versus middle-aged people despite the relatively small RR. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

High dietary ratio of omega-6 to omega-3 polyunsaturated acids during pregnancy and prevalence of post-partum depression.

PubMed

da Rocha, Camilla M M; Kac, Gilberto

2012-01-01

Observational studies suggest association between low concentrations of omega-3 family fatty acids and greater risk for post-partum depression (PPD). The objective was to investigate the effect of unbalanced dietary intake of omega-6/omega-3 ratio >9:1 in the prevalence for PPD. The study comprises a prospective cohort with four waves of follow-up during pregnancy and one following delivery. PPD was evaluated according to the Edinburgh Post-partum Depression Scale (PPD ≥ 11) in 106 puerperae between 2005 and 2007, in Rio de Janeiro, Brazil. Independent variables included socio-demographic, obstetric, pre-pregnancy body mass index (BMI) and dietary intake data, which were obtained by means of a food frequency questionnaire in the first trimester of pregnancy. Statistical analysis involved calculation of PPD prevalence and multivariate Poisson regression with robust variance. PPD prevalence amounted to 26.4% [n = 28; confidence interval (CI) 95%: 18.0-34.8], and higher prevalences of PPD were observed in women who consumed an omega-6/omega-3 ratio >9:1 (60.0%) and in those with pre-pregnancy BMI <18.5 kg/m(2) (66.7%). These variables held as factors associated to PPD in the multivariate model, elevating the chances of occurrence of the outcome in 2.50 (CI 95%: 1.21-5.14) and 4.01 times (CI 95%: 1.96-8.20), respectively. Analyses were adjusted for age, schooling, pre-pregnancy BMI, lipids consumption and time elapsed since delivery. It verified an association between omega-6/omega-3 ratio above 9:1, the levels recommended by the Institute of Medicine, and the prevalence of PPD. These results add to the evidence regarding the importance of omega-6 and omega-3 fatty acids in the regulation of mental health mechanisms. © 2010 Blackwell Publishing Ltd.

High-throughput quantitative biochemical characterization of algal biomass by NIR spectroscopy; multiple linear regression and multivariate linear regression analysis.

PubMed

Laurens, L M L; Wolfrum, E J

2013-12-18

One of the challenges associated with microalgal biomass characterization and the comparison of microalgal strains and conversion processes is the rapid determination of the composition of algae. We have developed and applied a high-throughput screening technology based on near-infrared (NIR) spectroscopy for the rapid and accurate determination of algal biomass composition. We show that NIR spectroscopy can accurately predict the full composition using multivariate linear regression analysis of varying lipid, protein, and carbohydrate content of algal biomass samples from three strains. We also demonstrate a high quality of predictions of an independent validation set. A high-throughput 96-well configuration for spectroscopy gives equally good prediction relative to a ring-cup configuration, and thus, spectra can be obtained from as little as 10-20 mg of material. We found that lipids exhibit a dominant, distinct, and unique fingerprint in the NIR spectrum that allows for the use of single and multiple linear regression of respective wavelengths for the prediction of the biomass lipid content. This is not the case for carbohydrate and protein content, and thus, the use of multivariate statistical modeling approaches remains necessary.

Membrane Introduction Mass Spectrometry Combined with an Orthogonal Partial-Least Squares Calibration Model for Mixture Analysis.

PubMed

Li, Min; Zhang, Lu; Yao, Xiaolong; Jiang, Xingyu

2017-01-01

The emerging membrane introduction mass spectrometry technique has been successfully used to detect benzene, toluene, ethyl benzene and xylene (BTEX), while overlapped spectra have unfortunately hindered its further application to the analysis of mixtures. Multivariate calibration, an efficient method to analyze mixtures, has been widely applied. In this paper, we compared univariate and multivariate analyses for quantification of the individual components of mixture samples. The results showed that the univariate analysis creates poor models with regression coefficients of 0.912, 0.867, 0.440 and 0.351 for BTEX, respectively. For multivariate analysis, a comparison to the partial-least squares (PLS) model shows that the orthogonal partial-least squares (OPLS) regression exhibits an optimal performance with regression coefficients of 0.995, 0.999, 0.980 and 0.976, favorable calibration parameters (RMSEC and RMSECV) and a favorable validation parameter (RMSEP). Furthermore, the OPLS exhibits a good recovery of 73.86 - 122.20% and relative standard deviation (RSD) of the repeatability of 1.14 - 4.87%. Thus, MIMS coupled with the OPLS regression provides an optimal approach for a quantitative BTEX mixture analysis in monitoring and predicting water pollution.

Examining the spatially non-stationary associations between the second demographic transition and infant mortality: A Poisson GWR approach.

PubMed

Yang, Tse-Chuan; Shoff, Carla; Matthews, Stephen A

2013-01-01

Based on ecological studies, second demographic transition (SDT) theorists concluded that some areas in the US were in vanguard of the SDT compared to others, implying spatial nonstationarity may be inherent in the SDT process. Linking the SDT to the infant mortality literature, we sought out to answer two related questions: Are the main components of the SDT, specifically marriage postponement, cohabitation, and divorce, associated with infant mortality? If yes, do these associations vary across the US? We applied global Poisson and geographically weighted Poisson regression (GWPR) models, a place-specific analytic approach, to county-level data in the contiguous US. After accounting for the racial/ethnic and socioeconomic compositions of counties and prenatal care utilization, we found (1) marriage postponement was negatively related to infant mortality in the southwestern states, but positively associated with infant mortality in parts of Indiana, Kentucky, and Tennessee, (2) cohabitation rates were positively related to infant mortality, and this relationship was stronger in California, coastal Virginia, and the Carolinas than other areas, and (3) a positive association between divorce rates and infant mortality in southwestern and northeastern areas of the US. These spatial patterns suggested that the associations between the SDT and infant mortality were stronger in the areas in vanguard of the SDT than in others. The comparison between global Poisson and GWPR results indicated that a place-specific spatial analysis not only fit the data better, but also provided insights into understanding the non-stationarity of the associations between the SDT and infant mortality.

Logistic regression for dichotomized counts.

PubMed

Preisser, John S; Das, Kalyan; Benecha, Habtamu; Stamm, John W

2016-12-01

Sometimes there is interest in a dichotomized outcome indicating whether a count variable is positive or zero. Under this scenario, the application of ordinary logistic regression may result in efficiency loss, which is quantifiable under an assumed model for the counts. In such situations, a shared-parameter hurdle model is investigated for more efficient estimation of regression parameters relating to overall effects of covariates on the dichotomous outcome, while handling count data with many zeroes. One model part provides a logistic regression containing marginal log odds ratio effects of primary interest, while an ancillary model part describes the mean count of a Poisson or negative binomial process in terms of nuisance regression parameters. Asymptotic efficiency of the logistic model parameter estimators of the two-part models is evaluated with respect to ordinary logistic regression. Simulations are used to assess the properties of the models with respect to power and Type I error, the latter investigated under both misspecified and correctly specified models. The methods are applied to data from a randomized clinical trial of three toothpaste formulations to prevent incident dental caries in a large population of Scottish schoolchildren. © The Author(s) 2014.

Impact of hepatitis B vaccination on acute hepatitis B epidemiology in European Union/European Economic Area countries, 2006 to 2014

PubMed Central

Miglietta, Alessandro; Quinten, Chantal; Lopalco, Pier Luigi; Duffell, Erika

2018-01-01

Hepatitis B prevention in European Union/European Economic Area (EU/EEA) countries relies on vaccination programmes. We describe the epidemiology of acute hepatitis B virus (HBV) at country and EU/EEA level during 2006–2014. Using a multi-level mixed-effects Poisson regression model we assessed differences in the acute HBV infection notification rates between groups of countries that started universal HBV vaccination before/in vs after 1995; implemented or not a catch-up strategy; reached a vaccine coverage ≥ 95% vs < 95% and had a hepatitis B surface antigen prevalence ≥ 1% vs < 1%. Joinpoint regression analysis was used to assess trends by groups of countries, and additional Poisson regression models to evaluate the association between three-dose HBV vaccine coverage and acute HBV infection notification rates at country and EU/EEA level. The EU/EEA acute HBV infection notification rate decreased from 1.6 per 100,000 population in 2006 to 0.7 in 2014. No differences (p > 0.05) were found in the acute HBV infection notification rates between groups of countries, while as vaccine coverage increased, such rates decreased (p < 0.01). Countries with universal HBV vaccination before 1995, a catch-up strategy, and a vaccine coverage ≥ 95% had significant decreasing trends (p < 0.01). Ending HBV transmission in Europe by 2030 will require high vaccine coverage delivered through universal programmes, supported, where appropriate, by catch-up vaccination campaigns. PMID:29439751

Identification of the prediction model for dengue incidence in Can Tho city, a Mekong Delta area in Vietnam.

PubMed

Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Manh, Cuong Do

2015-01-01

The Mekong Delta is highly vulnerable to climate change and a dengue endemic area in Vietnam. This study aims to examine the association between climate factors and dengue incidence and to identify the best climate prediction model for dengue incidence in Can Tho city, the Mekong Delta area in Vietnam. We used three different regression models comprising: standard multiple regression model (SMR), seasonal autoregressive integrated moving average model (SARIMA), and Poisson distributed lag model (PDLM) to examine the association between climate factors and dengue incidence over the period 2003-2010. We validated the models by forecasting dengue cases for the period of January-December, 2011 using the mean absolute percentage error (MAPE). Receiver operating characteristics curves were used to analyze the sensitivity of the forecast of a dengue outbreak. The results indicate that temperature and relative humidity are significantly associated with changes in dengue incidence consistently across the model methods used, but not cumulative rainfall. The Poisson distributed lag model (PDLM) performs the best prediction of dengue incidence for a 6, 9, and 12-month period and diagnosis of an outbreak however the SARIMA model performs a better prediction of dengue incidence for a 3-month period. The simple or standard multiple regression performed highly imprecise prediction of dengue incidence. We recommend a follow-up study to validate the model on a larger scale in the Mekong Delta region and to analyze the possibility of incorporating a climate-based dengue early warning method into the national dengue surveillance system. Copyright © 2014 Elsevier B.V. All rights reserved.

Flood-frequency prediction methods for unregulated streams of Tennessee, 2000

USGS Publications Warehouse

Law, George S.; Tasker, Gary D.

2003-01-01

Up-to-date flood-frequency prediction methods for unregulated, ungaged rivers and streams of Tennessee have been developed. Prediction methods include the regional-regression method and the newer region-of-influence method. The prediction methods were developed using stream-gage records from unregulated streams draining basins having from 1 percent to about 30 percent total impervious area. These methods, however, should not be used in heavily developed or storm-sewered basins with impervious areas greater than 10 percent. The methods can be used to estimate 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence-interval floods of most unregulated rural streams in Tennessee. A computer application was developed that automates the calculation of flood frequency for unregulated, ungaged rivers and streams of Tennessee. Regional-regression equations were derived by using both single-variable and multivariable regional-regression analysis. Contributing drainage area is the explanatory variable used in the single-variable equations. Contributing drainage area, main-channel slope, and a climate factor are the explanatory variables used in the multivariable equations. Deleted-residual standard error for the single-variable equations ranged from 32 to 65 percent. Deleted-residual standard error for the multivariable equations ranged from 31 to 63 percent. These equations are included in the computer application to allow easy comparison of results produced by the different methods. The region-of-influence method calculates multivariable regression equations for each ungaged site and recurrence interval using basin characteristics from 60 similar sites selected from the study area. Explanatory variables that may be used in regression equations computed by the region-of-influence method include contributing drainage area, main-channel slope, a climate factor, and a physiographic-region factor. Deleted-residual standard error for the region-of-influence method tended to be only slightly smaller than those for the regional-regression method and ranged from 27 to 62 percent.

Multivariate logistic regression analysis of postoperative complications and risk model establishment of gastrectomy for gastric cancer: A single-center cohort report.

PubMed

Zhou, Jinzhe; Zhou, Yanbing; Cao, Shougen; Li, Shikuan; Wang, Hao; Niu, Zhaojian; Chen, Dong; Wang, Dongsheng; Lv, Liang; Zhang, Jian; Li, Yu; Jiao, Xuelong; Tan, Xiaojie; Zhang, Jianli; Wang, Haibo; Zhang, Bingyuan; Lu, Yun; Sun, Zhenqing

2016-01-01

Reporting of surgical complications is common, but few provide information about the severity and estimate risk factors of complications. If have, but lack of specificity. We retrospectively analyzed data on 2795 gastric cancer patients underwent surgical procedure at the Affiliated Hospital of Qingdao University between June 2007 and June 2012, established multivariate logistic regression model to predictive risk factors related to the postoperative complications according to the Clavien-Dindo classification system. Twenty-four out of 86 variables were identified statistically significant in univariate logistic regression analysis, 11 significant variables entered multivariate analysis were employed to produce the risk model. Liver cirrhosis, diabetes mellitus, Child classification, invasion of neighboring organs, combined resection, introperative transfusion, Billroth II anastomosis of reconstruction, malnutrition, surgical volume of surgeons, operating time and age were independent risk factors for postoperative complications after gastrectomy. Based on logistic regression equation, p=Exp∑BiXi / (1+Exp∑BiXi), multivariate logistic regression predictive model that calculated the risk of postoperative morbidity was developed, p = 1/(1 + e((4.810-1.287X1-0.504X2-0.500X3-0.474X4-0.405X5-0.318X6-0.316X7-0.305X8-0.278X9-0.255X10-0.138X11))). The accuracy, sensitivity and specificity of the model to predict the postoperative complications were 86.7%, 76.2% and 88.6%, respectively. This risk model based on Clavien-Dindo grading severity of complications system and logistic regression analysis can predict severe morbidity specific to an individual patient's risk factors, estimate patients' risks and benefits of gastric surgery as an accurate decision-making tool and may serve as a template for the development of risk models for other surgical groups.

PARAMETRIC AND NON PARAMETRIC (MARS: MULTIVARIATE ADDITIVE REGRESSION SPLINES) LOGISTIC REGRESSIONS FOR PREDICTION OF A DICHOTOMOUS RESPONSE VARIABLE WITH AN EXAMPLE FOR PRESENCE/ABSENCE OF AMPHIBIANS

EPA Science Inventory

The purpose of this report is to provide a reference manual that could be used by investigators for making informed use of logistic regression using two methods (standard logistic regression and MARS). The details for analyses of relationships between a dependent binary response ...

Factors associated with suicidal ideation among university students.

