Subgroup Analysis of Trials Is Rarely Easy (SATIRE): a study protocol for a systematic review to characterize the analysis, reporting, and claim of subgroup effects in randomized trials

PubMed Central

Sun, Xin; Briel, Matthias; Busse, Jason W; Akl, Elie A; You, John J; Mejza, Filip; Bala, Malgorzata; Diaz-Granados, Natalia; Bassler, Dirk; Mertz, Dominik; Srinathan, Sadeesh K; Vandvik, Per Olav; Malaga, German; Alshurafa, Mohamed; Dahm, Philipp; Alonso-Coello, Pablo; Heels-Ansdell, Diane M; Bhatnagar, Neera; Johnston, Bradley C; Wang, Li; Walter, Stephen D; Altman, Douglas G; Guyatt, Gordon H

2009-01-01

Background Subgroup analyses in randomized trials examine whether effects of interventions differ between subgroups of study populations according to characteristics of patients or interventions. However, findings from subgroup analyses may be misleading, potentially resulting in suboptimal clinical and health decision making. Few studies have investigated the reporting and conduct of subgroup analyses and a number of important questions remain unanswered. The objectives of this study are: 1) to describe the reporting of subgroup analyses and claims of subgroup effects in randomized controlled trials, 2) to assess study characteristics associated with reporting of subgroup analyses and with claims of subgroup effects, and 3) to examine the analysis, and interpretation of subgroup effects for each study's primary outcome. Methods We will conduct a systematic review of 464 randomized controlled human trials published in 2007 in the 118 Core Clinical Journals defined by the National Library of Medicine. We will randomly select journal articles, stratified in a 1:1 ratio by higher impact versus lower impact journals. According to 2007 ISI total citations, we consider the New England Journal of Medicine, JAMA, Lancet, Annals of Internal Medicine, and BMJ as higher impact journals. Teams of two reviewers will independently screen full texts of reports for eligibility, and abstract data, using standardized, pilot-tested extraction forms. We will conduct univariable and multivariable logistic regression analyses to examine the association of pre-specified study characteristics with reporting of subgroup analyses and with claims of subgroup effects for the primary and any other outcomes. Discussion A clear understanding of subgroup analyses, as currently conducted and reported in published randomized controlled trials, will reveal both strengths and weaknesses of this practice. Our findings will contribute to a set of recommendations to optimize the conduct and reporting of subgroup analyses, and claim and interpretation of subgroup effects in randomized trials. PMID:19900273

Neither fixed nor random: weighted least squares meta-analysis.

PubMed

Stanley, T D; Doucouliagos, Hristos

2015-06-15

This study challenges two core conventional meta-analysis methods: fixed effect and random effects. We show how and explain why an unrestricted weighted least squares estimator is superior to conventional random-effects meta-analysis when there is publication (or small-sample) bias and better than a fixed-effect weighted average if there is heterogeneity. Statistical theory and simulations of effect sizes, log odds ratios and regression coefficients demonstrate that this unrestricted weighted least squares estimator provides satisfactory estimates and confidence intervals that are comparable to random effects when there is no publication (or small-sample) bias and identical to fixed-effect meta-analysis when there is no heterogeneity. When there is publication selection bias, the unrestricted weighted least squares approach dominates random effects; when there is excess heterogeneity, it is clearly superior to fixed-effect meta-analysis. In practical applications, an unrestricted weighted least squares weighted average will often provide superior estimates to both conventional fixed and random effects. Copyright © 2015 John Wiley & Sons, Ltd.

Interventions to Improve Medication Adherence among Older Adults: Meta-Analysis of Adherence Outcomes among Randomized Controlled Trials

ERIC Educational Resources Information Center

Conn, Vicki S.; Hafdahl, Adam R.; Cooper, Pamela S.; Ruppar, Todd M.; Mehr, David R.; Russell, Cynthia L.

2009-01-01

Purpose: This study investigated the effectiveness of interventions to improve medication adherence (MA) in older adults. Design and Methods: Meta-analysis was used to synthesize results of 33 published and unpublished randomized controlled trials. Random-effects models were used to estimate overall mean effect sizes (ESs) for MA, knowledge,…

Evaluating the Flipped Classroom: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Wozny, Nathan; Balser, Cary; Ives, Drew

2018-01-01

Despite recent interest in flipped classrooms, rigorous research evaluating their effectiveness is sparse. In this study, the authors implement a randomized controlled trial to evaluate the effect of a flipped classroom technique relative to a traditional lecture in an introductory undergraduate econometrics course. Random assignment enables the…

Effects of live sax music on various physiological parameters, pain level, and mood level in cancer patients: a randomized controlled trial.

PubMed

Burrai, Francesco; Micheluzzi, Valentina; Bugani, Valentina

2014-01-01

Few randomized controlled trial studies have focused on the effect of music in cancer patients, and there are no randomized controlled trials on the effects of live music with saxophone in cancer patients. To determine the effects of live saxophone music on various physiological parameters, pain level, and mood level. A randomized controlled trial study. 52 cancer patients were randomized to a control group (n = 26), an experimental group (n = 26) whose members received 30 minutes of live music therapy with saxophone. Systolic and diastolic blood pressure, pulse rate, glycemia, oxygen saturation, pain level, and mood level were measured before and after the live music performance. There was a statistical difference between the groups for oxygen saturation (0.003) and mood level (0.001). Live music performed with a saxophone could be introduced in oncology care to improve the oxygen saturation and mood in cancer patients.

Zero-inflated count models for longitudinal measurements with heterogeneous random effects.

PubMed

Zhu, Huirong; Luo, Sheng; DeSantis, Stacia M

2017-08-01

Longitudinal zero-inflated count data arise frequently in substance use research when assessing the effects of behavioral and pharmacological interventions. Zero-inflated count models (e.g. zero-inflated Poisson or zero-inflated negative binomial) with random effects have been developed to analyze this type of data. In random effects zero-inflated count models, the random effects covariance matrix is typically assumed to be homogeneous (constant across subjects). However, in many situations this matrix may be heterogeneous (differ by measured covariates). In this paper, we extend zero-inflated count models to account for random effects heterogeneity by modeling their variance as a function of covariates. We show via simulation that ignoring intervention and covariate-specific heterogeneity can produce biased estimates of covariate and random effect estimates. Moreover, those biased estimates can be rectified by correctly modeling the random effects covariance structure. The methodological development is motivated by and applied to the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study, the largest clinical trial of alcohol dependence performed in United States with 1383 individuals.

Teacher Effectiveness and Causal Inference in Observational Studies

ERIC Educational Resources Information Center

Rose, Roderick A.

2013-01-01

An important target of education policy is to improve overall teacher effectiveness using evidence-based policies. Randomized control trials (RCTs), which randomly assign study participants or groups of participants to treatment and control conditions, are not always practical or possible and observational studies using rigorous quasi-experimental…

Application of random effects to the study of resource selection by animals

USGS Publications Warehouse

Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.

2006-01-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Application of random effects to the study of resource selection by animals.

PubMed

Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L

2006-07-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Individualizing drug dosage with longitudinal data.

PubMed

Zhu, Xiaolu; Qu, Annie

2016-10-30

We propose a two-step procedure to personalize drug dosage over time under the framework of a log-linear mixed-effect model. We model patients' heterogeneity using subject-specific random effects, which are treated as the realizations of an unspecified stochastic process. We extend the conditional quadratic inference function to estimate both fixed-effect coefficients and individual random effects on a longitudinal training data sample in the first step and propose an adaptive procedure to estimate new patients' random effects and provide dosage recommendations for new patients in the second step. An advantage of our approach is that we do not impose any distribution assumption on estimating random effects. Moreover, the new approach can accommodate more general time-varying covariates corresponding to random effects. We show in theory and numerical studies that the proposed method is more efficient compared with existing approaches, especially when covariates are time varying. In addition, a real data example of a clozapine study confirms that our two-step procedure leads to more accurate drug dosage recommendations. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Biases in Estimating Treatment Effects Due to Attrition in Randomized Controlled Trials and Cluster Randomized Controlled Trials: A Simulation Study

ERIC Educational Resources Information Center

Dong, Nianbo; Lipsey, Mark W.

2011-01-01

Attrition occurs when study participants who were assigned to the treatment and control conditions do not provide outcome data and thus do not contribute to the estimation of the treatment effects. It is very common in experimental studies in education as illustrated, for instance, in a meta-analysis studying "the effects of attrition on baseline…

Log-gamma linear-mixed effects models for multiple outcomes with application to a longitudinal glaucoma study

PubMed Central

Zhang, Peng; Luo, Dandan; Li, Pengfei; Sharpsten, Lucie; Medeiros, Felipe A.

2015-01-01

Glaucoma is a progressive disease due to damage in the optic nerve with associated functional losses. Although the relationship between structural and functional progression in glaucoma is well established, there is disagreement on how this association evolves over time. In addressing this issue, we propose a new class of non-Gaussian linear-mixed models to estimate the correlations among subject-specific effects in multivariate longitudinal studies with a skewed distribution of random effects, to be used in a study of glaucoma. This class provides an efficient estimation of subject-specific effects by modeling the skewed random effects through the log-gamma distribution. It also provides more reliable estimates of the correlations between the random effects. To validate the log-gamma assumption against the usual normality assumption of the random effects, we propose a lack-of-fit test using the profile likelihood function of the shape parameter. We apply this method to data from a prospective observation study, the Diagnostic Innovations in Glaucoma Study, to present a statistically significant association between structural and functional change rates that leads to a better understanding of the progression of glaucoma over time. PMID:26075565

Can Propensity Score Analysis Approximate Randomized Experiments Using Pretest and Demographic Information in Pre-K Intervention Research?

PubMed

Dong, Nianbo; Lipsey, Mark W

2017-01-01

It is unclear whether propensity score analysis (PSA) based on pretest and demographic covariates will meet the ignorability assumption for replicating the results of randomized experiments. This study applies within-study comparisons to assess whether pre-Kindergarten (pre-K) treatment effects on achievement outcomes estimated using PSA based on a pretest and demographic covariates can approximate those found in a randomized experiment. Data-Four studies with samples of pre-K children each provided data on two math achievement outcome measures with baseline pretests and child demographic variables that included race, gender, age, language spoken at home, and mother's highest education. Research Design and Data Analysis-A randomized study of a pre-K math curriculum provided benchmark estimates of effects on achievement measures. Comparison samples from other pre-K studies were then substituted for the original randomized control and the effects were reestimated using PSA. The correspondence was evaluated using multiple criteria. The effect estimates using PSA were in the same direction as the benchmark estimates, had similar but not identical statistical significance, and did not differ from the benchmarks at statistically significant levels. However, the magnitude of the effect sizes differed and displayed both absolute and relative bias larger than required to show statistical equivalence with formal tests, but those results were not definitive because of the limited statistical power. We conclude that treatment effect estimates based on a single pretest and demographic covariates in PSA correspond to those from a randomized experiment on the most general criteria for equivalence.

Testing the Intervention Effect in Single-Case Experiments: A Monte Carlo Simulation Study

ERIC Educational Resources Information Center

Heyvaert, Mieke; Moeyaert, Mariola; Verkempynck, Paul; Van den Noortgate, Wim; Vervloet, Marlies; Ugille, Maaike; Onghena, Patrick

2017-01-01

This article reports on a Monte Carlo simulation study, evaluating two approaches for testing the intervention effect in replicated randomized AB designs: two-level hierarchical linear modeling (HLM) and using the additive method to combine randomization test "p" values (RTcombiP). Four factors were manipulated: mean intervention effect,…

The Relationship of Class Size Effects and Teacher Salary

ERIC Educational Resources Information Center

Peevely, Gary; Hedges, Larry; Nye, Barbara A.

2005-01-01

The effects of class size on academic achievement have been studied for decades. Although the results of small-scale, randomized experiments and large-scale, econometric studies point to positive effects of small classes, some scholars see the evidence as ambiguous. Recent analyses from a 4-year, large-scale, randomized experiment on the effects…

Randomized Controlled Trials Evaluating Effect of Television Advertising on Food Intake in Children: Why Such a Sensitive Topic is Lacking Top-Level Evidence?

PubMed

Gregori, Dario; Ballali, Simonetta; Vecchio, Maria Gabriella; Sciré, Antonella Silvia; Foltran, Francesca; Berchialla, Paola

2014-01-01

The aim of this study was to perform a systematic review of evidence coming from randomized controlled trials (RCT) aimed at assessing the effect of television advertising on food intake in children from 4 to 12 years old. Randomized controlled trials were searched in PubMed database and included if they assessed the effect of direct exposure to television food advertising over the actual energy intake of children. Seven studies out of 2166 fulfilled the inclusion criteria. The association between television advertising and energy intake is based on a very limited set of randomized researches lacking a solid ground of first-level evidence.

Quality of surgical randomized controlled trials for acute cholecystitis: assessment based on CONSORT and additional check items.

PubMed

Shikata, Satoru; Nakayama, Takeo; Yamagishi, Hisakazu

2008-01-01

In this study, we conducted a limited survey of reports of surgical randomized controlled trials, using the consolidated standards of reporting trials (CONSORT) statement and additional check items to clarify problems in the evaluation of surgical reports. A total of 13 randomized trials were selected from two latest review articles on biliary surgery. Each randomized trial was evaluated according to 28 quality measures that comprised items from the CONSORT statement plus additional items. Analysis focused on relationships between the quality of each study and the estimated effect gap ("pooled estimate in meta-analysis" -- "estimated effect of each study"). No definite relationships were found between individual study quality and the estimated effect gap. The following items could have been described but were not provided in almost all the surgical RCT reports: "clearly defined outcomes"; "details of randomization"; "participant flow charts"; "intention-to-treat analysis"; "ancillary analyses"; and "financial conflicts of interest". The item, "participation of a trial methodologist in the study" was not found in any of the reports. Although the quality of reporting trials is not always related to a biased estimation of treatment effect, the items used for quality measures must be described to enable readers to evaluate the quality and applicability of the reporting. Further development of an assessment tool is needed for items specific to surgical randomized controlled trials.

A Bayesian comparative effectiveness trial in action: developing a platform for multisite study adaptive randomization.

PubMed

Brown, Alexandra R; Gajewski, Byron J; Aaronson, Lauren S; Mudaranthakam, Dinesh Pal; Hunt, Suzanne L; Berry, Scott M; Quintana, Melanie; Pasnoor, Mamatha; Dimachkie, Mazen M; Jawdat, Omar; Herbelin, Laura; Barohn, Richard J

2016-08-31

In the last few decades, the number of trials using Bayesian methods has grown rapidly. Publications prior to 1990 included only three clinical trials that used Bayesian methods, but that number quickly jumped to 19 in the 1990s and to 99 from 2000 to 2012. While this literature provides many examples of Bayesian Adaptive Designs (BAD), none of the papers that are available walks the reader through the detailed process of conducting a BAD. This paper fills that gap by describing the BAD process used for one comparative effectiveness trial (Patient Assisted Intervention for Neuropathy: Comparison of Treatment in Real Life Situations) that can be generalized for use by others. A BAD was chosen with efficiency in mind. Response-adaptive randomization allows the potential for substantially smaller sample sizes, and can provide faster conclusions about which treatment or treatments are most effective. An Internet-based electronic data capture tool, which features a randomization module, facilitated data capture across study sites and an in-house computation software program was developed to implement the response-adaptive randomization. A process for adapting randomization with minimal interruption to study sites was developed. A new randomization table can be generated quickly and can be seamlessly integrated in the data capture tool with minimal interruption to study sites. This manuscript is the first to detail the technical process used to evaluate a multisite comparative effectiveness trial using adaptive randomization. An important opportunity for the application of Bayesian trials is in comparative effectiveness trials. The specific case study presented in this paper can be used as a model for conducting future clinical trials using a combination of statistical software and a web-based application. ClinicalTrials.gov Identifier: NCT02260388 , registered on 6 October 2014.

Two Universality Classes for the Many-Body Localization Transition

NASA Astrophysics Data System (ADS)

Khemani, Vedika; Sheng, D. N.; Huse, David A.

2017-08-01

We provide a systematic comparison of the many-body localization (MBL) transition in spin chains with nonrandom quasiperiodic versus random fields. We find evidence suggesting that these belong to two separate universality classes: the first dominated by "intrinsic" intrasample randomness, and the second dominated by external intersample quenched randomness. We show that the effects of intersample quenched randomness are strongly growing, but not yet dominant, at the system sizes probed by exact-diagonalization studies on random models. Thus, the observed finite-size critical scaling collapses in such studies appear to be in a preasymptotic regime near the nonrandom universality class, but showing signs of the initial crossover towards the external-randomness-dominated universality class. Our results provide an explanation for why exact-diagonalization studies on random models see an apparent scaling near the transition while also obtaining finite-size scaling exponents that strongly violate Harris-Chayes bounds that apply to disorder-driven transitions. We also show that the MBL phase is more stable for the quasiperiodic model as compared to the random one, and the transition in the quasiperiodic model suffers less from certain finite-size effects.

The effectiveness of foot reflexology in inducing ovulation: a sham-controlled randomized trial.

PubMed

Holt, Jane; Lord, Jonathan; Acharya, Umesh; White, Adrian; O'Neill, Nyree; Shaw, Steve; Barton, Andy

2009-06-01

To determine whether foot reflexology, a complementary therapy, has an effect greater than sham reflexology on induction of ovulation. Sham-controlled randomized trial with patients and statistician blinded. Infertility clinic in Plymouth, United Kingdom. Forty-eight women attending the clinic with anovulation. Women were randomized to receive eight sessions of either genuine foot reflexology or sham reflexology with gentle massage over 10 weeks. The primary outcome was ovulation detected by serum progesterone level of >30 nmol/L during the study period. Twenty-six patients were randomized to genuine reflexology and 22 to sham (one randomized patient was withdrawn). Patients remained blinded throughout the trial. The rate of ovulation during true reflexology was 11 out of 26 (42%), and during sham reflexology it was 10 out of 22 (46%). Pregnancy rates were 4 out of 26 in the true group and 2 out of 22 in the control group. Because of recruitment difficulties, the required sample size of 104 women was not achieved. Patient blinding of reflexology studies is feasible. Although this study was too small to reach a definitive conclusion on the specific effect of foot reflexology, the results suggest that any effect on ovulation would not be clinically relevant. Sham reflexology may have a beneficial general effect, which this study was not designed to detect.

Regional or general anesthesia for fast-track hip and knee replacement - what is the evidence?

PubMed Central

Kehlet, Henrik; Aasvang, Eske Kvanner

2015-01-01

Regional anesthesia for knee and hip arthroplasty may have favorable outcome effects compared with general anesthesia by effectively blocking afferent input, providing initial postoperative analgesia, reducing endocrine metabolic responses, and providing sympathetic blockade with reduced bleeding and less risk of thromboembolic complications but with undesirable effects on lower limb motor and urinary bladder function. Old randomized studies supported the use of regional anesthesia with fewer postoperative pulmonary and thromboembolic complications, and this has been supported by recent large non-randomized epidemiological database cohort studies. In contrast, the data from newer randomized trials are conflicting, and recent studies using modern general anesthetic techniques may potentially support the use of general versus spinal anesthesia. In summary, the lack of properly designed large randomized controlled trials comparing modern general anesthesia and spinal anesthesia for knee and hip arthroplasty prevents final recommendations and calls for prospective detailed studies in this clinically important field. PMID:26918127

Effects of Check & Connect on Attendance, Behavior, and Academics: A Randomized Effectiveness Trial

ERIC Educational Resources Information Center

Maynard, Brandy R.; Kjellstrand, Elizabeth K.; Thompson, Aaron M.

2014-01-01

The present study evaluates the effectiveness of Check & Connect (C&C) in a randomly assigned sample of students who were all receiving Communities in Schools (CIS) services. The research questions for the study include: Are there differences in attendance, academics, and behavior for CIS students who also receive C&C compared to…

Comprehensive genotyping in dyslipidemia: mendelian dyslipidemias caused by rare variants and Mendelian randomization studies using common variants.

PubMed

Tada, Hayato; Kawashiri, Masa-Aki; Yamagishi, Masakazu

2017-04-01

Dyslipidemias, especially hyper-low-density lipoprotein cholesterolemia and hypertriglyceridemia, are important causal risk factors for coronary artery disease. Comprehensive genotyping using the 'next-generation sequencing' technique has facilitated the investigation of Mendelian dyslipidemias, in addition to Mendelian randomization studies using common genetic variants associated with plasma lipids and coronary artery disease. The beneficial effects of low-density lipoprotein cholesterol-lowering therapies on coronary artery disease have been verified by many randomized controlled trials over the years, and subsequent genetic studies have supported these findings. More recently, Mendelian randomization studies have preceded randomized controlled trials. When the on-target/off-target effects of rare variants and common variants exhibit the same direction, novel drugs targeting molecules identified by investigations of rare Mendelian lipid disorders could be promising. Such a strategy could aid in the search for drug discovery seeds other than those for dyslipidemias.

From randomized controlled trials to observational studies.

PubMed

Silverman, Stuart L

2009-02-01

Randomized controlled trials are considered the gold standard in the hierarchy of research designs for evaluating the efficacy and safety of a treatment intervention. However, their results can have limited applicability to patients in clinical settings. Observational studies using large health care databases can complement findings from randomized controlled trials by assessing treatment effectiveness in patients encountered in day-to-day clinical practice. Results from these designs can expand upon outcomes of randomized controlled trials because of the use of larger and more diverse patient populations with common comorbidities and longer follow-up periods. Furthermore, well-designed observational studies can identify clinically important differences among therapeutic options and provide data on long-term drug effectiveness and safety.

Bayesian statistical inference enhances the interpretation of contemporary randomized controlled trials.

PubMed

Wijeysundera, Duminda N; Austin, Peter C; Hux, Janet E; Beattie, W Scott; Laupacis, Andreas

2009-01-01

Randomized trials generally use "frequentist" statistics based on P-values and 95% confidence intervals. Frequentist methods have limitations that might be overcome, in part, by Bayesian inference. To illustrate these advantages, we re-analyzed randomized trials published in four general medical journals during 2004. We used Medline to identify randomized superiority trials with two parallel arms, individual-level randomization and dichotomous or time-to-event primary outcomes. Studies with P<0.05 in favor of the intervention were deemed "positive"; otherwise, they were "negative." We used several prior distributions and exact conjugate analyses to calculate Bayesian posterior probabilities for clinically relevant effects. Of 88 included studies, 39 were positive using a frequentist analysis. Although the Bayesian posterior probabilities of any benefit (relative risk or hazard ratio<1) were high in positive studies, these probabilities were lower and variable for larger benefits. The positive studies had only moderate probabilities for exceeding the effects that were assumed for calculating the sample size. By comparison, there were moderate probabilities of any benefit in negative studies. Bayesian and frequentist analyses complement each other when interpreting the results of randomized trials. Future reports of randomized trials should include both.

The Effect of a Home-Based Walking Intervention on Quality of Life, Body Composition, and Estrogen Metabolism in Postmenopausal Breast Cancer Survivors

DTIC Science & Technology

2006-09-01

Effect sizes are also shown for each randomization group (i.e., effect size from pretest to posttest ) and for the comparison of the two randomization...questions were answered. This study was designed to be a pilot study to quantify effect sizes of the effect of walking on quality of life...physical activity, body composition, and depending on inclusion criteria, estrogen metabolism. Second, this study was designed to assess the degree to

Effect of Educational Package on Lifestyle of Primiparous Mothers during Postpartum Period: A Randomized Controlled Clinical Trial

ERIC Educational Resources Information Center

Khodabandeh, Farzaneh; Mirghafourvand, Mojgan; KamaliFard, Mahin; Mohammad-Alizadeh-Charandabi, Sakineh; Asghari Jafarabadi, Mohammad

2017-01-01

A healthy lifestyle is important for mothers during the postpartum period. This study was conducted to determine the effects of a lifestyle educational package in primiparous women. This randomized clinical trial was conducted on 220 mothers assigned to two groups using block randomization. In the intervention group, the mothers received…

Meta-analysis of two studies in the presence of heterogeneity with applications in rare diseases.

PubMed

Friede, Tim; Röver, Christian; Wandel, Simon; Neuenschwander, Beat

2017-07-01

Random-effects meta-analyses are used to combine evidence of treatment effects from multiple studies. Since treatment effects may vary across trials due to differences in study characteristics, heterogeneity in treatment effects between studies must be accounted for to achieve valid inference. The standard model for random-effects meta-analysis assumes approximately normal effect estimates and a normal random-effects model. However, standard methods based on this model ignore the uncertainty in estimating the between-trial heterogeneity. In the special setting of only two studies and in the presence of heterogeneity, we investigate here alternatives such as the Hartung-Knapp-Sidik-Jonkman method (HKSJ), the modified Knapp-Hartung method (mKH, a variation of the HKSJ method) and Bayesian random-effects meta-analyses with priors covering plausible heterogeneity values; R code to reproduce the examples is presented in an appendix. The properties of these methods are assessed by applying them to five examples from various rare diseases and by a simulation study. Whereas the standard method based on normal quantiles has poor coverage, the HKSJ and mKH generally lead to very long, and therefore inconclusive, confidence intervals. The Bayesian intervals on the whole show satisfying properties and offer a reasonable compromise between these two extremes. © 2016 The Authors. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

ERIC Educational Resources Information Center

Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben

2016-01-01

The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…

Assessing variance components in multilevel linear models using approximate Bayes factors: A case study of ethnic disparities in birthweight

PubMed Central

Saville, Benjamin R.; Herring, Amy H.; Kaufman, Jay S.

2013-01-01

Racial/ethnic disparities in birthweight are a large source of differential morbidity and mortality worldwide and have remained largely unexplained in epidemiologic models. We assess the impact of maternal ancestry and census tract residence on infant birth weights in New York City and the modifying effects of race and nativity by incorporating random effects in a multilevel linear model. Evaluating the significance of these predictors involves the test of whether the variances of the random effects are equal to zero. This is problematic because the null hypothesis lies on the boundary of the parameter space. We generalize an approach for assessing random effects in the two-level linear model to a broader class of multilevel linear models by scaling the random effects to the residual variance and introducing parameters that control the relative contribution of the random effects. After integrating over the random effects and variance components, the resulting integrals needed to calculate the Bayes factor can be efficiently approximated with Laplace’s method. PMID:24082430

A comparison of three random effects approaches to analyze repeated bounded outcome scores with an application in a stroke revalidation study.

PubMed

Molas, Marek; Lesaffre, Emmanuel

2008-12-30

Discrete bounded outcome scores (BOS), i.e. discrete measurements that are restricted on a finite interval, often occur in practice. Examples are compliance measures, quality of life measures, etc. In this paper we examine three related random effects approaches to analyze longitudinal studies with a BOS as response: (1) a linear mixed effects (LM) model applied to a logistic transformed modified BOS; (2) a model assuming that the discrete BOS is a coarsened version of a latent random variable, which after a logistic-normal transformation, satisfies an LM model; and (3) a random effects probit model. We consider also the extension whereby the variability of the BOS is allowed to depend on covariates. The methods are contrasted using a simulation study and on a longitudinal project, which documents stroke rehabilitation in four European countries using measures of motor and functional recovery. Copyright 2008 John Wiley & Sons, Ltd.

Randomized clinical trials and observational studies in the assessment of drug safety.

PubMed

Sawchik, J; Hamdani, J; Vanhaeverbeek, M

2018-05-01

Randomized clinical trials are considered as the preferred design to assess the potential causal relationships between drugs or other medical interventions and intended effects. For this reason, randomized clinical trials are generally the basis of development programs in the life cycle of drugs and the cornerstone of evidence-based medicine. Instead, randomized clinical trials are not the design of choice for the detection and assessment of rare, delayed and/or unexpected effects related to drug safety. Moreover, the highly homogeneous populations resulting from restrictive eligibility criteria make randomized clinical trials inappropriate to describe comprehensively the safety profile of drugs. In that context, observational studies have a key added value when evaluating the benefit-risk balance of the drugs. However, observational studies are more prone to bias than randomized clinical trials and they have to be designed, conducted and reported judiciously. In this article, we discuss the strengths and limitations of randomized clinical trials and of observational studies, more particularly regarding their contribution to the knowledge of medicines' safety profile. In addition, we present general recommendations for the sensible use of observational data. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Utility and Cost-Effectiveness of Motivational Messaging to Increase Survey Response in Physicians: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Chan, Randolph C. H.; Mak, Winnie W. S.; Pang, Ingrid H. Y.; Wong, Samuel Y. S.; Tang, Wai Kwong; Lau, Joseph T. F.; Woo, Jean; Lee, Diana T. F.; Cheung, Fanny M.

2018-01-01

The present study examined whether, when, and how motivational messaging can boost the response rate of postal surveys for physicians based on Higgin's regulatory focus theory, accounting for its cost-effectiveness. A three-arm, blinded, randomized controlled design was used. A total of 3,270 doctors were randomly selected from the registration…

The Ecological Effects of Universal and Selective Violence Prevention Programs for Middle School Students: A Randomized Trial

ERIC Educational Resources Information Center

Simon, Thomas R.; Ikeda, Robin M.; Smith, Emilie Phillips; Reese, Le'Roy E.; Rabiner, David L.; Miller, Shari; Winn, Donna-Marie; Dodge, Kenneth A.; Asher, Steven R.; Horne, Arthur M.; Orpinas, Pamela; Martin, Roy; Quinn, William H.; Tolan, Patrick H.; Gorman-Smith, Deborah; Henry, David B.; Gay, Franklin N.; Schoeny, Michael; Farrell, Albert D.; Meyer, Aleta L.; Sullivan, Terri N.; Allison, Kevin W.