PubMed

Santos, Hugo Gedeon Barros Dos; Marcon, Samira Reschetti; Espinosa, Mariano Martínez; Baptista, Makilin Nunes; Paulo, Paula Mirianh Cabral de

2017-05-15

to analyze the factors associated with suicidal ideation in a representative sample of university students. cross-sectional study, carried out with 637 students of the Federal University of Mato Grosso. The presence of suicidal ideation, demographic and socioeconomic variables, use of alcohol through the Alcohol, Smoking and Substance Involvement Screening Test, and depressive symptoms (Major Depression Inventory) were investigated. Bivariate analysis was performed with the Chi-square test and multivariate analysis using the Poisson regression model. it was found that 9.9% of the students had suicidal thoughts in the previous 30 days and, in the bivariate analysis, the variables economic class, sexual orientation, religious practice, suicide attempts in the family and among friends, alcohol consumption and depressive symptoms were associated with suicidal ideation. In the multivariate analysis sexual orientation, suicide attempts in the family and the presence of depressive symptoms remained as associated factors. these findings constitute a situational diagnosis that enables the formulation of academic policies and preventive actions to confront this situation on the university campus. analisar os fatores associados à ideação suicida em uma amostra representativa de estudantes universitários. estudo transversal analítico, realizado com 637 estudantes de uma Universidade Federal de Mato Grosso. Investigadas variáveis de presença de ideação suicida, demográficas e socioeconômica, uso de álcool por meio do Alcohol, Smoking and Substance Involvement Screening Test, e sintomas depressivos (Inventário de Depressão Maior). A análise bivariada foi realizada com o teste do Qui-quadrado, e a análise múltipla pelo modelo de regressão Poisson. constatou-se que 9,9% dos estudantes tinham ideias suicidas nos últimos 30 dias, e na análise bivariada as variáveis classe econômica, orientação sexual, prática religiosa, tentativas de suicídio na família e entre amigos, consumo de álcool e sintomas depressivos apresentaram associação com ideação suicida. Na análise múltipla permaneceu como fatores associados orientação sexual, tentativas de suicídio na família e presença de sintomas depressivos. tais achados constituem um diagnóstico situacional que possibilita a formulação de políticas acadêmicas e de ações de prevenção para o enfrentamento dessa situação no campus universitário. analizar los factores asociados a la ideación suicida en una muestra representativa de estudiantes universitarios. estudio transversal analítico, realizado con 637 estudiantes en una Universidad Federal de Mato Grosso. Fueron investigadas las variables: presencia de ideación suicida; demográficas y socioeconómicas; uso de alcohol por medio del Alcohol, Smoking and Substance Involvement Screening Test; y síntomas depresivos (Inventario de Depresión Mayor). El análisis bivariado fue realizado con el test de Chi-cuadrado y el análisis múltiple con el modelo de regresión de Poisson. se constató que 9,9% de los estudiantes tuvieron ideas suicidas en los últimos 30 días, y en el análisis bivariado las variables: clase económica; orientación sexual; práctica religiosa; intentos de suicidio en la familia y entre amigos; consumo de alcohol; y síntomas depresivos, presentaron asociación con ideación suicida. En el análisis múltiple permanecieron como factores asociados la orientación sexual, los intentos de suicidio en la familia y la presencia de síntomas depresivos. estos hallazgos constituyen un diagnóstico situacional que posibilita la formulación de políticas académicas y de acciones de prevención para enfrentar esa situación en el campus universitario.

Causal diagrams and multivariate analysis II: precision work.

PubMed

Jupiter, Daniel C

2014-01-01

In this Investigators' Corner, I continue my discussion of when and why we researchers should include variables in multivariate regression. My examination focuses on studies comparing treatment groups and situations for which we can either exclude variables from multivariate analyses or include them for reasons of precision. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Why are we regressing?

PubMed

Jupiter, Daniel C

2012-01-01

In this first of a series of statistical methodology commentaries for the clinician, we discuss the use of multivariate linear regression. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Quality of life and use of health care resources among patients with chronic depression

PubMed Central

Villoro, Renata; Merino, María; Hidalgo-Vega, Alvaro

2016-01-01

Purpose This study estimates the health-related quality of life and the health care resource utilization of patients diagnosed with chronic depression (CD) in Spain. Patients and methods We used the Spanish National Health Survey 2011–2012, a cross-sectional survey representative at the national level, that selects people aged between 18 and 64 years (n=14,691). We estimated utility indices through the EuroQol five-dimensional descriptive system questionnaire included in the survey. We calculated percentage use of health care resources (medical visits, hospitalizations, emergency services, and drug consumption) and average number of resources used when available. A systematic comparison was made between people diagnosed with CD and other chronic conditions (OCCs). The chi-square test, Mann–Whitney U-test, and Kruskal–Wallis test were used to determine the statistical significance of differences between comparison groups. Multivariate analyses (Poisson regression, logistic regression, and linear regression) were also carried out to assess the relationship between quality of life and consumption of health care resources. Results Approximately, 6.1% of the subjects aged between 18 and 64 years were diagnosed with CD (average age 48.3±11 years, 71.7% females). After controlling for age, sex, and total number of comorbidities, a diagnosis of CD reduced utility scores by 0.09 (P<0.05) vs OCCs, and increased the average number of hospitalizations by 15%, the average number of days at hospital by 51%, and the average number of visits to emergency services by 15% (P<0.05). CD also increased the average number of visits to secondary care by 14% and visits to general practitioners by 4%. People with CD had a higher probability of consuming drugs than people with OCCs (odds ratio [OR]: 1.24, P<0.05), but only 38.6% took antidepressants. Conclusion People with CD had significantly lower health-related quality of life than people with OCCs. CD was associated with increased hospital length of stay and involved a higher consumption of emergency services and drugs than OCCs. PMID:27713651

Intimate partner violence, relationship power inequity, and incidence of HIV infection in young women in South Africa: a cohort study.

PubMed

Jewkes, Rachel K; Dunkle, Kristin; Nduna, Mzikazi; Shai, Nwabisa

2010-07-03

Cross-sectional studies have shown that intimate partner violence and gender inequity in relationships are associated with increased prevalence of HIV in women. Yet temporal sequence and causality have been questioned, and few HIV prevention programmes address these issues. We assessed whether intimate partner violence and relationship power inequity increase risk of incident HIV infection in South African women. We did a longitudinal analysis of data from a previously published cluster-randomised controlled trial undertaken in the Eastern Cape province of South Africa in 2002-06. 1099 women aged 15-26 years who were HIV negative at baseline and had at least one additional HIV test over 2 years of follow-up were included in the analysis. Gender power equity and intimate partner violence were measured by a sexual relationship power scale and the WHO violence against women instrument, respectively. Incidence rate ratios (IRRs) of HIV acquisition at 2 years were derived from Poisson models, adjusted for study design and herpes simplex virus type 2 infection, and used to calculate population attributable fractions. 128 women acquired HIV during 2076 person-years of follow-up (incidence 6.2 per 100 person-years). 51 of 325 women with low relationship power equity at baseline acquired HIV (8.5 per 100 person-years) compared with 73 of 704 women with medium or high relationship power equity (5.5 per 100 person-years); adjusted multivariable Poisson model IRR 1.51, 95% CI 1.05-2.17, p=0.027. 45 of 253 women who reported more than one episode of intimate partner violence at baseline acquired HIV (9.6 per 100 person-years) compared with 83 of 846 who reported one or no episodes (5.2 per 100 person-years); adjusted multivariable Poisson model IRR 1.51, 1.04-2.21, p=0.032. The population attributable fractions were 13.9% (95% CI 2.0-22.2) for relationship power equity and 11.9% (1.4-19.3) for intimate partner violence. Relationship power inequity and intimate partner violence increase risk of incident HIV infection in young South African women. Policy, interventions, and programmes for HIV prevention must address both of these risk factors and allocate appropriate resources. National Institute of Mental Health and South African Medical Research Council. Copyright 2010 Elsevier Ltd. All rights reserved.

PM10 modeling in the Oviedo urban area (Northern Spain) by using multivariate adaptive regression splines

NASA Astrophysics Data System (ADS)

Nieto, Paulino José García; Antón, Juan Carlos Álvarez; Vilán, José Antonio Vilán; García-Gonzalo, Esperanza

2014-10-01

The aim of this research work is to build a regression model of the particulate matter up to 10 micrometers in size (PM10) by using the multivariate adaptive regression splines (MARS) technique in the Oviedo urban area (Northern Spain) at local scale. This research work explores the use of a nonparametric regression algorithm known as multivariate adaptive regression splines (MARS) which has the ability to approximate the relationship between the inputs and outputs, and express the relationship mathematically. In this sense, hazardous air pollutants or toxic air contaminants refer to any substance that may cause or contribute to an increase in mortality or serious illness, or that may pose a present or potential hazard to human health. To accomplish the objective of this study, the experimental dataset of nitrogen oxides (NOx), carbon monoxide (CO), sulfur dioxide (SO2), ozone (O3) and dust (PM10) were collected over 3 years (2006-2008) and they are used to create a highly nonlinear model of the PM10 in the Oviedo urban nucleus (Northern Spain) based on the MARS technique. One main objective of this model is to obtain a preliminary estimate of the dependence between PM10 pollutant in the Oviedo urban area at local scale. A second aim is to determine the factors with the greatest bearing on air quality with a view to proposing health and lifestyle improvements. The United States National Ambient Air Quality Standards (NAAQS) establishes the limit values of the main pollutants in the atmosphere in order to ensure the health of healthy people. Firstly, this MARS regression model captures the main perception of statistical learning theory in order to obtain a good prediction of the dependence among the main pollutants in the Oviedo urban area. Secondly, the main advantages of MARS are its capacity to produce simple, easy-to-interpret models, its ability to estimate the contributions of the input variables, and its computational efficiency. Finally, on the basis of these numerical calculations, using the multivariate adaptive regression splines (MARS) technique, conclusions of this research work are exposed.

Circulating CD4+CD28null and extra-thymic CD4+CD8+ double positive T cells are independently associated with disease damage in systemic lupus erythematosus patients.

PubMed

Ugarte-Gil, M F; Sánchez-Zúñiga, C; Gamboa-Cárdenas, R V; Aliaga-Zamudio, M; Zevallos, F; Tineo-Pozo, G; Cucho-Venegas, J M; Mosqueira-Riveros, A; Medina, M; Perich-Campos, R A; Alfaro-Lozano, J L; Rodriguez-Bellido, Z; Alarcón, G S; Pastor-Asurza, C A

2016-03-01

To determine whether circulating CD4+CD28null and extra-thymic CD4+CD8+ double positive (DP) T cells are independently associated with damage accrual in systemic lupus erythematosus (SLE) patients. This cross-sectional study was conducted between September 2013 and April 2014 in consecutive SLE patients from our Rheumatology Department. CD4+CD28null and CD4+CD8+ DP T-cell frequencies were analyzed by flow-cytometry. The association of damage (SLICC/ACR Damage Index, SDI) and CD4+CD28null and CD4+CD8+ DP T cells was examined by univariable and multivariable Poisson regression models, adjusting for possible confounders. All analyses were performed using SPSS 21.0. Patients' (n = 133) mean (SD) age at diagnosis was 35.5 (16.8) years, 124 (93.2%) were female; all were mestizo (mixed Caucasian and Amerindian ancestry). Disease duration was 7.4 (6.8) years. The SLE Disease Activity Index was 5.5 (4.2), and the SDI 0.9 (1.2). The percentages of CD4+CD28null and CD4+CD8+ DP T cells were 17.1 (14.4) and 0.4 (1.4), respectively. The percentage of CD4+CD28null and CD4+CD8+ DP T cells were positively associated with a higher SDI in both univariable (rate ratio (RR) 1.02, 95% confidence interval (CI): 1.01-1.03 and 1.17, 95% CI: 1.07-1.27, respectively; p < 0.001 for both) and multivariable analyses RR 1.02, 95% CI: 1.01-1.03, p = 0.001 for CD4+CD28null T cells and 1.28, 95% CI: 1.13-1.44, p < 0.001 for CD4+CD8+ DP T cells). Only the renal domain remained associated with CD4+CD28null in multivariable analyses (RR 1.023 (1.002-1.045); p = 0.034). In SLE patients, CD4+CD28null and CD4+CD8+ DP T cells are independently associated with disease damage. Longitudinal studies are warranted to determine the predictive value of these associations. © The Author(s) 2015.

A refined method for multivariate meta-analysis and meta-regression

PubMed Central

Jackson, Daniel; Riley, Richard D

2014-01-01

Making inferences about the average treatment effect using the random effects model for meta-analysis is problematic in the common situation where there is a small number of studies. This is because estimates of the between-study variance are not precise enough to accurately apply the conventional methods for testing and deriving a confidence interval for the average effect. We have found that a refined method for univariate meta-analysis, which applies a scaling factor to the estimated effects’ standard error, provides more accurate inference. We explain how to extend this method to the multivariate scenario and show that our proposal for refined multivariate meta-analysis and meta-regression can provide more accurate inferences than the more conventional approach. We explain how our proposed approach can be implemented using standard output from multivariate meta-analysis software packages and apply our methodology to two real examples. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:23996351

Multivariate meta-analysis for non-linear and other multi-parameter associations

PubMed Central

Gasparrini, A; Armstrong, B; Kenward, M G

2012-01-01

In this paper, we formalize the application of multivariate meta-analysis and meta-regression to synthesize estimates of multi-parameter associations obtained from different studies. This modelling approach extends the standard two-stage analysis used to combine results across different sub-groups or populations. The most straightforward application is for the meta-analysis of non-linear relationships, described for example by regression coefficients of splines or other functions, but the methodology easily generalizes to any setting where complex associations are described by multiple correlated parameters. The modelling framework of multivariate meta-analysis is implemented in the package mvmeta within the statistical environment R. As an illustrative example, we propose a two-stage analysis for investigating the non-linear exposure–response relationship between temperature and non-accidental mortality using time-series data from multiple cities. Multivariate meta-analysis represents a useful analytical tool for studying complex associations through a two-stage procedure. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22807043

A land use regression model for ambient ultrafine particles in Montreal, Canada: A comparison of linear regression and a machine learning approach.