2009-01-01

This study reports the findings of a multisite randomized trial evaluating the separate and combined effects of 2 school-based approaches to reduce violence among early adolescents. A total of 37 schools at 4 sites were randomized to 4 conditions: (1) a universal intervention that involved implementing a student curriculum and teacher training…

Random electric field instabilities of relaxor ferroelectrics

NASA Astrophysics Data System (ADS)

Arce-Gamboa, José R.; Guzmán-Verri, Gian G.

2017-06-01

Relaxor ferroelectrics are complex oxide materials which are rather unique to study the effects of compositional disorder on phase transitions. Here, we study the effects of quenched cubic random electric fields on the lattice instabilities that lead to a ferroelectric transition and show that, within a microscopic model and a statistical mechanical solution, even weak compositional disorder can prohibit the development of long-range order and that a random field state with anisotropic and power-law correlations of polarization emerges from the combined effect of their characteristic dipole forces and their inherent charge disorder. We compare and reproduce several key experimental observations in the well-studied relaxor PbMg1/3Nb2/3O3-PbTiO3.

WWC Review of the Report "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children." What Works Clearinghouse Single Study Review

ERIC Educational Resources Information Center

What Works Clearinghouse, 2015

2015-01-01

For the 2014 study, "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children", researchers examined the effect of a daily before-school physical activity program on behavioral outcomes of students in grades K-2. The study sample included 202 students who…

Effects of gut-directed hypnotherapy on IBS in different clinical settings-results from two randomized, controlled trials.

PubMed

Lindfors, Perjohan; Unge, Peter; Arvidsson, Patrik; Nyhlin, Henry; Björnsson, Einar; Abrahamsson, Hasse; Simrén, Magnus

2012-02-01

Gut-directed hypnotherapy has been found to be effective in irritable bowel syndrome (IBS). However, randomized, controlled studies are rare and few have been performed outside highly specialized research centers. The objective of this study was to study the effect of gut-directed hypnotherapy in IBS in different clinical settings outside the traditional research units. The study population included IBS patients refractory to standard management. In study 1, patients were randomized to receive gut-directed hypnotherapy (12 sessions, 1 h/week) in psychology private practices or supportive therapy, whereas patients were randomized to receive gut-directed hypnotherapy in a small county hospital or to serve as waiting list controls in study 2. Gastrointestinal symptom severity and quality of life were evaluated at baseline, at 3 months follow-up and after 1 year. We randomized 138 IBS patients refractory to standard management, 90 in study 1 and 48 in study 2. In both the studies, IBS-related symptoms were improved at 3 months in the gut-directed hypnotherapy groups (P<0.05), but not in the control groups (ns). In study 1, a significantly greater improvement of IBS-related symptom severity could be detected in the gut-directed hypnotherapy group than in the control group (P<0.05), and a trend in the same direction was seen in study 2 (P=0.17). The results seen at 3 months were sustained up to 1 year. Gut-directed hypnotherapy is an effective treatment alternative for patients with refractory IBS, but the effectiveness is lower when the therapy is given outside the highly specialized research centers.

Review of Randomized Controlled Trials of Massage in Preterm Infants

PubMed Central

Niemi, Anna-Kaisa

2017-01-01

Preterm birth affects about 10% of infants born in the United States. Massage therapy is being used in some neonatal intensive care units for its potential beneficial effects on preterm infants. This article reviews published randomized controlled trials on the effects of massage in preterm infants. Most studies evaluating the effect of massage in weight gain in premature infants suggest a positive effect on weight gain. Increase in vagal tone has been reported in infants who receive massage and has been suggested as a possible mechanism for improved weight gain. More studies are needed on the underlying mechanisms of the effects of massage therapy on weight gain in preterm infants. While some trials suggest improvements in developmental scores, decreased stress behavior, positive effects on immune system, improved pain tolerance and earlier discharge from the hospital, the number of such studies is small and further evidence is needed. Further studies, including randomized controlled trials, are needed on the effects of massage in preterm infants. PMID:28368368

Testing homogeneity in Weibull-regression models.

PubMed

Bolfarine, Heleno; Valença, Dione M

2005-10-01

In survival studies with families or geographical units it may be of interest testing whether such groups are homogeneous for given explanatory variables. In this paper we consider score type tests for group homogeneity based on a mixing model in which the group effect is modelled as a random variable. As opposed to hazard-based frailty models, this model presents survival times that conditioned on the random effect, has an accelerated failure time representation. The test statistics requires only estimation of the conventional regression model without the random effect and does not require specifying the distribution of the random effect. The tests are derived for a Weibull regression model and in the uncensored situation, a closed form is obtained for the test statistic. A simulation study is used for comparing the power of the tests. The proposed tests are applied to real data sets with censored data.

Effects of Selected Meditative Asanas on Kinaesthetic Perception and Speed of Movement

ERIC Educational Resources Information Center

Singh, Kanwaljeet; Bal, Baljinder S.; Deol, Nishan S.

2009-01-01

Study aim: To assess the effects of selected meditative "asanas" on kinesthetic perception and movement speed. Material and methods: Thirty randomly selected male students aged 18-24 years volunteered to participate in the study. They were randomly assigned into two groups: A (medidative) and B (control). The Nelson's movement speed and…

Does EEG-Neurofeedback Improve Neurocognitive Functioning in Children with Attention-Deficit/Hyperactivity Disorder? A Systematic Review and a Double-Blind Placebo-Controlled Study

ERIC Educational Resources Information Center

Vollebregt, Madelon A.; van Dongen-Boomsma, Martine; Buitelaar, Jan K.; Slaats-Willemse, Dorine

2014-01-01

Background: The number of placebo-controlled randomized studies relating to EEG-neurofeedback and its effect on neurocognition in attention-deficient/hyperactivity disorder (ADHD) is limited. For this reason, a double blind, randomized, placebo-controlled study was designed to assess the effects of EEG-neurofeedback on neurocognitive functioning…

The Effects of Self- and Peer-Monitoring in Social Studies Performance of Students with Learning Disabilities and Low Achieving Students

ERIC Educational Resources Information Center

Kim, Woori; Ok, Min Wook; Yoo, Yongseok

2018-01-01

This study employed group randomized trials to investigate the effects of self- and peer-monitoring on the academic vocabulary and content knowledge of students with learning disabilities and low achieving students in social studies. Fourth grade students were randomly assigned to either treatment or control groups on a class level. Results…

Intrathecal Baclofen in Children with Spastic Cerebral Palsy: A Double-Blind, Randomized, Placebo-Controlled, Dose-Finding Study

ERIC Educational Resources Information Center

Hoving, Marjanke A.; van Raak, Elisabeth P. M.; Spincemaille, Geert H. J. J.; Palmans, Liesbeth J.; Sleypen, Frans A. M.; Vles, Johan S. H.

2007-01-01

Intrathecal baclofen (ITB) therapy can be very effective in the treatment of intractable spasticity, but its effectiveness and safety have not yet been thoroughly studied in children with cerebral palsy (CP). The aims of this double-blind, randomized, placebo-controlled, dose-finding study were to select children eligible for continuous ITB…

The Effects of Improvisational Music Therapy on Joint Attention Behaviors in Autistic Children: A Randomized Controlled Study

ERIC Educational Resources Information Center

Kim, Jinah; Wigram, Tony; Gold, Christian

2008-01-01

The purpose of this study was to investigate the effects of improvisational music therapy on joint attention behaviors in pre-school children with autism. It was a randomized controlled study employing a single subject comparison design in two different conditions, improvisational music therapy and play sessions with toys, and using standardized…

Randomization at the level of primary care practice: use of pre-intervention data and random effects models.

PubMed

Nixon, R M; Duffy, S W; Fender, G R; Day, N E; Prevost, T C

2001-06-30

The Anglia menorrhagia education study tests the effectiveness of an education package for the treatment of menorrhagia given to doctors at a primary care level. General practices were randomized to receive or not receive the package. It is hoped that this intervention will reduce the proportion of women suffering from menorrhagia that are referred to hospital. Data are available on the treatment and referral of women in the practices in the education and control groups, both pre- and post-intervention. We define and demonstrate a random effects logistic regression model that includes pre-intervention data for calculating the effectiveness of the intervention. Copyright 2001 John Wiley & Sons, Ltd.

Selenium and Preeclampsia: a Systematic Review and Meta-analysis.

PubMed

Xu, Min; Guo, Dan; Gu, Hao; Zhang, Li; Lv, Shuyan

2016-06-01

Conflicting results exist between selenium concentration and preeclampsia. The role of selenium in the development of preeclampsia is unclear. We conducted a meta-analysis to compare the blood selenium level in patients with preeclampsia and healthy pregnant women, and to determine the effectiveness of selenium supplementation in preventing preeclampsia. We searched PubMed, ScienceDirect, the Cochrane Library, and relevant references for English language literature up to November 25, 2014. Mean difference from observational studies and relative risk from randomized controlled trials were meta-analyzed by a random-effect model. Thirteen observational studies with 1515 participants and 3 randomized controlled trials with 439 participants were included in the meta-analysis. Using a random-effect model, a statistically significant difference in blood selenium concentration of -6.47 μg/l (95 % confidence interval (CI) -11.24 to -1.7, p = 0.008) was seen after comparing the mean difference of observational studies. In randomized controlled trials, using a random-effect model, the relative risk for preeclampsia was 0.28 (0.09 to 0.84) for selenium supplementation (p = 0.02). Evidence from observational studies indicates an inverse association of blood selenium level and the risk of preeclampsia. Supplementation with selenium significantly reduces the incidence of preeclampsia. However, more prospective clinical trials are required to assess the association between selenium supplementation and preeclampsia and to determine the dose, beginning time, and duration of selenium supplementation.

Randomness increases self-reported anxiety and neurophysiological correlates of performance monitoring

PubMed Central

Kay, Aaron C.; Inzlicht, Michael

2015-01-01

Several prominent theories spanning clinical, social and developmental psychology suggest that people are motivated to see the world as a sensible orderly place. These theories presuppose that randomness is aversive because it is associated with unpredictability. If this is the case, thinking that the world is random should lead to increased anxiety and heightened monitoring of one’s actions and their consequences. Here, we conduct experimental tests of both of these ideas. Participants read one of three passages: (i) comprehensible order, (ii) incomprehensible order and (iii) randomness. In Study 1, we examined the effects of these passages on self-reported anxiety. In Study 2, we examined the effects of the same manipulation on the error-related negativity (ERN), an event-related brain potential associated with performance monitoring. We found that messages about randomness increased self-reported anxiety and ERN amplitude relative to comprehensible order, whereas incomprehensible order had intermediate effects. These results lend support to the theoretically important idea that randomness is unsettling because it implies that the world is unpredictable. PMID:25062840

e-Learning versus lecture-based courses in ECG interpretation for undergraduate medical students: a randomized noninferiority study.

PubMed

Montassier, Emmanuel; Hardouin, Jean-Benoît; Segard, Julien; Batard, Eric; Potel, Gilles; Planchon, Bernard; Trochu, Jean-Noël; Pottier, Pierre

2016-04-01

An ECG is pivotal for the diagnosis of coronary heart disease. Previous studies have reported deficiencies in ECG interpretation skills that have been responsible for misdiagnosis. However, the optimal way to acquire ECG interpretation skills is still under discussion. Thus, our objective was to compare the effectiveness of e-learning and lecture-based courses for learning ECG interpretation skills in a large randomized study. We conducted a prospective, randomized, controlled, noninferiority study. Participants were recruited from among fifth-year medical students and were assigned to the e-learning group or the lecture-based group using a computer-generated random allocation sequence. The e-learning and lecture-based groups were compared on a score of effectiveness, comparing the 95% unilateral confidence interval (95% UCI) of the score of effectiveness with the mean effectiveness in the lecture-based group, adjusted for a noninferiority margin. Ninety-eight students were enrolled. As compared with the lecture-based course, e-learning was noninferior with regard to the postcourse test score (15.1; 95% UCI 14.2; +∞), which can be compared with 12.5 [the mean effectiveness in the lecture-based group (15.0) minus the noninferiority margin (2.5)]. Furthermore, there was a significant increase in the test score points in both the e-learning and lecture-based groups during the study period (both P<0.0001). Our randomized study showed that the e-learning course is an effective tool for the acquisition of ECG interpretation skills by medical students. These preliminary results should be confirmed with further multicenter studies before the implementation of e-learning courses for learning ECG interpretation skills during medical school.

Random versus Blocked Practice in Treatment for Childhood Apraxia of Speech

ERIC Educational Resources Information Center

Maas, Edwin; Farinella, Kimberly A.

2012-01-01

Purpose: To compare the relative effects of random vs. blocked practice schedules in treatment for childhood apraxia of speech (CAS). Although there have been repeated suggestions in the literature to use random practice in CAS treatment, no systematic studies exist that have directly compared random with blocked practice in this population.…

The conditional power of randomization tests for single-case effect sizes in designs with randomized treatment order: A Monte Carlo simulation study.

PubMed

Michiels, Bart; Heyvaert, Mieke; Onghena, Patrick

2018-04-01

The conditional power (CP) of the randomization test (RT) was investigated in a simulation study in which three different single-case effect size (ES) measures were used as the test statistics: the mean difference (MD), the percentage of nonoverlapping data (PND), and the nonoverlap of all pairs (NAP). Furthermore, we studied the effect of the experimental design on the RT's CP for three different single-case designs with rapid treatment alternation: the completely randomized design (CRD), the randomized block design (RBD), and the restricted randomized alternation design (RRAD). As a third goal, we evaluated the CP of the RT for three types of simulated data: data generated from a standard normal distribution, data generated from a uniform distribution, and data generated from a first-order autoregressive Gaussian process. The results showed that the MD and NAP perform very similarly in terms of CP, whereas the PND performs substantially worse. Furthermore, the RRAD yielded marginally higher power in the RT, followed by the CRD and then the RBD. Finally, the power of the RT was almost unaffected by the type of the simulated data. On the basis of the results of the simulation study, we recommend at least 20 measurement occasions for single-case designs with a randomized treatment order that are to be evaluated with an RT using a 5% significance level. Furthermore, we do not recommend use of the PND, because of its low power in the RT.

Particle Tracking on the BNL Relativistic Heavy Ion Collider

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

Dell, G. F.

1986-08-07

Tracking studies including the effects of random multipole errors as well as the effects of random and systematic multipole errors have been made for RHIC. Initial results for operating at an off diagonal working point are discussed.

Within-Subject Testing of the Signaled-Reinforcement Effect on Operant Responding as Measured by Response Rate and Resistance to Change

ERIC Educational Resources Information Center

Reed, Phil; Doughty, Adam H.

2005-01-01

Response rates under random-interval schedules are lower when a brief (500 ms) signal accompanies reinforcement than when there is no signal. The present study examined this signaled-reinforcement effect and its relation to resistance to change. In Experiment 1, rats responded on a multiple random-interval 60-s random-interval 60-s schedule, with…

Effect of intervention programs in schools to reduce screen time: a meta-analysis.

PubMed

Friedrich, Roberta Roggia; Polet, Jéssica Pinto; Schuch, Ilaine; Wagner, Mário Bernardes

2014-01-01

to evaluate the effects of intervention program strategies on the time spent on activities such as watching television, playing videogames, and using the computer among schoolchildren. a search for randomized controlled trials available in the literature was performed in the following electronic databases: PubMed, Lilacs, Embase, Scopus, Web of Science, and Cochrane Library using the following Keywords randomized controlled trial, intervention studies, sedentary lifestyle, screen time, and school. A summary measure based on the standardized mean difference was used with a 95% confidence interval. a total of 1,552 studies were identified, of which 16 were included in the meta-analysis. The interventions in the randomized controlled trials (n=8,785) showed a significant effect in reducing screen time, with a standardized mean difference (random effect) of: -0.25 (-0.37, -0.13), p<0.01. interventions have demonstrated the positive effects of the decrease of screen time among schoolchildren. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Practicing Field Hockey Skills Along the Contextual Interference Continuum: A Comparison of Five Practice Schedules

PubMed Central

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J. Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners. PMID:24149204

Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

PubMed

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

Observational studies are complementary to randomized controlled trials.

PubMed

Grootendorst, Diana C; Jager, Kitty J; Zoccali, Carmine; Dekker, Friedo W

2010-01-01

Randomized controlled trials (RCTs) are considered the gold standard study design to investigate the effect of health interventions, including treatment. However, in some situations, it may be unnecessary, inappropriate, impossible, or inadequate to perform an RCT. In these special situations, well-designed observational studies, including cohort and case-control studies, may provide an alternative to doing nothing in order to obtain estimates of treatment effect. It should be noted that such studies should be performed with caution and correctly. The aims of this review are (1) to explain why RCTs are considered the optimal study design to evaluate treatment effects, (2) to describe the situations in which an RCT is not possible and observational studies are an adequate alternative, and (3) to explain when randomization is not needed and can be approximated in observational studies. Examples from the nephrology literature are used for illustration. Copyright 2009 S. Karger AG, Basel.

The prognostic impact of cancer stem-like cell biomarker aldehyde dehydrogenase-1 (ALDH1) in ovarian cancer: A meta-analysis.

PubMed

Ruscito, Ilary; Darb-Esfahani, Silvia; Kulbe, Hagen; Bellati, Filippo; Zizzari, Ilaria Grazia; Rahimi Koshkaki, Hassan; Napoletano, Chiara; Caserta, Donatella; Rughetti, Aurelia; Kessler, Mirjana; Sehouli, Jalid; Nuti, Marianna; Braicu, Elena Ioana

2018-05-10

To investigate the association of cancer stem cell biomarker aldehyde dehydrogenase-1 (ALDH1) with ovarian cancer patients' prognosis and clinico-pathological characteristics. The electronic searches were performed in January 2018 through the databases PubMed, MEDLINE and Scopus by searching the terms: "ovarian cancer" AND "immunohistochemistry" AND ["aldehyde dehydrogenase-1" OR "ALDH1" OR "cancer stem cell"]. Studies evaluating the impact of ALDH1 expression on ovarian cancer survival and clinico-pathological variables were selected. 233 studies were retrieved. Thirteen studies including 1885 patients met all selection criteria. ALDH1-high expression was found to be significantly associated with poor 5-year OS (OR = 3.46; 95% CI: 1.61-7.42; P = 0.001, random effects model) and 5-year PFS (OR = 2.14; 95% CI: 1.11-4.13; P = 0.02, random effects model) in ovarian cancer patients. No correlation between ALDH1 expression and tumor histology (OR = 0.60; 95% CI: 0.36-1.02; P = 0.06, random effects model), FIGO Stage (OR = 0.65; 95% CI: 0.33-1.30; P = 0.22, random effects model), tumor grading (OR = 0.76; 95% CI: 0.40-1.45; P = 0.41, random effects model) lymph nodal status (OR = 2.05; 95% CI: 0.81-5.18; P = 0.13, random effects model) or patients' age at diagnosis (OR = 0.83; 95% CI: 0.54-1.29; P = 0.41, fixed effects model) was identified. Basing on the available evidence, this meta-analysis showed that high levels of ALDH1 expression correlate with worse OS and PFS in ovarian cancer patients. Copyright © 2018. Published by Elsevier Inc.

Meta-analysis in evidence-based healthcare: a paradigm shift away from random effects is overdue.

PubMed

Doi, Suhail A R; Furuya-Kanamori, Luis; Thalib, Lukman; Barendregt, Jan J

2017-12-01

Each year up to 20 000 systematic reviews and meta-analyses are published whose results influence healthcare decisions, thus making the robustness and reliability of meta-analytic methods one of the world's top clinical and public health priorities. The evidence synthesis makes use of either fixed-effect or random-effects statistical methods. The fixed-effect method has largely been replaced by the random-effects method as heterogeneity of study effects led to poor error estimation. However, despite the widespread use and acceptance of the random-effects method to correct this, it too remains unsatisfactory and continues to suffer from defective error estimation, posing a serious threat to decision-making in evidence-based clinical and public health practice. We discuss here the problem with the random-effects approach and demonstrate that there exist better estimators under the fixed-effect model framework that can achieve optimal error estimation. We argue for an urgent return to the earlier framework with updates that address these problems and conclude that doing so can markedly improve the reliability of meta-analytical findings and thus decision-making in healthcare.

The Effects of Team-Based Learning on Social Studies Knowledge Acquisition in High School

ERIC Educational Resources Information Center

Wanzek, Jeanne; Vaughn, Sharon; Kent, Shawn C.; Swanson, Elizabeth A.; Roberts, Greg; Haynes, Martha; Fall, Anna-Mária; Stillman-Spisak, Stephanie J.; Solis, Michael

2014-01-01

This randomized control trial examined the efficacy of team-based learning implemented within 11th-grade social studies classes. A randomized blocked design was implemented with 26 classes randomly assigned to treatment or comparison. In the treatment classes teachers implemented team-based learning practices to support students in engaging in…

Clinical Knowledge from Observational Studies: Everything You Wanted to Know but Were Afraid to Ask.

PubMed

Gershon, Andrea S; Jafarzadeh, S Reza; Wilson, Kevin C; Walkey, Allan J

2018-05-07

Well-done randomized trials provide accurate estimates of treatment effect by producing groups that are similar on all measures except for the intervention of interest. However, inferences of efficacy in tightly-controlled experimental settings may not translate into similar effectiveness in real-world settings. Observational studies generally enable inferences over a wider range of patient characteristics and evaluation of a broader range of outcomes over a longer period than randomized trials. However, clinicians are often reluctant to incorporate the findings of observational studies into clinical practice. Reason for uncertainty regarding observational studies include a lack of familiarity with observational research methods, occasional disagreements between results of observational studies and randomized trials, the perceived risk of spurious results from systematic bias, and prior teaching that randomized trials are the most reliable source of medical evidence. We propose that a better understanding of observational research will enhance clinicians' ability to distinguish reliable observational studies from those that are subjected to biases and, therefore, provide more confidence to apply observational research results into clinical practice when appropriate. Herein, we explain why observational studies may be perceived as less conclusive than randomized trials, address situations in which observational research and randomized trials produced different findings, and provide information on observational study design so that quality can be evaluated. We conclude that observational research is a valuable source of medical evidence and that clinical action is strongest when supported by both high quality observational studies and randomized trials.

Risk of Lymphoma in Patients With Inflammatory Bowel Disease Treated With Anti-Tumor Necrosis Factor Alpha Agents: A Systematic Review and Meta-analysis.

PubMed

Yang, Chen; Huang, Junlin; Huang, Xiaowen; Huang, Shaozhuo; Cheng, Jiaxin; Liao, Weixin; Chen, Xuewen; Wang, Xueyi; Dai, Shixue

2018-05-12

The association between anti-tumor necrosis factor alpha agents and the risk of lymphoma in patients with inflammatory bowel disease has already been sufficiently reported. However, the results of these studies are inconsistent. Hence, this analysis was conducted to investigate whether anti-tumor necrosis factor alpha agents can increase the risk of lymphoma in inflammatory bowel disease patients. MEDLINE, EMBASE and the Cochrane Library were searched to identify relevant studies which evaluated the risk of lymphoma in inflammatory bowel disease patients treated with anti-tumor necrosis factor alpha agents. A random-effects meta-analysis was performed to calculate the pooled incidence rate ratios as well as risk ratios. Twelve studies comprising 285811 participants were included. The result showed that there was no significantly increased risk of lymphoma between anti-tumor necrosis factor alpha agents exposed and anti-tumor necrosis factor alpha agents unexposed groups (random effects: incidence rate ratio [IRR], 1.43 95%CI, 0.91-2.25, p= 0.116; random effects: risk ratio [RR], 0.83 95%CI, 0.47-1.48, p=0.534). However, monotherapy of anti-tumor necrosis factor alpha agents (random effects: IRR=1.65, 95%CI, 1.16-2.35; p=0.006; random effects: RR=1.00, 95%CI, 0.39-2.59; p=0.996) or combination therapy (random effects: IRR=3.36, 95%CI, 2.23-5.05; p< 0.001; random effects: RR=1.90, 95%CI, 0.66-5.44; p=0.233) can significantly increase the risk of lymphoma. Exposition of anti-tumor necrosis factor alpha agents in patients with inflammatory bowel disease is not associated with a higher risk of lymphoma. Combination therapy and anti-tumor necrosis factor alpha agents monotherapy can significantly increase the risk of lymphoma in patients with inflammatory bowel disease.

The need for randomization in animal trials: an overview of systematic reviews.

PubMed

Hirst, Jennifer A; Howick, Jeremy; Aronson, Jeffrey K; Roberts, Nia; Perera, Rafael; Koshiaris, Constantinos; Heneghan, Carl

2014-01-01

Randomization, allocation concealment, and blind outcome assessment have been shown to reduce bias in human studies. Authors from the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES) collaboration recently found that these features protect against bias in animal stroke studies. We extended the scope the work from CAMARADES to include investigations of treatments for any condition. We conducted an overview of systematic reviews. We searched Medline and Embase for systematic reviews of animal studies testing any intervention (against any control) and we included any disease area and outcome. We included reviews comparing randomized versus not randomized (but otherwise controlled), concealed versus unconcealed treatment allocation, or blinded versus unblinded outcome assessment. Thirty-one systematic reviews met our inclusion criteria: 20 investigated treatments for experimental stroke, 4 reviews investigated treatments for spinal cord diseases, while 1 review each investigated treatments for bone cancer, intracerebral hemorrhage, glioma, multiple sclerosis, Parkinson's disease, and treatments used in emergency medicine. In our sample 29% of studies reported randomization, 15% of studies reported allocation concealment, and 35% of studies reported blinded outcome assessment. We pooled the results in a meta-analysis, and in our primary analysis found that failure to randomize significantly increased effect sizes, whereas allocation concealment and blinding did not. In our secondary analyses we found that randomization, allocation concealment, and blinding reduced effect sizes, especially where outcomes were subjective. Our study demonstrates the need for randomization, allocation concealment, and blind outcome assessment in animal research across a wide range of outcomes and disease areas. Since human studies are often justified based on results from animal studies, our results suggest that unduly biased animal studies should not be allowed to constitute part of the rationale for human trials.

Approximate Confidence Intervals for Moment-Based Estimators of the Between-Study Variance in Random Effects Meta-Analysis

ERIC Educational Resources Information Center

Jackson, Dan; Bowden, Jack; Baker, Rose

2015-01-01

Moment-based estimators of the between-study variance are very popular when performing random effects meta-analyses. This type of estimation has many advantages including computational and conceptual simplicity. Furthermore, by using these estimators in large samples, valid meta-analyses can be performed without the assumption that the treatment…

Efficacy of Virtual Patients in Medical Education: A Meta-Analysis of Randomized Studies

ERIC Educational Resources Information Center

Consorti, Fabrizio; Mancuso, Rosaria; Nocioni, Martina; Piccolo, Annalisa

2012-01-01

A meta-analysis was performed to assess the Effect Size (ES) from randomized studies comparing the effect of educational interventions in which Virtual patients (VPs) were used either as an alternative method or additive to usual curriculum versus interventions based on more traditional methods. Meta-analysis was designed, conducted and reported…

The Role of Exposure Condition in the Effectiveness of Explicit Correction

ERIC Educational Resources Information Center

Yilmaz, Yucel

2016-01-01

This article reports on a study that investigated the effects of two feedback exposure conditions on the acquisition of two Turkish morphemes. The study followed a randomized experimental design with an immediate and a delayed posttest. Forty-two Chinese-speaking learners of Turkish were randomly assigned to one of three groups: receivers,…

Complex Applications of HLM in Studies of Science and Mathematics Achievement: Cross-Classified Random Effects Models

ERIC Educational Resources Information Center

Moreno, Mario; Harwell, Michael; Guzey, S. Selcen; Phillips, Alison; Moore, Tamara J.

2016-01-01

Hierarchical linear models have become a familiar method for accounting for a hierarchical data structure in studies of science and mathematics achievement. This paper illustrates the use of cross-classified random effects models (CCREMs), which are likely less familiar. The defining characteristic of CCREMs is a hierarchical data structure…

Study protocol: a randomized controlled trial investigating the effects of a psychosexual training program for adolescents with autism spectrum disorder.

PubMed

Visser, Kirsten; Greaves-Lord, Kirstin; Tick, Nouchka T; Verhulst, Frank C; Maras, Athanasios; van der Vegt, Esther J M

2015-08-28

Previous research shows that adolescents with autism spectrum disorder (ASD) run several risks in their psychosexual development and that these adolescents can have limited access to reliable information on puberty and sexuality, emphasizing the need for specific guidance of adolescents with ASD in their psychosexual development. Few studies have investigated the effects of psychosexual training programs for adolescents with ASD and to date no randomized controlled trials are available to study the effects of psychosexual interventions for this target group. The randomized controlled trial (RCT) described in this study protocol aims to investigate the effects of the Tackling Teenage Training (TTT) program on the psychosexual development of adolescents with ASD. This parallel clinical trial, conducted in the South-West of the Netherlands, has a simple equal randomization design with an intervention and a waiting-list control condition. Two hundred adolescents and their parents participate in this study. We assess the participants in both conditions using self-report as well as parent-report questionnaires at three time points during 1 year: at baseline (T1), post-treatment (T2), and for follow-up (T3). To our knowledge, the current study is the first that uses a randomized controlled design to study the effects of a psychosexual training program for adolescents with ASD. It has a number of methodological strengths, namely a large sample size, a wide range of functionally relevant outcome measures, the use of multiple informants, and a standardized research and intervention protocol. Also some limitations of the described study are identified, for instance not making a comparison between two treatment conditions, and no use of blinded observational measures to investigate the ecological validity of the research results. Dutch Trial Register NTR2860. Registered on 20 April 2011.

Systematic review and meta-analysis of secondary prophylaxis for prevention of HIV-related toxoplasmic encephalitis relapse using trimethoprim-sulfamethoxazole.

PubMed

Connolly, Mark P; Haitsma, Gertruud; Hernández, Adrián V; Vidal, José E

2017-09-01

A recent systematic literature and meta-analysis reported relative efficacy of trimethoprim-sulfamethoxazole (TMP-SMX) for the treatment of toxoplasmic encephalitis (TE) in HIV-infected adults. Here, we estimated relapse rates during secondary prophylaxis with TMP-SMX, and further explored differences in relapse rates prior to introduction of highly active antiretroviral therapy (HAART) and the widespread adoption of HAART. A systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials yielded 707 studies whereby 663 were excluded after abstract screening, and 38 were excluded after full review leaving 6 studies for extraction. We performed double data extraction with a third-party adjudicator. Study designs varied with only one randomized study, four prospective cohorts and one retrospective cohort. Relapse rates were transformed using the Freeman-Tukey method and pooled using both fixed-effect and random-effects meta-analysis models. The TMP-SMX relapse rate was 16.4% (95% CI = 6.2% to 30.3%) based on random-effects models. When the disaggregated pre-HAART studies (n = 4) were included, the relapse rate was 14.9% (random effects; 95% CI = 3.7% to 31.9%). Analysis of two post-HAART studies indicated a relapse rate of 19.2% (random effects; 95% CI = 2.8% to 45.6%). Comparing the relapse rates between pre- and post-HAART studies were contrary to what might be expected based on known benefits of HAART therapy in this population. Nevertheless, cautious interpretation is necessary considering the heterogeneity of the included studies and a limited number of subjects receiving TMP-SMX reported in the post-HAART era.

Random-effects linear modeling and sample size tables for two special crossover designs of average bioequivalence studies: the four-period, two-sequence, two-formulation and six-period, three-sequence, three-formulation designs.

PubMed

Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael

2013-12-01

Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.

Logistic random effects regression models: a comparison of statistical packages for binary and ordinal outcomes.

PubMed

Li, Baoyue; Lingsma, Hester F; Steyerberg, Ewout W; Lesaffre, Emmanuel

2011-05-23

Logistic random effects models are a popular tool to analyze multilevel also called hierarchical data with a binary or ordinal outcome. Here, we aim to compare different statistical software implementations of these models. We used individual patient data from 8509 patients in 231 centers with moderate and severe Traumatic Brain Injury (TBI) enrolled in eight Randomized Controlled Trials (RCTs) and three observational studies. We fitted logistic random effects regression models with the 5-point Glasgow Outcome Scale (GOS) as outcome, both dichotomized as well as ordinal, with center and/or trial as random effects, and as covariates age, motor score, pupil reactivity or trial. We then compared the implementations of frequentist and Bayesian methods to estimate the fixed and random effects. Frequentist approaches included R (lme4), Stata (GLLAMM), SAS (GLIMMIX and NLMIXED), MLwiN ([R]IGLS) and MIXOR, Bayesian approaches included WinBUGS, MLwiN (MCMC), R package MCMCglmm and SAS experimental procedure MCMC.Three data sets (the full data set and two sub-datasets) were analysed using basically two logistic random effects models with either one random effect for the center or two random effects for center and trial. For the ordinal outcome in the full data set also a proportional odds model with a random center effect was fitted. The packages gave similar parameter estimates for both the fixed and random effects and for the binary (and ordinal) models for the main study and when based on a relatively large number of level-1 (patient level) data compared to the number of level-2 (hospital level) data. However, when based on relatively sparse data set, i.e. when the numbers of level-1 and level-2 data units were about the same, the frequentist and Bayesian approaches showed somewhat different results. The software implementations differ considerably in flexibility, computation time, and usability. There are also differences in the availability of additional tools for model evaluation, such as diagnostic plots. The experimental SAS (version 9.2) procedure MCMC appeared to be inefficient. On relatively large data sets, the different software implementations of logistic random effects regression models produced similar results. Thus, for a large data set there seems to be no explicit preference (of course if there is no preference from a philosophical point of view) for either a frequentist or Bayesian approach (if based on vague priors). The choice for a particular implementation may largely depend on the desired flexibility, and the usability of the package. For small data sets the random effects variances are difficult to estimate. In the frequentist approaches the MLE of this variance was often estimated zero with a standard error that is either zero or could not be determined, while for Bayesian methods the estimates could depend on the chosen "non-informative" prior of the variance parameter. The starting value for the variance parameter may be also critical for the convergence of the Markov chain.

Using instrumental variables to disentangle treatment and placebo effects in blinded and unblinded randomized clinical trials influenced by unmeasured confounders

NASA Astrophysics Data System (ADS)

Chaibub Neto, Elias

2016-11-01

Clinical trials traditionally employ blinding as a design mechanism to reduce the influence of placebo effects. In practice, however, it can be difficult or impossible to blind study participants and unblinded trials are common in medical research. Here we show how instrumental variables can be used to quantify and disentangle treatment and placebo effects in randomized clinical trials comparing control and active treatments in the presence of confounders. The key idea is to use randomization to separately manipulate treatment assignment and psychological encouragement conversations/interactions that increase the participants’ desire for improved symptoms. The proposed approach is able to improve the estimation of treatment effects in blinded studies and, most importantly, opens the doors to account for placebo effects in unblinded trials.

Dynamic probability of reinforcement for cooperation: Random game termination in the centipede game.

PubMed

Krockow, Eva M; Colman, Andrew M; Pulford, Briony D

2018-03-01

Experimental games have previously been used to study principles of human interaction. Many such games are characterized by iterated or repeated designs that model dynamic relationships, including reciprocal cooperation. To enable the study of infinite game repetitions and to avoid endgame effects of lower cooperation toward the final game round, investigators have introduced random termination rules. This study extends previous research that has focused narrowly on repeated Prisoner's Dilemma games by conducting a controlled experiment of two-player, random termination Centipede games involving probabilistic reinforcement and characterized by the longest decision sequences reported in the empirical literature to date (24 decision nodes). Specifically, we assessed mean exit points and cooperation rates, and compared the effects of four different termination rules: no random game termination, random game termination with constant termination probability, random game termination with increasing termination probability, and random game termination with decreasing termination probability. We found that although mean exit points were lower for games with shorter expected game lengths, the subjects' cooperativeness was significantly reduced only in the most extreme condition with decreasing computer termination probability and an expected game length of two decision nodes. © 2018 Society for the Experimental Analysis of Behavior.

Analog model for quantum gravity effects: phonons in random fluids.

PubMed

Krein, G; Menezes, G; Svaiter, N F

2010-09-24

We describe an analog model for quantum gravity effects in condensed matter physics. The situation discussed is that of phonons propagating in a fluid with a random velocity wave equation. We consider that there are random fluctuations in the reciprocal of the bulk modulus of the system and study free phonons in the presence of Gaussian colored noise with zero mean. We show that, in this model, after performing the random averages over the noise function a free conventional scalar quantum field theory describing free phonons becomes a self-interacting model.

Quantum random walks on congested lattices and the effect of dephasing.

PubMed

Motes, Keith R; Gilchrist, Alexei; Rohde, Peter P

2016-01-27

We consider quantum random walks on congested lattices and contrast them to classical random walks. Congestion is modelled on lattices that contain static defects which reverse the walker's direction. We implement a dephasing process after each step which allows us to smoothly interpolate between classical and quantum random walks as well as study the effect of dephasing on the quantum walk. Our key results show that a quantum walker escapes a finite boundary dramatically faster than a classical walker and that this advantage remains in the presence of heavily congested lattices.

Baseline adjustments for binary data in repeated cross-sectional cluster randomized trials.

PubMed

Nixon, R M; Thompson, S G

2003-09-15

Analysis of covariance models, which adjust for a baseline covariate, are often used to compare treatment groups in a controlled trial in which individuals are randomized. Such analysis adjusts for any baseline imbalance and usually increases the precision of the treatment effect estimate. We assess the value of such adjustments in the context of a cluster randomized trial with repeated cross-sectional design and a binary outcome. In such a design, a new sample of individuals is taken from the clusters at each measurement occasion, so that baseline adjustment has to be at the cluster level. Logistic regression models are used to analyse the data, with cluster level random effects to allow for different outcome probabilities in each cluster. We compare the estimated treatment effect and its precision in models that incorporate a covariate measuring the cluster level probabilities at baseline and those that do not. In two data sets, taken from a cluster randomized trial in the treatment of menorrhagia, the value of baseline adjustment is only evident when the number of subjects per cluster is large. We assess the generalizability of these findings by undertaking a simulation study, and find that increased precision of the treatment effect requires both large cluster sizes and substantial heterogeneity between clusters at baseline, but baseline imbalance arising by chance in a randomized study can always be effectively adjusted for. Copyright 2003 John Wiley & Sons, Ltd.

No evidence for intervention-dependent influence of methodological features on treatment effect.

PubMed

Jacobs, Wilco C H; Kruyt, Moyo C; Moojen, Wouter A; Verbout, Ab J; Oner, F Cumhur

2013-12-01

The goal of this systematic review was to evaluate if the influence of methodological features on treatment effect differs between types of intervention. MEDLINE, Embase, Web of Science, Cochrane methodology register, and reference lists were searched for meta-epidemiologic studies on the influence of methodological features on treatment effect. Studies analyzing influence of methodological features related to internal validity were included. We made a distinction among surgical, pharmaceutical, and therapeutical as separate types of intervention. Heterogeneity was calculated to identify differences among these types. Fourteen meta-epidemiologic studies were found with 51 estimates of influence of methodological features on treatment effect. Heterogeneity was observed among the intervention types for randomization. Surgical intervention studies showed a larger treatment effect when randomized; this was in contrast to pharmaceutical studies that found the opposite. For allocation concealment and double blinding, the influence of methodological features on the treatment effect was comparable across different types of intervention. For the remaining methodological features, there were insufficient observations. The influence of allocation concealment and double blinding on the treatment effect is consistent across studies of different interventional types. The influence of randomization although, may be different between surgical and nonsurgical studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Cost-Effectiveness of a Long-Term Internet-Delivered Worksite Health Promotion Programme on Physical Activity and Nutrition: A Cluster Randomized Controlled Trial

ERIC Educational Resources Information Center

Robroek, Suzan J. W.; Polinder, Suzanne; Bredt, Folef J.; Burdorf, Alex

2012-01-01

This study aims to evaluate the cost-effectiveness of a long-term workplace health promotion programme on physical activity (PA) and nutrition. In total, 924 participants enrolled in a 2-year cluster randomized controlled trial, with departments (n = 74) within companies (n = 6) as the unit of randomization. The intervention was compared with a…

The Modern Design of Experiments for Configuration Aerodynamics: A Case Study

NASA Technical Reports Server (NTRS)

DeLoach, Richard

2006-01-01

The effects of slowly varying and persisting covariate effects on the accuracy and precision of experimental result is reviewed, as is the rationale for run-order randomization as a quality assurance tactic employed in the Modern Design of Experiments (MDOE) to defend against such effects. Considerable analytical complexity is introduced by restrictions on randomization in configuration aerodynamics tests because they involve hard-to-change configuration variables that cannot be randomized conveniently. Tradeoffs are examined between quality and productivity associated with varying degrees of rigor in accounting for such randomization restrictions. Certain characteristics of a configuration aerodynamics test are considered that may justify a relaxed accounting for randomization restrictions to achieve a significant reduction in analytical complexity with a comparably negligible adverse impact on the validity of the experimental results.

A Course in... Topics in Random Media.

ERIC Educational Resources Information Center

Glandt, Eduardo D.

1988-01-01

Describes an engineering course for graduate study in random media. Summarizes random media as bulk properties of ordered and disordered two-phase materials. Gives course outline for one semester. Topics include: disordered systems, microstructure determination, survey of models, connectivity, and effective properties. (MVL)

A Randomized Clinical Trial of Cognitive-Behavioral Treatment for PTSD in Women

DTIC Science & Technology

2004-10-01

This study is a randomized clinical trial comparing two types of individual psychotherapy for treating PTSD in 384 female veterans and active duty...Exposure therapy will be more effective than Present Centered Therapy for the treatment of PTSD in female veterans and active duty personnel. The study has entered the randomized phase. There are no conclusions to date.

Non-steroidal anti-inflammatory drugs for the common cold.

PubMed

Kim, Soo Young; Chang, Yoon-Jung; Cho, Hye Min; Hwang, Ye-Won; Moon, Yoo Sun

2015-09-21

Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely used for the treatment of pain and fever associated with the common cold. To determine the effects of NSAIDs versus placebo (and other treatments) on signs and symptoms of the common cold, and to determine any adverse effects of NSAIDs in people with the common cold. We searched CENTRAL (2015, Issue 4, April), (January 1966 to April week 3, 2015), EMBASE (January 1980 to April 2015), CINAHL (January 1982 to April 2015) and ProQuest Digital Dissertations (January 1938 to April 2015). Randomised controlled trials (RCTs) of NSAIDS in adults or children with the common cold. Four review authors extracted data. We subdivided trials into placebo-controlled RCTs and head-to-head comparisons of NSAIDs. We extracted and summarised data on global analgesic effects (such as reduction of headache and myalgia), non-analgesic effects (such as reduction of nasal symptoms, cough, sputum and sneezing) and side effects. We expressed dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CI) and continuous data as mean differences (MD) or standardised mean differences (SMD). We pooled data using the fixed-effect and random-effects models. We included nine RCTs with 1069 participants, describing 37 comparisons: six were NSAIDs versus placebo and three were NSAIDs versus NSAIDs. The overall risk of bias in the included studies was mixed. In a pooled analysis, NSAIDs did not significantly reduce the total symptom score (SMD -0.40, 95% CI -1.03 to 0.24, three studies, random-effects model), or duration of colds (MD -0.23, 95% CI -1.75 to 1.29, two studies, random-effects model). For respiratory symptoms, cough did not improve (SMD -0.05, 95% CI -0.66 to 0.56, two studies, random-effects model) but the sneezing score significantly improved (SMD -0.44, 95% CI -0.75 to -0.12, two studies, random-effects model). For outcomes related to the analgesic effects of NSAIDs (headache, ear pain, and muscle and joint pain) the treatment produced significant benefits. The risk of adverse effects was not high with NSAIDs (RR 2.94, 95% CI 0.51 to 17.03, two studies, random-effects model) but it is difficult to conclude that such drugs are no different from placebo. The quality of the evidence may be estimated as 'moderate' because of imprecision. The major limitations of this review are that the results of the studies are quite diverse and the number of studies for one result is quite small. NSAIDs are somewhat effective in relieving the discomfort caused by a cold but there is no clear evidence of their effect in easing respiratory symptoms. The balance of benefit and harms needs to be considered when using NSAIDs for colds.

The role of randomized cluster crossover trials for comparative effectiveness testing in anesthesia: design of the Benzodiazepine-Free Cardiac Anesthesia for Reduction in Postoperative Delirium (B-Free) trial.

PubMed

Spence, Jessica; Belley-Côté, Emilie; Lee, Shun Fu; Bangdiwala, Shrikant; Whitlock, Richard; LeManach, Yannick; Syed, Summer; Lamy, Andre; Jacobsohn, Eric; MacIsaac, Sarah; Devereaux, P J; Connolly, Stuart

2018-07-01

Increasingly, clinicians and researchers recognize that studies of interventions need to evaluate not only their therapeutic efficacy (i.e., the effect on an outcome in ideal, controlled settings) but also their real-world effectiveness in broad, unselected patient groups. Effectiveness trials inform clinical practice by comparing variations in therapeutic approaches that fall within the standard of care. In this article, we discuss the need for studies of comparative effectiveness in anesthesia and the limitations of individual patient randomized-controlled trials in determining comparative effectiveness. We introduce the concept of randomized cluster crossover trials as a means of answering questions of comparative effectiveness in anesthesia, using the design of the Benzodiazepine-Free Cardiac Anesthesia for Reduction in Postoperative Delirium (B-Free) trial (Clinicaltrials.gov identifier NCT03053869).

Designing Studies That Would Address the Multilayered Nature of Health Care

PubMed Central

Pennell, Michael; Rhoda, Dale; Hade, Erinn M.; Paskett, Electra D.

2010-01-01

We review design and analytic methods available for multilevel interventions in cancer research with particular attention to study design, sample size requirements, and potential to provide statistical evidence for causal inference. The most appropriate methods will depend on the stage of development of the research and whether randomization is possible. Early on, fractional factorial designs may be used to screen intervention components, particularly when randomization of individuals is possible. Quasi-experimental designs, including time-series and multiple baseline designs, can be useful once the intervention is designed because they require few sites and can provide the preliminary evidence to plan efficacy studies. In efficacy and effectiveness studies, group-randomized trials are preferred when randomization is possible and regression discontinuity designs are preferred otherwise if assignment based on a quantitative score is possible. Quasi-experimental designs may be used, especially when combined with recent developments in analytic methods to reduce bias in effect estimates. PMID:20386057

Conflicting results between randomized trials and observational studies on the impact of proton pump inhibitors on cardiovascular events when coadministered with dual antiplatelet therapy: systematic review.

PubMed

Melloni, Chiara; Washam, Jeffrey B; Jones, W Schuyler; Halim, Sharif A; Hasselblad, Victor; Mayer, Stephanie B; Heidenfelder, Brooke L; Dolor, Rowena J

2015-01-01

Discordant results have been reported on the effects of concomitant use of proton pump inhibitors (PPIs) and dual antiplatelet therapy (DAPT) for cardiovascular outcomes. We conducted a systematic review comparing the effectiveness and safety of concomitant use of PPIs and DAPT in the postdischarge treatment of unstable angina/non-ST-segment-elevation myocardial infarction patients. We searched for clinical studies in MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews, from 1995 to 2012. Reviewers screened and extracted data, assessed applicability and quality, and graded the strength of evidence. We performed meta-analyses of direct comparisons when outcomes and follow-up periods were comparable. Thirty-five studies were eligible. Five (4 randomized controlled trials and 1 observational) assessed the effect of omeprazole when added to DAPT; the other 30 (observational) assessed the effect of PPIs as a class when compared with no PPIs. Random-effects meta-analyses of the studies assessing PPIs as a class consistently reported higher event rates in patients receiving PPIs for various clinical outcomes at 1 year (composite ischemic end points, all-cause mortality, nonfatal MI, stroke, revascularization, and stent thrombosis). However, the results from randomized controlled trials evaluating omeprazole compared with placebo showed no difference in ischemic outcomes, despite a reduction in upper gastrointestinal bleeding with omeprazole. Large, well-conducted observational studies of PPIs and randomized controlled trials of omeprazole seem to provide conflicting results for the effect of PPIs on cardiovascular outcomes when coadministered with DAPT. Prospective trials that directly compare pharmacodynamic parameters and clinical events among specific PPI agents in patients with unstable angina/non-ST-segment-elevation myocardial infarction treated with DAPT are warranted. © 2015 American Heart Association, Inc.

Treatment of Adolescent Marijuana Abuse: A Randomized Clinical Trial. Presentation 1: Structure of the Cannabis Youth Treatment Study.

ERIC Educational Resources Information Center

Titus, Janet C.; Dennis, Michael L.; Diamond, Guy; Godley, Susan H.; Babor, Thomas; Donaldson, Jean; Herrell, James; Tims, Frank; Webb, Charles

The Cannabis Youth Treatment (CYT) study is a multi-site randomized field experiment examining five outpatient treatment protocols for adolescents who abuse or are dependent on marijuana. The purpose of the CYT project is twofold: (a) to test the relative clinical effectiveness and cost-effectiveness of five promising interventions targeted at…

Randomized Study of the Impact of Cooperative Learning: Distance Education in Public Health

ERIC Educational Resources Information Center

Riley, William; Anderson, Paige

2006-01-01

The purpose of this study is to explore the effects of cooperative learning on cognitive outcomes in a public health graduate level Web-based distance education course. Specifically, the authors use a randomized control trial to determine the impact of two teaching pedagogies on learning effectiveness in three areas of the cognitive domain: (1)…

Confidence Intervals for the Between-Study Variance in Random Effects Meta-Analysis Using Generalised Cochran Heterogeneity Statistics

ERIC Educational Resources Information Center

Jackson, Dan

2013-01-01

Statistical inference is problematic in the common situation in meta-analysis where the random effects model is fitted to just a handful of studies. In particular, the asymptotic theory of maximum likelihood provides a poor approximation, and Bayesian methods are sensitive to the prior specification. Hence, less efficient, but easily computed and…

Challenging Medical Students with an Interim Assessment: A Positive Effect on Formal Examination Score in a Randomized Controlled Study

ERIC Educational Resources Information Center

Bekkink, Marleen Olde; Donders, Rogier; van Muijen, Goos N. P.; Ruiter, Dirk J.

2012-01-01

Until now, positive effects of assessment at a medical curriculum level have not been demonstrated. This study was performed to determine whether an interim assessment, taken during a small group work session of an ongoing biomedical course, results in students' increased performance at the formal course examination. A randomized controlled trial…

The Effects of Math Video Games on Learning: A Randomized Evaluation Study with Innovative Impact Estimation Techniques. CRESST Report 841

ERIC Educational Resources Information Center

Chung, Gregory K. W. K.; Choi, Kilchan; Baker, Eva L.; Cai, Li

2014-01-01

A large-scale randomized controlled trial tested the effects of researcher-developed learning games on a transfer measure of fractions knowledge. The measure contained items similar to standardized assessments. Thirty treatment and 29 control classrooms (~1500 students, 9 districts, 26 schools) participated in the study. Students in treatment…

Effects of Joint Attention Mediated Learning for Toddlers with Autism Spectrum Disorders: An Initial Randomized Controlled Study

ERIC Educational Resources Information Center

Schertz, Hannah H.; Odom, Samuel L.; Baggett, Kathleen M.; Sideris, John H.

2013-01-01

The purpose of this study was to determine effects of the Joint Attention Mediated Learning (JAML) intervention on acquisition of joint attention and other early social communication competencies for toddlers with autism spectrum disorders (ASD). Twenty-three parents and their toddlers were randomly assigned to JAML or a control condition.…

Increase in the Random Dopant Induced Threshold Fluctuations and Lowering in Sub 100 nm MOSFETs Due to Quantum Effects: A 3-D Density-Gradient Simulation Study

NASA Technical Reports Server (NTRS)

Asenov, Asen; Slavcheva, G.; Brown, A. R.; Davies, J. H.; Saini, S.

2000-01-01

In this paper we present a detailed simulation study of the influence of quantum mechanical effects in the inversion layer on random dopant induced threshold voltage fluctuations and lowering in sub 100 nm MOSFETs. The simulations have been performed using a 3-D implementation of the density gradient (DG) formalism incorporated in our established 3-D atomistic simulation approach. This results in a self-consistent 3-D quantum mechanical picture, which implies not only the vertical inversion layer quantisation but also the lateral confinement effects related to current filamentation in the 'valleys' of the random potential fluctuations. We have shown that the net result of including quantum mechanical effects, while considering statistical dopant fluctuations, is an increase in both threshold voltage fluctuations and lowering. At the same time, the random dopant induced threshold voltage lowering partially compensates for the quantum mechanical threshold voltage shift in aggressively scaled MOSFETs with ultrathin gate oxides.

Randomized Trial of the Effect of Four Second-Generation Antipsychotics and One First-Generation Antipsychotic on Cigarette Smoking, Alcohol, and Drug Use in Chronic Schizophrenia.

PubMed

Mohamed, Somaia; Rosenheck, Robert A; Lin, Haiqun; Swartz, Marvin; McEvoy, Joseph; Stroup, Scott

2015-07-01

No large-scale randomized trial has compared the effect of different second-generation antipsychotic drugs and any first-generation drug on alcohol, drug and nicotine use in patients with schizophrenia. The Clinical Antipsychotic Trial of Intervention Effectiveness study randomly assigned 1432 patients formally diagnosed with schizophrenia to four second-generation antipsychotic drugs (olanzapine, risperidone quetiapine, and ziprasidone) and one first-generation antipsychotic (perphenazine) and followed them for up to 18 months. Secondary outcome data documented cigarettes smoked in the past week and alcohol and drug use severity ratings. At baseline, 61% of patients smoked, 35% used alcohol, and 23% used illicit drugs. Although there were significant effects of time showing reduction in substance use over the 18 months (all p < 0.0001), this study found no evidence that any antipsychotic was robustly superior to any other in a secondary analysis of data on substance use outcomes from a large 18-month randomized schizophrenia trial.

Effects of glyphosate exposure on sperm concentration in rodents: A systematic review and meta-analysis.

PubMed

Cai, Wenyan; Ji, Ying; Song, Xianping; Guo, Haoran; Han, Lei; Zhang, Feng; Liu, Xin; Zhang, Hengdong; Zhu, Baoli; Xu, Ming

2017-10-01

Correlation between exposure to glyphosate and sperm concentrations is important in reproductive toxicity risk assessment for male reproductive functions. Many studies have focused on reproductive toxicity on glyphosate, however, results are still controversial. We conducted a systematic review of epidemiological studies on the association between glyphosate exposure and sperm concentrations of rodents. The aim of this study is to explore the potential adverse effects of glyphosate on reproductive function of male rodents. Systematic and comprehensive literature search was performed in MEDLINE, TOXLINE, Embase, WANFANG and CNKI databases with different combinations of glyphosate exposure and sperm concentration. 8 studies were eventually identified and random-effect model was conducted. Heterogeneity among study results was calculated via chi-square tests. Ten independent experimental datasets from these eight studies were acquired to synthesize the random-effect model. A decrease in sperm concentrations was found with mean difference of sperm concentrations(MDsperm)=-2.774×10 6 /sperm/g/testis(95%CI=-0.969 to -4.579) in random-effect model after glyphosate exposure. There was also a significant decrease after fitting the random-effect model: MDsperm=-1.632×10 6 /sperm/g/testis (95%CI=-0.662 to -2.601). The results of meta-analysis support the hypothesis that glyphosate exposure decreased sperm concentration in rodents. Therefore, we conclude that glyphosate is toxic to male rodent's reproductive system. Copyright © 2017. Published by Elsevier B.V.

Random electric field instabilities of relaxor ferroelectrics

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

Arce-Gamboa, Jose R.; Guzman-Verri, Gian G.

Relaxor ferroelectrics are complex oxide materials which are rather unique to study the effects of compositional disorder on phase transitions. Here, we study the effects of quenched cubic random electric fields on the lattice instabilities that lead to a ferroelectric transition and show that, within a microscopic model and a statistical mechanical solution, even weak compositional disorder can prohibit the development of long-range order and that a random field state with anisotropic and power-law correlations of polarization emerges from the combined effect of their characteristic dipole forces and their inherent charge disorder. As a result, we compare and reproduce severalmore » key experimental observations in the well-studied relaxor PbMg 1/3Nb 2/3O 3–PbTiO 3.« less

Random electric field instabilities of relaxor ferroelectrics

DOE PAGES

Arce-Gamboa, Jose R.; Guzman-Verri, Gian G.

2017-06-13

Relaxor ferroelectrics are complex oxide materials which are rather unique to study the effects of compositional disorder on phase transitions. Here, we study the effects of quenched cubic random electric fields on the lattice instabilities that lead to a ferroelectric transition and show that, within a microscopic model and a statistical mechanical solution, even weak compositional disorder can prohibit the development of long-range order and that a random field state with anisotropic and power-law correlations of polarization emerges from the combined effect of their characteristic dipole forces and their inherent charge disorder. As a result, we compare and reproduce severalmore » key experimental observations in the well-studied relaxor PbMg 1/3Nb 2/3O 3–PbTiO 3.« less

On random field Completely Automated Public Turing Test to Tell Computers and Humans Apart generation.

PubMed

Kouritzin, Michael A; Newton, Fraser; Wu, Biao

2013-04-01

Herein, we propose generating CAPTCHAs through random field simulation and give a novel, effective and efficient algorithm to do so. Indeed, we demonstrate that sufficient information about word tests for easy human recognition is contained in the site marginal probabilities and the site-to-nearby-site covariances and that these quantities can be embedded directly into certain conditional probabilities, designed for effective simulation. The CAPTCHAs are then partial random realizations of the random CAPTCHA word. We start with an initial random field (e.g., randomly scattered letter pieces) and use Gibbs resampling to re-simulate portions of the field repeatedly using these conditional probabilities until the word becomes human-readable. The residual randomness from the initial random field together with the random implementation of the CAPTCHA word provide significant resistance to attack. This results in a CAPTCHA, which is unrecognizable to modern optical character recognition but is recognized about 95% of the time in a human readability study.

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial.

PubMed

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia.

Glutamine Randomized Studies in Early Life: The Unsolved Riddle of Experimental and Clinical Studies

PubMed Central

Briassouli, Efrossini; Briassoulis, George

2012-01-01

Glutamine may have benefits during immaturity or critical illness in early life but its effects on outcome end hardpoints are controversial. Our aim was to review randomized studies on glutamine supplementation in pups, infants, and children examining whether glutamine affects outcome. Experimental work has proposed various mechanisms of glutamine action but none of the randomized studies in early life showed any effect on mortality and only a few showed some effect on inflammatory response, organ function, and a trend for infection control. Although apparently safe in animal models (pups), premature infants, and critically ill children, glutamine supplementation does not reduce mortality or late onset sepsis, and its routine use cannot be recommended in these sensitive populations. Large prospectively stratified trials are needed to better define the crucial interrelations of “glutamine-heat shock proteins-stress response” in critical illness and to identify the specific subgroups of premature neonates and critically ill infants or children who may have a greater need for glutamine and who may eventually benefit from its supplementation. The methodological problems noted in the reviewed randomized experimental and clinical trials should be seriously considered in any future well-designed large blinded randomized controlled trial involving glutamine supplementation in critical illness. PMID:23019424

The Impact of Five Missing Data Treatments on a Cross-Classified Random Effects Model

ERIC Educational Resources Information Center

Hoelzle, Braden R.