PubMed

Weichenthal, Scott; Ryswyk, Keith Van; Goldstein, Alon; Bagg, Scott; Shekkarizfard, Maryam; Hatzopoulou, Marianne

2016-04-01

Existing evidence suggests that ambient ultrafine particles (UFPs) (<0.1µm) may contribute to acute cardiorespiratory morbidity. However, few studies have examined the long-term health effects of these pollutants owing in part to a need for exposure surfaces that can be applied in large population-based studies. To address this need, we developed a land use regression model for UFPs in Montreal, Canada using mobile monitoring data collected from 414 road segments during the summer and winter months between 2011 and 2012. Two different approaches were examined for model development including standard multivariable linear regression and a machine learning approach (kernel-based regularized least squares (KRLS)) that learns the functional form of covariate impacts on ambient UFP concentrations from the data. The final models included parameters for population density, ambient temperature and wind speed, land use parameters (park space and open space), length of local roads and rail, and estimated annual average NOx emissions from traffic. The final multivariable linear regression model explained 62% of the spatial variation in ambient UFP concentrations whereas the KRLS model explained 79% of the variance. The KRLS model performed slightly better than the linear regression model when evaluated using an external dataset (R(2)=0.58 vs. 0.55) or a cross-validation procedure (R(2)=0.67 vs. 0.60). In general, our findings suggest that the KRLS approach may offer modest improvements in predictive performance compared to standard multivariable linear regression models used to estimate spatial variations in ambient UFPs. However, differences in predictive performance were not statistically significant when evaluated using the cross-validation procedure. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Access disparities to Magnet hospitals for patients undergoing neurosurgical operations

PubMed Central

Missios, Symeon; Bekelis, Kimon

2017-01-01

Background Centers of excellence focusing on quality improvement have demonstrated superior outcomes for a variety of surgical interventions. We investigated the presence of access disparities to hospitals recognized by the Magnet Recognition Program of the American Nurses Credentialing Center (ANCC) for patients undergoing neurosurgical operations. Methods We performed a cohort study of all neurosurgery patients who were registered in the New York Statewide Planning and Research Cooperative System (SPARCS) database from 2009–2013. We examined the association of African-American race and lack of insurance with Magnet status hospitalization for neurosurgical procedures. A mixed effects propensity adjusted multivariable regression analysis was used to control for confounding. Results During the study period, 190,535 neurosurgical patients met the inclusion criteria. Using a multivariable logistic regression, we demonstrate that African-Americans had lower admission rates to Magnet institutions (OR 0.62; 95% CI, 0.58–0.67). This persisted in a mixed effects logistic regression model (OR 0.77; 95% CI, 0.70–0.83) to adjust for clustering at the patient county level, and a propensity score adjusted logistic regression model (OR 0.75; 95% CI, 0.69–0.82). Additionally, lack of insurance was associated with lower admission rates to Magnet institutions (OR 0.71; 95% CI, 0.68–0.73), in a multivariable logistic regression model. This persisted in a mixed effects logistic regression model (OR 0.72; 95% CI, 0.69–0.74), and a propensity score adjusted logistic regression model (OR 0.72; 95% CI, 0.69–0.75). Conclusions Using a comprehensive all-payer cohort of neurosurgery patients in New York State we identified an association of African-American race and lack of insurance with lower rates of admission to Magnet hospitals. PMID:28684152

Remote sensing and GIS-based landslide hazard analysis and cross-validation using multivariate logistic regression model on three test areas in Malaysia

NASA Astrophysics Data System (ADS)

Pradhan, Biswajeet

2010-05-01

This paper presents the results of the cross-validation of a multivariate logistic regression model using remote sensing data and GIS for landslide hazard analysis on the Penang, Cameron, and Selangor areas in Malaysia. Landslide locations in the study areas were identified by interpreting aerial photographs and satellite images, supported by field surveys. SPOT 5 and Landsat TM satellite imagery were used to map landcover and vegetation index, respectively. Maps of topography, soil type, lineaments and land cover were constructed from the spatial datasets. Ten factors which influence landslide occurrence, i.e., slope, aspect, curvature, distance from drainage, lithology, distance from lineaments, soil type, landcover, rainfall precipitation, and normalized difference vegetation index (ndvi), were extracted from the spatial database and the logistic regression coefficient of each factor was computed. Then the landslide hazard was analysed using the multivariate logistic regression coefficients derived not only from the data for the respective area but also using the logistic regression coefficients calculated from each of the other two areas (nine hazard maps in all) as a cross-validation of the model. For verification of the model, the results of the analyses were then compared with the field-verified landslide locations. Among the three cases of the application of logistic regression coefficient in the same study area, the case of Selangor based on the Selangor logistic regression coefficients showed the highest accuracy (94%), where as Penang based on the Penang coefficients showed the lowest accuracy (86%). Similarly, among the six cases from the cross application of logistic regression coefficient in other two areas, the case of Selangor based on logistic coefficient of Cameron showed highest (90%) prediction accuracy where as the case of Penang based on the Selangor logistic regression coefficients showed the lowest accuracy (79%). Qualitatively, the cross application model yields reasonable results which can be used for preliminary landslide hazard mapping.

Serum dehydroepiandrosterone sulphate, psychosocial factors and musculoskeletal pain in workers.

PubMed

Marinelli, A; Prodi, A; Pesel, G; Ronchese, F; Bovenzi, M; Negro, C; Larese Filon, F

2017-12-30

The serum level of dehydroepiandrosterone sulphate (DHEA-S) has been suggested as a biological marker of stress. To assess the association between serum DHEA-S, psychosocial factors and musculoskeletal (MS) pain in university workers. The study population included voluntary workers at the scientific departments of the University of Trieste (Italy) who underwent periodical health surveillance from January 2011 to June 2012. DHEA-S level was analysed in serum. The assessment tools included the General Health Questionnaire (GHQ) and a modified Nordic musculoskeletal symptoms questionnaire. The relation between DHEA-S, individual characteristics, pain perception and psychological factors was assessed by means of multivariable linear regression analysis. There were 189 study participants. The study population was characterized by high reward and low effort. Pain perception in the neck, shoulder, upper limbs, upper back and lower back was reported by 42, 32, 19, 29 and 43% of people, respectively. In multivariable regression analysis, gender, age and pain perception in the shoulder and upper limbs were significantly related to serum DHEA-S. Effort and overcommitment were related to shoulder and neck pain but not to DHEA-S. The GHQ score was associated with pain perception in different body sites and inversely to DHEA-S but significance was lost in multivariable regression analysis. DHEA-S was associated with age, gender and perception of MS pain, while effort-reward imbalance dimensions and GHQ score failed to reach the statistical significance in multivariable regression analysis. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Independent Prognostic Factors for Acute Organophosphorus Pesticide Poisoning.

PubMed

Tang, Weidong; Ruan, Feng; Chen, Qi; Chen, Suping; Shao, Xuebo; Gao, Jianbo; Zhang, Mao

2016-07-01

Acute organophosphorus pesticide poisoning (AOPP) is becoming a significant problem and a potential cause of human mortality because of the abuse of organophosphate compounds. This study aims to determine the independent prognostic factors of AOPP by using multivariate logistic regression analysis. The clinical data for 71 subjects with AOPP admitted to our hospital were retrospectively analyzed. This information included the Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, admission blood cholinesterase levels, 6-h post-admission blood cholinesterase levels, cholinesterase activity, blood pH, and other factors. Univariate analysis and multivariate logistic regression analyses were conducted to identify all prognostic factors and independent prognostic factors, respectively. A receiver operating characteristic curve was plotted to analyze the testing power of independent prognostic factors. Twelve of 71 subjects died. Admission blood lactate levels, 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, blood pH, and APACHE II scores were identified as prognostic factors for AOPP according to the univariate analysis, whereas only 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, and blood pH were independent prognostic factors identified by multivariate logistic regression analysis. The receiver operating characteristic analysis suggested that post-admission 6-h lactate clearance rates were of moderate diagnostic value. High 6-h post-admission blood lactate levels, low blood pH, and low post-admission 6-h lactate clearance rates were independent prognostic factors identified by multivariate logistic regression analysis. Copyright © 2016 by Daedalus Enterprises.

Quality Reporting of Multivariable Regression Models in Observational Studies: Review of a Representative Sample of Articles Published in Biomedical Journals.

PubMed

Real, Jordi; Forné, Carles; Roso-Llorach, Albert; Martínez-Sánchez, Jose M

2016-05-01

Controlling for confounders is a crucial step in analytical observational studies, and multivariable models are widely used as statistical adjustment techniques. However, the validation of the assumptions of the multivariable regression models (MRMs) should be made clear in scientific reporting. The objective of this study is to review the quality of statistical reporting of the most commonly used MRMs (logistic, linear, and Cox regression) that were applied in analytical observational studies published between 2003 and 2014 by journals indexed in MEDLINE.Review of a representative sample of articles indexed in MEDLINE (n = 428) with observational design and use of MRMs (logistic, linear, and Cox regression). We assessed the quality of reporting about: model assumptions and goodness-of-fit, interactions, sensitivity analysis, crude and adjusted effect estimate, and specification of more than 1 adjusted model.The tests of underlying assumptions or goodness-of-fit of the MRMs used were described in 26.2% (95% CI: 22.0-30.3) of the articles and 18.5% (95% CI: 14.8-22.1) reported the interaction analysis. Reporting of all items assessed was higher in articles published in journals with a higher impact factor.A low percentage of articles indexed in MEDLINE that used multivariable techniques provided information demonstrating rigorous application of the model selected as an adjustment method. Given the importance of these methods to the final results and conclusions of observational studies, greater rigor is required in reporting the use of MRMs in the scientific literature.

Added sugars and periodontal disease in young adults: an analysis of NHANES III data.

PubMed

Lula, Estevam C O; Ribeiro, Cecilia C C; Hugo, Fernando N; Alves, Cláudia M C; Silva, Antônio A M

2014-10-01

Added sugar consumption seems to trigger a hyperinflammatory state and may result in visceral adiposity, dyslipidemia, and insulin resistance. These conditions are risk factors for periodontal disease. However, the role of sugar intake in the cause of periodontal disease has not been adequately studied. We evaluated the association between the frequency of added sugar consumption and periodontal disease in young adults by using NHANES III data. Data from 2437 young adults (aged 18-25 y) who participated in NHANES III (1988-1994) were analyzed. We estimated the frequency of added sugar consumption by using food-frequency questionnaire responses. We considered periodontal disease to be present in teeth with bleeding on probing and a probing depth ≥3 mm at one or more sites. We evaluated this outcome as a discrete variable in Poisson regression models and as a categorical variable in multinomial logistic regression models adjusted for sex, age, race-ethnicity, education, poverty-income ratio, tobacco exposure, previous diagnosis of diabetes, and body mass index. A high consumption of added sugars was associated with a greater prevalence of periodontal disease in middle [prevalence ratio (PR): 1.39; 95% CI: 1.02, 1.89] and upper (PR: 1.42; 95% CI: 1.08, 1.85) tertiles of consumption in the adjusted Poisson regression model. The upper tertile of added sugar intake was associated with periodontal disease in ≥2 teeth (PR: 1.73; 95% CI: 1.19, 2.52) but not with periodontal disease in only one tooth (PR: 0.85; 95% CI: 0.54, 1.34) in the adjusted multinomial logistic regression model. A high frequency of consumption of added sugars is associated with periodontal disease, independent of traditional risk factors, suggesting that this consumption pattern may contribute to the systemic inflammation observed in periodontal disease and associated noncommunicable diseases. © 2014 American Society for Nutrition.

MODELING SNAKE MICROHABITAT FROM RADIOTELEMETRY STUDIES USING POLYTOMOUS LOGISTIC REGRESSION

EPA Science Inventory

Multivariate analysis of snake microhabitat has historically used techniques that were derived under assumptions of normality and common covariance structure (e.g., discriminant function analysis, MANOVA). In this study, polytomous logistic regression (PLR which does not require ...

Methods for analyzing matched designs with double controls: excess risk is easily estimated and misinterpreted when evaluating traffic deaths.

PubMed

Redelmeier, Donald A; Tibshirani, Robert J

2018-06-01

To demonstrate analytic approaches for matched studies where two controls are linked to each case and events are accumulating counts rather than binary outcomes. A secondary intent is to clarify the distinction between total risk and excess risk (unmatched vs. matched perspectives). We review past research testing whether elections can lead to increased traffic risks. The results are reinterpreted by analyzing both the total count of individuals in fatal crashes and the excess count of individuals in fatal crashes, each time accounting for the matched double controls. Overall, 1,546 individuals were in fatal crashes on the 10 election days (average = 155/d), and 2,593 individuals were in fatal crashes on the 20 control days (average = 130/d). Poisson regression of total counts yielded a relative risk of 1.19 (95% confidence interval: 1.12-1.27). Poisson regression of excess counts yielded a relative risk of 3.22 (95% confidence interval: 2.72-3.80). The discrepancy between analyses of total counts and excess counts replicated with alternative statistical models and was visualized in graphical displays. Available approaches provide methods for analyzing count data in matched designs with double controls and help clarify the distinction between increases in total risk and increases in excess risk. Copyright © 2018 Elsevier Inc. All rights reserved.

Epidemiology of occupational injury among cleaners in the healthcare sector.

PubMed

Alamgir, Hasanat; Yu, Shicheng

2008-09-01

The cleaning profession has been associated with multiple ergonomic and chemical hazards which elevate the risk for occupational injury. This study investigated the epidemiology of occupational injury among cleaners in healthcare work settings in the Canadian province of British Columbia. Incidents of occupational injury among cleaners, resulting in lost time from work or medical care, over a period of 1 year in two healthcare regions were extracted from a standardized operational database and with person-years obtained from payroll data. Detailed analysis was conducted using Poisson regression modeling. A total of 145 injuries were identified among cleaners, with an annual incidence rate of 32.1 per 100 person-years. After adjustment for age, gender, subsector, facility, experience and employment status, Poisson regression models demonstrated that a significantly higher relative risk (RR) of all injury, musculoskeletal injury and cuts was associated with cleaning work in acute care facilities, compared with long-term care facilities. Female cleaners were at a higher RR of all injuries and contusions than male cleaners. A lower risk of all injury and allergy and irritation incidents among part-time or casual workers was found. Cleaners with >10 years of experience were at significantly lower risk for all injury, contusion and allergy and irritation incidents. Cleaners were found to be at an elevated risk of all injury categories compared with healthcare workers in general.

WINPEPI updated: computer programs for epidemiologists, and their teaching potential

PubMed Central

2011-01-01

Background The WINPEPI computer programs for epidemiologists are designed for use in practice and research in the health field and as learning or teaching aids. The programs are free, and can be downloaded from the Internet. Numerous additions have been made in recent years. Implementation There are now seven WINPEPI programs: DESCRIBE, for use in descriptive epidemiology; COMPARE2, for use in comparisons of two independent groups or samples; PAIRSetc, for use in comparisons of paired and other matched observations; LOGISTIC, for logistic regression analysis; POISSON, for Poisson regression analysis; WHATIS, a "ready reckoner" utility program; and ETCETERA, for miscellaneous other procedures. The programs now contain 122 modules, each of which provides a number, sometimes a large number, of statistical procedures. The programs are accompanied by a Finder that indicates which modules are appropriate for different purposes. The manuals explain the uses, limitations and applicability of the procedures, and furnish formulae and references. Conclusions WINPEPI is a handy resource for a wide variety of statistical routines used by epidemiologists. Because of its ready availability, portability, ease of use, and versatility, WINPEPI has a considerable potential as a learning and teaching aid, both with respect to practical procedures in the planning and analysis of epidemiological studies, and with respect to important epidemiological concepts. It can also be used as an aid in the teaching of general basic statistics. PMID:21288353

Tuberculosis and the role of war in the modern era.