2012-01-01

The present study compared the performance of five missing data treatment methods within a Cross-Classified Random Effects Model environment under various levels and patterns of missing data given a specified sample size. Prior research has shown the varying effect of missing data treatment options within the context of numerous statistical…

A Randomized Effectiveness Trial of Brief Parent Training: Six-Month Follow-Up

ERIC Educational Resources Information Center

Kjøbli, John; Bjørnebekk, Gunnar

2013-01-01

Objective: To examine the follow-up effectiveness of brief parent training (BPT) for children with emerging or existing conduct problems. Method: With the use of a randomized controlled trial and parent and teacher reports, this study examined the effectiveness of BPT compared to regular services 6 months after the end of the intervention.…

Study on the Vehicle Dynamic Load Considering the Vehicle-Pavement Coupled Effect

NASA Astrophysics Data System (ADS)

Xu, H. L.; He, L.; An, D.

2017-11-01

The vibration of vehicle-pavement interaction system is sophisticated random vibration process and the vehicle-pavement coupled effect was not considered in the previous study. A new linear elastic model of the vehicle-pavement coupled system was established in the paper. The new model was verified with field measurement which could reflect the real vibration between vehicle and pavement. Using the new model, the study on the vehicle dynamic load considering the vehicle-pavement coupled effect showed that random forces (centralization) between vehicle and pavement were influenced largely by vehicle-pavement coupled effect. Numerical calculation indicated that the maximum of random forces in coupled model was 2.4 times than that in uncoupled model. Inquiring the reason, it was found that the main vibration frequency of the vehicle non-suspension system was similar with that of the vehicle suspension system in the coupled model and the resonance vibration lead to vehicle dynamic load increase significantly.

Examining the Minimal Required Elements of a Computer-Tailored Intervention Aimed at Dietary Fat Reduction: Results of a Randomized Controlled Dismantling Study

ERIC Educational Resources Information Center

Kroeze, Willemieke; Oenema, Anke; Dagnelie, Pieter C.; Brug, Johannes

2008-01-01

This study investigated the minimally required feedback elements of a computer-tailored dietary fat reduction intervention to be effective in improving fat intake. In all 588 Healthy Dutch adults were randomly allocated to one of four conditions in an randomized controlled trial: (i) feedback on dietary fat intake [personal feedback (P feedback)],…

Relaxation Therapy and Anxiety, Self-Esteem, and Emotional Regulation among Adults with Intellectual Disabilities: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Bouvet, Cyrille; Coulet, Aurélie

2016-01-01

This pilot study is a randomized controlled trial on the effects of relaxation on anxiety, self-esteem, and emotional regulation in adults with intellectual disabilities (ID) working in a center of supported employment in France. We studied 30 adults with mild or moderate ID who were split at random into a relaxation group (RG, 15 subjects), who…

Memory consolidation and contextual interference effects with computer games.

PubMed

Shewokis, Patricia A

2003-10-01

Some investigators of the contextual interference effect contend that there is a direct relation between the amount of practice and the contextual interference effect based on the prediction that the improvement in learning tasks in a random practice schedule, compared to a blocked practice schedule, increases in magnitude as the amount of practice during acquisition on the tasks increases. Research using computer games in contextual interference studies has yielded a large effect (f = .50) with a random practice schedule advantage during transfer. These investigations had a total of 36 and 72 acquisition trials, respectively. The present study tested this prediction by having 72 college students, who were randomly assigned to a blocked or random practice schedule, practice 102 trials of three computer-game tasks across three days. After a 24-hr. interval, 6 retention and 5 transfer trials were performed. Dependent variables were time to complete an event in seconds and number of errors. No significant differences were found for retention and transfer. These results are discussed in terms of how the amount of practice, task-related factors, and memory consolidation mediate the contextual interference effect.

Systematic review on the health effects of exposure to radiofrequency electromagnetic fields from mobile phone base stations.

PubMed

Röösli, Martin; Frei, Patrizia; Mohler, Evelyn; Hug, Kerstin

2010-12-01

to review and evaluate the recent literature on the health effects of exposure to mobile phone base station (MPBS) radiation. we performed a systematic review of randomized human trials conducted in laboratory settings and of epidemiological studies that investigated the health effects of MPBS radiation in the everyday environment. we included in the analysis 17 articles that met our basic quality criteria: 5 randomized human laboratory trials and 12 epidemiological studies. The majority of the papers (14) examined self-reported non-specific symptoms of ill-health. Most of the randomized trials did not detect any association between MPBS radiation and the development of acute symptoms during or shortly after exposure. The sporadically observed associations did not show a consistent pattern with regard to symptoms or types of exposure. We also found that the more sophisticated the exposure assessment, the less likely it was that an effect would be reported. Studies on health effects other than non-specific symptoms and studies on MPBS exposure in children were scarce. the evidence for a missing relationship between MPBS exposure up to 10 volts per metre and acute symptom development can be considered strong because it is based on randomized, blinded human laboratory trials. At present, there is insufficient data to draw firm conclusions about health effects from long-term low-level exposure typically occurring in the everyday environment.

Quantum random walks on congested lattices and the effect of dephasing

PubMed Central

Motes, Keith R.; Gilchrist, Alexei; Rohde, Peter P.

2016-01-01

We consider quantum random walks on congested lattices and contrast them to classical random walks. Congestion is modelled on lattices that contain static defects which reverse the walker’s direction. We implement a dephasing process after each step which allows us to smoothly interpolate between classical and quantum random walks as well as study the effect of dephasing on the quantum walk. Our key results show that a quantum walker escapes a finite boundary dramatically faster than a classical walker and that this advantage remains in the presence of heavily congested lattices. PMID:26812924

Albumin in Burn Shock Resuscitation: A Meta-Analysis of Controlled Clinical Studies.

PubMed

Navickis, Roberta J; Greenhalgh, David G; Wilkes, Mahlon M

2016-01-01

Critical appraisal of outcomes after burn shock resuscitation with albumin has previously been restricted to small relatively old randomized trials, some with high risk of bias. Extensive recent data from nonrandomized studies assessing the use of albumin can potentially reduce bias and add precision. The objective of this meta-analysis was to determine the effect of burn shock resuscitation with albumin on mortality and morbidity in adult patients. Randomized and nonrandomized controlled clinical studies evaluating mortality and morbidity in adult patients receiving albumin for burn shock resuscitation were identified by multiple methods, including computer database searches and examination of journal contents and reference lists. Extracted data were quantitatively combined by random-effects meta-analysis. Four randomized and four nonrandomized studies with 688 total adult patients were included. Treatment effects did not differ significantly between the included randomized and nonrandomized studies. Albumin infusion during the first 24 hours showed no significant overall effect on mortality. However, significant statistical heterogeneity was present, which could be abolished by excluding two studies at high risk of bias. After those exclusions, albumin infusion was associated with reduced mortality. The pooled odds ratio was 0.34 with a 95% confidence interval of 0.19 to 0.58 (P < .001). Albumin administration was also accompanied by decreased occurrence of compartment syndrome (pooled odds ratio, 0.19; 95% confidence interval, 0.07-0.50; P < .001). This meta-analysis suggests that albumin can improve outcomes of burn shock resuscitation. However, the scope and quality of current evidence are limited, and additional trials are needed.

Logistic random effects regression models: a comparison of statistical packages for binary and ordinal outcomes

PubMed Central

2011-01-01

Background Logistic random effects models are a popular tool to analyze multilevel also called hierarchical data with a binary or ordinal outcome. Here, we aim to compare different statistical software implementations of these models. Methods We used individual patient data from 8509 patients in 231 centers with moderate and severe Traumatic Brain Injury (TBI) enrolled in eight Randomized Controlled Trials (RCTs) and three observational studies. We fitted logistic random effects regression models with the 5-point Glasgow Outcome Scale (GOS) as outcome, both dichotomized as well as ordinal, with center and/or trial as random effects, and as covariates age, motor score, pupil reactivity or trial. We then compared the implementations of frequentist and Bayesian methods to estimate the fixed and random effects. Frequentist approaches included R (lme4), Stata (GLLAMM), SAS (GLIMMIX and NLMIXED), MLwiN ([R]IGLS) and MIXOR, Bayesian approaches included WinBUGS, MLwiN (MCMC), R package MCMCglmm and SAS experimental procedure MCMC. Three data sets (the full data set and two sub-datasets) were analysed using basically two logistic random effects models with either one random effect for the center or two random effects for center and trial. For the ordinal outcome in the full data set also a proportional odds model with a random center effect was fitted. Results The packages gave similar parameter estimates for both the fixed and random effects and for the binary (and ordinal) models for the main study and when based on a relatively large number of level-1 (patient level) data compared to the number of level-2 (hospital level) data. However, when based on relatively sparse data set, i.e. when the numbers of level-1 and level-2 data units were about the same, the frequentist and Bayesian approaches showed somewhat different results. The software implementations differ considerably in flexibility, computation time, and usability. There are also differences in the availability of additional tools for model evaluation, such as diagnostic plots. The experimental SAS (version 9.2) procedure MCMC appeared to be inefficient. Conclusions On relatively large data sets, the different software implementations of logistic random effects regression models produced similar results. Thus, for a large data set there seems to be no explicit preference (of course if there is no preference from a philosophical point of view) for either a frequentist or Bayesian approach (if based on vague priors). The choice for a particular implementation may largely depend on the desired flexibility, and the usability of the package. For small data sets the random effects variances are difficult to estimate. In the frequentist approaches the MLE of this variance was often estimated zero with a standard error that is either zero or could not be determined, while for Bayesian methods the estimates could depend on the chosen "non-informative" prior of the variance parameter. The starting value for the variance parameter may be also critical for the convergence of the Markov chain. PMID:21605357

Effectiveness and cost-effectiveness of telehealthcare for chronic obstructive pulmonary disease: study protocol for a cluster randomized controlled trial.

PubMed

Udsen, Flemming Witt; Lilholt, Pernille Heyckendorff; Hejlesen, Ole; Ehlers, Lars Holger

2014-05-21

Several feasibility studies show promising results of telehealthcare on health outcomes and health-related quality of life for patients suffering from chronic obstructive pulmonary disease, and some of these studies show that telehealthcare may even lower healthcare costs. However, the only large-scale trial we have so far - the Whole System Demonstrator Project in England - has raised doubts about these results since it conclude that telehealthcare as a supplement to usual care is not likely to be cost-effective compared with usual care alone. The present study is known as 'TeleCare North' in Denmark. It seeks to address these doubts by implementing a large-scale, pragmatic, cluster-randomized trial with nested economic evaluation. The purpose of the study is to assess the effectiveness and the cost-effectiveness of a telehealth solution for patients suffering from chronic obstructive pulmonary disease compared to usual practice. General practitioners will be responsible for recruiting eligible participants (1,200 participants are expected) for the trial in the geographical area of the North Denmark Region. Twenty-six municipality districts in the region define the randomization clusters. The primary outcomes are changes in health-related quality of life, and the incremental cost-effectiveness ratio measured from baseline to follow-up at 12 months. Secondary outcomes are changes in mortality and physiological indicators (diastolic and systolic blood pressure, pulse, oxygen saturation, and weight). There has been a call for large-scale clinical trials with rigorous cost-effectiveness assessments in telehealthcare research. This study is meant to improve the international evidence base for the effectiveness and cost-effectiveness of telehealthcare to patients suffering from chronic obstructive pulmonary disease by implementing a large-scale pragmatic cluster-randomized clinical trial. Clinicaltrials.gov, http://NCT01984840, November 14, 2013.

Occupational exposure to polychlorinated biphenyls and risk of cutaneous melanoma: a meta-analysis.

PubMed

Boffetta, Paolo; Catalani, Simona; Tomasi, Cesare; Pira, Enrico; Apostoli, Pietro

2018-01-01

The aim of this study was to carry out a meta-analysis of studies on exposure to polychlorinated biphenyls (PCBs) and the risk of malignant melanoma (MM). We searched Scopus, PubMed, and reference lists; among 807 potentially relevant articles, we selected those based on 12 populations. Data were extracted according to a standardized form; the Newcastle-Ottawa Scale was used to assess study quality. Meta-analyses were carried out according to fixed-effect and random-effects models. The fixed-effect summary relative risk (RR) for MM was 0.91 [95% confidence interval (CI): 0.82-1.00]; the random-effects summary RR was 1.05 (95% CI: 0.78-1.32). The random-effects summary RR from eight occupational cohorts was 1.13 (95% CI: 0.91-1.35) and that from four community-based studies was 0.84 (95% CI: 0.36-1.31). The quality of the studies and the methods for PCB exposure assessment did not influence the RR. These results do not support the hypothesis of an association between PCB exposure and the risk of MM.

The Heterogeneous Effect of Information on Student Performance: Evidence from a Randomized Control Trial in Mexico. Policy Research Working Paper 7422

ERIC Educational Resources Information Center

Avitabile, Ciro; de Hoyos, Rafael

2015-01-01

A randomized control trial was conducted to study whether providing 10th grade students with information about the returns to upper secondary and tertiary education, and a source of financial aid for tertiary education, can contribute to improve student performance. The study finds that the intervention had no effects on the probability of taking…

Theory of Mind Training in Children with Autism: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Begeer, Sander; Gevers, Carolien; Clifford, Pamela; Verhoeve, Manja; Kat, Kirstin; Hoddenbach, Elske; Boer, Frits

2011-01-01

Many children with Autism Spectrum Disorders (ASD) participate in social skills or Theory of Mind (ToM) treatments. However, few studies have shown evidence for their effectiveness. The current study used a randomized controlled design to test the effectiveness of a 16-week ToM treatment in 8-13 year old children with ASD and normal IQs (n = 40).…

Methods to Limit Attrition in Longitudinal Comparative Effectiveness Trials: Lessons from the Lithium Use for Bipolar Disorder (LiTMUS) Study

PubMed Central

Sylvia, Louisa G.; Reilly-Harrington, Noreen A.; Leon, Andrew C.; Kansky, Christine I.; Ketter, Terence A.; Calabrese, Joseph R.; Thase, Michael E.; Bowden, Charles L.; Friedman, Edward S.; Ostacher, Michael J.; Iosifescu, Dan V.; Severe, Joanne; Nierenberg, Andrew A.

2013-01-01

Background High attrition rates which occur frequently in longitudinal clinical trials of interventions for bipolar disorder limit the interpretation of results. Purpose The aim of this article is to present design approaches that limited attrition in the Lithium Use for Bipolar Disorder (LiTMUS) Study. Methods LiTMUS was a 6-month randomized, longitudinal multi-site comparative effectiveness trial that examined bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium, in addition to other treatments needed for mood stabilization administered in a guideline-informed, empirically supported, and personalized fashion (N=283). Results Components of the study design that may have contributed to the low attrition rate of the study included use of: (1) an intent-to-treat design; (2) a randomized adjunctive single-blind design; (3) participant reimbursement; (4) intent-to-attend the next study visit (includes a discussion of attendance obstacles when intention is low); (5) quality care with limited participant burden; and (6) target windows for study visits. Limitations Site differences and the effectiveness and tolerability data have not been analyzed yet. Conclusions These components of the LiTMUS study design may have reduced the probability of attrition which would inform the design of future randomized clinical effectiveness trials. PMID:22076437

Balancing Participation across Students in Large College Classes via Randomized Participation Credit

ERIC Educational Resources Information Center

McCleary, Daniel F.; Aspiranti, Kathleen B.; Foster, Lisa N.; Blondin, Carolyn A.; Gaylon, Charles E.; Yaw, Jared S.; Forbes, Bethany N.; Williams, Robert L.

2011-01-01

The study examines the effects of randomized credit on the percentage of students participating at four predefined levels. Students recorded their comments on specially designed record cards, and days were randomly selected for participation credit. This arrangement balanced participation across students while cutting instructor time for recording…

A Preliminary Investigation of a Randomized Dependent Group Contingency for Hallway Transitions

ERIC Educational Resources Information Center

Deshais, Meghan A.; Fisher, Alyssa B.; Kahng, SungWoo

2018-01-01

We conducted a preliminary investigation of a randomized dependent group contingency to decrease disruptive behavior during hallway transitions. Two first-graders, identified by their classroom teacher, participated in this study. A multiple baseline across transitions was used to evaluate the effects of the randomized dependent group contingency…

Robotic-assisted versus laparoscopic colorectal surgery: a meta-analysis of four randomized controlled trials

PubMed Central

2014-01-01

Background Robotic-assisted laparoscopy is popularly performed for colorectal disease. The objective of this meta-analysis was to compare the safety and efficacy of robotic-assisted colorectal surgery (RCS) and laparoscopic colorectal surgery (LCS) for colorectal disease based on randomized controlled trial studies. Methods Literature searches of electronic databases (Pubmed, Web of Science, and Cochrane Library) were performed to identify randomized controlled trial studies that compared the clinical or oncologic outcomes of RCS and LCS. This meta-analysis was performed using the Review Manager (RevMan) software (version 5.2) that is provided by the Cochrane Collaboration. The data used were mean differences and odds ratios for continuous and dichotomous variables, respectively. Fixed-effects or random-effects models were adopted according to heterogeneity. Results Four randomized controlled trial studies were identified for this meta-analysis. In total, 110 patients underwent RCS, and 116 patients underwent LCS. The results revealed that estimated blood losses (EBLs), conversion rates and times to the recovery of bowel function were significantly reduced following RCS compared with LCS. There were no significant differences in complication rates, lengths of hospital stays, proximal margins, distal margins or harvested lymph nodes between the two techniques. Conclusions RCS is a promising technique and is a safe and effective alternative to LCS for colorectal surgery. The advantages of RCS include reduced EBLs, lower conversion rates and shorter times to the recovery of bowel function. Further studies are required to define the financial effects of RCS and the effects of RCS on long-term oncologic outcomes. PMID:24767102

Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages.

PubMed

Kim, Yoonsang; Choi, Young-Ku; Emery, Sherry

2013-08-01

Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods' performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages-SAS GLIMMIX Laplace and SuperMix Gaussian quadrature-perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes.

Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages

PubMed Central

Kim, Yoonsang; Emery, Sherry

2013-01-01

Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods’ performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages—SAS GLIMMIX Laplace and SuperMix Gaussian quadrature—perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes. PMID:24288415

Systematic review of physiotherapy interventions to improve gross motor capacity and performance in children and adolescents with an acquired brain injury.

PubMed

Baque, Emmah; Sakzewski, Leanne; Barber, Lee; Boyd, Roslyn N

2016-01-01

To systematically review the efficacy of physiotherapy interventions to improve gross motor capacity, performance and societal participation in children aged 5-17 years with an acquired brain injury (ABI). Randomized and non-randomized controlled trials, cohort, case series, case-control and case studies were included and classified according to grades of evidence. Methodological quality of studies was assessed using the Downs and Black (D&B) scale and quantitative data was analysed using effect sizes. Two home-based studies investigated functional strength training (one randomized controlled trial, n = 20, level 2b, D&B = 16/32 and one non-randomized self-control study, n = 19, level 4, D&B = 15/32). Four studies evaluated virtual reality including: one pilot study, n = 50, level 4, D&B = 22/32; one single-subject, non-concurrent, randomized multiple baseline study, n = 3, level 4, D&B = 15/32; one case series study, n = 2, level 4, D&B = 15/32; one case study, n = 1, level 4, D&B = 15/32. Effect sizes for the randomized controlled trial ranged between 0.30-1.29 for the Functional Reach and Timed Up and Go outcome measures. There is preliminary evidence to support the efficacy of physiotherapy interventions to improve gross motor outcomes in children with an ABI. Both functional strength training and virtual-reality based therapy are potential treatment options for clinicians to prescribe in either home or clinical settings.

Parallel Mitogenome Sequencing Alleviates Random Rooting Effect in Phylogeography.

PubMed

Hirase, Shotaro; Takeshima, Hirohiko; Nishida, Mutsumi; Iwasaki, Wataru

2016-04-28

Reliably rooted phylogenetic trees play irreplaceable roles in clarifying diversification in the patterns of species and populations. However, such trees are often unavailable in phylogeographic studies, particularly when the focus is on rapidly expanded populations that exhibit star-like trees. A fundamental bottleneck is known as the random rooting effect, where a distant outgroup tends to root an unrooted tree "randomly." We investigated whether parallel mitochondrial genome (mitogenome) sequencing alleviates this effect in phylogeography using a case study on the Sea of Japan lineage of the intertidal goby Chaenogobius annularis Eighty-three C. annularis individuals were collected and their mitogenomes were determined by high-throughput and low-cost parallel sequencing. Phylogenetic analysis of these mitogenome sequences was conducted to root the Sea of Japan lineage, which has a star-like phylogeny and had not been reliably rooted. The topologies of the bootstrap trees were investigated to determine whether the use of mitogenomes alleviated the random rooting effect. The mitogenome data successfully rooted the Sea of Japan lineage by alleviating the effect, which hindered phylogenetic analysis that used specific gene sequences. The reliable rooting of the lineage led to the discovery of a novel, northern lineage that expanded during an interglacial period with high bootstrap support. Furthermore, the finding of this lineage suggested the existence of additional glacial refugia and provided a new recent calibration point that revised the divergence time estimation between the Sea of Japan and Pacific Ocean lineages. This study illustrates the effectiveness of parallel mitogenome sequencing for solving the random rooting problem in phylogeographic studies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Assessing the comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial.

PubMed

Wang, Chenchen; Iversen, Maura D; McAlindon, Timothy; Harvey, William F; Wong, John B; Fielding, Roger A; Driban, Jeffrey B; Price, Lori Lyn; Rones, Ramel; Gamache, Tressa; Schmid, Christopher H

2014-09-08

Knee osteoarthritis (OA) causes pain and long-term disability with annual healthcare costs exceeding $185 billion in the United States. Few medical remedies effectively influence the course of the disease. Finding effective treatments to maintain function and quality of life in patients with knee OA is one of the national priorities identified by the Institute of Medicine. We are currently conducting the first comparative effectiveness and cost-effectiveness randomized trial of Tai Chi versus a physical-therapy regimen in a sample of patients with symptomatic and radiographically confirmed knee OA. This article describes the design and conduct of this trial. A single-center, 52-week, comparative effectiveness randomized controlled trial of Tai Chi versus a standardized physical-therapy regimen is being conducted at an urban tertiary medical center in Boston, Massachusetts. The study population consists of adults ≥ 40 years of age with symptomatic and radiographic knee OA (American College of Rheumatology criteria). Participants are randomly allocated to either 12 weeks of Tai Chi (2x/week) or Physical Therapy (2x/week for 6 weeks, followed by 6 weeks of rigorously monitored home exercise). The primary outcome measure is pain (Western Ontario and McMaster Universities WOMAC) subscale at 12 weeks. Secondary outcomes include WOMAC stkiffness and function domain scores, lower extremity strength and power, functional balance, physical performance tests, psychological and psychosocial functioning, durability effects, health related quality of life, and healthcare utilization at 12, 24 and 52 weeks. This study will be the first randomized comparative-effectiveness and cost-effectiveness trial of Tai Chi versus Physical Therapy in a large symptomatic knee OA population with long-term follow up. We present here a robust and well-designed randomized comparative-effectiveness trial that also explores multiple outcomes to elucidate the potential mechanisms of mind-body effect for a major disabling disease with substantial health burdens and economic costs. Results of this study are expected to have important public health implications for the large and growing population with knee OA. ClinicalTrials.gov identifier: NCT01258985.

Simulation of diffuse-charge capacitance in electric double layer capacitors

NASA Astrophysics Data System (ADS)

Sun, Ning; Gersappe, Dilip

2017-01-01

We use a Lattice Boltzmann Model (LBM) in order to simulate diffuse-charge dynamics in Electric Double Layer Capacitors (EDLCs). Simulations are carried out for both the charge and the discharge processes on 2D systems of complex random electrode geometries (pure random, random spheres and random fibers). The steric effect of concentrated solutions is considered by using a Modified Poisson-Nernst-Planck (MPNP) equations and compared with regular Poisson-Nernst-Planck (PNP) systems. The effects of electrode microstructures (electrode density, electrode filler morphology, filler size, etc.) on the net charge distribution and charge/discharge time are studied in detail. The influence of applied potential during discharging process is also discussed. Our studies show how electrode morphology can be used to tailor the properties of supercapacitors.

The Role of Prostatitis in Prostate Cancer: Meta-Analysis

PubMed Central

Yunxia, Zhang; Zhu, Hong; Liu, Junjiang; Pumill, Chris

2013-01-01

Objective Use systematic review methods to quantify the association between prostatitis and prostate cancer, under both fixed and random effects model. Evidence Acquisition Case control studies of prostate cancer with information on prostatitis history. All studies published between 1990-2012, were collected to calculate a pooled odds ratio. Selection criteria: the selection criteria are as follows: human case control studies; published from May 1990 to July 2012; containing number of prostatitis, and prostate cancer cases. Evidence Synthesis In total, 20 case control studies were included. A significant association between prostatitis and prostate cancer was found, under both fixed effect model (pooled OR=1.50, 95%CI: 1.39-1.62), and random effects model (OR=1.64, 95%CI: 1.36-1.98). Personal interview based case control studies showed a high level of association (fixed effect model: pooled OR=1.59, 95%CI: 1.47-1.73, random effects model: pooled OR= 1.87, 95%CI: 1.52-2.29), compared with clinical based studies (fixed effect model: pooled OR=1.05, 95%CI: 0.86-1.28, random effects model: pooled OR= 0.98, 95%CI: 0.67-1.45). Additionally, pooled ORs, were calculated for each decade. In a fixed effect model: 1990’s: OR=1.58, 95% CI: 1.35-1.84; 2000’s: OR=1.59, 95% CI: 1.40-1.79; 2010’s: OR=1.37, 95% CI: 1.22-1.56. In a random effects model: 1990’s: OR=1.98, 95% CI: 1.08-3.62; 2000’s: OR=1.64, 95% CI: 1.23-2.19; 2010’s: OR=1.34, 95% CI: 1.03-1.73. Finally a meta-analysis stratified by each country was conducted. In fixed effect models, U.S: pooled OR =1.45, 95%CI: 1.34-1.57; China: pooled OR =4.67, 95%CI: 3.08-7.07; Cuba: pooled OR =1.43, 95%CI: 1.00-2.04; Italy: pooled OR =0.61, 95%CI: 0.13-2.90. In random effects model, U.S: pooled OR=1.50, 95%CI: 1.25-1.80; China: pooled OR =4.67, 95%CI: 3.08-7.07; Cuba: pooled OR =1.43, 95%CI: 1.00-2.04; Italy: pooled OR =0.61, 95%CI: 0.13-2.90.CONCLUSIONS: the present meta-analysis provides the statistical evidence that the association between prostatitis and prostate cancer is significant. PMID:24391995

Randomized Controlled Studies and Alternative Designs in Outcome Studies: Challenges and Opportunities

ERIC Educational Resources Information Center

Shadish, William R.

2011-01-01

This article reviews several decades of the author's meta-analytic and experimental research on the conditions under which nonrandomized experiments can approximate the results from randomized experiments (REs). Several studies make clear that we can expect accurate effect estimates from the regression discontinuity design, though its statistical…

Non-steroidal anti-inflammatory drugs for the common cold.

PubMed

Kim, Soo Young; Chang, Yoon-Jung; Cho, Hye Min; Hwang, Ye-Won; Moon, Yoo Sun

2013-06-04

Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely used for the treatment of pain and fever associated with the common cold. However, there is no systematic review to assess the effects of NSAIDs in treating the common cold. To determine the effects of NSAIDs versus placebo (and other treatments) on signs and symptoms of the common cold, and to determine any adverse effects of NSAIDs in people with the common cold. We searched CENTRAL (The Cochrane Library 2013, Issue 1), MEDLINE (January 1966 to April week 4, 2013), EMBASE (January 1980 to April 2013), CINAHL (January 1982 to April 2013) and ProQuest Digital Dissertations (January 1938 to April 2013). Randomised controlled trials (RCTs) of NSAIDS in adults or children with the common cold. Four review authors extracted data. We subdivided trials into placebo-controlled RCTs and head-to-head comparisons of NSAIDs. We extracted and summarised data on global efficacies of analgesic effects (such as reduction of headache and myalgia), non-analgesic effects (such as reduction of nasal symptoms, cough, sputum and sneezing) and side effects. We expressed dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CI) and continuous data as mean differences (MD) or standardised mean differences (SMD). We pooled data using the fixed- and random-effects models. We included nine RCTs with 1069 participants, describing 37 comparisons: six were NSAIDs versus placebo and three were NSAIDs versus NSAIDs. The overall risk of bias in the included studies was mixed. In a pooled analysis, NSAIDs did not significantly reduce the total symptom score (SMD -0.40, 95% CI -1.03 to 0.24, three studies, random-effects model), or duration of colds (MD -0.23, 95% CI -1.75 to 1.29, two studies, random-effects model). For respiratory symptoms, cough did not improve (SMD -0.05, 95% CI -0.66 to 0.56, two studies, random-effects model) but the sneezing score significantly improved (SMD -0.44, 95% CI -0.75 to -0.12, two studies, random-effects model). For outcomes related to the analgesic effects of NSAIDs (headache, ear pain, and muscle and joint pain) the treatment produced significant benefits. The risk of adverse effects was not high with NSAIDs (RR 2.94, 95% CI 0.51 to 17.03, two studies, random-effects model) and it is difficult to conclude that such drugs are not different from placebo. NSAIDs are somewhat effective in relieving discomfort caused by a cold but there is no clear evidence of their effect in easing respiratory symptoms. The balance of benefit and harms needs to be considered when using NSAIDs for colds.