PubMed

Drobniewski, F A; Verlander, N Q

2000-12-01

Tuberculosis (TB) remains a major global health problem; historically, major wars have increased TB notifications. This study evaluated whether modern conflicts worldwide affected TB notifications between 1975 and 1995. Dates of conflicts were obtained and matched with national TB notification data reported to the World Health Organization. Overall notification rates were calculated pre and post conflict. Poisson regression analysis was applied to all conflicts with sufficient data for detailed trend analysis. Thirty-six conflicts were identified, for which 3-year population and notification data were obtained. Overall crude TB notification rates were 81.9 and 105.1/100,000 pre and post start of conflict in these countries. Sufficient data existed in 16 countries to apply Poisson regression analysis to model 5-year pre and post start of conflict trends. This analysis indicated that the risk of presenting with TB in any country 2.5 years after the outbreak of conflict relative to 2.5 years before the outbreak was 1.016 (95%CI 0.9435-1.095). The modelling suggested that in the modern era war may not significantly damage efforts to control TB in the long term. This might be due to the limited scale of most of these conflicts compared to the large-scale civilian disruption associated with 'world wars'. The management of TB should be considered in planning post-conflict refugee and reconstruction programmes.

Effectiveness of preventive home visits in reducing the risk of falls in old age: a randomized controlled trial

PubMed Central

Luck, Tobias; Motzek, Tom; Luppa, Melanie; Matschinger, Herbert; Fleischer, Steffen; Sesselmann, Yves; Roling, Gudrun; Beutner, Katrin; König, Hans-Helmut; Behrens, Johann; Riedel-Heller, Steffi G

2013-01-01

Background Falls in older people are a major public health issue, but the underlying causes are complex. We sought to evaluate the effectiveness of preventive home visits as a multifactorial, individualized strategy to reduce falls in community-dwelling older people. Methods Data were derived from a prospective randomized controlled trial with follow-up examination after 18 months. Two hundred and thirty participants (≥80 years of age) with functional impairment were randomized to intervention and control groups. The intervention group received up to three preventive home visits including risk assessment, home counseling intervention, and a booster session. The control group received no preventive home visits. Structured interviews at baseline and follow-up provided information concerning falls in both study groups. Random-effects Poisson regression evaluated the effect of preventive home visits on the number of falls controlling for covariates. Results Random-effects Poisson regression showed a significant increase in the number of falls between baseline and follow-up in the control group (incidence rate ratio 1.96) and a significant decrease in the intervention group (incidence rate ratio 0.63) controlling for age, sex, family status, level of care, and impairment in activities of daily living. Conclusion Our results indicate that a preventive home visiting program can be effective in reducing falls in community-dwelling older people. PMID:23788832

Using perinatal morbidity scoring tools as a primary study outcome.

PubMed

Hutcheon, Jennifer A; Bodnar, Lisa M; Platt, Robert W

2017-11-01

Perinatal morbidity scores are tools that score or weight different adverse events according to their relative severity. Perinatal morbidity scores are appealing for maternal-infant health researchers because they provide a way to capture a broad range of adverse events to mother and newborn while recognising that some events are considered more serious than others. However, they have proved difficult to implement as a primary outcome in applied research studies because of challenges in testing if the scores are significantly different between two or more study groups. We outline these challenges and describe a solution, based on Poisson regression, that allows differences in perinatal morbidity scores to be formally evaluated. The approach is illustrated using an existing maternal-neonatal scoring tool, the Adverse Outcome Index, to evaluate the safety of labour and delivery before and after the closure of obstetrical services in small rural communities. Applying the proposed Poisson regression to the case study showed a protective risk ratio for adverse outcome following closures as compared with the original analysis, where no difference was found. This approach opens the door for considerably broader use of perinatal morbidity scoring tools as a primary outcome in applied population and clinical maternal-infant health research studies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Models for forecasting the flowering of Cornicabra olive groves.

PubMed

Rojo, Jesús; Pérez-Badia, Rosa

2015-11-01

This study examined the impact of weather-related variables on flowering phenology in the Cornicabra olive tree and constructed models based on linear and Poisson regression to forecast the onset and length of the pre-flowering and flowering phenophases. Spain is the world's leading olive oil producer, and the Cornicabra variety is the second largest Spanish variety in terms of surface area. However, there has been little phenological research into this variety. Phenological observations were made over a 5-year period (2009-2013) at four sampling sites in the province of Toledo (central Spain). Results showed that the onset of the pre-flowering phase is governed largely by temperature, which displayed a positive correlation with the temperature in the start of dormancy (November) and a negative correlation during the months prior to budburst (January, February and March). A similar relationship was recorded for the onset of flowering. Other weather-related variables, including solar radiation and rainfall, also influenced the succession of olive flowering phenophases. Linear models proved the most suitable for forecasting the onset and length of the pre-flowering period and the onset of flowering. The onset and length of pre-flowering can be predicted up to 1 or 2 months prior to budburst, whilst the onset of flowering can be forecast up to 3 months beforehand. By contrast, a nonlinear model using Poisson regression was best suited to predict the length of the flowering period.

Atmospheric pollutants and hospital admissions due to pneumonia in children

PubMed Central

Negrisoli, Juliana; Nascimento, Luiz Fernando C.

2013-01-01

OBJECTIVE: To analyze the relationship between exposure to air pollutants and hospitalizations due to pneumonia in children of Sorocaba, São Paulo, Brazil. METHODS: Time series ecological study, from 2007 to 2008. Daily data were obtained from the State Environmental Agency for Pollution Control for particulate matter, nitric oxide, nitrogen dioxide, ozone, besides air temperature and relative humidity. The data concerning pneumonia admissions were collected in the public health system of Sorocaba. Correlations between the variables of interest using Pearson cofficient were calculated. Models with lags from zero to five days after exposure to pollutants were performed to analyze the association between the exposure to environmental pollutants and hospital admissions. The analysis used the generalized linear model of Poisson regression, being significant p<0.05. RESULTS: There were 1,825 admissions for pneumonia, with a daily mean of 2.5±2.1. There was a strong correlation between pollutants and hospital admissions, except for ozone. Regarding the Poisson regression analysis with the multi-pollutant model, only nitrogen dioxide was statistically significant in the same day (relative risk - RR=1.016), as well as particulate matter with a lag of four days (RR=1.009) after exposure to pollutants. CONCLUSIONS: There was an acute effect of exposure to nitrogen dioxide and a later effect of exposure to particulate matter on children hospitalizations for pneumonia in Sorocaba. PMID:24473956

Bullying among adolescents in a Brazilian urban center – “Health in Beagá” Study

PubMed Central

da Costa, Michelle Ralil; Xavier, César Coelho; Andrade, Amanda Cristina de Souza; Proietti, Fernando Augusto; Caiaffa, Waleska Teixeira

2015-01-01

OBJECTIVE To analyze the prevalence of bullying and its associated factors in Brazilian adolescents. METHODS Data were used from a population-based household survey conducted by the Urban Health Observatory (OSUBH) utilizing probability sampling in three stages: census tracts, residences, and individuals. The survey included 598 adolescents (14-17 years old) who responded questions on bullying, sociodemographic characteristics, health-risk behaviors, educational well-being, family structure, physical activity, markers of nutritional habits, and subjective well-being (body image, personal satisfaction, and satisfaction with their present and future life). Univariate and multivariate analysis was done using robust Poisson regression. RESULTS The prevalence of bullying was 26.2% (28.0% among males, 24.0% among females). The location of most bullying cases was at or on route to school (70.5%), followed by on the streets (28.5%), at home (9.8%), while practicing sports (7.3%), at parties (4.6%), at work (1.7%), and at other locations (1.6%). Reports of bullying were associated with life dissatisfaction, difficulty relating to parents, involvement in fights with peers and insecurity in the neighborhood. CONCLUSIONS A high prevalence of bullying among participating adolescents was found, and the school serves as the main bullying location, although other sites such as home, parties and workplace were also reported. Characteristics regarding self-perception and adolescent perceptions of their environment were also associated with bullying, thus advancing the knowledge of this type of violence, especially in urban centers of developing countries. PMID:26274869

Trends in presentation, management and survival of patients with de novo metastatic breast cancer in a Southeast Asian setting

PubMed Central

Bhoo-Pathy, Nirmala; Verkooijen, Helena Marieke; Tan, Ern-Yu; Miao, Hui; Taib, Nur Aishah Mohd; Brand, Judith S.; Dent, Rebecca A.; See, Mee-Hoong; Subramaniam, ShriDevi; Chan, Patrick; Lee, Soo-Chin; Hartman, Mikael; Yip, Cheng-Har

2015-01-01

Up to 25% of breast cancer patients in Asia present with de novo metastatic disease. We examined the survival trends of Asian patients with metastatic breast cancer over fifteen years. The impact of changes in patient’s demography, tumor characteristics, tumor burden, and treatment on survival trend were examined. Patients with de novo metastatic breast cancer from three hospitals in Malaysia and Singapore (N = 856) were grouped by year of diagnosis: 1996–2000, 2001–2005 and 2006–2010. Step-wise multivariable Poisson regression was used to estimate the contribution of above-mentioned factors on the survival trend. Proportions of patients presenting with metastatic breast cancer were 10% in 1996–2000, 7% in 2001–2005, and 9% in 2006–2010. Patients in 2006–2010 were significantly older, appeared to have higher disease burden, and received more chemotherapy, endocrine therapy, and surgery of primary tumor. The three-year relative survival in the above periods were 20·6% (95% CI: 13·9%–28·2%), 28·8% (95% CI: 23·4%–34·2%), and 33·6% (95% CI: 28·8%–38·5%), respectively. Adjustment for treatment considerably attenuated the relative excess risk of mortality in recent years, compared to other factors. Substantial improvements in survival were observed in patients with de novo metastatic breast cancer in this study. PMID:26536962

[Individual and contextual determinants of dental caries in Brazilian 12-year-olds in 2010].

PubMed

Freire, Maria do Carmo Matias; Reis, Sandra Cristina Guimarães Bahia; Figueiredo, Nilcema; Peres, Karen Glazer; Moreira, Rafael da Silveira; Antunes, José Leopoldo Ferreira

2013-12-01

To estimate the prevalence and severity of dental caries in Brazilian children and the association with individual and contextual factors. Data were taken from the Brazilian Oral Health Survey (SBBrasil 2010) a sample of 7,247 12-year-olds. The data were collected using clinical examinations and interviews. The dependent variables were the prevalence of dental caries (decayed, missing and filled teeth [DMFT] ≥ 1 and DMFT ≥ 4). Bivariate (Rao Scott test) and multivariate (Poisson regression) analyses were carried out. The individual variables were sociodemographic variables, periodontal health and reporting discomfort while brushing. Contextual factors were the presence of water fluoridation, the percentage of residences connected to the water supply and median income of the municipality. The prevalence of DMFT ≥ 1 was 56.0%. Mean DMFT was 2.04 (95%CI 1.76;2.31) and 22.2% of children had DMFT ≥ 4. Caries experience was significantly more common in children with black, brown or yellow skin; in low-income families; in children with dental calculus or bleeding gums and in those who reported discomfort while brushing. Living in towns with fluoridated tap water, with low coverage of water supply and with low median income were contextual factors associated with the disease. The prevalence of dental caries in Brazilian 12-year-olds was low, according to World Health Organization criteria. There were significant geographical and socioeconomic inequalities in levels of the disease.

Epidemiology of work-related injuries requiring hospitalization among sawmill workers in British Columbia, 1989-1997.

PubMed

Alamgir, Hasanat; Demers, Paul A; Koehoorn, Mieke; Ostry, Aleck; Tompa, Emile

2007-01-01

This study describes hospitalized injuries among workers in British Columbia lumber industry. Between April 1989 and December 1997, from the hospital records of 5,745 male sawmill workers were analyzed for the present study. Work relatedness was determined using either ICD-9 external cause of injury codes, which have a digit-indicating place of occurrence, or a payment field, which can identify workers compensation agency. Poisson regression models were used to analyze differences in hospitalization rates across race, job category, age group, and calendar year. The crude and adjusted rate ratios were calculated along with the 95% confidence intervals (CIs). During the follow-up period, there were 164 work related hospitalization resulting in a rate for work-related hospitalization of 5.38 per 1,000 person years. The higher rates by nature of injury were for dislocation, sprains & strains, open wounds, and fracture of upper limbs. During the study period, the higher rates of injury by causes were machinery related, falls, and struck against. In the multivariate models, there were no statistically significant relationship of injury risk with age and race. In respect to occupation, compared to foremen/supervisor, other sawmills' workers did not have significantly elevated risk of injury. The trend analyses found a significant negative trend (P = 0.004) of injury risk over the whole study period. Knowing the causes and nature of injury and their related risk factors are helpful to employers, compensation officials, and other stakeholders to target preventive measures.

Risks associated with crack cocaine smoking among exotic dancers in Baltimore, MD.

PubMed

Sherman, Susan G; Reuben, Jacqueline; Chapman, Chris Serio; Lilleston, Pamela

2011-04-01

There is a dearth of research focusing on sex work in exotic dance clubs. We conducted a cross-sectional study to examine the prevalence and correlates of crack cocaine smoking among a sample of exotic dancers. The "block," a historical red-light district in downtown Baltimore, MD, is comprised of 30 adult-entertainment establishments. Between 01/09 and 08/09, we conducted a survey with exotic dancers (N=98). The survey explored demographic, and drug and sexual/drug risk behaviors. Bivariate and multivariate analysis was conducted using Poisson regression with robust variance estimates to examine correlates of current crack smoking. Crack cocaine smokers compared to non-crack cocaine smokers were significantly more likely to report: older age (29 vs. 23 years, respectively, p<0.0001); being White (79% vs. 50%, respectively, p=0.008); having been arrested (93% vs. 67%, respectively, p=0.008); daily alcohol consumption (36% vs. 17%, p=0.047); current heroin injection (57% vs. 13%, p<0.001); and current sex exchange (79% vs. 30%, p<0.001). In the presence of other variables, crack cocaine smokers compared to non-crack cocaine smokers were significantly older, more likely to report current heroin injection, and more likely to report current sex exchange. We found high levels of drug use and sexual risk behaviors as well as a number of risks behaviors associated with crack cocaine smoking among this very under-studied population. Targeted interventions are greatly needed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Lung cancer incidence among Norwegian silicon carbide industry workers: associations with particulate exposure factors

PubMed Central

Kjærheim, Kristina; Føreland, Solveig; Eduard, Wijnand; Kjuus, Helge

2012-01-01

Objectives An increased lung cancer risk associated with total dust exposure in the silicon carbide (SiC) industry has previously been reported. The aim of the present study was to examine the relative importance of specific exposure factors by using a comprehensive, historic job exposure matrix based on about 8000 measurements. Methods Cumulative exposure to total and respirable dust, respirable quartz, cristobalite, and SiC particles and SiC fibres was assessed for 1687 long-term workers employed during 1913–2003 in the Norwegian SiC industry. Standardised incidence ratios for lung cancer, with follow-up during 1953–2008, were calculated stratified by cumulative exposure categories. Poisson regression analyses were performed using both categorised and log-transformed cumulative exposure variables. Results The lung cancer incidence was about twofold increased at the highest level of exposure to each of the exposure factors (standardised incidence ratios 1.9–2.3 for all agents). Internal analyses showed associations between exposure level and lung cancer incidence for all investigated factors, but a significant trend only for total dust and cristobalite. In multivariate analyses, cristobalite showed the most consistent associations, followed by SiC fibres. Conclusions The results indicated that crystalline silica in the form of cristobalite was the most important occupational exposure factor responsible for lung cancer excess in the Norwegian SiC industry. SiC fibres seemed to have an additional effect. PMID:22611173

Large contribution of human papillomavirus in vaginal neoplastic lesions: a worldwide study in 597 samples.