Effectiveness of Supplemental Kindergarten Vocabulary Instruction for English Learners: A Randomized Study of Immediate and Longer-Term Effects of Two Approaches

ERIC Educational Resources Information Center

Vadasy, Patricia F.; Sanders, Elizabeth A.; Nelson, J. Ron

2015-01-01

A two-cohort cluster randomized trial was conducted to estimate effects of small-group supplemental vocabulary instruction for at-risk kindergarten English learners (ELs). "Connections" students received explicit instruction in high-frequency decodable root words, and interactive book reading (IBR) students were taught the same words in…

Effects of a Meditation Program on Nurses' Power and Quality of Life.

PubMed

Chang, Sun Ju; Kwak, Eun Young; Hahm, Bong-Jin; Seo, Se Hee; Lee, Da Woon; Jang, Sun Joo

2016-07-01

This study evaluated the effects of meditation programs on nurses' power and quality of life. In this study, Barrett's power theory derived from Rogers' unitary human being science was used as a theoretical framework. A randomized controlled design with 50 recruited and randomly allocated participants was used. The results demonstrated that the eight-week meditation program significantly improved nurses' power and quality of life. These results suggest that meditation has positive effects on power and quality of life. © The Author(s) 2016.

Modeling pattern in collections of parameters

USGS Publications Warehouse

Link, W.A.

1999-01-01

Wildlife management is increasingly guided by analyses of large and complex datasets. The description of such datasets often requires a large number of parameters, among which certain patterns might be discernible. For example, one may consider a long-term study producing estimates of annual survival rates; of interest is the question whether these rates have declined through time. Several statistical methods exist for examining pattern in collections of parameters. Here, I argue for the superiority of 'random effects models' in which parameters are regarded as random variables, with distributions governed by 'hyperparameters' describing the patterns of interest. Unfortunately, implementation of random effects models is sometimes difficult. Ultrastructural models, in which the postulated pattern is built into the parameter structure of the original data analysis, are approximations to random effects models. However, this approximation is not completely satisfactory: failure to account for natural variation among parameters can lead to overstatement of the evidence for pattern among parameters. I describe quasi-likelihood methods that can be used to improve the approximation of random effects models by ultrastructural models.

Do little interactions get lost in dark random forests?

PubMed

Wright, Marvin N; Ziegler, Andreas; König, Inke R

2016-03-31

Random forests have often been claimed to uncover interaction effects. However, if and how interaction effects can be differentiated from marginal effects remains unclear. In extensive simulation studies, we investigate whether random forest variable importance measures capture or detect gene-gene interactions. With capturing interactions, we define the ability to identify a variable that acts through an interaction with another one, while detection is the ability to identify an interaction effect as such. Of the single importance measures, the Gini importance captured interaction effects in most of the simulated scenarios, however, they were masked by marginal effects in other variables. With the permutation importance, the proportion of captured interactions was lower in all cases. Pairwise importance measures performed about equal, with a slight advantage for the joint variable importance method. However, the overall fraction of detected interactions was low. In almost all scenarios the detection fraction in a model with only marginal effects was larger than in a model with an interaction effect only. Random forests are generally capable of capturing gene-gene interactions, but current variable importance measures are unable to detect them as interactions. In most of the cases, interactions are masked by marginal effects and interactions cannot be differentiated from marginal effects. Consequently, caution is warranted when claiming that random forests uncover interactions.

Effects of Massage on Blood Pressure in Patients With Hypertension and Prehypertension: A Meta-analysis of Randomized Controlled Trials.

PubMed

Liao, I-Chen; Chen, Shiah-Lian; Wang, Mei-Yeh; Tsai, Pei-Shan

2016-01-01

Massage may help reduce blood pressure; previous studies on the effect of massage on blood pressure have presented conflicting findings. In addition, no systematic review is available. The aim of this study was to evaluate the evidence concerning the effect of massage on blood pressure in patients with hypertension or prehypertension. A search was performed on electronic database records up to October 31, 2013, based on the following medical subject headings or keywords: hypertension, massage, chiropractic, manipulation, and blood pressure. The methodological quality of randomized controlled trials was assessed based on the Cochrane collaboration tool. A meta-analysis was performed to evaluate the effect of massage on hypertension. The study selection, data extraction, and validation were performed independently by 2 reviewers. Nine randomized controlled trials met our inclusion criteria. The results of this study show that massage contributes to significantly enhanced reduction in both systolic blood pressure (SBP) (mean difference, -7.39 mm Hg) and diastolic blood pressure (DBP) (mean difference, -5.04 mm Hg) as compared with control treatments in patients with hypertension and prehypertension. The effect size (Hedges g) for SBP and DBP was -0.728 (95% confidence interval, -1.182 to -0.274; P = .002) and -0.334 (95% confidence interval, -0.560 to -0.107; P = .004), respectively. This systematic review found a medium effect of massage on SBP and a small effect on DBP in patients with hypertension or prehypertension. High-quality randomized controlled trials are urgently required to confirm these results, although the findings of this study can be used to guide future research.

Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE): a pragmatic trial of complex treatment for a complex disorder.

PubMed

Nierenberg, Andrew A; Sylvia, Louisa G; Leon, Andrew C; Reilly-Harrington, Noreen A; Shesler, Leah W; McElroy, Susan L; Friedman, Edward S; Thase, Michael E; Shelton, Richard C; Bowden, Charles L; Tohen, Mauricio; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Kocsis, James H; McInnis, Melvin G; Schoenfeld, David; Bobo, William V; Calabrese, Joseph R

2014-02-01

Classic and second-generation antipsychotic mood stabilizers are recommended for treatment of bipolar disorder, yet there are no randomized comparative effectiveness studies that have examined the 'real-world' advantages and disadvantages of these medications. We describe the strategic decisions in the design of the Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE). This article outlines the key issues and solutions the investigators faced in designing a clinical trial that would maximize generalizability and inform real-world clinical treatment of bipolar disorder. Bipolar CHOICE was a 6-month, multi-site, prospective, randomized clinical trial of outpatients with bipolar disorder. This study compares the effectiveness of quetiapine versus lithium, each with adjunctive personalized treatments (APTs). The co-primary outcomes selected are the overall benefits and harms of the study medications (as measured by the Clinical Global Impression-Efficacy Index) and the Necessary Clinical Adjustments (a measure of the number of medication changes). Secondary outcomes are continuous measures of mood, the Framingham General Cardiovascular Risk Score, and the Longitudinal Interval Follow up Evaluation Range of Impaired Functioning Tool (LIFE-RIFT). The final study design consisted of a single-blind, randomized comparative effectiveness trial of quetiapine versus lithium, plus APT, across 10 sites. Other important study considerations included limited exclusion criteria to maximize generalizability, flexible dosing of APT medications to mimic real-world treatment, and an intent-to-treat analysis plan. In all, 482 participants were randomized to the study, and 364 completed the study. The potential limitations of the study include the heterogeneity of APT, selection of study medications, lack of a placebo-control group, and participants' ability to pay for study medications. We expect that this study will inform our understanding of the benefits and harms of lithium, a classic mood stabilizer, compared to quetiapine, a second-generation antipsychotic with broad-spectrum activity in bipolar disorder, and will provide an example of a well-designed and well-conducted randomized comparative effectiveness clinical trial.

POLICY IMPLICATIONS OF ADJUSTING RANDOMIZED TRIAL DATA FOR ECONOMIC EVALUATIONS: A DEMONSTRATION FROM THE ASCUS-LSIL TRIAGE STUDY

PubMed Central

Campos, Nicole G.; Castle, Philip E.; Schiffman, Mark; Kim, Jane J.

2013-01-01

Background Although the randomized controlled trial (RCT) is widely considered the most reliable method for evaluation of health care interventions, challenges to both internal and external validity exist. Thus, the efficacy of an intervention in a trial setting does not necessarily represent the real-world performance that decision makers seek to inform comparative effectiveness studies and economic evaluations. Methods Using data from the ASCUS-LSIL Triage Study (ALTS), we performed a simplified economic evaluation of age-based management strategies to detect cervical intraepithelial neoplasia grade 3 (CIN3) among women who were referred to the study with low-grade squamous intraepithelial lesions (LSIL). We used data from the trial itself to adjust for 1) potential lead time bias and random error that led to variation in the observed prevalence of CIN3 by study arm, and 2) potential ascertainment bias among providers in the most aggressive management arm. Results We found that using unadjusted RCT data may result in counterintuitive cost-effectiveness results when random error and/or bias are present. Following adjustment, the rank order of management strategies changed for two of the three age groups we considered. Conclusion Decision analysts need to examine study design, available trial data and cost-effectiveness results closely in order to detect evidence of potential bias. Adjustment for random error and bias in RCTs may yield different policy conclusions relative to unadjusted trial data. PMID:22147881

Finite-sample corrected generalized estimating equation of population average treatment effects in stepped wedge cluster randomized trials.

PubMed

Scott, JoAnna M; deCamp, Allan; Juraska, Michal; Fay, Michael P; Gilbert, Peter B

2017-04-01

Stepped wedge designs are increasingly commonplace and advantageous for cluster randomized trials when it is both unethical to assign placebo, and it is logistically difficult to allocate an intervention simultaneously to many clusters. We study marginal mean models fit with generalized estimating equations for assessing treatment effectiveness in stepped wedge cluster randomized trials. This approach has advantages over the more commonly used mixed models that (1) the population-average parameters have an important interpretation for public health applications and (2) they avoid untestable assumptions on latent variable distributions and avoid parametric assumptions about error distributions, therefore, providing more robust evidence on treatment effects. However, cluster randomized trials typically have a small number of clusters, rendering the standard generalized estimating equation sandwich variance estimator biased and highly variable and hence yielding incorrect inferences. We study the usual asymptotic generalized estimating equation inferences (i.e., using sandwich variance estimators and asymptotic normality) and four small-sample corrections to generalized estimating equation for stepped wedge cluster randomized trials and for parallel cluster randomized trials as a comparison. We show by simulation that the small-sample corrections provide improvement, with one correction appearing to provide at least nominal coverage even with only 10 clusters per group. These results demonstrate the viability of the marginal mean approach for both stepped wedge and parallel cluster randomized trials. We also study the comparative performance of the corrected methods for stepped wedge and parallel designs, and describe how the methods can accommodate interval censoring of individual failure times and incorporate semiparametric efficient estimators.

Effectiveness of deep versus moderate muscle relaxation during laparoscopic donor nephrectomy in enhancing postoperative recovery: study protocol for a randomized controlled study.

PubMed

Bruintjes, Moira H D; Braat, Andries E; Dahan, Albert; Scheffer, Gert-Jan; Hilbrands, Luuk B; d'Ancona, Frank C H; Donders, Rogier A R T; van Laarhoven, Cornelis J H M; Warlé, Michiel C

2017-03-04

Postoperative recovery after live donor nephrectomy is largely determined by the consequences of postoperative pain and analgesia consumptions. The use of deep neuromuscular blockade has been shown to reduce postoperative pain scores after laparoscopic surgery. In this study, we will investigate whether deep neuromuscular blockade also improves the early quality of recovery after live donor nephrectomy. The RELAX-study is a phase IV, multicenter, double-blinded, randomized controlled trial, in which 96 patients, scheduled for living donor nephrectomy, will be randomized into two groups: one with deep and one with moderate neuromuscular blockade. Deep neuromuscular blockade is defined as a post-tetanic count of 1-2. Our primary outcome measurement will be the Quality of Recovery-40 questionnaire (overall score) at 24 h after extubation. This study is, to our knowledge, the first randomized study to assess the effectiveness of deep neuromuscular blockade during laparoscopic donor nephrectomy in enhancing postoperative recovery. The study findings may also be applicable for other laparoscopic procedures. clinicaltrials.gov, NCT02838134 . Registered on 29 June 2016.

Continuous Time Random Walks with memory and financial distributions

NASA Astrophysics Data System (ADS)

Montero, Miquel; Masoliver, Jaume

2017-11-01

We study financial distributions from the perspective of Continuous Time Random Walks with memory. We review some of our previous developments and apply them to financial problems. We also present some new models with memory that can be useful in characterizing tendency effects which are inherent in most markets. We also briefly study the effect on return distributions of fractional behaviors in the distribution of pausing times between successive transactions.

Issues Relating to Selective Reporting When Including Non-Randomized Studies in Systematic Reviews on the Effects of Healthcare Interventions

ERIC Educational Resources Information Center

Norris, Susan L.; Moher, David; Reeves, Barnaby C.; Shea, Beverley; Loke, Yoon; Garner, Sarah; Anderson, Laurie; Tugwell, Peter; Wells, George

2013-01-01

Background: Selective outcome and analysis reporting (SOR and SAR) occur when only a subset of outcomes measured and analyzed in a study is fully reported, and are an important source of potential bias. Key methodological issues: We describe what is known about the prevalence and effects of SOR and SAR in both randomized controlled trials (RCTs)…

Educational interventions in childhood obesity: a systematic review with meta-analysis of randomized clinical trials.

PubMed

Sbruzzi, Graciele; Eibel, Bruna; Barbiero, Sandra M; Petkowicz, Rosemary O; Ribeiro, Rodrigo A; Cesa, Claudia C; Martins, Carla C; Marobin, Roberta; Schaan, Camila W; Souza, Willian B; Schaan, Beatriz D; Pellanda, Lucia C

2013-05-01

To assess the effectiveness of educational interventions including behavioral modification, nutrition and physical activity to prevent or treat childhood obesity through a systematic review and meta-analysis of randomized trials. A search of databases (PubMed, EMBASE and Cochrane CENTRAL) and references of published studies (from inception until May 2012) was conducted. Eligible studies were randomized trials enrolling children 6 to 12 years old and assessing the impact of educational interventions during 6 months or longer on waist circumference, body mass index (BMI), blood pressure and lipid profile to prevent or treat childhood obesity. Calculations were performed using a random effects method and pooled-effect estimates were obtained using the final values. Of 22.852 articles retrieved, 26 trials (23.617 participants) were included. There were no differences in outcomes assessed in prevention studies. However, in treatment studies, educational interventions were associated with a significant reduction in waist circumference [-3.21 cm (95%CI -6.34, -0.07)], BMI [-0.86 kg/m(2) (95%CI -1.59, -0.14)] and diastolic blood pressure [-3.68 mmHg (95%CI -5.48, -1.88)]. Educational interventions are effective in treatment, but not prevention, of childhood obesity and its consequences. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of Cosmos caudatus (Ulam raja) supplementation in patients with type 2 diabetes: Study protocol for a randomized controlled trial.

PubMed

Cheng, Shi-Hui; Ismail, Amin; Anthony, Joseph; Ng, Ooi Chuan; Hamid, Azizah Abdul; Yusof, Barakatun-Nisak Mohd

2016-02-27

Type 2 diabetes mellitus is a major health threat worldwide. Cosmos caudatus is one of the medicinal plants used to treat type 2 diabetes. Therefore, this study aims to determine the effectiveness and safety of C. caudatus in patients with type 2 diabetes. Metabolomic approach will be carried out to compare the metabolite profiles between C. Caudatus treated diabetic patients and diabetic controls. This is a single-center, randomized, controlled, two-arm parallel design clinical trial that will be carried out in a tertiary hospital in Malaysia. In this study, 100 patients diagnosed with type 2 diabetes will be enrolled. Diabetic patients who meet the eligibility criteria will be randomly allocated to two groups, which are diabetic C. caudatus treated(U) group and diabetic control (C) group. Primary and secondary outcomes will be measured at baseline, 4, 8, and 12 weeks. The serum and urine metabolome of both groups will be examined using proton NMR spectroscopy. The study will be the first randomized controlled trial to assess whether C. caudatus can confer beneficial effect in patients with type 2 diabetes. The results of this trial will provide clinical evidence on the effectiveness and safety of C. caudatus in patients with type 2 diabetes. ClinicalTrials.gov identifier: NCT02322268.

The blocked-random effect in pictures and words.

PubMed

Toglia, M P; Hinman, P J; Dayton, B S; Catalano, J F

1997-06-01

Picture and word recall was examined in conjunction with list organization. 60 subjects studied a list of 30 items, either words or their pictorial equivalents. The 30 words/pictures, members of five conceptual categories, each represented by six exemplars, were presented either blocked by category or in a random order. While pictures were recalled better than words and a standard blocked-random effect was observed, the interaction indicated that the recall advantage of a blocked presentation was restricted to the word lists. A similar pattern emerged for clustering. These findings are discussed in terms of limitations upon the pictorial superiority effect.

Using Non-experimental Data to Estimate Treatment Effects

PubMed Central

Stuart, Elizabeth A.; Marcus, Sue M.; Horvitz-Lennon, Marcela V.; Gibbons, Robert D.; Normand, Sharon-Lise T.

2009-01-01

While much psychiatric research is based on randomized controlled trials (RCTs), where patients are randomly assigned to treatments, sometimes RCTs are not feasible. This paper describes propensity score approaches, which are increasingly used for estimating treatment effects in non-experimental settings. The primary goal of propensity score methods is to create sets of treated and comparison subjects who look as similar as possible, in essence replicating a randomized experiment, at least with respect to observed patient characteristics. A study to estimate the metabolic effects of antipsychotic medication in a sample of Florida Medicaid beneficiaries with schizophrenia illustrates methods. PMID:20563313

Random measurement error: Why worry? An example of cardiovascular risk factors.

PubMed

Brakenhoff, Timo B; van Smeden, Maarten; Visseren, Frank L J; Groenwold, Rolf H H

2018-01-01

With the increased use of data not originally recorded for research, such as routine care data (or 'big data'), measurement error is bound to become an increasingly relevant problem in medical research. A common view among medical researchers on the influence of random measurement error (i.e. classical measurement error) is that its presence leads to some degree of systematic underestimation of studied exposure-outcome relations (i.e. attenuation of the effect estimate). For the common situation where the analysis involves at least one exposure and one confounder, we demonstrate that the direction of effect of random measurement error on the estimated exposure-outcome relations can be difficult to anticipate. Using three example studies on cardiovascular risk factors, we illustrate that random measurement error in the exposure and/or confounder can lead to underestimation as well as overestimation of exposure-outcome relations. We therefore advise medical researchers to refrain from making claims about the direction of effect of measurement error in their manuscripts, unless the appropriate inferential tools are used to study or alleviate the impact of measurement error from the analysis.

A Randomized Trial of Telephone Psychotherapy and Pharmacotherapy for Depression: Continuation and Durability of Effects

ERIC Educational Resources Information Center

Ludman, Evette J.; Simon, Gregory E.; Tutty, Steve; Von Korff, Michael

2007-01-01

Randomized trial evidence and expert guidelines are mixed regarding the value of combined pharmacotherapy and psychotherapy as initial treatment for depression. This study describes long-term results of a randomized trial (N = 393) evaluating telephone-based cognitive-behavioral therapy (CBT) plus care management for primary care patients…

On Measuring and Reducing Selection Bias with a Quasi-Doubly Randomized Preference Trial

ERIC Educational Resources Information Center

Joyce, Ted; Remler, Dahlia K.; Jaeger, David A.; Altindag, Onur; O'Connell, Stephen D.; Crockett, Sean

2017-01-01

Randomized experiments provide unbiased estimates of treatment effects, but are costly and time consuming. We demonstrate how a randomized experiment can be leveraged to measure selection bias by conducting a subsequent observational study that is identical in every way except that subjects choose their treatment--a quasi-doubly randomized…

Can Group Interventions Facilitate Forgiveness of an Ex-Spouse?: A Randomized Clinical Trial

ERIC Educational Resources Information Center

Rye, Mark S.; Pargament, Kenneth I.; Pan, Wei; Yingling, David W.; Shogren, Karrie A.; Ito, Masako

2005-01-01

This study evaluated the effectiveness of 2 versions of an 8-session forgiveness group intervention for divorced individuals. Participants (randomized, n = 192; analyzed, n = 149) were randomly assigned to a secular forgiveness condition, a religious forgiveness condition, or a no-intervention comparison condition. Measures of forgiveness and…

Clinical Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE): A Pragmatic Trial of Complex Treatment for a Complex Disorder

PubMed Central

Nierenberg, Andrew A.; Sylvia, Louisa G.; Leon, Andrew C.; Reilly-Harrington, Noreen; Shesler, Leah W.; McElroy, Susan L.; Friedman, Edward S.; Thase, Michael E.; Shelton, Richard C.; Bowden, Charles; Tohen, Mauricio; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence; Kocsis, James; McInnis, Melvin G.; Schoenfeld, David; Bobo, William V.; Calabrese, Joseph R.

2015-01-01

Background Classic and second generation antipsychotic mood stabilizers are recommended for treatment of bipolar disorder, yet there are no randomized comparative effectiveness studies that have examined the “real-world” advantages and disadvantages of these medications Purpose We describe the strategic decisions in the design of the Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE). This paper outlines the key issues and solutions the investigators faced in designing a clinical trial that would maximize generalizability and inform real-world clinical treatment of bipolar disorder. Methods Bipolar CHOICE was a 6-month, multi-site, prospective, randomized clinical trial of outpatients with bipolar disorder. This study compares the effectiveness of quetiapine versus lithium, each with adjunctive personalized treatments. The co-primary outcomes selected are the overall benefits and harms of the study medications (as measured by the Clinical Global Impression-Efficacy Index) and the Necessary Clinical Adjustments (a measure of the number of medication changes). Secondary outcomes are continuous measures of mood, the Framingham General Cardiovascular Risk Score and the Longitudinal Interval Follow up Evaluation Range of Impaired Functioning Tool. Results The final study design consisted of a single-blind, randomized comparative effectiveness trial of quetiapine versus lithium, plus adjunctive personalized treatment (APT), across ten sites. Other important study considerations included limited exclusion criteria to maximize generalizability, flexible dosing of APT medications to mimic real-world treatment, and an intent-to-treat analysis plan. 482 participants were randomized to the study and 364 completed. Limitations The potential limitations of the study include the heterogeneity of APT, selection of study medications, lack of a placebo-control group, and participants’ ability to pay for study medications. Conclusion We expect that this study will inform our understanding of the benefits and harms of lithium, a classic mood stabilizer, compared to quetiapine, a second generation antipsychotic with broad-spectrum activity in bipolar disorder and will provide an example of a well-designed and well-conducted randomized comparative effectiveness clinical trial. PMID:24346608

Effect of the degree of disorder on electronic and optical properties in random superlattices

NASA Technical Reports Server (NTRS)

Wang, E. G.; Su, W. P.; Ting, C. S.

1994-01-01

A three-dimensional tight-binding calculation is developed and used to study disorder effects in a realistic random superlattice. With increasing disorder, a tendency of possible indirect-direct band-gap transition is suggested. Direct evidence of mobility edges between localized and extended states in three-dimensional random systems is given. As system disorder increases, the optical absorption intensities increase dramatically from five to forty-five times stronger than the ordered (GaAs)(sub 1)/(AlAs)(sub 1) superlattice. It is believed that the degree of disorder significantly affects electronic and optical properties of GaAs/AlAs random superlattices.

[Realization of design regarding experimental research in the clinical real-world research].

PubMed

He, Q; Shi, J P

2018-04-10

Real world study (RWS), a further verification and supplement for explanatory randomized controlled trial to evaluate the effectiveness of intervention measures in real clinical environment, has increasingly become the focus in the field of research on medical and health care services. However, some people mistakenly equate real world study with observational research, and argue that intervention and randomization cannot be carried out in real world study. In fact, both observational and experimental design are the basic designs in real world study, while the latter usually refers to pragmatic randomized controlled trial and registry-based randomized controlled trial. Other nonrandomized controlled and adaptive designs can also be adopted in the RWS.

The Effectiveness of Healthy Start Home Visit Program: Cluster Randomized Controlled Trial

ERIC Educational Resources Information Center

Leung, Cynthia; Tsang, Sandra; Heung, Kitty

2015-01-01

Purpose: The study reported the effectiveness of a home visit program for disadvantaged Chinese parents with preschool children, using cluster randomized controlled trial design. Method: Participants included 191 parents and their children from 24 preschools, with 84 dyads (12 preschools) in the intervention group and 107 dyads (12 preschools) in…

The Effect of CAI on Reading Achievement.

ERIC Educational Resources Information Center

Hardman, Regina

A study determined whether computer assisted instruction (CAI) had an effect on students' reading achievement. Subjects were 21 randomly selected fourth-grade students at D. S. Wentworth Elementary School on the south side of Chicago in a low-income neighborhood who received a year's exposure to a CAI program, and 21 randomly selected students at…

Hybrid Implementation Model of Community-Partnered Early Intervention for Toddlers with Autism: A Randomized Trial

ERIC Educational Resources Information Center

Shire, Stephanie Y.; Chang, Ya-Chih; Shih, Wendy; Bracaglia, Suzanne; Kodjoe, Maria; Kasari, Connie

2017-01-01

Background: Interventions found to be effective in research settings are often not as effective when implemented in community settings. Considering children with autism, studies have rarely examined the efficacy of laboratory-tested interventions on child outcomes in community settings using randomized controlled designs. Methods: One hundred and…

A Randomized Controlled Design Investigating the Effects of Classroom-Based Physical Activity on Children's Fluid Intelligence and Achievement

ERIC Educational Resources Information Center

Fedewa, Alicia L.; Ahn, Soyeon; Erwin, Heather; Davis, Matthew C.

2015-01-01

Existing literature shows promising effects of physical activity on children's cognitive outcomes. This study assessed via a randomized, controlled design whether additional curricular physical activity during the school day resulted in gains for children's fluid intelligence and standardized achievement outcomes. Participants were children…

The Effect of Diffused Aromatherapy on Test Anxiety among Baccalaureate Nursing Students

ERIC Educational Resources Information Center

Johnson, Catherine E.

2013-01-01

A quantitative, randomized, pretest, posttest study was conducted to assess the effect of aromatherapy on cognitive test anxiety among nursing students. Sophomore nursing students (n = 39) from a private, 4-year college, were randomized into either the control group (n = 18) or the experimental group (n = 21). Each participant completed the…

Effects of an Early Numeracy Intervention on Struggling Kindergarteners' Mathematics Performance

ERIC Educational Resources Information Center

Bryant, Brian R.; Bryant, Diane Pedrotty; Roberts, Greg; Fall, Anna-Maria

2016-01-01

The purpose of this study was to investigate the effects of an early numeracy intervention delivered by kindergarten teachers to students identified as having mathematics difficulties. A multigroup growth-modeling-with-random-assignment-to-intervention-condition design was employed. Thirty-two teachers were randomly assigned to the treatment or…

Moving from Efficacy to Effectiveness in Cognitive Behavioral Therapy for Psychosis: A Randomized Clinical Practice Trial

ERIC Educational Resources Information Center

Lincoln, Tania M.; Ziegler, Michael; Mehl, Stephanie; Kesting, Marie-Luise; Lullmann, Eva; Westermann, Stefan; Rief, Winfried

2012-01-01

Objective: Randomized controlled trials have attested the efficacy of cognitive behavioral therapy (CBT) in reducing psychotic symptoms. Now, studies are needed to investigate its effectiveness in routine clinical practice settings. Method: Eighty patients with schizophrenia spectrum disorders who were seeking outpatient treatment were randomized…

A Randomized Trial Investigating the Effect of a Brief Lifestyle Intervention on Freshman-Year Weight Gain

ERIC Educational Resources Information Center

Middleton, Kathryn R.; Perri, Michael G.

2014-01-01

Objective: The current study was a randomized controlled trial investigating the effect of an innovative, short-term lifestyle intervention on weight gain in female freshman college students. Participants: Ninety-five freshmen were recruited from a large public university in the United States. Methods: Participants completed baseline assessments…

Free School Fruit--Sustained Effect 1 Year Later

ERIC Educational Resources Information Center

Bere, E.; Veierod, M. B.; Bjelland, M.; Klepp, K.-I.

2006-01-01

This study reports the effect of a school-randomized fruit and vegetable intervention consisting of a subscription to the Norwegian School Fruit Programme at no parental cost, and the Fruit and Vegetables Make the Marks (FVMM) educational programme, both delivered in the school year of 2001-02. Nine randomly chosen schools received the…

Assessing the Generalizability of Randomized Trial Results to Target Populations

PubMed Central

Stuart, Elizabeth A.; Bradshaw, Catherine P.; Leaf, Philip J.

2014-01-01

Recent years have seen increasing interest in and attention to evidence-based practices, where the “evidence” generally comes from well-conducted randomized trials. However, while those trials yield accurate estimates of the effect of the intervention for the participants in the trial (known as “internal validity”), they do not always yield relevant information about the effects in a particular target population (known as “external validity”). This may be due to a lack of specification of a target population when designing the trial, difficulties recruiting a sample that is representative of a pre-specified target population, or to interest in considering a target population somewhat different from the population directly targeted by the trial. This paper first provides an overview of existing design and analysis methods for assessing and enhancing the ability of a randomized trial to estimate treatment effects in a target population. It then provides a case study using one particular method, which weights the subjects in a randomized trial to match the population on a set of observed characteristics. The case study uses data from a randomized trial of School-wide Positive Behavioral Interventions and Supports (PBIS); our interest is in generalizing the results to the state of Maryland. In the case of PBIS, after weighting, estimated effects in the target population were similar to those observed in the randomized trial. The paper illustrates that statistical methods can be used to assess and enhance the external validity of randomized trials, making the results more applicable to policy and clinical questions. However, there are also many open research questions; future research should focus on questions of treatment effect heterogeneity and further developing these methods for enhancing external validity. Researchers should think carefully about the external validity of randomized trials and be cautious about extrapolating results to specific populations unless they are confident of the similarity between the trial sample and that target population. PMID:25307417

Assessing the generalizability of randomized trial results to target populations.

PubMed

Stuart, Elizabeth A; Bradshaw, Catherine P; Leaf, Philip J

2015-04-01

Recent years have seen increasing interest in and attention to evidence-based practices, where the "evidence" generally comes from well-conducted randomized trials. However, while those trials yield accurate estimates of the effect of the intervention for the participants in the trial (known as "internal validity"), they do not always yield relevant information about the effects in a particular target population (known as "external validity"). This may be due to a lack of specification of a target population when designing the trial, difficulties recruiting a sample that is representative of a prespecified target population, or to interest in considering a target population somewhat different from the population directly targeted by the trial. This paper first provides an overview of existing design and analysis methods for assessing and enhancing the ability of a randomized trial to estimate treatment effects in a target population. It then provides a case study using one particular method, which weights the subjects in a randomized trial to match the population on a set of observed characteristics. The case study uses data from a randomized trial of school-wide positive behavioral interventions and supports (PBIS); our interest is in generalizing the results to the state of Maryland. In the case of PBIS, after weighting, estimated effects in the target population were similar to those observed in the randomized trial. The paper illustrates that statistical methods can be used to assess and enhance the external validity of randomized trials, making the results more applicable to policy and clinical questions. However, there are also many open research questions; future research should focus on questions of treatment effect heterogeneity and further developing these methods for enhancing external validity. Researchers should think carefully about the external validity of randomized trials and be cautious about extrapolating results to specific populations unless they are confident of the similarity between the trial sample and that target population.

The effects of mental practice in neurological rehabilitation; a systematic review and meta-analysis

PubMed Central

Braun, Susy; Kleynen, Melanie; van Heel, Tessa; Kruithof, Nena; Wade, Derick; Beurskens, Anna

2013-01-01

Objective: To investigate the beneficial and adverse effects of a mental practice intervention on activities, cognition, and emotion in patients after stroke, patients with Parkinson's disease or multiple sclerosis. Methods: Electronic databases PubMed/Medline, PEDro, Science Direct, Cochrane Library, PsycINFO, Rehadat, Embase, and Picarta were searched until June 2012. Fourteen randomized controlled trials in stroke and two randomized controlled trials in Parkinson's disease were included, representing 491 patients (421 with stroke). No randomized controlled trials in multiple sclerosis were identified. The methodologic quality of the included trials was assessed with the Amsterdam-Maastricht-Consensus-List (AMCL). Information on study characteristics and outcomes was summarized and evidence for effects described. Data from individual studies in stroke with same outcome measures were pooled. Results: The included 16 randomized controlled trials were heterogeneous and methodologic quality varied. Ten trials reported significant effects in favor of mental practice in patients with stroke (n = 9) and Parkinson's disease (n = 1). In six studies mental practice had similar effects as therapy as usual (n = 5 in stroke and n = 1 in Parkinson's disease). Of six performed meta-analyses with identical measures in stroke studies only two showed significant effects of mental practice: short-term improvement of arm-hand-ability (ARAT: SMD 0.62; 95% CI: 0.05 to 1.19) and improvement of performance of activities (NRS: SMD 0.9; 95% CI: 0.04 to 1.77). Five studies found effects on cognition (e.g., effects on attention, plan actions in unfamiliar surroundings) and four reported observed side-effects, both positive (e.g., might increase motivation and arousal and reduce depression) and negative (e.g., diminished concentration, irritation). Conclusions: Mental practice might have positive effects on performance of activities in patients with neurological diseases, but this review reports less positive results than earlier published ones. Strengths and limitations of past studies are pointed out. Methodologic recommendations for future studies are given. PMID:23935572

Sensitivity Analysis for Multivalued Treatment Effects: An Example of a Cross-Country Study of Teacher Participation and Job Satisfaction

ERIC Educational Resources Information Center

Chang, Chi

2015-01-01

It is known that interventions are hard to assign randomly to subjects in social psychological studies, because randomized control is difficult to implement strictly and precisely. Thus, in nonexperimental studies and observational studies, controlling the impact of covariates on the dependent variables and addressing the robustness of the…

Systematic review on the health effects of exposure to radiofrequency electromagnetic fields from mobile phone base stations

PubMed Central

Frei, Patrizia; Mohler, Evelyn; Hug, Kerstin

2010-01-01

Abstract Objective To review and evaluate the recent literature on the health effects of exposure to mobile phone base station (MPBS) radiation. Methods We performed a systematic review of randomized human trials conducted in laboratory settings and of epidemiological studies that investigated the health effects of MPBS radiation in the everyday environment. Findings We included in the analysis 17 articles that met our basic quality criteria: 5 randomized human laboratory trials and 12 epidemiological studies. The majority of the papers (14) examined self-reported non-specific symptoms of ill-health. Most of the randomized trials did not detect any association between MPBS radiation and the development of acute symptoms during or shortly after exposure. The sporadically observed associations did not show a consistent pattern with regard to symptoms or types of exposure. We also found that the more sophisticated the exposure assessment, the less likely it was that an effect would be reported. Studies on health effects other than non-specific symptoms and studies on MPBS exposure in children were scarce. Conclusion The evidence for a missing relationship between MPBS exposure up to 10 volts per metre and acute symptom development can be considered strong because it is based on randomized, blinded human laboratory trials. At present, there is insufficient data to draw firm conclusions about health effects from long-term low-level exposure typically occurring in the everyday environment. PMID:21124713

The Long-Term Effectiveness of a Selective, Personality-Targeted Prevention Program in Reducing Alcohol Use and Related Harms: A Cluster Randomized Controlled Trial

ERIC Educational Resources Information Center

Newton, Nicola C.; Conrod, Patricia J.; Slade, Tim; Carragher, Natacha; Champion, Katrina E.; Barrett, Emma L.; Kelly, Erin V.; Nair, Natasha K.; Stapinski, Lexine; Teesson, Maree

2016-01-01

Background: This study investigated the long-term effectiveness of Preventure, a selective personality-targeted prevention program, in reducing the uptake of alcohol, harmful use of alcohol, and alcohol-related harms over a 3-year period. Methods: A cluster randomized controlled trial was conducted to assess the effectiveness of Preventure.…

The Effects of a Computerized Study Program on the Acquisition of Science Vocabulary

ERIC Educational Resources Information Center

Rollins, Karen F.

2012-01-01

The following study examined the difference in science vocabulary acquisition comparing computer-assisted learning and a traditional study review sheet. Fourth and fifth grade students from a suburban school in central Texas were randomly selected and randomly assigned to either experimental group or control group. Both groups were given a…

Unbiased Causal Inference from an Observational Study: Results of a Within-Study Comparison

ERIC Educational Resources Information Center

Pohl, Steffi; Steiner, Peter M.; Eisermann, Jens; Soellner, Renate; Cook, Thomas D.

2009-01-01

Adjustment methods such as propensity scores and analysis of covariance are often used for estimating treatment effects in nonexperimental data. Shadish, Clark, and Steiner used a within-study comparison to test how well these adjustments work in practice. They randomly assigned participating students to a randomized or nonrandomized experiment.…

A random wave model for the Aharonov-Bohm effect

NASA Astrophysics Data System (ADS)

Houston, Alexander J. H.; Gradhand, Martin; Dennis, Mark R.

2017-05-01

We study an ensemble of random waves subject to the Aharonov-Bohm effect. The introduction of a point with a magnetic flux of arbitrary strength into a random wave ensemble gives a family of wavefunctions whose distribution of vortices (complex zeros) is responsible for the topological phase associated with the Aharonov-Bohm effect. Analytical expressions are found for the vortex number and topological charge densities as functions of distance from the flux point. Comparison is made with the distribution of vortices in the isotropic random wave model. The results indicate that as the flux approaches half-integer values, a vortex with the same sign as the fractional part of the flux is attracted to the flux point, merging with it in the limit of half-integer flux. We construct a statistical model of the neighbourhood of the flux point to study how this vortex-flux merger occurs in more detail. Other features of the Aharonov-Bohm vortex distribution are also explored.

Accounting for Heterogeneity in Relative Treatment Effects for Use in Cost-Effectiveness Models and Value-of-Information Analyses

PubMed Central

Soares, Marta O.; Palmer, Stephen; Ades, Anthony E.; Harrison, David; Shankar-Hari, Manu; Rowan, Kathy M.

2015-01-01

Cost-effectiveness analysis (CEA) models are routinely used to inform health care policy. Key model inputs include relative effectiveness of competing treatments, typically informed by meta-analysis. Heterogeneity is ubiquitous in meta-analysis, and random effects models are usually used when there is variability in effects across studies. In the absence of observed treatment effect modifiers, various summaries from the random effects distribution (random effects mean, predictive distribution, random effects distribution, or study-specific estimate [shrunken or independent of other studies]) can be used depending on the relationship between the setting for the decision (population characteristics, treatment definitions, and other contextual factors) and the included studies. If covariates have been measured that could potentially explain the heterogeneity, then these can be included in a meta-regression model. We describe how covariates can be included in a network meta-analysis model and how the output from such an analysis can be used in a CEA model. We outline a model selection procedure to help choose between competing models and stress the importance of clinical input. We illustrate the approach with a health technology assessment of intravenous immunoglobulin for the management of adult patients with severe sepsis in an intensive care setting, which exemplifies how risk of bias information can be incorporated into CEA models. We show that the results of the CEA and value-of-information analyses are sensitive to the model and highlight the importance of sensitivity analyses when conducting CEA in the presence of heterogeneity. The methods presented extend naturally to heterogeneity in other model inputs, such as baseline risk. PMID:25712447

Accounting for Heterogeneity in Relative Treatment Effects for Use in Cost-Effectiveness Models and Value-of-Information Analyses.

PubMed

Welton, Nicky J; Soares, Marta O; Palmer, Stephen; Ades, Anthony E; Harrison, David; Shankar-Hari, Manu; Rowan, Kathy M

2015-07-01

Cost-effectiveness analysis (CEA) models are routinely used to inform health care policy. Key model inputs include relative effectiveness of competing treatments, typically informed by meta-analysis. Heterogeneity is ubiquitous in meta-analysis, and random effects models are usually used when there is variability in effects across studies. In the absence of observed treatment effect modifiers, various summaries from the random effects distribution (random effects mean, predictive distribution, random effects distribution, or study-specific estimate [shrunken or independent of other studies]) can be used depending on the relationship between the setting for the decision (population characteristics, treatment definitions, and other contextual factors) and the included studies. If covariates have been measured that could potentially explain the heterogeneity, then these can be included in a meta-regression model. We describe how covariates can be included in a network meta-analysis model and how the output from such an analysis can be used in a CEA model. We outline a model selection procedure to help choose between competing models and stress the importance of clinical input. We illustrate the approach with a health technology assessment of intravenous immunoglobulin for the management of adult patients with severe sepsis in an intensive care setting, which exemplifies how risk of bias information can be incorporated into CEA models. We show that the results of the CEA and value-of-information analyses are sensitive to the model and highlight the importance of sensitivity analyses when conducting CEA in the presence of heterogeneity. The methods presented extend naturally to heterogeneity in other model inputs, such as baseline risk. © The Author(s) 2015.

Quenched bond randomness: Superfluidity in porous media and the strong violation of universality

NASA Astrophysics Data System (ADS)

Falicov, Alexis; Berker, A. Nihat

1997-04-01

The effects of quenched bond randomness are most readily studied with superfluidity immersed in a porous medium. A lattice model for3He-4He mixtures and incomplete4He fillings in aerogel yields the signature effect of bond randomness, namely the conversion of symmetry-breaking first-order phase transitions into second-order phase transitions, the λ-line reaching zero temperature, and the elimination of non-symmetry-breaking first-order phase transitions. The model recognizes the importance of the connected nature of aerogel randomness and thereby yields superfluidity at very low4He concentrations, a phase separation entirely within the superfluid phase, and the order-parameter contrast between mixtures and incomplete fillings, all in agreement with experiments. The special properties of the helium mixture/aerogel system are distinctly linked to the aerogel properties of connectivity, randomness, and tenuousness, via the additional study of a regularized “jungle-gym” aerogel. Renormalization-group calculations indicate that a strong violation of the empirical universality principle of critical phenomena occurs under quenched bond randomness. It is argued that helium/aerogel critical properties reflect this violation and further experiments are suggested. Renormalization-group analysis also shows that, adjoiningly to the strong universality violation (which hinges on the occurrence or non-occurrence of asymptotic strong coupling—strong randomness under rescaling), there is a new “hyperuniversality” at phase transitions with asymptotic strong coupling—strong randomness behavior, for example assigning the same critical exponents to random- bond tricriticality and random- field criticality.

Dynamic analysis of a pumped-storage hydropower plant with random power load

NASA Astrophysics Data System (ADS)

Zhang, Hao; Chen, Diyi; Xu, Beibei; Patelli, Edoardo; Tolo, Silvia

2018-02-01

This paper analyzes the dynamic response of a pumped-storage hydropower plant in generating mode. Considering the elastic water column effects in the penstock, a linearized reduced order dynamic model of the pumped-storage hydropower plant is used in this paper. As the power load is always random, a set of random generator electric power output is introduced to research the dynamic behaviors of the pumped-storage hydropower plant. Then, the influences of the PI gains on the dynamic characteristics of the pumped-storage hydropower plant with the random power load are analyzed. In addition, the effects of initial power load and PI parameters on the stability of the pumped-storage hydropower plant are studied in depth. All of the above results will provide theoretical guidance for the study and analysis of the pumped-storage hydropower plant.

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial

PubMed Central

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

Objectives: This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. Methods: This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Results: Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Conclusion: Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia. PMID:25674110

A comparison of observation-level random effect and Beta-Binomial models for modelling overdispersion in Binomial data in ecology & evolution.

PubMed

Harrison, Xavier A

2015-01-01

Overdispersion is a common feature of models of biological data, but researchers often fail to model the excess variation driving the overdispersion, resulting in biased parameter estimates and standard errors. Quantifying and modeling overdispersion when it is present is therefore critical for robust biological inference. One means to account for overdispersion is to add an observation-level random effect (OLRE) to a model, where each data point receives a unique level of a random effect that can absorb the extra-parametric variation in the data. Although some studies have investigated the utility of OLRE to model overdispersion in Poisson count data, studies doing so for Binomial proportion data are scarce. Here I use a simulation approach to investigate the ability of both OLRE models and Beta-Binomial models to recover unbiased parameter estimates in mixed effects models of Binomial data under various degrees of overdispersion. In addition, as ecologists often fit random intercept terms to models when the random effect sample size is low (<5 levels), I investigate the performance of both model types under a range of random effect sample sizes when overdispersion is present. Simulation results revealed that the efficacy of OLRE depends on the process that generated the overdispersion; OLRE failed to cope with overdispersion generated from a Beta-Binomial mixture model, leading to biased slope and intercept estimates, but performed well for overdispersion generated by adding random noise to the linear predictor. Comparison of parameter estimates from an OLRE model with those from its corresponding Beta-Binomial model readily identified when OLRE were performing poorly due to disagreement between effect sizes, and this strategy should be employed whenever OLRE are used for Binomial data to assess their reliability. Beta-Binomial models performed well across all contexts, but showed a tendency to underestimate effect sizes when modelling non-Beta-Binomial data. Finally, both OLRE and Beta-Binomial models performed poorly when models contained <5 levels of the random intercept term, especially for estimating variance components, and this effect appeared independent of total sample size. These results suggest that OLRE are a useful tool for modelling overdispersion in Binomial data, but that they do not perform well in all circumstances and researchers should take care to verify the robustness of parameter estimates of OLRE models.

Effect of Reiki therapy on pain and anxiety in adults: an in-depth literature review of randomized trials with effect size calculations.

PubMed

Thrane, Susan; Cohen, Susan M

2014-12-01

The objective of this study was to calculate the effect of Reiki therapy for pain and anxiety in randomized clinical trials. A systematic search of PubMed, ProQuest, Cochrane, PsychInfo, CINAHL, Web of Science, Global Health, and Medline databases was conducted using the search terms pain, anxiety, and Reiki. The Center for Reiki Research also was examined for articles. Studies that used randomization and a control or usual care group, used Reiki therapy in one arm of the study, were published in 2000 or later in peer-reviewed journals in English, and measured pain or anxiety were included. After removing duplicates, 49 articles were examined and 12 articles received full review. Seven studies met the inclusion criteria: four articles studied cancer patients, one examined post-surgical patients, and two analyzed community dwelling older adults. Effect sizes were calculated for all studies using Cohen's d statistic. Effect sizes for within group differences ranged from d = 0.24 for decrease in anxiety in women undergoing breast biopsy to d = 2.08 for decreased pain in community dwelling adults. The between group differences ranged from d = 0.32 for decrease of pain in a Reiki versus rest intervention for cancer patients to d = 4.5 for decrease in pain in community dwelling adults. Although the number of studies is limited, based on the size Cohen's d statistics calculated in this review, there is evidence to suggest that Reiki therapy may be effective for pain and anxiety. Continued research using Reiki therapy with larger sample sizes, consistently randomized groups, and standardized treatment protocols is recommended. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Effect of Reiki Therapy on Pain and Anxiety in Adults: An In-Depth Literature Review of Randomized Trials with Effect Size Calculations

PubMed Central

Thrane, Susan; Cohen, Susan M.

2013-01-01

Objective To calculate the effect of Reiki therapy for pain and anxiety in randomized clinical trials. Data Sources A systematic search of PubMed, ProQuest, Cochrane, PsychInfo, CINAHL, Web of Science, Global Health, and Medline databases was conducted using the search terms pain, anxiety, and Reiki. The Center for Reiki Research was also examined for articles. Study Selection Studies that used randomization and a control or usual care group, used Reiki therapy in one arm of the study, published in 2000 or later in peer-reviewed journals in English, and measured pain or anxiety were included. Results After removing duplicates, 49 articles were examined and 12 articles received full review. Seven studies met the inclusion criteria: four articles studied cancer patients; one examined post-surgical patients; and two analyzed community dwelling older adults. Effect sizes were calculated for all studies using Cohen’s d statistic. Effect sizes for within group differences ranged from d=0.24 for decrease in anxiety in women undergoing breast biopsy to d=2.08 for decreased pain in community dwelling adults. The between group differences ranged from d=0.32 for decrease of pain in a Reiki versus rest intervention for cancer patients to d=4.5 for decrease in pain in community dwelling adults. Conclusions While the number of studies is limited, based on the size Cohen’s d statistics calculated in this review, there is evidence to suggest that Reiki therapy may be effective for pain and anxiety. Continued research using Reiki therapy with larger sample sizes, consistently randomized groups, and standardized treatment protocols is recommended. PMID:24582620

The risk-stratified osteoporosis strategy evaluation study (ROSE): a randomized prospective population-based study. Design and baseline characteristics.

PubMed

Rubin, Katrine Hass; Holmberg, Teresa; Rothmann, Mette Juel; Høiberg, Mikkel; Barkmann, Reinhard; Gram, Jeppe; Hermann, Anne Pernille; Bech, Mickael; Rasmussen, Ole; Glüer, Claus C; Brixen, Kim

2015-02-01

The risk-stratified osteoporosis strategy evaluation study (ROSE) is a randomized prospective population-based study investigating the effectiveness of a two-step screening program for osteoporosis in women. This paper reports the study design and baseline characteristics of the study population. 35,000 women aged 65-80 years were selected at random from the population in the Region of Southern Denmark and-before inclusion-randomized to either a screening group or a control group. As first step, a self-administered questionnaire regarding risk factors for osteoporosis based on FRAX(®) was issued to both groups. As second step, subjects in the screening group with a 10-year probability of major osteoporotic fractures ≥15% were offered a DXA scan. Patients diagnosed with osteoporosis from the DXA scan were advised to see their GP and discuss pharmaceutical treatment according to Danish National guidelines. The primary outcome is incident clinical fractures as evaluated through annual follow-up using the Danish National Patient Registry. The secondary outcomes are cost-effectiveness, participation rate, and patient preferences. 20,904 (60%) women participated and included in the baseline analyses (10,411 in screening and 10,949 in control group). The mean age was 71 years. As expected by randomization, the screening and control groups had similar baseline characteristics. Screening for osteoporosis is at present not evidence based according to the WHO screening criteria. The ROSE study is expected to provide knowledge of the effectiveness of a screening strategy that may be implemented in health care systems to prevent fractures.

Pelvic floor muscle training for bowel dysfunction following colorectal cancer surgery: A systematic review.

PubMed

Lin, Kuan-Yin; Granger, Catherine L; Denehy, Linda; Frawley, Helena C

2015-11-01

To identify, evaluate and synthesize the evidence examining the effectiveness of pelvic floor muscle training (PFMT) on bowel dysfunction in patients who have undergone colorectal cancer surgery. Eight electronic databases (MEDLINE 1950-2014; CINAHL 1982-2014; EMBASE 1980-2014; Scopus 1823-2014; PsycINFO 1806-2014; Web of Science 1970-2014; Cochrane Library 2014; PEDro 1999-2014) were systematically searched in March 2014. Reference lists of identified articles were cross referenced and hand searched. Randomized controlled trials, cohort studies and case series were included if they investigated the effects of conservative treatments, including PFMT on bowel function in patients with colorectal cancer following surgery. Two reviewers independently assessed the risk of bias of studies using the Newcastle-Ottawa Scale (NOS). Six prospective non-randomized studies and two retrospective studies were included. The mean (SD) NOS risk of bias score was 4.9 (1.2) out of 9; studies were limited by a lack of non-exposed cohort, lack of independent blinded assessment, heterogeneous treatment protocols, and lack of long-term follow-up. The majority of studies reported significant improvements in stool frequency, incontinence episodes, severity of fecal incontinence, and health-related quality of life (HRQoL) after PFMT. Meta-analysis was not possible due to lack of randomized controlled trials. Pelvic floor muscle training for patients following surgery for colorectal cancer appears to be associated with improvements in bowel function and HRQoL. Results from non-randomized studies are promising but randomized controlled trials with sufficient power are needed to confirm the effectiveness of PFMT in this population. © 2014 Wiley Periodicals, Inc.

Effects of psychoeducation on helpful support for complicated grief: a preliminary randomized controlled single-blind study.

PubMed

Nam, I S

2016-01-01

Complicated grief is a distinct psychological response of individuals facing the loss of a loved one and can lead to many types of adverse health outcomes. Although social support may be beneficial, few studies have examined the beneficial effects of helpful support on complicated grief following bereavement. A randomized controlled trial was conducted. Bereaved participants and supporters were randomized to psychoeducation on complicated grief and helpful social support or psychoeducation on complicated grief. The primary outcome was the Inventory of Complicated Grief. The results showed that psychoeducation of supporters of bereaved individuals has significant beneficial effects. Particularly, symptoms of complicated grief were decreased in bereaved individuals with supporters that received psychoeducation. The results highlight the potential of psychoeducation to facilitate helpful social support and reduce complicated grief.

Random forests as cumulative effects models: A case study of lakes and rivers in Muskoka, Canada.

PubMed

Jones, F Chris; Plewes, Rachel; Murison, Lorna; MacDougall, Mark J; Sinclair, Sarah; Davies, Christie; Bailey, John L; Richardson, Murray; Gunn, John

2017-10-01

Cumulative effects assessment (CEA) - a type of environmental appraisal - lacks effective methods for modeling cumulative effects, evaluating indicators of ecosystem condition, and exploring the likely outcomes of development scenarios. Random forests are an extension of classification and regression trees, which model response variables by recursive partitioning. Random forests were used to model a series of candidate ecological indicators that described lakes and rivers from a case study watershed (The Muskoka River Watershed, Canada). Suitability of the candidate indicators for use in cumulative effects assessment and watershed monitoring was assessed according to how well they could be predicted from natural habitat features and how sensitive they were to human land-use. The best models explained 75% of the variation in a multivariate descriptor of lake benthic-macroinvertebrate community structure, and 76% of the variation in the conductivity of river water. Similar results were obtained by cross-validation. Several candidate indicators detected a simulated doubling of urban land-use in their catchments, and a few were able to detect a simulated doubling of agricultural land-use. The paper demonstrates that random forests can be used to describe the combined and singular effects of multiple stressors and natural environmental factors, and furthermore, that random forests can be used to evaluate the performance of monitoring indicators. The numerical methods presented are applicable to any ecosystem and indicator type, and therefore represent a step forward for CEA. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Quantifying the placebo effect in psychological outcomes of exercise training: a meta-analysis of randomized trials.

PubMed

Lindheimer, Jacob B; O'Connor, Patrick J; Dishman, Rod K

2015-05-01

The placebo effect could account for some or all of the psychological benefits attributed to exercise training. The magnitude of the placebo effect in psychological outcomes of randomized controlled exercise training trials has not been quantified. The aim of this investigation was to estimate the magnitude of the population placebo effect in psychological outcomes from placebo conditions used in exercise training studies and compare it to the observed effect of exercise training. Articles published before 1 July 2013 were located using Google Scholar, MEDLINE, PsycINFO, and The Cochrane Library. To be included in the analysis, studies were required to have (1) a design that randomly assigned participants to exercise training, placebo, and control conditions and (2) an assessment of a subjective (i.e., anxiety, depression, energy, fatigue) or an objective (i.e., cognitive) psychological outcome. Meta-analytic and multi-level modeling techniques were used to analyze effects from nine studies involving 661 participants. Hedges' d effect sizes were calculated, and random effects models were used to estimate the overall magnitude of the placebo and exercise training effects. After adjusting for nesting effects, the placebo mean effect size was 0.20 (95% confidence interval [CI] -0.02, 0.41) and the observed effect of exercise training was 0.37 (95% CI 0.11, 0.63). A small body of research suggests both that (1) the placebo effect is approximately half of the observed psychological benefits of exercise training and (2) there is an urgent need for creative research specifically aimed at better understanding the role of the placebo effect in the mental health consequences of exercise training.

Mendelian randomization in nutritional epidemiology

PubMed Central

Qi, Lu

2013-01-01

Nutritional epidemiology aims to identify dietary and lifestyle causes for human diseases. Causality inference in nutritional epidemiology is largely based on evidence from studies of observational design, and may be distorted by unmeasured or residual confounding and reverse causation. Mendelian randomization is a recently developed methodology that combines genetic and classical epidemiological analysis to infer causality for environmental exposures, based on the principle of Mendel’s law of independent assortment. Mendelian randomization uses genetic variants as proxiesforenvironmentalexposuresofinterest.AssociationsderivedfromMendelian randomization analysis are less likely to be affected by confounding and reverse causation. During the past 5 years, a body of studies examined the causal effects of diet/lifestyle factors and biomarkers on a variety of diseases. The Mendelian randomization approach also holds considerable promise in the study of intrauterine influences on offspring health outcomes. However, the application of Mendelian randomization in nutritional epidemiology has some limitations. PMID:19674341

Comparative effectiveness research in cancer with observational data.

PubMed

Giordano, Sharon H

2015-01-01

Observational studies are increasingly being used for comparative effectiveness research. These studies can have the greatest impact when randomized trials are not feasible or when randomized studies have not included the population or outcomes of interest. However, careful attention must be paid to study design to minimize the likelihood of selection biases. Analytic techniques, such as multivariable regression modeling, propensity score analysis, and instrumental variable analysis, also can also be used to help address confounding. Oncology has many existing large and clinically rich observational databases that can be used for comparative effectiveness research. With careful study design, observational studies can produce valid results to assess the benefits and harms of a treatment or intervention in representative real-world populations.

Effectiveness of the Self-Regulation eHealth Intervention "MyPlan1.0." on Physical Activity Levels of Recently Retired Belgian Adults: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Van Dyck, Delfien; Plaete, Jolien; Cardon, Greet; Crombez, Geert; De Bourdeaudhuij, Ilse

2016-01-01

The study purpose was to test the effectiveness of the self-regulation eHealth intervention "MyPlan1.0." to increase physical activity (PA) in recently retired Belgian adults. This study was a randomized controlled trial with three points of follow-up/modules (baseline to 1-week to 1-month follow-up). In total, 240 recently retired…

Tai Chi Improves Sleep Quality in Healthy Adults and Patients with Chronic Conditions: A Systematic Review and Meta-analysis

PubMed Central

Raman, Gowri; Zhang, Yuan; Minichiello, Vincent J; D'Ambrosio, Carolyn M.; Wang, Chenchen

2017-01-01

Background Physical activity and exercise appear to improve sleep quality. However, the quantitative effects of Tai Chi on sleep quality in the adult population have rarely been examined. We conducted a systematic review and meta-analysis evaluating the effects of Tai Chi on sleep quality in healthy adults and disease populations. Methods Medline, Cochrane Central databases, and review of references were searched through July 31, 2013. English-language studies of all designs evaluating Tai Chi’s effect on sleep outcomes in adults were examined. Data were extracted and verified by 2 reviewers. Extracted information included study setting and design, population characteristics, type and duration of interventions, outcomes, risk of bias and main results. Random effect models meta-analysis was used to assess the magnitude of treatment effect when at least 3 trials reported on the same sleep outcomes. Results Eleven studies (9 randomized and 2 non-randomized trials) totaling 994 subjects published between 2004 and 2012 were identified. All studies except one reported Pittsburg Sleep Quality Index. Nine randomized trials reported that 1.5 to 3 hour each week for a duration of 6 to 24 weeks of Tai Chi significantly improved sleep quality (Effect Size, 0.89; 95% confidence interval [CI], 0.28 to 1.50), in community-dwelling healthy participants and in patients with chronic conditions. Improvement in health outcomes including physical performance, pain reduction, and psychological well-being occurred in the Tai Chi group compared with various controls. Limitations Studies were heterogeneous and some trials were lacking in methodological rigor. Conclusions Tai Chi significantly improved sleep quality in both healthy adults and patients with chronic health conditions, which suggests that Tai Chi may be considered as an alternative behavioral therapy in the treatment of insomnia. High-quality, well-controlled randomized trials are needed to better inform clinical decisions. PMID:28845367

A simple method for assessing occupational exposure via the one-way random effects model.