PubMed

Alemany, L; Saunier, M; Tinoco, L; Quirós, B; Alvarado-Cabrero, I; Alejo, M; Joura, E A; Maldonado, P; Klaustermeier, J; Salmerón, J; Bergeron, C; Petry, K U; Guimerà, N; Clavero, O; Murillo, R; Clavel, C; Wain, V; Geraets, D T; Jach, R; Cross, P; Carrilho, C; Molina, C; Shin, H R; Mandys, V; Nowakowski, A M; Vidal, A; Lombardi, L; Kitchener, H; Sica, A R; Magaña-León, C; Pawlita, M; Quint, W; Bravo, I G; Muñoz, N; de Sanjosé, S; Bosch, F X

2014-11-01

This work describes the human papillomavirus (HPV) prevalence and the HPV type distribution in a large series of vaginal intraepithelial neoplasia (VAIN) grades 2/3 and vaginal cancer worldwide. We analysed 189 VAIN 2/3 and 408 invasive vaginal cancer cases collected from 31 countries from 1986 to 2011. After histopathological evaluation of sectioned formalin-fixed paraffin-embedded samples, HPV DNA detection and typing was performed using the SPF-10/DNA enzyme immunoassay (DEIA)/LiPA25 system (version 1). A subset of 146 vaginal cancers was tested for p16(INK4a) expression, a cellular surrogate marker for HPV transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance. HPV DNA was detected in 74% (95% confidence interval (CI): 70-78%) of invasive cancers and in 96% (95% CI: 92-98%) of VAIN 2/3. Among cancers, the highest detection rates were observed in warty-basaloid subtype of squamous cell carcinomas, and in younger ages. Concerning the type-specific distribution, HPV16 was the most frequently type detected in both precancerous and cancerous lesions (59%). p16(INK4a) overexpression was found in 87% of HPV DNA positive vaginal cancer cases. HPV was identified in a large proportion of invasive vaginal cancers and in almost all VAIN 2/3. HPV16 was the most common type detected. A large impact in the reduction of the burden of vaginal neoplastic lesions is expected among vaccinated cohorts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cancer incidence among male Swedish veterinarians and other workers of the veterinary industry: a record-linkage study.

PubMed

Travier, Noemie; Gridley, Gloria; Blair, Aaron; Dosemeci, Mustafa; Boffetta, Paolo

2003-08-01

To investigate the risk of cancer among veterinarians in a large record-linkage study from Sweden. We used the nationwide, Swedish Cancer Environment Registry III, which links the Cancer Register data for 1971-1989 to the national population censuses from 1960 and 1970, to compare the incidence of cancer among male veterinarians to that of the remaining part of the active population using multivariable Poisson regression models and standardized incidence ratios. One thousand one hundred and seventy eight men classified as veterinarians or workers in the veterinary industry at either census were identified. Veterinarians in the veterinary industry experienced increased risk of esophageal (relative risk (RR) 3.78, 95% confidence interval (CI) 1.42-10.09), colon (RR: 2.36, 95% CI: 1.42-3.91), pancreatic (RR: 2.10, 95% CI: 0.94-4.68) and brain (RR: 2.51, 95% CI: 1.04-6.03) cancers as well as melanoma of the skin (RR: 2.77, 95% CI: 1.24-6.17). Similar excess risks were observed when veterinarians were compared with individuals of similar socioeconomic status. The increased risks of esophageal, colon, pancreatic and brain cancers as well as melanoma observed among veterinarians did not seem to be explained by the high socio-economic status of this occupational group. Therefore, it is possible that some of these results reflect the carcinogenicity of occupational exposures, including animal viruses, solar or ionizing radiations and anesthetics.

Ergonomic and Socioeconomic Risk Factors for Hospital Workers’ Compensation Injury Claims

PubMed Central

Boyer, Jon; Galizzi, Monica; Cifuentes, Manuel; d’Errico, Angelo; Gore, Rebecca; Punnett, Laura; Slatin, Craig

2018-01-01

Background Hospital workers are a diverse population with high rates of musculoskeletal disorders (MSDs). The risk of MSD leading to workers’ compensation (WC) claims is likely to show a gradient by socioeconomic status (SES) that may be partly explained by working conditions. Methods A single community hospital provided workforce demographics and WC claim records for 2003–2005. An ergonomic job exposure matrix (JEM) was developed for these healthcare jobs from direct observation of physical workload and extraction of physical and psychosocial job requirements from the O*NET online database. Occupational exposures and SES categories were assigned to workers through their O*NET job titles. Univariate and multivariate Poisson regression analyses were performed to estimate the propensity to file an injury claim in relation to individual factors, occupational exposures, and SES. Results The jobs with the highest injury rates were nurses, semi-professionals, and semi-skilled. Increased physical work and psychological demands along with low job tenure were associated with an increase in risk, while risk decreased with psychosocial rewards and supervisor support. Both occupational and individual factors mediated the relationship between SES and rate of injury claims. Conclusions Physical and organizational features of these hospital jobs along with low job tenure predicted WC injury claim risk and explained a substantial proportion of the effects of SES. Further studies that include lifestyle risk factors and control for prior injuries and co-morbidities are warranted to strengthen the current study findings. PMID:19479820

A prospective study of physical fitness, obesity, and the subsequent risk of mental disorders among healthy young adults in army training.

PubMed

Gubata, Marlene E; Urban, Nadia; Cowan, David N; Niebuhr, David W

2013-07-01

Mental health disorders contribute substantially to medical and occupational morbidity. The role of fitness and physical activity in the prevention of mental health disorders is not well established, but epidemiologic data suggest that physical activity can protect against anxiety and depression. The analyses presented in this report, from a prospective cohort study, evaluate the association between fitness (as measured by a 5-minute step test), and being overweight (defined as exceeding weight and body fat allowances) at military entrance, with subsequent onset of mental disorder diagnosis in the first year of service. The association between risk factors and mental disorder diagnosis was analyzed using multivariate Poisson regression with the adjusted incidence rate ratio (aIRR) as the measure of association. Among weight-qualified participants, factors associated with increased incidence of mental disorder included failing the physical fitness test (aIRR: 1.36, p<0.0001), female sex (aIRR: 2.17, p<0.0001), and smoking (aIRR: 1.49, p<0.0001). Among fit participants, being overweight was not significantly associated with mental disorder (aIRR: 1.11, p=0.1540). This test has potential military utility as an adjunct part of the medical examination process. Additional research is needed among civilians to determine if similar associations exist. If so, intervention studies should be conducted to determine if improving physical fitness reduces subsequent psychiatric disorder risk, particularly among young adults entering into stressful situations. Published by Elsevier Inc.

Transitioning to employment with a rheumatic disease: the role of independence, overprotection, and social support.

PubMed

Jetha, Arif; Badley, Elizabeth; Beaton, Dorcas; Fortin, Paul R; Shiff, Natalie J; Rosenberg, Alan M; Tucker, Lori B; Mosher, Dianne P; Gignac, Monique A M

2014-12-01

To examine perceived independence, overprotection, and support, and their association with the employment participation of young adults with rheumatic disease. One hundred and forty-three young adults, ages 18 to 30 years, with systemic lupus erythematosus (54.5%) and juvenile arthritis (45.5%) completed a 30-min online questionnaire of their work and education experiences. Information collected was demographic, health (e.g., pain, fatigue, disease activity), work context (e.g., career satisfaction, helpfulness of job accommodation/benefits, and workplace activity limitations), and psychosocial (e.g., independence, social support, and overprotection). Log-Poisson regression analysis examined factors associated with employment status. Over half of respondents were employed (59%) and 26% were enrolled in school. Respondents reported moderate to high perceptions of independence and social support. However, 27% reported that "quite a bit" to "a great deal" of overprotection characterized their relationships with those closest to them. At the bivariate level, employed participants and those indicating greater perceived independence reported greater social support and less overprotection. Multivariable analysis revealed that being employed was associated with older age, more job accommodations/benefits perceived as being helpful, and greater perceived independence. This is one of the first studies examining the employment of young adults with rheumatic diseases. Findings highlight the importance of psychosocial perceptions such as independence and overprotection, in addition to support related to working. Additional research is needed to better understand the role of those close to young adults with rheumatic diseases in supporting independence and encouraging employment.

Effects of weather and heliophysical conditions on emergency ambulance calls for elevated arterial blood pressure.

PubMed

Vencloviene, Jone; Babarskiene, Ruta M; Dobozinskas, Paulius; Sakalyte, Gintare; Lopatiene, Kristina; Mikelionis, Nerijus

2015-02-27

We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009-2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs), in which the conditions for the emergency calls were made coded I.10-I.15. The Kaunas Weather Station provided daily records of air temperature (T), wind speed (WS), relative humidity, and barometric pressure (BP). We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS>600 km/s) increased the daily number of elevated arterial blood pressure (EABP) by 12% (RR=1.12; 95% confidence interval (CI) 1.04-1.21); and WS≥3.5 knots during days of T<1.5 °C and T≥12.5 °C by 8% (RR=1.08; CI 1.04-1.12). An increase of T by 10 °C and an elevation of BP two days after by 10 hPa were associated with a decrease in RR by 3%. An additional effect of T was detected during days of T≥17.5 °C only in females. Women and patients with grade III arterial hypertension at the time of the ambulance call were more sensitive to weather conditions. These results may help in the understanding of the population's sensitivity to different weather conditions.

Workplace stress and prescription of antidepressant medications: a prospective study on a sample of Italian workers.

PubMed

d'Errico, Angelo; Cardano, Mario; Landriscina, Tania; Marinacci, Chiara; Pasian, Sherri; Petrelli, Alessio; Costa, Giuseppe

2011-04-01

The main aim of this study was to examine prospectively the relationship between antidepressant prescriptions (ADP), as a proxy of depressive symptoms, and work-related stress, measured according to the demand-control model. A cohort of 2,046 union workers who participated in a survey on working conditions and health in 1999-2000 was followed up to 2005, through the Regional Drug Prescription Register, for an ADP. The relative risks associated with demand, control and job strain were estimated using Poisson regression, adjusting for age, sex and other workplace factors (shift work, overtime, loud noise and psychological violence). In final multivariable models, high demand significantly increased the risk of depressive symptoms among blue collars (RR = 1.82), whereas among white collars, it was significantly protective (RR = 0.38). No significant relationship was found for job control or strain in either occupational class. The direct association observed elsewhere among blue collars between depressive symptoms and demand was confirmed, but not for job control or job strain. It cannot be ruled out that the association with demand was at least in part determined by reverse causation, due to exposure over-reporting among subjects with subclinical depressive symptoms at baseline. The protective effect of demand among white collars is not consistent with the literature and may be attributable to the particular characteristics of this sample, which included mainly workers employed in public administrative positions.

Occupational injury among full-time, part-time and casual health care workers.

PubMed

Alamgir, Hasanat; Yu, Shicheng; Chavoshi, Negar; Ngan, Karen

2008-08-01

Previous epidemiological studies have conflicting suggestions on the association of occupational injury risks with employment category across industries. This specific issue has not been examined for direct patient care occupations in the health care sector. To investigate whether work-related injury rates differ by employment category (part time, full time or casual) for registered nurses (RNs) in acute care and care aides (CAs) in long-term facilities. Incidents of occupational injury resulting in compensated time loss from work, over a 1-year period within three health regions in British Columbia (BC), Canada, were extracted from a standardized operational database. Detailed analysis was conducted using Poisson regression modeling. Among 8640 RNs in acute care, 37% worked full time, 24% part time and 25% casual. The overall rates of injuries were 7.4, 5.3 and 5.5 per 100 person-years, respectively. Among the 2967 CAs in long-term care, 30% worked full time, 20% part time and 40% casual. The overall rates of injuries were 25.8, 22.9 and 18.1 per 100 person-years, respectively. In multivariate models, having adjusted for age, gender, facility and health region, full-time RNs had significantly higher risk of sustaining injuries compared to part-time and casual workers. For CAs, full-time workers had significantly higher risk of sustaining injuries compared to casual workers. Full-time direct patient care occupations have greater risk of injury compared to part-time and casual workers within the health care sector.

Screening for Syphilis and Other Sexually Transmitted Infections in Pregnant Women - Guam, 2014.

PubMed

Cha, Susan; Malik, Tasneem; Abara, Winston E; DeSimone, Mia S; Schumann, Bernadette; Mallada, Esther; Klemme, Michael; Aguon, Vince; Santos, Anne Marie; Peterman, Thomas A; Bolan, Gail; Kamb, Mary L

2017-06-23

Prenatal screening and treatment for sexually transmitted infections (STIs) can prevent adverse perinatal outcomes. In Guam, the largest of the three U.S. territories in the Pacific, primary and secondary syphilis rates among women increased 473%, from 1.1 to 6.3 per 100,000 during 2009-2013 (1). In 2013, the first congenital syphilis case after no cases since 2008 was reported (1,2). Little is known about STI screening coverage and factors associated with inadequate screening among pregnant women in Guam. This study evaluated the prevalence of screening for syphilis, human immunodeficiency virus (HIV), chlamydia, and gonorrhea, and examined correlates of inadequate screening among pregnant women in Guam. Data came from the medical records of a randomly selected sample of mothers with live births in 2014 at a large public hospital. Bivariate analyses and multivariable models using Poisson regression were conducted to determine factors associated with inadequate screening for syphilis and other STIs. Although most (93.5%) women received syphilis screening during pregnancy, 26.8% were not screened sufficiently early to prevent adverse pregnancy outcomes. Many women were not screened for HIV infection (31.1%), chlamydia (25.3%), or gonorrhea (25.7%). Prenatal care and insurance were important factors affecting STI screening during pregnancy. Prenatal care providers play an important role in preventing congenital infections. Policies and programs increasing STI and HIV services for pregnant women and improved access to and use of prenatal care are essential for promoting healthy mothers and infants.