PubMed

Krishnamoorthy, K; Mathew, Thomas; Peng, Jie

2016-11-01

A one-way random effects model is postulated for the log-transformed shift-long personal exposure measurements, where the random effect in the model represents an effect due to the worker. Simple closed-form confidence intervals are proposed for the relevant parameters of interest using the method of variance estimates recovery (MOVER). The performance of the confidence bounds is evaluated and compared with those based on the generalized confidence interval approach. Comparison studies indicate that the proposed MOVER confidence bounds are better than the generalized confidence bounds for the overall mean exposure and an upper percentile of the exposure distribution. The proposed methods are illustrated using a few examples involving industrial hygiene data.

Reiki therapy for postoperative oral pain in pediatric patients: pilot data from a double-blind, randomized clinical trial.

PubMed

Kundu, Anjana; Lin, Yuting; Oron, Assaf P; Doorenbos, Ardith Z

2014-02-01

To examine the effects of Reiki as an adjuvant therapy to opioid therapy for postoperative pain control in pediatric patients. This was a double-blind, randomized controlled study of children undergoing dental procedures. Participants were randomly assigned to receive either Reiki therapy or the control therapy (sham Reiki) preoperatively. Postoperative pain scores, opioid requirements, and side effects were assessed. Family members were also asked about perioperative care satisfaction. Multiple linear regressions were used for analysis. Thirty-eight children participated. The blinding procedure was successful. No statistically significant difference was observed between groups on all outcome measures. Our study provides a successful example of a blinding procedure for Reiki therapy among children in the perioperative period. This study does not support the effectiveness of Reiki as an adjuvant therapy to opioid therapy for postoperative pain control in pediatric patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reiki therapy for postoperative oral pain in pediatric patients: Pilot data from a double-blind, randomized clinical trial

PubMed Central

Kundu, Anjana; Lin, Yuting; Oron, Assaf P.; Doorenbos, Ardith Z.

2014-01-01

Purpose To examine the effects of Reiki as an adjuvant therapy to opioid therapy for postoperative pain control in pediatric patients. Methods This was a double-blind, randomized controlled study of children undergoing dental procedures. Participants were randomly assigned to receive either Reiki therapy or the control therapy (sham Reiki) preoperatively. Postoperative pain scores, opioid requirements, and side effects were assessed. Family members were also asked about perioperative care satisfaction. Multiple linear regressions were used for analysis. Results Thirty-eight children participated. The blinding procedure was successful. No statistically significant difference was observed between groups on all outcome measures. Implications Our study provides a successful example of a blinding procedure for Reiki therapy among children in the perioperative period. This study does not support the effectiveness of Reiki as an adjuvant therapy to opioid therapy for postoperative pain control in pediatric patients. PMID:24439640

Effects of an internet-based cognitive behavioral therapy intervention on improving work engagement and other work-related outcomes: an analysis of secondary outcomes of a randomized controlled trial.

PubMed

Imamura, Kotaro; Kawakami, Norito; Furukawa, Toshi A; Matsuyama, Yutaka; Shimazu, Akihito; Umanodan, Rino; Kawakami, Sonoko; Kasai, Kiyoto

2015-05-01

This study reported a randomized controlled trial of the effectiveness of an Internet-based cognitive behavioral therapy (iCBT) program on work engagement and secondary work-related outcomes. Participants who fulfilled the inclusion criteria were randomly allocated to an intervention or a control group (N = 381 for each). A 6-week, 6-lesson iCBT program using a Manga (Japanese comic) story was provided only to the intervention group. Work engagement was assessed at baseline and at 3- and 6-month follow-ups for both groups. The iCBT program showed a significant intervention effect on work engagement (P = 0.04) with small effect sizes (Cohen's d = 0.16 at 6-month follow-up). The study showed computerized cognitive behavior therapy delivered via the Internet to be effective (with a small effect size) in increasing work engagement in the general working population. UMIN Clinical Trials Registry (UMIN-CTR) UMIN000006210.

Probabilistic Material Strength Degradation Model for Inconel 718 Components Subjected to High Temperature, High-Cycle and Low-Cycle Mechanical Fatigue, Creep and Thermal Fatigue Effects

NASA Technical Reports Server (NTRS)

Bast, Callie C.; Boyce, Lola

1995-01-01

The development of methodology for a probabilistic material strength degradation is described. The probabilistic model, in the form of a postulated randomized multifactor equation, provides for quantification of uncertainty in the lifetime material strength of aerospace propulsion system components subjected to a number of diverse random effects. This model is embodied in the computer program entitled PROMISS, which can include up to eighteen different effects. Presently, the model includes five effects that typically reduce lifetime strength: high temperature, high-cycle mechanical fatigue, low-cycle mechanical fatigue, creep and thermal fatigue. Results, in the form of cumulative distribution functions, illustrated the sensitivity of lifetime strength to any current value of an effect. In addition, verification studies comparing predictions of high-cycle mechanical fatigue and high temperature effects with experiments are presented. Results from this limited verification study strongly supported that material degradation can be represented by randomized multifactor interaction models.

A pilot cluster randomized controlled trial of structured goal-setting following stroke.

PubMed

Taylor, William J; Brown, Melanie; William, Levack; McPherson, Kathryn M; Reed, Kirk; Dean, Sarah G; Weatherall, Mark

2012-04-01

To determine the feasibility, the cluster design effect and the variance and minimal clinical importance difference in the primary outcome in a pilot study of a structured approach to goal-setting. A cluster randomized controlled trial. Inpatient rehabilitation facilities. People who were admitted to inpatient rehabilitation following stroke who had sufficient cognition to engage in structured goal-setting and complete the primary outcome measure. Structured goal elicitation using the Canadian Occupational Performance Measure. Quality of life at 12 weeks using the Schedule for Individualised Quality of Life (SEIQOL-DW), Functional Independence Measure, Short Form 36 and Patient Perception of Rehabilitation (measuring satisfaction with rehabilitation). Assessors were blinded to the intervention. Four rehabilitation services and 41 patients were randomized. We found high values of the intraclass correlation for the outcome measures (ranging from 0.03 to 0.40) and high variance of the SEIQOL-DW (SD 19.6) in relation to the minimally importance difference of 2.1, leading to impractically large sample size requirements for a cluster randomized design. A cluster randomized design is not a practical means of avoiding contamination effects in studies of inpatient rehabilitation goal-setting. Other techniques for coping with contamination effects are necessary.

Effect of fermented milk-based probiotic preparations on Helicobacter pylori eradication: a systematic review and meta-analysis of randomized-controlled trials.

PubMed

Sachdeva, Aarti; Nagpal, Jitender

2009-01-01

To evaluate the effect of fermented milk-based probiotic preparations on Helicobacter pylori eradication. Systematic review of randomized controlled trials. Electronic databases and hand search of reviews, bibliographies of books and abstracts and proceedings of international conferences. Included trials had to be randomized or quasi-randomized and controlled, using fermented milk-based probiotics in the intervention group, treating Helicobacter-infected patients and evaluating improvement or eradication of H. pylori as an outcome. The search identified 10 eligible randomized controlled trials. Data were available for 963 patients, of whom 498 were in the treatment group and 465 in the control group. The pooled odds ratio (studies n=9) for eradication by intention-to-treat analysis in the treatment versus control group was 1.91 (1.38-2.67; P<0.0001) using the fixed effects model; test for heterogeneity (Cochran's Q=5.44; P=0.488). The pooled risk difference was 0.10 (95% CI 0.05-0.15; P<0.0001) by the fixed effects model (Cochran's Q=13.41; P=0.144). The pooled odds ratio for the number of patients with any adverse effect was 0.51 (95% CI 0.10-2.57; P=0.41; random effects model; heterogeneity by Cochran's Q=68.5; P<0.0001). Fermented milk-based probiotic preparations improve H. pylori eradication rates by approximately 5-15%, whereas the effect on adverse effects is heterogeneous.

Modeling for Ultrasonic Health Monitoring of Foams with Embedded Sensors

NASA Technical Reports Server (NTRS)

Wang, L.; Rokhlin, S. I.; Rokhlin, Stanislav, I.

2005-01-01

In this report analytical and numerical methods are proposed to estimate the effective elastic properties of regular and random open-cell foams. The methods are based on the principle of minimum energy and on structural beam models. The analytical solutions are obtained using symbolic processing software. The microstructure of the random foam is simulated using Voronoi tessellation together with a rate-dependent random close-packing algorithm. The statistics of the geometrical properties of random foams corresponding to different packing fractions have been studied. The effects of the packing fraction on elastic properties of the foams have been investigated by decomposing the compliance into bending and axial compliance components. It is shown that the bending compliance increases and the axial compliance decreases when the packing fraction increases. Keywords: Foam; Elastic properties; Finite element; Randomness

Studies in astronomical time series analysis: Modeling random processes in the time domain

NASA Technical Reports Server (NTRS)

Scargle, J. D.

1979-01-01

Random process models phased in the time domain are used to analyze astrophysical time series data produced by random processes. A moving average (MA) model represents the data as a sequence of pulses occurring randomly in time, with random amplitudes. An autoregressive (AR) model represents the correlations in the process in terms of a linear function of past values. The best AR model is determined from sampled data and transformed to an MA for interpretation. The randomness of the pulse amplitudes is maximized by a FORTRAN algorithm which is relatively stable numerically. Results of test cases are given to study the effects of adding noise and of different distributions for the pulse amplitudes. A preliminary analysis of the optical light curve of the quasar 3C 273 is given.

Effectiveness of the Dader Method for pharmaceutical care in patients with bipolar I disorder: EMDADER-TAB: study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background Bipolar I disorder (BD-I) is a chronic mental illness characterized by the presence of one or more manic episodes, or both depressive and manic episodes, usually separated by asymptomatic intervals. Pharmacists can contribute to the management of BD-I, mainly with the use of effective and safe drugs, and improve the patient’s life quality through pharmaceutical care. Some studies have shown the effect of pharmaceutical care in the achievement of therapeutic goals in different illnesses; however, to our knowledge, there is a lack of randomized controlled trials designed to assess the effect of pharmacist intervention in patients with BD. The aim of this study is to assess the effectiveness of the Dader Method for pharmaceutical care in patients with BD-I. Methods/design Randomized, controlled, prospective, single-center clinical trial with duration of 12 months will be performed to compare the effect of Dader Method of pharmaceutical care with the usual care process of patients in a psychiatric clinic. Patients diagnosed with BD-I aged between 18 and 65 years who have been discharged or referred from outpatients service of the San Juan de Dios Clinic (Antioquia, Colombia) will be included. Patients will be randomized into the intervention group who will receive pharmaceutical care provided by pharmacists working in collaboration with psychiatrists, or into the control group who will receive usual care and verbal-written counseling regarding BD. Study outcomes will be assessed at baseline and at 3, 6, 9, and 12 months after randomization. The primary outcome will be to measure the number of hospitalizations, emergency service consultations, and unscheduled outpatient visits. Effectiveness, safety, adherence, and quality of life will be assessed as secondary outcomes. Statistical analyses will be performed using two-tailed McNemar tests, Pearson chi-square tests, and Student’s t-tests; a P value <0.05 will be considered as statistically significant. Discussion As far as we know, this is the first randomized controlled trial to assess the effect of the Dader Method for pharmaceutical care in patients with BD-I and it could generate valuable information and recommendations about the role of pharmacists in the improvement of therapeutic goals, solution of drug-related problems, and adherence. Trial registration Registration number NCT01750255 on August 6, 2012. First patient randomized on 24 November 2011. PMID:24885673

Network meta-analysis of disconnected networks: How dangerous are random baseline treatment effects?

PubMed

Béliveau, Audrey; Goring, Sarah; Platt, Robert W; Gustafson, Paul

2017-12-01

In network meta-analysis, the use of fixed baseline treatment effects (a priori independent) in a contrast-based approach is regularly preferred to the use of random baseline treatment effects (a priori dependent). That is because, often, there is not a need to model baseline treatment effects, which carry the risk of model misspecification. However, in disconnected networks, fixed baseline treatment effects do not work (unless extra assumptions are made), as there is not enough information in the data to update the prior distribution on the contrasts between disconnected treatments. In this paper, we investigate to what extent the use of random baseline treatment effects is dangerous in disconnected networks. We take 2 publicly available datasets of connected networks and disconnect them in multiple ways. We then compare the results of treatment comparisons obtained from a Bayesian contrast-based analysis of each disconnected network using random normally distributed and exchangeable baseline treatment effects to those obtained from a Bayesian contrast-based analysis of their initial connected network using fixed baseline treatment effects. For the 2 datasets considered, we found that the use of random baseline treatment effects in disconnected networks was appropriate. Because those datasets were not cherry-picked, there should be other disconnected networks that would benefit from being analyzed using random baseline treatment effects. However, there is also a risk for the normality and exchangeability assumption to be inappropriate in other datasets even though we have not observed this situation in our case study. We provide code, so other datasets can be investigated. Copyright © 2017 John Wiley & Sons, Ltd.

Randomized Study of a Prebirth Coparenting Intervention with Adolescent and Young Fathers

ERIC Educational Resources Information Center

Fagan, Jay

2008-01-01

This randomized study tested the effects of 2 prebirth interventions, Minnesota Early Learning Design coparenting and childbirth curricula, on young African American and Hispanic fathers and their adolescent partners (N = 154). The coparenting intervention (n = 44) was associated with changing fathers' perceptions of their coparenting behavior…

Calcium supplementation for the prevention of colorectal adenomas: A systematic review and meta-analysis of randomized controlled trials.

PubMed

Bonovas, Stefanos; Fiorino, Gionata; Lytras, Theodore; Malesci, Alberto; Danese, Silvio

2016-05-14

To determine the efficacy of calcium supplementation in reducing the recurrence of colorectal adenomas. We conducted a systematic review and meta-analysis of published studies. We searched PubMed, Scopus, the Cochrane Library, the WHO International Clinical Trials Registry Platform, and the ClinicalTrials.gov website, through December 2015. Randomized, placebo-controlled trials assessing supplemental calcium intake for the prevention of recurrence of adenomas were eligible for inclusion. Two reviewers independently selected studies based on predefined criteria, extracted data and outcomes (recurrence of colorectal adenomas, and advanced or "high-risk" adenomas), and rated each trial's risk-of-bias. Between-study heterogeneity was assessed, and pooled risk ratio (RR) estimates with their 95% confidence intervals (95%CI) were calculated using fixed- and random-effects models. To express the treatment effect in clinical terms, we calculated the number needed to treat (NNT) to prevent one adenoma recurrence. We also assessed the quality of evidence using GRADE. Four randomized, placebo-controlled trials met the eligibility criteria and were included. Daily doses of elemental calcium ranged from 1200 to 2000 mg, while the duration of treatment and follow-up of participants ranged from 36 to 60 mo. Synthesis of intention-to-treat data, for participants who had undergone follow-up colonoscopies, indicated a modest protective effect of calcium in prevention of adenomas (fixed-effects, RR = 0.89, 95%CI: 0.82-0.96; random-effects, RR = 0.87, 95%CI: 0.77-0.98; high quality of evidence). The NNT was 20 (95%CI: 12-61) to prevent one colorectal adenoma recurrence within a period of 3 to 5 years. On the other hand, the association between calcium treatment and advanced adenomas did not reach statistical significance (fixed-effects, RR = 0.92, 95%CI: 0.75-1.13; random-effects, RR = 0.92, 95%CI: 0.71-1.18; moderate quality of evidence). Our results suggest a modest chemopreventive effect of calcium supplements against recurrent colorectal adenomas over a period of 36 to 60 mo. Further research is warranted.

Calcium supplementation for the prevention of colorectal adenomas: A systematic review and meta-analysis of randomized controlled trials

PubMed Central

Bonovas, Stefanos; Fiorino, Gionata; Lytras, Theodore; Malesci, Alberto; Danese, Silvio

2016-01-01

AIM: To determine the efficacy of calcium supplementation in reducing the recurrence of colorectal adenomas. METHODS: We conducted a systematic review and meta-analysis of published studies. We searched PubMed, Scopus, the Cochrane Library, the WHO International Clinical Trials Registry Platform, and the ClinicalTrials.gov website, through December 2015. Randomized, placebo-controlled trials assessing supplemental calcium intake for the prevention of recurrence of adenomas were eligible for inclusion. Two reviewers independently selected studies based on predefined criteria, extracted data and outcomes (recurrence of colorectal adenomas, and advanced or “high-risk” adenomas), and rated each trial’s risk-of-bias. Between-study heterogeneity was assessed, and pooled risk ratio (RR) estimates with their 95% confidence intervals (95%CI) were calculated using fixed- and random-effects models. To express the treatment effect in clinical terms, we calculated the number needed to treat (NNT) to prevent one adenoma recurrence. We also assessed the quality of evidence using GRADE. RESULTS: Four randomized, placebo-controlled trials met the eligibility criteria and were included. Daily doses of elemental calcium ranged from 1200 to 2000 mg, while the duration of treatment and follow-up of participants ranged from 36 to 60 mo. Synthesis of intention-to-treat data, for participants who had undergone follow-up colonoscopies, indicated a modest protective effect of calcium in prevention of adenomas (fixed-effects, RR = 0.89, 95%CI: 0.82-0.96; random-effects, RR = 0.87, 95%CI: 0.77-0.98; high quality of evidence). The NNT was 20 (95%CI: 12-61) to prevent one colorectal adenoma recurrence within a period of 3 to 5 years. On the other hand, the association between calcium treatment and advanced adenomas did not reach statistical significance (fixed-effects, RR = 0.92, 95%CI: 0.75-1.13; random-effects, RR = 0.92, 95%CI: 0.71-1.18; moderate quality of evidence). CONCLUSION: Our results suggest a modest chemopreventive effect of calcium supplements against recurrent colorectal adenomas over a period of 36 to 60 mo. Further research is warranted. PMID:27182169

Mechanisms for an effect of acetylcysteine on renal function after exposure to radio-graphic contrast material: study protocol.

PubMed

Sandilands, Euan A; Cameron, Sharon; Paterson, Frances; Donaldson, Sam; Briody, Lesley; Crowe, Jane; Donnelly, Julie; Thompson, Adrian; Johnston, Neil R; Mackenzie, Ivor; Uren, Neal; Goddard, Jane; Webb, David J; Megson, Ian L; Bateman, Nicholas; Eddleston, Michael

2012-02-03

Contrast-induced nephropathy is a common complication of contrast administration in patients with chronic kidney disease and diabetes. Its pathophysiology is not well understood; similarly the role of intravenous or oral acetylcysteine is unclear. Randomized controlled trials to date have been conducted without detailed knowledge of the effect of acetylcysteine on renal function. We are conducting a detailed mechanistic study of acetylcysteine on normal and impaired kidneys, both with and without contrast. This information would guide the choice of dose, route, and appropriate outcome measure for future clinical trials in patients with chronic kidney disease. We designed a 4-part study. We have set up randomised controlled cross-over studies to assess the effect of intravenous (50 mg/kg/hr for 2 hrs before contrast exposure, then 20 mg/kg/hr for 5 hrs) or oral acetylcysteine (1200 mg twice daily for 2 days, starting the day before contrast exposure) on renal function in normal and diseased kidneys, and normal kidneys exposed to contrast. We have also set up a parallel-group randomized controlled trial to assess the effect of intravenous or oral acetylcysteine on patients with chronic kidney disease stage III undergoing elective coronary angiography. The primary outcome is change in renal blood flow; secondary outcomes include change in glomerular filtration rate, tubular function, urinary proteins, and oxidative balance. Contrast-induced nephropathy represents a significant source of hospital morbidity and mortality. Over the last ten years, acetylcysteine has been administered prior to contrast to reduce the risk of contrast-induced nephropathy. Randomized controlled trials, however, have not reliably demonstrated renoprotection; a recent large randomized controlled trial assessing a dose of oral acetylcysteine selected without mechanistic insight did not reduce the incidence of contrast-induced nephropathy. Our study should reveal the mechanism of effect of acetylcysteine on renal function and identify an appropriate route for future dose response studies and in time randomized controlled trials. Clinical Trials.gov: NCT00558142; EudraCT: 2006-003509-18.

The Effects of Social Capital Levels in Elementary Schools on Organizational Information Sharing

ERIC Educational Resources Information Center

Ekinci, Abdurrahman

2012-01-01

This study aims to assess the effects of social capital levels at elementary schools on organizational information sharing as reported by teachers. Participants were 267 teachers selected randomly from 16 elementary schools; schools also selected randomly among 42 elementary schools located in the city center of Batman. The data were analyzed by…

Robin Hood Effects on Motivation in Math: Family Interest Moderates the Effects of Relevance Interventions

ERIC Educational Resources Information Center

Häfner, Isabelle; Flunger, Barbara; Dicke, Anna-Lena; Gaspard, Hanna; Brisson, Brigitte M.; Nagengast, Benjamin; Trautwein, Ulrich

2017-01-01

Using a cluster randomized field trial, the present study tested whether 2 relevance interventions affected students' value beliefs, self-concept, and effort in math differently depending on family background (socioeconomic status, family interest (FI), and parental utility value). Eighty-two classrooms were randomly assigned to either 1 of 2…

Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial

USDA-ARS?s Scientific Manuscript database

Knee osteoarthritis (OA), a disorder of cartilage and periarticular bone, is a public health problem without effective medical treatments. Some studies have suggested that vitamin D may protect against structural progression. A 2-year randomized, placebo-controlled, double-blind, clinical trial invo...

The Effectiveness of Two Grammar Treatment Procedures for Children with SLI: A Randomized Clinical Trial

ERIC Educational Resources Information Center

Smith-Lock, Karen M.; Leitão, Suze; Prior, Polly; Nickels, Lyndsey

2015-01-01

Purpose: This study compared the effectiveness of two grammar treatment procedures for children with specific language impairment. Method: A double-blind superiority trial with cluster randomization was used to compare a cueing procedure, designed to elicit a correct production following an initial error, to a recasting procedure, which required…

Effectiveness of a Web-Based Intervention to Reduce Alcohol Consumption among French Hazardous Drinkers: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Guillemont, Juliette; Cogordan, Chloé; Nalpas, Bertrand; Nguyen-Thanh, Vi?t; Richard, Jean-Baptiste; Arwidson, Pierre

2017-01-01

This study aims to evaluate the effectiveness of a web-based intervention to reduce alcohol consumption among hazardous drinkers. A two-group parallel randomized controlled trial was conducted among adults identified as hazardous drinkers according to the Alcohol Use Disorders Identification Test. The intervention delivers personalized normative…

An Empirical Comparison of Randomized Control Trials and Regression Discontinuity Estimations

ERIC Educational Resources Information Center

Barrera-Osorio, Felipe; Filmer, Deon; McIntyre, Joe

2014-01-01

Randomized controlled trials (RCTs) and regression discontinuity (RD) studies both provide estimates of causal effects. A major difference between the two is that RD only estimates local average treatment effects (LATE) near the cutoff point of the forcing variable. This has been cited as a drawback to RD designs (Cook & Wong, 2008).…

Effectiveness of Stepped Care for Chronic Fatigue Syndrome: A Randomized Noninferiority Trial

ERIC Educational Resources Information Center

Tummers, Marcia; Knoop, Hans; Bleijenberg, Gijs

2010-01-01

Objective: In this randomized noninferiority study, the effectiveness and efficiency of stepped care for chronic fatigue syndrome (CFS) was compared to care as usual. Stepped care was formed by guided self-instruction, followed by cognitive behavior therapy (CBT) if the patient desired it. Care as usual encompassed CBT after a waiting period.…

The Random-Effect DINA Model

ERIC Educational Resources Information Center

Huang, Hung-Yu; Wang, Wen-Chung

2014-01-01

The DINA (deterministic input, noisy, and gate) model has been widely used in cognitive diagnosis tests and in the process of test development. The outcomes known as slip and guess are included in the DINA model function representing the responses to the items. This study aimed to extend the DINA model by using the random-effect approach to allow…

Pilot study evaluating a brief mindfulness intervention for those with chronic pain: study protocol for a randomized controlled trial.

PubMed

Howarth, Ana; Perkins-Porras, Linda; Smith, Jared G; Subramaniam, Jeevakan; Copland, Claire; Hurley, Mike; Beith, Iain; Riaz, Muhammad; Ussher, Michael

2016-06-02

The burden of chronic pain is a major challenge, impacting the quality of life of patients. Intensive programmes of mindfulness-based therapy can help patients to cope with chronic pain but can be time consuming and require a trained specialist to implement. The self-management model of care is now integral to the care of patients with chronic pain; home-based interventions can be very acceptable, making a compelling argument for investigating brief, self-management interventions. The aim of this study is two-fold: to assess the immediate effects of a brief self-help mindfulness intervention for coping with chronic pain and to assess the feasibility of conducting a definitive randomized controlled trial to determine the effectiveness of such an intervention. A randomized controlled pilot study will be conducted to evaluate a brief mindfulness intervention for those with chronic pain. Ninety chronic pain patients who attend hospital outpatient clinics will be recruited and allocated randomly to either the control or treatment group on a 1:1 basis using the computer-generated list of random numbers. The treatment group receives mindfulness audios and the control group receives audios of readings from a non-fiction book, all of which are 15 minutes in length. Immediate effects of the intervention are assessed with brief psychological measures immediately before and after audio use. Mindfulness, mood, health-related quality of life, pain catastrophizing and experience of the intervention are assessed with standardized measures, brief ratings and brief telephone follow-ups, at baseline and after one week and one month. Feasibility is assessed by estimation of effect sizes for outcomes, patient adherence and experience, and appraisal of resource allocation in provision of the intervention. This trial will assess whether a brief mindfulness-based intervention is effective for immediately reducing perceived distress and pain with the side effect of increasing relaxation in chronic pain patients and will determine the feasibility of conducting a definitive randomized controlled trial. Patient recruitment began in January 2015 and is due to be completed in June 2016. ISRCTN61538090 Registered 20 April 2015.

Random-effects meta-analysis: the number of studies matters.

PubMed

Guolo, Annamaria; Varin, Cristiano

2017-06-01

This paper investigates the impact of the number of studies on meta-analysis and meta-regression within the random-effects model framework. It is frequently neglected that inference in random-effects models requires a substantial number of studies included in meta-analysis to guarantee reliable conclusions. Several authors warn about the risk of inaccurate results of the traditional DerSimonian and Laird approach especially in the common case of meta-analysis involving a limited number of studies. This paper presents a selection of likelihood and non-likelihood methods for inference in meta-analysis proposed to overcome the limitations of the DerSimonian and Laird procedure, with a focus on the effect of the number of studies. The applicability and the performance of the methods are investigated in terms of Type I error rates and empirical power to detect effects, according to scenarios of practical interest. Simulation studies and applications to real meta-analyses highlight that it is not possible to identify an approach uniformly superior to alternatives. The overall recommendation is to avoid the DerSimonian and Laird method when the number of meta-analysis studies is modest and prefer a more comprehensive procedure that compares alternative inferential approaches. R code for meta-analysis according to all of the inferential methods examined in the paper is provided.

Mass media influence spreading in social networks with community structure

NASA Astrophysics Data System (ADS)

Candia, Julián; Mazzitello, Karina I.

2008-07-01

We study an extension of Axelrod's model for social influence, in which cultural drift is represented as random perturbations, while mass media are introduced by means of an external field. In this scenario, we investigate how the modular structure of social networks affects the propagation of mass media messages across a society. The community structure of social networks is represented by coupled random networks, in which two random graphs are connected by intercommunity links. Considering inhomogeneous mass media fields, we study the conditions for successful message spreading and find a novel phase diagram in the multidimensional parameter space. These findings show that social modularity effects are of paramount importance for designing successful, cost-effective advertising campaigns.

Predicting longitudinal trajectories of health probabilities with random-effects multinomial logit regression.

PubMed

Liu, Xian; Engel, Charles C

2012-12-20

Researchers often encounter longitudinal health data characterized with three or more ordinal or nominal categories. Random-effects multinomial logit models are generally applied to account for potential lack of independence inherent in such clustered data. When parameter estimates are used to describe longitudinal processes, however, random effects, both between and within individuals, need to be retransformed for correctly predicting outcome probabilities. This study attempts to go beyond existing work by developing a retransformation method that derives longitudinal growth trajectories of unbiased health probabilities. We estimated variances of the predicted probabilities by using the delta method. Additionally, we transformed the covariates' regression coefficients on the multinomial logit function, not substantively meaningful, to the conditional effects on the predicted probabilities. The empirical illustration uses the longitudinal data from the Asset and Health Dynamics among the Oldest Old. Our analysis compared three sets of the predicted probabilities of three health states at six time points, obtained from, respectively, the retransformation method, the best linear unbiased prediction, and the fixed-effects approach. The results demonstrate that neglect of retransforming random errors in the random-effects multinomial logit model results in severely biased longitudinal trajectories of health probabilities as well as overestimated effects of covariates on the probabilities. Copyright © 2012 John Wiley & Sons, Ltd.

Recruitment and accrual of women in a placebo-controlled clinical pilot study on manual therapy.