[The short-term effects of air pollution on mortality. The results of the EMCAM project in the city of Seville, 1992-1996. Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica y la Mortalidad].

PubMed

Ocaña-Riola, R; Daponte-Codina, A; Gutiérrez-Cuadra, P; Mayoral-Cortes, J M; Gurucelain-Raposo, J L; Maldonado-Pérez, J A; Serrano-Aguilar, J; Garrido-de la Sierra, R

1999-01-01

As part of the EMECAM Project, the objective of this study is that of assessing the impact of air pollution on the daily mortality in Seville throughout the 1992-1996 period. During the 1992-1996 period, readings were taken daily of the amounts of SO2, particles in suspension (PM10) and NO2 present in the air in the city of Seville, in addition to the number of deaths daily due to different causes. For analyzing this data, a multivariable Poisson regression model was used for modeling each one of the causes of death in terms of the air immission readings, controlling other confusion-causing variables. A relationship was found to exist between the rises in the NO2 levels and the daily death rate throughout the months of May to October. For each 10 micrograms/m3 rise, the risk of death or all causes showed a 2% rise, the same rise in the NO2 levels leading to a 3% rise in the risk of death resulting from cardiovascular diseases. A relationship exists between the levels of NO2 air pollution and the daily death rate in Seville. The findings provide scientific knowledge and information which can be of use for preventing the impact of air pollution on human health.

Assessing the Burden of Diabetes Mellitus in Emergency Departments in the United States: The National Hospital Ambulatory Medical Care Survey (NHAMCS)

PubMed Central

Asao, Keiko; Kaminski, James; McEwen, Laura N.; Wu, Xiejian; Lee, Joyce M.; Herman, William H.

2014-01-01

Objective To evaluate the performance of three alternative methods to identify diabetes in patients visiting Emergency Departments (EDs), and to describe the characteristics of patients with diabetes who are not identified when the alternative methods are used. Research Design and Methods We used data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) 2009 and 2010. We assessed the sensitivity and specificity of using providers’ diagnoses and diabetes medications (both excluding and including biguanides) to identify diabetes compared to using the checkbox for diabetes as the gold standard. We examined the characteristics of patients whose diabetes was missed using multivariate Poisson regression models. Results The checkbox identified 5,567 ED visits by adult patients with diabetes. Compared to the checkbox, the sensitivity was 12.5% for providers’ diagnoses alone, 20.5% for providers’ diagnoses and diabetes medications excluding biguanides, and 21.5% for providers’ diagnoses and diabetes medications including biguanides. The specificity of all three of the alternative methods was >99%. Older patients were more likely to have diabetes not identified. Patients with self-payment, those who had glucose measured or received IV fluids in the ED, and those with more diagnosis codes and medications, were more likely to have diabetes identified. Conclusions NHAMCS's providers’ diagnosis codes and medication lists do not identify the majority of patients with diabetes visiting EDs. The newly introduced checkbox is helpful in measuring ED resource utilization by patients with diabetes. PMID:24680472

Psychological Aggression, Physical Aggression, and Injury in Nonpartner Relationships Among Men and Women in Treatment for Substance-Use Disorders*

PubMed Central

Murray, Regan L.; Chermack, Stephen T.; Walton, Maureen A.; Winters, Jamie; Booth, Brenda M.; Blow, Frederic C.

2008-01-01

Objective: This study focused on the prevalence and predictors of psychological aggression, physical aggression, and injury rates in nonintimate partner relationships in a substance-use disorder treatment sample. Method: The sample included 489 (76% men, 24% women) participants who completed screening measures for inclusion in a randomized control trial for an aggression-prevention treatment. Primary outcome measures included rates of past-year psychological aggression, physical aggression, and injury (both from the participant to nonpartners and from nonpartners to the participant). Potential predictors included individual factors (e.g., age, gender), developmental factors (e.g., family history of drug use, childhood physical abuse), and recent factors (e.g., depression, cocaine use). Results: Rates of participant-tononpartner psychological aggression (83%), physical aggression (61%), and injury (47%) were high, as were rates of nonpartner-to-participant aggression. Bivariate analyses revealed significant relationships between the aggression outcomes and most of the individual, developmental, and recent factors. However, multivariate analyses (zero-inflated Poisson regression) revealed that age, treatment status, current symptoms of depression, heavy periods of drinking, and cocaine use were related most frequently to the occurrence of aggression to and from nonpartners. Conclusions: Nonpartner aggression may be as common within a substance-use disorder sample as partner aggression, and it is associated with heavy drinking episodes, cocaine use, and depressive symptoms. The findings highlight the need for the development of effective violence interventions addressing violence in nonpartner relationship types. PMID:18925348

Sexually transmitted infection screening uptake and knowledge of sexually transmitted infection symptoms among female sex workers participating in a community randomised trial in Peru.

PubMed

Kohler, Pamela K; Campos, Pablo E; Garcia, Patricia J; Carcamo, Cesar P; Buendia, Clara; Hughes, James P; Mejia, Carolina; Garnett, Geoff P; Holmes, King K

2016-04-01

This study aims to evaluate condom use, sexually transmitted infection (STI) screening, and knowledge of STI symptoms among female sex workers in Peru associated with sex work venues and a community randomised trial of STI control. One component of the Peru PREVEN intervention conducted mobile-team outreach to female sex workers to reduce STIs and increase condom use and access to government clinics for STI screening and evaluation. Prevalence ratios were calculated using multivariate Poisson regression models with robust standard errors, clustering by city. As-treated analyses were conducted to assess outcomes associated with reported exposure to the intervention. Care-seeking was more frequent in intervention communities, but differences were not statistically significant. Female sex workers reporting exposure to the intervention had a significantly higher likelihood of condom use, STI screening at public health clinics, and symptom recognition compared to those not exposed. Compared with street- or bar-based female sex workers, brothel-based female sex workers reported significantly higher rates of condom use with last client, recent screening exams for STIs, and HIV testing. Brothel-based female sex workers also more often reported knowledge of STIs and recognition of STI symptoms in women and in men. Interventions to promote STI detection and prevention among female sex workers in Peru should consider structural or regulatory factors related to sex work venues. © The Author(s) 2015.

Bullying among adolescents in a Brazilian urban center - "Health in Beagá" Study.

PubMed

da Costa, Michelle Ralil; Xavier, César Coelho; Andrade, Amanda Cristina de Souza; Proietti, Fernando Augusto; Caiaffa, Waleska Teixeira

2015-01-01

To analyze the prevalence of bullying and its associated factors in Brazilian adolescents. Data were used from a population-based household survey conducted by the Urban Health Observatory (OSUBH) utilizing probability sampling in three stages: census tracts, residences, and individuals. The survey included 598 adolescents (14-17 years old) who responded questions on bullying, sociodemographic characteristics, health-risk behaviors, educational well-being, family structure, physical activity, markers of nutritional habits, and subjective well-being (body image, personal satisfaction, and satisfaction with their present and future life). Univariate and multivariate analysis was done using robust Poisson regression. The prevalence of bullying was 26.2% (28.0% among males, 24.0% among females). The location of most bullying cases was at or on route to school (70.5%), followed by on the streets (28.5%), at home (9.8%), while practicing sports (7.3%), at parties (4.6%), at work (1.7%), and at other locations (1.6%). Reports of bullying were associated with life dissatisfaction, difficulty relating to parents, involvement in fights with peers and insecurity in the neighborhood. A high prevalence of bullying among participating adolescents was found, and the school serves as the main bullying location, although other sites such as home, parties and workplace were also reported. Characteristics regarding self-perception and adolescent perceptions of their environment were also associated with bullying, thus advancing the knowledge of this type of violence, especially in urban centers of developing countries.

Maternal education is an independent determinant of cariogenic feeding practices in the first year of life.

PubMed

Feldens, C A; Kramer, P F; Sequeira, M C; Rodrigues, P H; Vitolo, M R

2012-04-01

To identify risk factors for cariogenic feeding practices in the first year of life. Cohort study. 500 children born within the public health care system in São Leopoldo, Brazil, were recruited in a follow-up program. Anthropometric and demographic data were collected soon after birth; data on feeding practices were assessed at 12 months of age using a standardised questionnaire; clinical examination at 4 years of age allowed identification of cariogenic feeding practices in the first year of life and to quantify their relative risks. In the present study, the attributable risks of each child were summed, and the outcome was assessed for the upper quartile of scores for cariogenic feeding practices. Adjusted relative risks for the outcome were estimated using robust Poisson regression models. A total of 327 children comprised the final study sample, i.e. were followed from birth to 4 years of age. Multivariate analysis showed that the risk of cariogenic feeding practices doubled in children from mothers with less than 5 years of education (RR 2.19, 95%CI 1.26-3.82) and was 70% higher in children from mothers with 5-8 years of education when compared with maternal education >8 years. The other independent variables were not associated with the outcome. Low maternal education is a risk factor for cariogenic feeding practices, independently of other factors. Mothers with low educational levels should be the focus of child health promotion interventions, especially those aimed at controlling dental caries.

Quadrivalent Human Papillomavirus Vaccine Uptake in Adolescent Boys and Maternal Utilization of Preventive Care and History of Sexually Transmitted Infections

PubMed Central

Chao, Chun; Sy, Lina S.; Ackerson, Bradley K.; Slezak, Jeff M.; Sidell, Margo A.; Jacobsen, Steven J.

2013-01-01

Objectives. We examined whether maternal utilization of preventive care and history of sexually transmitted infections (STIs) predicted quadrivalent human papillomavirus vaccine (HPV4) uptake among adolescent boys 1 year following the recommendation for permissive use of HPV4 for males. Methods. We linked maternal information with electronic health records of 254 489 boys aged 9 to 17 years who enrolled in Kaiser Permanente Southern California health plan from October 21, 2009, through December 21, 2010. We used multivariable Poisson regression with robust error variance to examine whether HPV4 initiation was associated with maternal uptake of influenza vaccine, Papanicolaou (Pap) screening, and history of STIs. Results. We identified a modest but statistically significant association between initiation of HPV4 series and maternal receipt of influenza vaccine (rate ratio [RR] = 1.16; 95% confidence interval [CI] = 1.07, 1.26) and Pap screening (RR = 1.13; 95% CI = 1.01, 1.26). Boys whose mothers had a history of genital warts were more likely to initiate HPV4 (RR = 1.47; 95% CI = 0.93, 2.34), although the association did not reach statistical significance (P = .1). Conclusions. Maternal utilization of preventive care and history of genital warts may influence HPV4 uptake among adolescent boys. The important role of maternal health characteristics and health behaviors needs be considered in intervention efforts to increase vaccine uptake among boys. PMID:23865707

Identifying neonates at a very high risk for mortality among children with congenital diaphragmatic hernia managed with extracorporeal membrane oxygenation.

PubMed

Haricharan, Ramanath N; Barnhart, Douglas C; Cheng, Hong; Delzell, Elizabeth

2009-01-01

The purpose of this study was to identify mortality risk factors in children with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO) and generate a prediction score for those at a very high risk for mortality. Data on first ECMO runs of all neonates with CDH, between January 1997 and June 2007, were obtained from the Extracorporeal Life Support Organization registry (N = 2678). The data were split into "training data (TD)" (n = 2006) and "validation data" (n = 672). The primary outcome analyzed was in-hospital mortality. Modified Poisson regression was used for analyses. Overall in-hospital mortality among 2678 neonates (males, 57%; median age at ECMO, 1 day) was 52%. The univariate and multivariable analyses were performed using TD. An empirically weighted mortality prediction score was generated with possible scores ranging from 0 to 35 points. Of 69 who scored 14 or higher in the TD, 62 died (positive predictive value [PPV], 90%), of 37 with 15 or higher, 35 died (PPV, 95%), of 23 with 16 or higher, 22 died (PPV, 96%). A cut-off point of 15 was chosen and was tested using the separate validation dataset. In validation data, the cut-off point 15 had a PPV of 96% (23 died of 24). Scoring 15 or higher on the prediction score identifies neonates with CDH at a very high risk for mortality among those managed with ECMO and could be used in surgical decision making and counseling.

ART attrition and risk factors among Option B+ patients in Haiti: A retrospective cohort study.

PubMed

Puttkammer, Nancy; Domerçant, Jean Wysler; Adler, Michelle; Yuhas, Krista; Myrtil, Martine; Young, Paul; François, Kesner; Grand'Pierre, Reynold; Lowrance, David

2017-01-01

In October 2012, the Haitian Ministry of Health endorsed the "Option B+" strategy to eliminate mother-to-child transmission of HIV and achieve HIV epidemic control. The objective of this paper is to assess and identify risk factors for attrition from the national ART program among Option B+ patients in the 12 months after ART initiation. This retrospective cohort study included patients newly initiating ART from October 2012-August 2013 at 68 ART sites covering 45% of all newly enrolled ART patients in all regions of Haiti. With data from electronic medical records, we carried out descriptive analysis of sociodemographic, clinical, and pregnancy-related correlates of ART attrition, and used a modified Poisson regression approach to estimate relative risks in a multivariable model. There were 2,166 Option B+ patients who initiated ART, of whom 1,023 were not retained by 12 months (47.2%). One quarter (25.3%) dropped out within 3 months of ART initiation. Protective factors included older age, more advanced HIV disease progression, and any adherence counseling prior to ART initiation, while risk factors included starting ART late in gestation, starting ART within 7 days of HIV testing, and using an atypical ART regimen. Our study demonstrates early ART attrition among Option B+ patients and contributes evidence on the characteristics of women who are most at risk of attrition in Haiti. Our findings highlight the importance of targeted strategies to support retention among Option B+ patients.

Body Image of Women Submitted to Breast Cancer Treatment

PubMed

Guedes, Thais Sousa Rodrigues; Dantas de Oliveira, Nayara Priscila; Holanda, Ayrton Martins; Reis, Mariane Albuquerque; Silva, Clécia Patrocínio da; Rocha e Silva, Bárbara Layse; Cancela, Marianna de Camargo; de Souza, Dyego Leandro Bezerra

2018-06-25

Background: The study of body image includes the perception of women regarding the physical appearance of their own body. The objective of the present study was to verify the prevalence of body image dissatisfaction and its associated factors in women submitted to breast cancer treatment. Methods: A cross-sectional study carried out with 103 female residents of the municipality of Natal (Northeast Brazil), diagnosed with breast cancer who had undergone cancer treatment for at least 12 months prior to the study, and remained under clinical monitoring. The variable body image was measured through the validated Body Image Scale (BIS). Socioeconomic variables and clinical history were also collected through an individual interview with each participant. The Pearson’s chi-squared test (Fisher’s Exact) was utilized for bivariate analysis, calculating the prevalence ratio with 95% confidence interval. Poisson regression with robust variance was utilized for multivariate analysis. The statistical significance considered was 0.05. Results: The prevalence of body image dissatisfaction was 74.8% CI (65%-82%). Statistically significant associations were observed between body image and multi-professional follow-up (p=0.009) and return to employment after treatment (p=0.022). Conclusion: It was concluded that women who reported employment after cancer treatment presented more alterations in self-perception concerning their appearance. Patients who did not receive multi-professional follow-up reported negative body image, evidencing the need for strategies that increase and improve healthcare, aiming to meet the demands of this population. Creative Commons Attribution License

Incident syphilis infection among people who inject drugs in Tijuana, Mexico

PubMed Central

Pines, Heather A.; Rusch, Melanie L.; Vera, Alicia; Rangel, Gudelia; Magis-Rodriguez, Carlos; Strathdee, Steffanie A.

2017-01-01

Given that syphilis is associated with HIV infection among people who inject drugs (PWID), we examined syphilis incidence among PWID in Tijuana, Mexico. From 2006–2007, 940 PWID (142 females and 798 males) were recruited via respondent driven sampling and followed for 18 months. At semi-annual visits, participants were tested for syphilis and completed surveys, which collected information on socio-demographics, sexual behaviors, substance use, and injection behaviors. Poisson regression was used to estimate syphilis incidence rates (IRs), incidence rate ratios (IRRs), and 95% confidence intervals (CIs). Twenty-one participants acquired syphilis during follow-up (IR=1.57 per 100 person-years, 95% CI: 1.02–2.41). In a multivariate analysis, syphilis incidence was higher among females (IRR=3.90, 95% CI: 1.37–11.09), HIV-positive participants (IRR=4.60, 95% CI: 1.58–13.39), and those who reported ever exchanging sex for drugs, money, or other goods (IRR=2.74, 95% CI: 0.97–7.76), while syphilis incidence was lower among those living in Tijuana for a longer duration (IRR=0.95 per year, 95% CI: 0.91–1.00) and those reporting ≥daily injection drug use (past 6 months) (IRR=0.22, 95% CI: 0.09–0.54). Our findings suggest interventions that address the destabilizing conditions associated with migration and integrate sexual and drug-related risk reduction strategies may help reduce syphilis incidence among PWID along the Mexico-US border. PMID:25614523

Malocclusion and oral health-related quality of life in Brazilian school children.

PubMed

Sardenberg, Fernanda; Martins, Milene T; Bendo, Cristiane B; Pordeus, Isabela A; Paiva, Saul M; Auad, Sheyla M; Vale, Miriam P

2013-01-01

To test the hypothesis that malocclusion and its impact on quality of life has no effect on 8- to 10-year-old Brazilian schoolchildren as measured by an oral health-related quality of life (OHRQoL) instrument. A cross-sectional study was carried out with a population-based sample of 1204 8- to 10-year-old children attending elementary schools in Belo Horizonte, Brazil. Dental examinations were carried out by two calibrated examiners. OHRQoL was assessed using the Brazilian version of the Child Perceptions Questionnaire. The Dental Aesthetic Index was used for the clinical assessment of malocclusion. Dental caries and socioeconomic factors were used as controlling variables. Bivariate analysis involved the chi-square test and the Fisher exact test. A Poisson regression model was employed for the multivariate analysis (P < .05). Anterior segment spacing and anterior mandibular overjet were significantly associated with impact on OHRQoL (P < .05). Schoolchildren with malocclusion were 1.30-fold (95% CI: 1.15-1.46; P < 0.001) more likely to experience a negative impact on OHRQoL than those without malocclusion. Children belonging to families with an income less than or equal to two times the minimum wage were 1.59-fold (95% CI: 1.35-1.88; P < 0.001) more likely to experience a negative impact on OHRQoL than those belonging to families with the highest income. Schoolchildren with malocclusion from lower-income families experience a greater negative impact on OHRQoL.

Personality disorder risk factors for suicide attempts over 10 years of follow-up.

PubMed

Ansell, Emily B; Wright, Aidan G C; Markowitz, John C; Sanislow, Charles A; Hopwood, Christopher J; Zanarini, Mary C; Yen, Shirley; Pinto, Anthony; McGlashan, Thomas H; Grilo, Carlos M

2015-04-01

Identifying personality disorder (PD) risk factors for suicide attempts is an important consideration for research and clinical care alike. However, most prior research has focused on single PDs or categorical PD diagnoses without considering unique influences of different PDs or of severity (sum) of PD criteria on the risk for suicide-related outcomes. This has usually been done with cross-sectional or retrospective assessment methods. Rarely are dimensional models of PDs examined in longitudinal, naturalistic prospective designs. In addition, it is important to consider divergent risk factors in predicting the risk of ever making a suicide attempt versus the risk of making an increasing number of attempts within the same model. This study examined 431 participants who were followed for 10 years in the Collaborative Longitudinal Personality Disorders Study. Baseline assessments of personality disorder criteria were summed as dimensional counts of personality pathology and examined as predictors of suicide attempts reported at annual interviews throughout the 10-year follow-up period. We used univariate and multivariate zero-inflated Poisson regression models to simultaneously evaluate PD risk factors for ever attempting suicide and for increasing numbers of attempts among attempters. Consistent with prior research, borderline PD was uniquely associated with ever attempting. However, only narcissistic PD was uniquely associated with an increasing number of attempts. These findings highlight the relevance of both borderline and narcissistic personality pathology as unique contributors to suicide-related outcomes. (c) 2015 APA, all rights reserved).

Factors associated with caries: a survey of students from southern Brazil

PubMed Central

Borges, Tássia Silvana; Schwanke, Natalí Lippert; Reuter, Cézane Priscila; Neto, Léo Kraether; Burgos, Miria Suzana

2016-01-01

Abstract Objective: To describe the factors associated with dental caries among students from Santa Cruz do Sul, Rio Grande do Sul, Brazil. Methods: A cross-sectional study was conducted in a random sample of 623 students of both genders, aged 10-17 years old. Tooth decay was performed using the index of the World Health Organization (1997), DMFT (permanent dentition) that expresses the sum of decayed, missing and filled teeth per person. The maternal educational level was rated using criteria of the Brazilian Association of Market Research Companies. The remaining variables were obtained by a structured questionnaire. Poisson regression analysis was used to test the association between variables using robust models and a subsequently adjusted model. Data were expressed as prevalence ratio (PR). Results: Multivariate analysis identified the following factors related to the experience of dental caries: residence in rural municipalities (PR: 1.15; 95%CI: 1.0-1.3), attending a city school (PR: 3.30; 95%CI: 1.1-9.4) or a state school (PR: 3.40; 95%CI: 1.1-9.6); and having an illiterate mother or a mother that only attended up to the 4th year of school (PR: 1.67; 95%CI: 1.1-2.4) or high school (PR: 1.54; 95%CI: 1.1-2.2). Conclusions: The presence of caries in students in southern Brazil was associated with residence in rural areas, mother with little education and attendance to a public school. PMID:27477791

Salting-out assisted liquid-liquid extraction and partial least squares regression to assay low molecular weight polycyclic aromatic hydrocarbons leached from soils and sediments

NASA Astrophysics Data System (ADS)

Bressan, Lucas P.; do Nascimento, Paulo Cícero; Schmidt, Marcella E. P.; Faccin, Henrique; de Machado, Leandro Carvalho; Bohrer, Denise

2017-02-01

A novel method was developed to determine low molecular weight polycyclic aromatic hydrocarbons in aqueous leachates from soils and sediments using a salting-out assisted liquid-liquid extraction, synchronous fluorescence spectrometry and a multivariate calibration technique. Several experimental parameters were controlled and the optimum conditions were: sodium carbonate as the salting-out agent at concentration of 2 mol L- 1, 3 mL of acetonitrile as extraction solvent, 6 mL of aqueous leachate, vortexing for 5 min and centrifuging at 4000 rpm for 5 min. The partial least squares calibration was optimized to the lowest values of root mean squared error and five latent variables were chosen for each of the targeted compounds. The regression coefficients for the true versus predicted concentrations were higher than 0.99. Figures of merit for the multivariate method were calculated, namely sensitivity, multivariate detection limit and multivariate quantification limit. The selectivity was also evaluated and other polycyclic aromatic hydrocarbons did not interfere in the analysis. Likewise, high performance liquid chromatography was used as a comparative methodology, and the regression analysis between the methods showed no statistical difference (t-test). The proposed methodology was applied to soils and sediments of a Brazilian river and the recoveries ranged from 74.3% to 105.8%. Overall, the proposed methodology was suitable for the targeted compounds, showing that the extraction method can be applied to spectrofluorometric analysis and that the multivariate calibration is also suitable for these compounds in leachates from real samples.

Proposing an Empirically Justified Reference Threshold for Blood Culture Sampling Rates in Intensive Care Units

PubMed Central

Castell, Stefanie; Schwab, Frank; Geffers, Christine; Bongartz, Hannah; Brunkhorst, Frank M.; Gastmeier, Petra; Mikolajczyk, Rafael T.

2014-01-01

Early and appropriate blood culture sampling is recommended as a standard of care for patients with suspected bloodstream infections (BSI) but is rarely taken into account when quality indicators for BSI are evaluated. To date, sampling of about 100 to 200 blood culture sets per 1,000 patient-days is recommended as the target range for blood culture rates. However, the empirical basis of this recommendation is not clear. The aim of the current study was to analyze the association between blood culture rates and observed BSI rates and to derive a reference threshold for blood culture rates in intensive care units (ICUs). This study is based on data from 223 ICUs taking part in the German hospital infection surveillance system. We applied locally weighted regression and segmented Poisson regression to assess the association between blood culture rates and BSI rates. Below 80 to 90 blood culture sets per 1,000 patient-days, observed BSI rates increased with increasing blood culture rates, while there was no further increase above this threshold. Segmented Poisson regression located the threshold at 87 (95% confidence interval, 54 to 120) blood culture sets per 1,000 patient-days. Only one-third of the investigated ICUs displayed blood culture rates above this threshold. We provided empirical justification for a blood culture target threshold in ICUs. In the majority of the studied ICUs, blood culture sampling rates were below this threshold. This suggests that a substantial fraction of BSI cases might remain undetected; reporting observed BSI rates as a quality indicator without sufficiently high blood culture rates might be misleading. PMID:25520442

Predicting volumes in four Hawaii hardwoods...first multivariate equations developed

Treesearch

David A. Sharpnack

1966-01-01

Multivariate regression equations were developed for predicting board-foot (Int. 1/ 4-inch log rule ) and cubic-foot volumes in each 8.15-foot section of trees of four Hawaii hardwood species. The species are koa (Acacia koa), ohia (Metrosideros polymorpha), robusta eucalyptus (Eucalyptus robusta), and...

A Multivariate Test of the Bott Hypothesis in an Urban Irish Setting

ERIC Educational Resources Information Center

Gordon, Michael; Downing, Helen

1978-01-01

Using a sample of 686 married Irish women in Cork City the Bott hypothesis was tested, and the results of a multivariate regression analysis revealed that neither network connectedness nor the strength of the respondent's emotional ties to the network had any explanatory power. (Author)

Structural factors associated with an increased risk of HIV and sexually transmitted infection transmission among street-involved youth

PubMed Central

Marshall, Brandon DL; Kerr, Thomas; Shoveller, Jean A; Montaner, Julio SG; Wood, Evan

2009-01-01

Background The prevalence of HIV and sexually transmitted infections (STIs) among street-involved youth greatly exceed that of the general adolescent population; however, little is known regarding the structural factors that influence disease transmission risk among this population. Methods Between September 2005 and October 2006, 529 street-involved youth were enroled in a prospective cohort known as the At Risk Youth Study (ARYS). We examined structural factors associated with number of sex partners using quasi-Poisson regression and consistent condom use using logistic regression. Results At baseline, 415 (78.4%) were sexually active, of whom 253 (61.0%) reported multiple sex partners and 288 (69.4%) reported inconsistent condom use in the past six months. In multivariate analysis, self-reported barriers to health services were inversely associated with consistent condom use (adjusted odds ratio [aOR] = 0.52, 95%CI: 0.25 – 1.07). Structural factors that were associated with greater numbers of sex partners included homelessness (adjusted incidence rate ratio [aIRR] = 1.54, 95%CI: 1.11 – 2.14) and having an area restriction that affects access to services (aIRR = 2.32, 95%CI: 1.28 – 4.18). Being searched or detained by the police was significant for males (aIRR = 1.36, 95%CI: 1.02 – 1.81). Conclusion Although limited by its cross-sectional design, our study found several structural factors amenable to policy-level interventions independently associated with sexual risk behaviours. These findings imply that the criminalization and displacement of street-involved youth may increase the likelihood that youth will engage in sexual risk behaviours and exacerbate the negative impact of resultant health outcomes. Moreover, our findings indicate that environmental-structural interventions may help to reduce the burden of these diseases among street youth in urban settings. PMID:19134203

Vitamin D Status and Quality of Life in Healthy Male High-Tech Employees.

PubMed

Tepper, Sigal; Dabush, Yael; Shahar, Danit R; Endevelt, Ronit; Geva, Diklah; Ish-Shalom, Sofia

2016-06-15

While low vitamin D status has been shown to be associated with decreased quality of life in unhealthy populations and women, only limited data are available regarding healthy adult men. Our aim was to evaluate the associations between health-related quality of life (QoL) and vitamin D status in adult men. High-tech employees aged 25-65 year were recruited from an occupational periodic examination clinic at Rambam Health Campus. QoL was assessed using the Centers for Disease Control and Prevention (CDC) Health-related quality of life questionnaire (HRQOL-4). Serum 25-hydroxyvitamin D (25(OH)D) and Body Mass Index (BMI) were measured; further information was collected about physical activity, education, sun exposure, sick-days, and musculoskeletal pain severity (visual analog scale). Three hundred and fifty-eight men were enrolled in the study; mean serum 25(OH)D level was 22.1 ± 7.9 ng/mL (range 4.6-54.5 ng/mL). In a multivariate logistic regression model, 25(OH)D was a significant independent determinant of self-rated health; Odds Ratio (OR) for self-rated health was 0.91 (95% confidence interval (CI) 0.85-0.97, p = 0.004), adjusted for age, BMI, pain severity, physical activity, and sun exposure. Every 1 ng/mL increase of 25(OH)D was associated with 9% reduction in the odds of reporting self-rated health as fair or poor. Poisson regression model demonstrated an association between physically unhealthy days and 25(OH)D levels (rate ratio 0.95, p < 0.001). In conclusion, serum levels of 25(OH)D were associated with self-rated health and with physically unhealthy days of HRQOL in healthy high-tech male workers. Future intervention studies are required to test the impact of vitamin D supplementation on QoL.

Household Implementation of Smoke-Free Rules in Homes and Cars: A Focus on Adolescent Smoking Behavior and Secondhand Smoke Exposure.

PubMed

Parks, Michael J; Kingsbury, John H; Boyle, Raymond G; Evered, Sharrilyn

2018-01-01

This study addresses the dearth of population-based research on how comprehensive household smoke-free rules (ie, in the home and car) relate to tobacco use and secondhand smoke (SHS) exposure among adolescents. Analysis of 2014 Minnesota Youth Tobacco Survey. Representative sample of Minnesota youth. A total of 1287 youth who lived with a smoker. Measures included household smoke-free rules (no rules, partial rules-home or car, but not both-and comprehensive rules), lifetime and 30-day cigarette use, 30-day cigarette and other product use, and SHS exposure in past 7 days in home and car. Weighted multivariate logistic, zero-inflated Poisson, and zero-inflated negative binomial regressions were used. Compared to comprehensive rules, partial and no smoke-free rules were significantly and positively related to lifetime cigarette use (respectively, adjusted odds ratio [AOR] = 1.80, 95% confidence interval [CI] = 1.24-2.61; AOR = 2.87, 95% CI = 1.93-4.25), and a similar significant pattern was found for 30-day cigarette use (respectively, AOR = 2.20, 95% CI = 1.21-4.02; AOR = 2.45, 95% CI = 1.34-4.50). No smoke-free rules significantly predicted using cigarettes and other tobacco products compared to comprehensive rules. In both descriptive and regression analyses, we found SHS exposure rates in both the home and car were significantly lower among youth whose household implemented comprehensive smoke-free rules. Comprehensive smoke-free rules protect youth from the harms of caregiver tobacco use. Relative to both partial and no smoke-free rules, comprehensive smoke-free rules have a marked impact on tobacco use and SHS exposure among youth who live with a smoker. Health promotion efforts should promote comprehensive smoke-free rules among all households and particularly households with children and adolescents.

Microbiota-Dependent Metabolite Trimethylamine N-Oxide and Coronary Artery Calcium in the Coronary Artery Risk Development in Young Adults Study (CARDIA).

PubMed

Meyer, Katie A; Benton, Thomas Z; Bennett, Brian J; Jacobs, David R; Lloyd-Jones, Donald M; Gross, Myron D; Carr, J Jeffrey; Gordon-Larsen, Penny; Zeisel, Steven H

2016-10-21

Clinical studies implicate trimethylamine N-oxide (TMAO; a gut microbiota-dependent nutrient metabolite) in cardiovascular disease risk. There is a lack of population-based data on the role of TMAO in advancing early atherosclerotic disease. We tested the prospective associations between TMAO and coronary artery calcium (CAC) and carotid intima-media thickness (cIMT). Data were from the Coronary Artery Risk Development in Young Adults Study (CARDIA), a biracial cohort of US adults recruited in 1985-1986 (n=5115). We randomly sampled 817 participants (aged 33-55 years) who attended examinations in 2000-2001, 2005-2006, and 2010-2011, at which CAC was measured by computed tomography and cIMT (2005-2006) by ultrasound. TMAO was quantified using liquid chromotography mass spectrometry on plasma collected in 2000-2001. Outcomes were incident CAC, defined as Agatston units=0 in 2000-2001 and >0 over 10-year follow-up, CAC progression (any increase over 10-year follow-up), and continuous cIMT. Over the study period, 25% (n=184) of those free of CAC in 2000-2001 (n=746) developed detectable CAC. In 2000-2001, median (interquartile range) TMAO was 2.6 (1.8-4.2) μmol/L. In multivariable-adjusted models, TMAO was not associated with 10-year CAC incidence (rate ratio=1.03; 95% CI: 0.71-1.52) or CAC progression (0.97; 0.68-1.38) in Poisson regression, or cIMT (beta coefficient: -0.009; -0.03 to 0.01) in linear regression, comparing the fourth to the first quartiles of TMAO. In this population-based study, TMAO was not associated with measures of atherosclerosis: CAC incidence, CAC progression, or cIMT. These data indicate that TMAO may not contribute significantly to advancing early atherosclerotic disease risk among healthy early-middle-aged adults. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Serum 25-hydroxyvitamin D is associated with cognitive executive function in Dutch prefrail and frail elderly: a cross-sectional study exploring the associations of 25-hydroxyvitamin D with glucose metabolism, cognitive performance and depression.

PubMed

Brouwer-Brolsma, Elske M; van de Rest, Ondine; Tieland, Michael; van der Zwaluw, Nikita L; Steegenga, Wilma T; Adam, Jos J; van Loon, Luc J C; Feskens, Edith J M; de Groot, Lisette C P G M

2013-11-01

The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH]D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels. Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria. Associations of 25(OH)D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression. No associations were observed for 25(OH)D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH)D was positively associated with executive functioning (β 0.007, P = .01) and tended to be associated with information-processing speed (β 0.006, P = .06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression. This cross-sectional study suggests an association of serum 25(OH)D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated. Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

Diabetes disease management in a community-based setting.

PubMed

Berg, Gregory D; Wadhwa, Sandeep

2002-06-01

The medical cost of diabetes in the United States in 1997 was at least $98 billion. This study illustrates the behavioral change and medical-care utilization impact that occurs in a community-based setting of a diabetes disease-management program that is applied to program participants in a health insurance plan's health maintenance organization and preferred provider organization. A historical control comparison of diabetes-management participants. One hundred twenty-seven identified diabetes patients are followed from baseline through 1 year. Differences in behavior are compared at program intake and at a 6-month reassessment. Differences in medical-service utilization are compared in the baseline year and the year subsequent to program enrollment. Poisson multivariate-regression models are estimated for counts of inpatient, emergency department, physician evaluation and management, and facility visits, while also controlling for potential confounders. Behaviors improved between program intake and the 6-month reassessment. From patient reports, the number of participants having a hemoglobin A1c test increased by 44.9 percent (p < .001), and there was a 53.2-percent decrease in symptoms of hyperglycemia (p = .002). From medical claims after program enrollment, a drop occurred during the program year in every dimension of medical-service utilization. Regression results show that in-patient admissions decreased by 391 (p < .001) per 1,000 for each group, while controlling for age, length of membership, and the number of comorbid claims for congestive heart failure. In the analysis of costs that were pre- and post-enrollment, which included disease-management program costs, a 4.34:1 return on investment was calculated. The diabetes program provides patients with comprehensive information and counseling relative to practicing self-management of diabetes through a number of integrated program components. This study strongly suggests that the implementation of such a program is associated with positive behavioral change and, thus, with substantial reduction in medical-service utilization. In addition, the intervention resulted in a net decrease in direct medical costs.

Chronic disease mortality associated with infectious agents: A comparative cohort study of migrants from the Former Soviet Union in Israel and Germany

PubMed Central

Ott, Jördis J; Paltiel, Ari M; Winkler, Volker; Becher, Heiko

2008-01-01

Background Prevalence of infectious diseases in migrant populations has been addressed in numerous studies. However, information is sparse on their mortality due to chronic diseases that are aetiologically associated with an infectious agent. This study investigates mortality related to infectious diseases with a specific focus on cancers of possibly infectious origin in voluntary migrants from the Former Soviet Union residing in Israel and in Germany. Methods Both groups of migrants arrived from the Former Soviet Union in their destination countries between 1990 and 2001. Population-based data on migrants in Israel were obtained from the Israel Central Bureau of Statistics. Data for migrants in Germany were obtained from a representative sample of all migrants from the Former Soviet Union in Germany. Cause of death information was available until 2003 for the Israeli cohort and until 2005 for the German cohort. Standardized mortality ratios were calculated relative to the destination country for selected causes of death for which infectious agents may be causally involved. Multivariate Poisson regression was applied to assess differences in mortality by length of residence in the host country. Results Both in Israel and in Germany these migrants have lower overall mortality than the population in their destination countries. However, they have significantly elevated mortality from viral hepatitis and from stomach and liver cancer when compared to the destination populations. Regression analysis shows that in Israel stomach cancer mortality is significantly higher among migrants at shorter durations of residence when compared to durations of more than nine years. Conclusion Higher mortality from cancers associated with infection and from viral hepatitis among migrants from the Former Soviet Union might result from higher prevalence of infections which were acquired in earlier years of life. The results highlight new challenges posed by diseases of infectious origin in migrants and call attention to the link between communicable and non-communicable diseases. PMID:18400085

State Laws Are Associated with School Lunch Duration and Promotion Practices.

PubMed

Turner, Lindsey; Leider, Julien; Piekarz-Porter, Elizabeth; Schwartz, Marlene B; Merlo, Caitlin; Brener, Nancy; Chriqui, Jamie F

2018-03-01

The changes in school meal programs stemming from the Healthy, Hunger-Free Kids Act of 2010 have expanded interest in strategies that increase student participation in school lunch and reduce plate waste. However, it remains unclear what factors are associated with schools' use of such strategies. This study examines whether state laws are associated with two types of school meal-related practices: (a) using promotional strategies (ie, taste tests, using posters or announcements) and (b) duration of lunch periods. This cross-sectional study utilized the nationally representative 2014 School Health Policies and Practices Study, combined with corresponding state laws gathered by the National Wellness Policy Study. School data were available from 414 public schools in 43 states. Outcome measures included 16 strategies to promote school meals and the amount of time students had to eat lunch after being seated. Multivariate logistic regression and Poisson regression were used to examine associations between state laws and school practices, after accounting for school demographic characteristics. Compared to schools in states with no law about engaging stakeholders in meal programs, schools in states with a law were more likely to conduct taste tests (64% vs 44%, P=0.016), collect suggestions from students (67% vs 50%, P=0.017), and invite family members to a school meal (71% vs 53%, P=0.015). Schools used more promotion strategies in states with a law than in states without a law (mean=10.4 vs 8.8, P=0.003). Schools were more likely to provide students at least 30 minutes to eat lunch after being seated in states with laws that addressed a minimum amount of time for lunch duration (43% vs 27%, P=0.042). State-level policy provisions are associated with school practices. Policy development in more states may support school practices that promote lunch participation and consumption. Copyright © 2018 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Using assemblage data in ecological indicators: A comparison and evaluation of commonly available statistical tools

USGS Publications Warehouse

Smith, Joseph M.; Mather, Martha E.

2012-01-01

Ecological indicators are science-based tools used to assess how human activities have impacted environmental resources. For monitoring and environmental assessment, existing species assemblage data can be used to make these comparisons through time or across sites. An impediment to using assemblage data, however, is that these data are complex and need to be simplified in an ecologically meaningful way. Because multivariate statistics are mathematical relationships, statistical groupings may not make ecological sense and will not have utility as indicators. Our goal was to define a process to select defensible and ecologically interpretable statistical simplifications of assemblage data in which researchers and managers can have confidence. For this, we chose a suite of statistical methods, compared the groupings that resulted from these analyses, identified convergence among groupings, then we interpreted the groupings using species and ecological guilds. When we tested this approach using a statewide stream fish dataset, not all statistical methods worked equally well. For our dataset, logistic regression (Log), detrended correspondence analysis (DCA), cluster analysis (CL), and non-metric multidimensional scaling (NMDS) provided consistent, simplified output. Specifically, the Log, DCA, CL-1, and NMDS-1 groupings were ≥60% similar to each other, overlapped with the fluvial-specialist ecological guild, and contained a common subset of species. Groupings based on number of species (e.g., Log, DCA, CL and NMDS) outperformed groupings based on abundance [e.g., principal components analysis (PCA) and Poisson regression]. Although the specific methods that worked on our test dataset have generality, here we are advocating a process (e.g., identifying convergent groupings with redundant species composition that are ecologically interpretable) rather than the automatic use of any single statistical tool. We summarize this process in step-by-step guidance for the future use of these commonly available ecological and statistical methods in preparing assemblage data for use in ecological indicators.

Severe Psychological Distress of Evacuees in Evacuation Zone Caused by the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Management Survey.

PubMed

Kunii, Yasuto; Suzuki, Yuriko; Shiga, Tetsuya; Yabe, Hirooki; Yasumura, Seiji; Maeda, Masaharu; Niwa, Shin-Ichi; Otsuru, Akira; Mashiko, Hirobumi; Abe, Masafumi

2016-01-01

Following the Great East Japan Earthquake on March 11, 2011, the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant has continued to affect the mental health status of residents in the evacuation zone. To examine the mental health status of evacuee after the nuclear accident, we conducted the Mental Health and Lifestyle Survey as part of the ongoing Fukushima Health Management Survey. We measured mental health status using the Kessler 6-item psychological distress scale (K6) in a total of 73,569 (response rate: 40.7%) evacuees aged 15 and over who lived in the evacuation zone in Fukushima Prefecture. We then dichotomized responders using a 12/13 cutoff on the K6, and compared the proportion of K6 scores ≥13 and ≤12 in each risk factor including demographic information, socioeconomic variables, and disaster-related variables. We also performed bivariate analyses between mental health status and possible risk factors using the chi-square test. Furthermore, we performed multivariate regression analysis using modified Poisson regression models. The median K6 score was 5 (interquartile range: 1-10). The number of psychological distress was 8,717 (14.6%). We found that significant differences in the prevalence of psychological distress by almost all survey items, including disaster-related risk factors, most of which were also associated with increased Prevalence ratios (PRs). Additionally, we found that psychological distress in each evacuation zone was significantly positively associated with the radiation levels in their environment (r = 0.768, p = 0.002). The earthquake, tsunami and subsequent nuclear accident likely caused severe psychological distress among residents in the evacuation zone in Fukushima Prefecture. The close association between psychological distress and the radiation levels shows that the nuclear accident seriously influenced the mental health of the residents, which might be exacerbated by increased risk perception. To provide prompt and appropriate support, continued psychosocial intervention for evacuees is strongly recommended.

Normal forms for Poisson maps and symplectic groupoids around Poisson transversals

NASA Astrophysics Data System (ADS)

Frejlich, Pedro; Mărcuț, Ioan

2018-03-01

Poisson transversals are submanifolds in a Poisson manifold which intersect all symplectic leaves transversally and symplectically. In this communication, we prove a normal form theorem for Poisson maps around Poisson transversals. A Poisson map pulls a Poisson transversal back to a Poisson transversal, and our first main result states that simultaneous normal forms exist around such transversals, for which the Poisson map becomes transversally linear, and intertwines the normal form data of the transversals. Our second result concerns symplectic integrations. We prove that a neighborhood of a Poisson transversal is integrable exactly when the Poisson transversal itself is integrable, and in that case we prove a normal form theorem for the symplectic groupoid around its restriction to the Poisson transversal, which puts all structure maps in normal form. We conclude by illustrating our results with examples arising from Lie algebras.