PubMed

Cambron, Jerrilyn A; Hawk, Cheryl; Evans, Roni; Long, Cynthia R

2004-06-01

To investigate the accrual rates and recruitment processes among 3 Midwestern sites during a pilot study on manual therapy for chronic pelvic pain. Multisite pilot study for a randomized, placebo-controlled clinical trial. Three chiropractic institutions in or near major metropolitan cities in the Midwestern United States. Thirty-nine women aged 18 to 45 with chronic pelvic pain of at least 6 months duration, diagnosed by a board certified gynecologist. The method of recruitment was collected for each individual who responded to an advertisement and completed an interviewer-administered telephone screen. Participants who were willing and eligible after 3 baseline visits were entered into a randomized clinical trial. The number of responses and accrual rates were determined for the overall study, each of the 3 treatment sites, and each of the 5 recruitment efforts. In this study, 355 women were screened over the telephone and 39 were randomized, making the rate of randomization approximately 10%. The most effective recruitment methods leading to randomization were direct mail (38%) and radio advertisements (34%). However, success of the recruitment process differed by site. Based on the accrual of this multisite pilot study, a full-scale trial would not be feasible using this study's parameters. However, useful information was gained on recruitment effectiveness, eligibility criteria, and screening protocols among the 3 metropolitan sites.

A case study of the effects of random errors in rawinsonde data on computations of ageostrophic winds

NASA Technical Reports Server (NTRS)

Moore, J. T.

1985-01-01

Data input for the AVE-SESAME I experiment are utilized to describe the effects of random errors in rawinsonde data on the computation of ageostrophic winds. Computer-generated random errors for wind direction and speed and temperature are introduced into the station soundings at 25 mb intervals from which isentropic data sets are created. Except for the isallobaric and the local wind tendency, all winds are computed for Apr. 10, 1979 at 2000 GMT. Divergence fields reveal that the isallobaric and inertial-geostrophic-advective divergences are less affected by rawinsonde random errors than the divergence of the local wind tendency or inertial-advective winds.

A randomized, double-blind, safety and tolerability study to assess the ophthalmic and renal effects of tafenoquine 200 mg weekly versus placebo for 6 months in healthy volunteers.

PubMed

Leary, Kevin J; Riel, Michael A; Roy, Michael J; Cantilena, Louis R; Bi, Daoqin; Brater, D Craig; van de Pol, Corina; Pruett, Khadeeja; Kerr, Caron; Veazey, James M; Beboso, Ronnie; Ohrt, Colin

2009-08-01

A randomized, double-blind, placebo-controlled study was conducted to assess the effect of tafenoquine, 200 mg weekly for 6 months on ophthalmic and renal safety. This trial was carried out after observations in previous clinical trials that tafenoquine may be associated with the development of corneal deposits and elevations in serum creatinine. In 120 healthy volunteers who received tafenoquine or placebo in a 2:1 randomization, there was no effect on night vision or other ophthalmic indices measured. Persons taking tafenoquine also showed no difference in mean change in glomerular filtration rate (GFR, mL/s/1.73 m(2)) after 6 months of dosing, with a treatment difference of -0.061 (95% confidence interval, -0.168, 0.045), and non-inferiority margin of -0.247 mL/s/1.73 m(2). Tafenoquine was well tolerated over the course of the study. The results of this study showed no clinically significant effects of tafenoquine on ophthalmic or renal function, and support its continued development as an antimalarial drug.

Community-based intervention packages for reducing maternal and neonatal morbidity and mortality and improving neonatal outcomes.

PubMed

Lassi, Zohra S; Bhutta, Zulfiqar A

2015-03-23

While maternal, infant and under-five child mortality rates in developing countries have declined significantly in the past two to three decades, newborn mortality rates have reduced much more slowly. While it is recognised that almost half of the newborn deaths can be prevented by scaling up evidence-based available interventions (such as tetanus toxoid immunisation to mothers, clean and skilled care at delivery, newborn resuscitation, exclusive breastfeeding, clean umbilical cord care, and/or management of infections in newborns), many require facility-based and outreach services. It has also been stated that a significant proportion of these mortalities and morbidities could also be potentially addressed by developing community-based packaged interventions which should also be supplemented by developing and strengthening linkages with the local health systems. Some of the recent community-based studies of interventions targeting women of reproductive age have shown variable impacts on maternal outcomes and hence it is uncertain if these strategies have consistent benefit across the continuum of maternal and newborn care. To assess the effectiveness of community-based intervention packages in reducing maternal and neonatal morbidity and mortality; and improving neonatal outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2014), World Bank's JOLIS (25 May 2014), BLDS at IDS and IDEAS database of unpublished working papers (25 May 2014), Google and Google Scholar (25 May 2014). All prospective randomised, cluster-randomised and quasi-randomised trials evaluating the effectiveness of community-based intervention packages in reducing maternal and neonatal mortality and morbidities, and improving neonatal outcomes. Two review authors independently assessed trials for inclusion, assessed trial quality and extracted the data. Data were checked for accuracy. The review included 26 cluster-randomised/quasi-randomised trials, covering a wide range of interventional packages, including two subsets from three trials. Assessment of risk of bias in these studies suggests concerns regarding insufficient information on sequence generation and regarding failure to adequately address incomplete outcome data, particularly from randomised controlled trials. We incorporated data from these trials using generic inverse variance method in which logarithms of risk ratio (RR) estimates were used along with the standard error of the logarithms of RR estimates.Our review showed a possible effect in terms of a reduction in maternal mortality (RR 0.80; 95% confidence interval (CI) 0.64 to 1.00, random-effects (11 studies, n = 167,311; random-effects, Tau² = 0.03, I² 20%). However, significant reduction was observed in maternal morbidity (average RR 0.75; 95% CI 0.61 to 0.92; four studies, n = 138,290; random-effects, Tau² = 0.02, I² = 28%); neonatal mortality (average RR 0.75; 95% CI 0.67 to 0.83; 21 studies, n = 302,646; random-effects, Tau² = 0.06, I² = 85%) including both early and late mortality; stillbirths (average RR 0.81; 95% CI 0.73 to 0.91; 15 studies, n = 201,181; random-effects, Tau² = 0.03, I² = 66%); and perinatal mortality (average RR 0.78; 95% CI 0.70 to 0.86; 17 studies, n = 282,327; random-effects Tau² = 0.04, I² = 88%) as a consequence of implementation of community-based interventional care packages.Community-based intervention packages also increased the uptake of tetanus immunisation by 5% (average RR 1.05; 95% CI 1.02 to 1.09; seven studies, n = 71,622; random-effects Tau² = 0.00, I² = 52%); use of clean delivery kits by 82% (average RR 1.82; 95% CI 1.10 to 3.02; four studies, n = 54,254; random-effects, Tau² = 0.23, I² = 90%); rates of institutional deliveries by 20% (average RR 1.20; 95% CI 1.04 to 1.39; 14 studies, n = 147,890; random-effects, Tau² = 0.05, I² = 80%); rates of early breastfeeding by 93% (average RR 1.93; 95% CI 1.55 to 2.39; 11 studies, n = 72,464; random-effects, Tau² = 0.14, I² = 98%), and healthcare seeking for neonatal morbidities by 42% (average RR 1.42; 95% CI 1.14 to 1.77, nine studies, n = 66,935, random-effects, Tau² = 0.09, I² = 92%). The review also showed a possible effect on increasing the uptake of iron/folic acid supplementation during pregnancy (average RR 1.47; 95% CI 0.99 to 2.17; six studies, n = 71,622; random-effects, Tau² = 0.26; I² = 99%).It has no impact on improving referrals for maternal morbidities, healthcare seeking for maternal morbidities, iron/folate supplementation, attendance of skilled birth attendance on delivery, and other neonatal care-related outcomes. We did not find studies that reported the impact of community-based intervention package on improving exclusive breastfeeding rates at six months of age. We assessed our primary outcomes for publication bias and observed slight asymmetry on the funnel plot for maternal mortality. Our review offers encouraging evidence that community-based intervention packages reduce morbidity for women, mortality and morbidity for babies, and improves care-related outcomes particularly in low- and middle-income countries. It has highlighted the value of integrating maternal and newborn care in community settings through a range of interventions, which can be packaged effectively for delivery through a range of community health workers and health promotion groups. While the importance of skilled delivery and facility-based services for maternal and newborn care cannot be denied, there is sufficient evidence to scale up community-based care through packages which can be delivered by a range of community-based workers.

Alternatives for randomization in lifestyle intervention studies in cancer patients were not better than conventional randomization.

PubMed

Velthuis, Miranda J; May, Anne M; Monninkhof, Evelyn M; van der Wall, Elsken; Peeters, Petra H M

2012-03-01

Assessing effects of lifestyle interventions in cancer patients has some specific challenges. Although randomization is urgently needed for evidence-based knowledge, sometimes it is difficult to apply conventional randomization (i.e., consent preceding randomization and intervention) in daily settings. Randomization before seeking consent was proposed by Zelen, and additional modifications were proposed since. We discuss four alternatives for conventional randomization: single and double randomized consent design, two-stage randomized consent design, and the design with consent to postponed information. We considered these designs when designing a study to assess the impact of physical activity on cancer-related fatigue and quality of life. We tested the modified Zelen design with consent to postponed information in a pilot. The design was chosen to prevent drop out of participants in the control group because of disappointment about the allocation. The result was a low overall participation rate most likely because of perceived lack of information by eligible patients and a relatively high dropout in the intervention group. We conclude that the alternatives were not better than conventional randomization. Copyright © 2012 Elsevier Inc. All rights reserved.

Longitudinal data analysis with non-ignorable missing data.

PubMed

Tseng, Chi-hong; Elashoff, Robert; Li, Ning; Li, Gang

2016-02-01

A common problem in the longitudinal data analysis is the missing data problem. Two types of missing patterns are generally considered in statistical literature: monotone and non-monotone missing data. Nonmonotone missing data occur when study participants intermittently miss scheduled visits, while monotone missing data can be from discontinued participation, loss to follow-up, and mortality. Although many novel statistical approaches have been developed to handle missing data in recent years, few methods are available to provide inferences to handle both types of missing data simultaneously. In this article, a latent random effects model is proposed to analyze longitudinal outcomes with both monotone and non-monotone missingness in the context of missing not at random. Another significant contribution of this article is to propose a new computational algorithm for latent random effects models. To reduce the computational burden of high-dimensional integration problem in latent random effects models, we develop a new computational algorithm that uses a new adaptive quadrature approach in conjunction with the Taylor series approximation for the likelihood function to simplify the E-step computation in the expectation-maximization algorithm. Simulation study is performed and the data from the scleroderma lung study are used to demonstrate the effectiveness of this method. © The Author(s) 2012.

Effectiveness of interactive discussion group in suicide risk assessment among general nurses in Taiwan: a randomized controlled trial.

PubMed

Wu, Chia-Yi; Lin, Yi-Yin; Yeh, Mei Chang; Huang, Lian-Hua; Chen, Shaw-Ji; Liao, Shih-Cheng; Lee, Ming-Been

2014-11-01

The evidence of suicide prevention training for nurses is scarce. Strategies to enhance general nurses' ability in suicide risk assessment are critical to develop effective training programs in general medical settings. This study was aimed to examine the effectiveness of an interactive discussion group in a suicide prevention training program for general nurses. In this randomized study with two groups of pre-post study design, the sample was recruited from the Medical, Surgical, and Emergency/Intensive Care Sectors of a 2000-bed general hospital via stratified randomization. Among the 111 nurses, 57 participants randomly assigned to the control group received a two-hour baseline suicide gatekeeper lecture, and 54 participants assigning to the experimental group received an additional five-hour group discussion about suicide risk assessment skills. Using a case vignette, the nurses discussed and assessed suicide risk factors specified in a 10-item Chinese SAD PERSONS Scale during a group discussion intervention. The findings revealed that the nurses achieved significant and consistent improvements of risk identification and assessment after the intervention without influencing their mental health status for assessing suicide risks. The result suggested an effective approach of interactive group discussion for facilitating critical thinking and learning suicide risk assessment skills among general nurses. Copyright © 2014 Elsevier Ltd. All rights reserved.

A facility specialist model for improving retention of nursing home staff: results from a randomized, controlled study.

PubMed

Pillemer, Karl; Meador, Rhoda; Henderson, Charles; Robison, Julie; Hegeman, Carol; Graham, Edwin; Schultz, Leslie

2008-07-01

This article reports on a randomized, controlled intervention study designed to reduce employee turnover by creating a retention specialist position in nursing homes. We collected data three times over a 1-year period in 30 nursing homes, sampled in stratified random manner from facilities in New York State and Connecticut and randomly assigned to treatment and control conditions. Staff outcomes were measured through certified nursing assistant interviews, and turnover rates were measured over the course of the year. In the intervention condition, a staff member was selected to be the facility retention specialist, who would advocate for and implement programs to improve staff retention and commitment throughout the facility. Retention specialists received an intensive 3-day training in retention leadership and in a number of evidence-based retention programs. Ongoing support was provided throughout the project. Treatment facilities experienced significant declines in turnover rates compared to control facilities. As predicted, we found positive effects on certified nursing assistant assessments of the quality of retention efforts and of care provided in the facility; we did not find effects for job satisfaction or stress. The study provides evidence for the effectiveness of the retention specialist model. Findings from a detailed process evaluation suggest modifications of the program that may increase program effects.

A randomized controlled trial of intranasal ketamine in migraine with prolonged aura.

PubMed

Afridi, Shazia K; Giffin, Nicola J; Kaube, Holger; Goadsby, Peter J

2013-02-12

The aim of our study was to test the hypothesis that ketamine would affect aura in a randomized controlled double-blind trial, and thus to provide direct evidence for the role of glutamatergic transmission in human aura. We performed a double-blinded, randomized parallel-group controlled study investigating the effect of 25 mg intranasal ketamine on migraine with prolonged aura in 30 migraineurs using 2 mg intranasal midazolam as an active control. Each subject recorded data from 3 episodes of migraine. Eighteen subjects completed the study. Ketamine reduced the severity (p = 0.032) but not duration of aura in this group, whereas midazolam had no effect. These data provide translational evidence for the potential importance of glutamatergic mechanisms in migraine aura and offer a pharmacologic parallel between animal experimental work on cortical spreading depression and the clinical problem. This study provides class III evidence that intranasal ketamine is effective in reducing aura severity in patients with migraine with prolonged aura.

Telephone-based continuing care counseling in substance abuse treatment: economic analysis of a randomized trial

PubMed Central

Daley, Marilyn C.; Neuman, Matthew J.; Blaakman, Aaron P.; McKay, James R.

2016-01-01

Purpose To investigate whether telephone-based continuing care (TEL) is a promising alternative to traditional face-to-face counseling for clients in treatment for substance abuse. Methods Patients with alcohol and/or cocaine dependence who had completed a 4-week intensive outpatient program were randomly assigned through urn randomization into one of three 12-week interventions: standard continuing care (STD), in-person relapse prevention (RP), or telephone-based continuing care (TEL). This study performed cost, cost-effectiveness, and cost-benefit analyses of TEL and RP compared to STD, using results from the randomized clinical trial with two years of follow up (359 participants). In addition, the study examined the potential moderating effect of baseline patient costs on economic outcomes. Results The study found that TEL was less expensive per client from the societal perspective ($569) than STD ($870) or RP ($1,684). TEL also was also significantly more effective, with an abstinence rate of 57.1% compared to 46.7% for STD (p<0.05). Thus TEL dominated STD, with a highly favorable negative incremental cost-effectiveness ratio (−$1,400 per abstinent year). TEL also proved favorable under a benefit-cost perspective. Conclusions TEL proved to be a cost-effective and cost-beneficial contributor to long-term recovery over two years. Because TEL dominated STD care interventions, wider adoption should be considered. PMID:26718395

Telephone-based continuing care counseling in substance abuse treatment: Economic analysis of a randomized trial.

PubMed

Shepard, Donald S; Daley, Marilyn C; Neuman, Matthew J; Blaakman, Aaron P; McKay, James R

2016-02-01

To investigate whether telephone-based continuing care (TEL) is a promising alternative to traditional face-to-face counseling for clients in treatment for substance abuse. Patients with alcohol and/or cocaine dependence who had completed a 4-week intensive outpatient program were randomly assigned through urn randomization into one of three 12-week interventions: standard continuing care (STD), in-person relapse prevention (RP), or telephone-based continuing care (TEL). This study performed cost, cost-effectiveness, and cost-benefit analyses of TEL and RP compared to STD, using results from the randomized clinical trial with two years of follow up (359 participants). In addition, the study examined the potential moderating effect of baseline patient costs on economic outcomes. The study found that TEL was less expensive per client from the societal perspective ($569) than STD ($870) or RP ($1684). TEL also was also significantly more effective, with an abstinence rate of 57.1% compared to 46.7% for STD (p<0.05). Thus TEL dominated STD, with a highly favorable negative incremental cost-effectiveness ratio (-$1400 per abstinent year). TEL also proved favorable under a benefit-cost perspective. TEL proved to be a cost-effective and cost-beneficial contributor to long-term recovery over two years. Because TEL dominated STD care interventions, wider adoption should be considered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effectiveness of a one-year multi-component day-camp intervention for overweight children: study protocol of the Odense overweight intervention study (OOIS).

PubMed

Larsen, Kristian Traberg; Huang, Tao; Møller, Niels Christian; Andersen, Lars Bo; Ried-Larsen, Mathias

2014-04-05

Childhood overweight has noticeable psychological and social consequences for the child and leads to an increased risk of mortality and morbidity later in life. With the high prevalence of overweight in children and adolescents, it is important to identify effective approaches for the prevention and treatment of overweight in children and young individuals. The primary aim of the study is to assess the effect of an intensive day-camp intervention on body mass index (BMI) in overweight children. The Odense Overweight Intervention Study is a semi-blinded randomized controlled trial. Overweight children from the Municipality of Odense, Denmark, were invited to participate in the trial. Based on power calculations 98 participants were found to be sufficient to randomize in order to find an effect of minimum 1.5 BMI points. Gender-stratified concealed block randomization with a ratio of 1:1 and random block sizes of two, four, and six ensured balance between study arms. The intervention consisted of a six-week multi-component day camp including increased physical activity, healthy diet and health education followed by 46 weeks of family-based habitual intervention. The standard care arm was offered two weekly hours of physical activity training for six weeks. The outcomes were measured at baseline and at six-week and 52-week follow-ups. Furthermore, BMI will be assessed again at 48-month follow-up. Test personnel were kept blinded. The intervention effect will be evaluated using mixed model analyses. During 2012 and 2013, 115 children were enrolled in the study. Fifty-nine children were randomized to the day-camp intervention arm and 56 to the standard intervention arm. This study will provide novel information about the long-term health effects of an intense day-camp intervention program on overweight children, due to the design and the follow-up period. Moreover, it will add to the knowledge on designing and implementing feasible camp settings for preventing overweight in children. NCT01574352 at http://clinicaltrials.gov on the 8th of March 2012.

Extract of valerian root (Valeriana officinalis L.) vs. placebo in treatment of obsessive-compulsive disorder: a randomized double-blind study.

PubMed

Pakseresht, Siroos; Boostani, Hatam; Sayyah, Mehdi

2011-10-11

Obsessive-Compulsive Disorder (OCD) is a common neuropsychiatric condition. Many herbs with psychotropic effects exist which can have fewer side effects compared to more conventional medications. Valeriana Officinalis L. is a well-known medicinal plant with a long history of usage in the world with an effect on GABA. This plant is reported to be safe on humans. Our objective in this study was to compare the efficacy of the extract of Valeriana Officinalis L. with placebo in the treatment of OCD. The study was an 8-week pilot double-blind randomized trial. Thirty-one adult outpatients who met the DSM-IV-TR criteria for OCD based on the structured clinical interview participated in the trial. In this double-blind and randomized trial, patients were randomly assigned to receive either capsule of the extract (765 mg/day) or placebo (30 mg/day) for 8 weeks. The results showed significant difference between the extract and placebo in the end of treatment (P=0.000). Somnolence was the only significant difference between the two groups in terms of observed side effects (P=0.02). The results suggest that Valeriana Officinalis L. has some antiobsessive and compulsive effects. However, further studies are needed to confirm these findings. Psychiatrists often find that many patients cannot tolerate the side effects of psychiatry medicine Valeriana Officinalis L. is a well-known medicinal plant with a long history of usage in world with effect on GABA.The results showed significant difference between the extract and placebo in the treatment of OCD. There was also no significant difference between the two groups in terms of observed side effects.

Effectiveness and Cost-Effectiveness of Different Weekly Frequencies of Pilates for Chronic Low Back Pain: Randomized Controlled Trial.

PubMed

Miyamoto, Gisela Cristiane; Moura, Katherinne Ferro; Franco, Yuri Rafael dos Santos; Oliveira, Naiane Teixeira Bastos de; Amaral, Diego Diulgeroglo Vicco; Branco, Amanda Nery Castelo; Silva, Maria Liliane da; Lin, Christine; Cabral, Cristina Maria Nunes

2016-03-01

The Pilates method has been recommended to patients with low back pain, but the evidence on effectiveness is inconclusive. In addition, there is still no evidence for the cost-effectiveness of this method or for the ideal number of sessions to achieve the highest effectiveness. The aim of this study will be to investigate the effectiveness and cost-effectiveness of the Pilates method with different weekly frequencies in the treatment of patients with nonspecific low back pain. This is a randomized controlled trial with blinded assessor. This study will be conducted at a physical therapy clinic in São Paulo, Brazil. Two hundred ninety-six patients with nonspecific low back pain between the ages of 18 and 80 years will be assessed and randomly allocated to 4 groups (n=74 patients per group). All groups will receive an educational booklet. The booklet group will not receive additional exercises. Pilates group 1 will follow a Pilates-based program once a week, Pilates group 2 will follow the same program twice a week, and Pilates group 3 will follow the same program 3 times a week. The intervention will last 6 weeks. A blinded assessor will evaluate pain, quality-adjusted life-years, general and specific disability, kinesiophobia, pain catastrophizing, and global perceived effect 6 weeks, 6 months, and 12 months after randomization. Therapists and patients will not be blinded. This will be the first study to investigate different weekly frequencies of treatment sessions for nonspecific low back pain. The results of this study will contribute to a better definition of treatment programs for this population. © 2016 American Physical Therapy Association.

The effect of ursodeoxycholic acid in liver functional restoration of patients with obstructive jaundice after endoscopic treatment: a prospective, randomized, and controlled study.

PubMed

Fekaj, Enver; Gjata, Arben; Maxhuni, Mehmet

2013-09-22

In patients with obstructive jaundice, multi-organ dysfunction may develop. This trial is a prospective, open-label, randomized, and controlled study with the objective to evaluate the effect of ursodeoxycholic acid in liver functional restoration in patients with obstructive jaundice after endoscopic treatment. The aim of this study is to evaluate the effect of ursodeoxycholic acid in liver functional restoration of patients with obstructive jaundice after endoscopic treatment. The hypothesis of this trial is that patients with obstructive jaundice, in which will be administered UDCA, in the early phase after endoscopic intervention will have better and faster functional restoration of the liver than patients in the control group.Patients with obstructive jaundice, randomly, will be divided into two groups: (A) test group in which will be administered ursodeoxycholic acid twenty-four hours after endoscopic procedure and will last fourteen days, and (B) control group.Serum-testing will include determination of bilirubin, alanine transaminase, aspartate transaminase, gama-glutamil transpeptidase, alkaline phosphatase, albumin, and cholesterol levels. These parameters will be determined one day prior endoscopic procedure, and on the third, fifth, seventh, tenth, twelfth and fourteenth days after endoscopic intervention. This trial is a prospective, open-label, randomized, and controlled study to asses the effect of ursodeoxycholic acid in liver functional restoration of patients with obstructive jaundice in the early phase after endoscopic treatment.

Lessons learned in research: an attempt to study the effects of magnetic therapy.

PubMed

Szor, Judy K; Holewinski, Paul

2002-02-01

Difficulties related to chronic wound healing research are frequently discussed, but results of less-than-perfect studies commonly are not published. A 16-week, randomized controlled double-blind study attempted to investigate the effect of static magnetic therapy on the healing of diabetic foot ulcers. Of 56 subjects, 37 completed the study. Because of the small sample size, randomization did not control for differences between the two groups, and the data could not be analyzed in any meaningful way. The challenges of performing magnetic therapy research are discussed and considerations for future studies are noted.

Design of the Resistance and Endurance exercise After ChemoTherapy (REACT) study: a randomized controlled trial to evaluate the effectiveness and cost-effectiveness of exercise interventions after chemotherapy on physical fitness and fatigue.

PubMed

Kampshoff, Caroline S; Buffart, Laurien M; Schep, Goof; van Mechelen, Willem; Brug, Johannes; Chinapaw, Mai J M

2010-11-30

Preliminary studies suggest that physical exercise interventions can improve physical fitness, fatigue and quality of life in cancer patients after completion of chemotherapy. Additional research is needed to rigorously test the effects of exercise programmes among cancer patients and to determine optimal training intensity accordingly. The present paper presents the design of a randomized controlled trial evaluating the effectiveness and cost-effectiveness of a high intensity exercise programme compared to a low-to-moderate intensity exercise programme and a waiting list control group on physical fitness and fatigue as primary outcomes. After baseline measurements, cancer patients who completed chemotherapy are randomly assigned to either a 12-week high intensity exercise programme or a low-to-moderate intensity exercise programme. Next, patients from both groups are randomly assigned to immediate training or a waiting list (i.e. waiting list control group). After 12 weeks, patients of the waiting list control group start with the exercise programme they have been allocated to.Both interventions consist of equal bouts of resistance and endurance interval exercises with the same frequency and duration, but differ in training intensity. Additionally, patients of both exercise programmes are counselled to improve compliance and achieve and maintain an active lifestyle, tailored to their individual preferences and capabilities.Measurements will be performed at baseline (t = 0), 12 weeks after randomization (t = 1), and 64 weeks after randomization (t = 2). The primary outcome measures are cardiorespiratory fitness and muscle strength assessed by means of objective performance indicators, and self-reported fatigue. Secondary outcome measures include health-related quality of life, self-reported physical activity, daily functioning, body composition, mood and sleep disturbances, and return to work. In addition, compliance and satisfaction with the interventions will be evaluated. Potential moderation by pre- and post-illness lifestyle, health and exercise-related attitudes, beliefs and motivation will also be assessed. Finally, the cost-effectiveness of both exercise interventions will be evaluated. This randomized controlled trial will be a rigorous test of effects of exercise programmes for cancer patients after chemotherapy, aiming to contribute to evidence-based practice in cancer rehabilitation programmes. This study is registered at the Netherlands Trial Register (NTR2153).

Will reducing sugar-sweetened beverage consumption reduce obesity? Evidence supporting conjecture is strong, but evidence when testing effect is weak

PubMed Central

Kaiser, Kathryn A.; Shikany, James M.; Keating, Karen D.; Allison, David B.

2014-01-01

We provide arguments to the debate question and update a previous meta-analysis with recently published studies on effects of sugar-sweetened beverages (SSBs) on body weight/composition indices (BWIs). We abstracted data from randomized controlled trials examining effects of consumption of SSBs on BWIs. Six new studies met these criteria: 1) human trials, 2) 3 weeks duration, 3) random assignment to conditions differing only in consumption of SSBs, and 4) including a BWI outcome. Updated meta-analysis of a total of seven studies that added SSBs to persons’ diets showed dose-dependent increases in weight. Updated meta-analysis of eight studies attempting to reduce SSB consumption showed an equivocal effect on BWIs in all randomized subjects. When limited to subjects overweight at baseline, meta-analysis showed a significant effect of roughly 0.25 standard deviations (more weight loss/less weight gain) relative to controls. Evidence to date is equivocal in showing that decreasing SSB consumption will reduce the prevalence of obesity. Although new evidence suggests that an effect may yet be demonstrable in some populations, the integrated effect size estimate remains very small and of equivocal statistical significance. Problems in this research area and suggestions for future research are highlighted. PMID:23742715

Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? A systematic review.

PubMed

Donnelly, Joseph E; Herrmann, Stephen D; Lambourne, Kate; Szabo, Amanda N; Honas, Jeffery J; Washburn, Richard A

2014-01-01

The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. TO ADDRESS THE QUESTION: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? PubMed and Embase were searched (January 1990-January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18-64 years). Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake.

Study design and "evidence" in patient-oriented research.

PubMed

Concato, John

2013-06-01

Individual studies in patient-oriented research, whether described as "comparative effectiveness" or using other terms, are based on underlying methodological designs. A simple taxonomy of study designs includes randomized controlled trials on the one hand, and observational studies (such as case series, cohort studies, and case-control studies) on the other. A rigid hierarchy of these design types is a fairly recent phenomenon, promoted as a tenet of "evidence-based medicine," with randomized controlled trials receiving gold-standard status in terms of producing valid results. Although randomized trials have many strengths, and contribute substantially to the evidence base in clinical care, making presumptions about the quality of a study based solely on category of research design is unscientific. Both the limitations of randomized trials as well as the strengths of observational studies tend to be overlooked when a priori assumptions are made. This essay presents an argument in support of a more balanced approach to evaluating evidence, and discusses representative examples from the general medical as well as pulmonary and critical care literature. The simultaneous consideration of validity (whether results are correct "internally") and generalizability (how well results apply to "external" populations) is warranted in assessing whether a study's results are accurate for patients likely to receive the intervention-examining the intersection of clinical and methodological issues in what can be called a medicine-based evidence approach. Examination of cause-effect associations in patient-oriented research should recognize both the strengths and limitations of randomized trials as well as observational studies.

Study protocol: to investigate effects of highly specialized rehabilitation for patients with multiple sclerosis. A randomized controlled trial of a personalized, multidisciplinary intervention

PubMed Central

2012-01-01

Background Multiple sclerosis (MS) is a complex, chronic and progressive disease and rehabilitation services can provide important support to patients. Few MS rehabilitation programs have been shown to provide health improvements to patients in a cost-effective manner. The objective of this study is to assess the effects in terms of changes measured by a variety of standardized quality of life, mastery, coping, compliance and individual goal-related endpoints. This combination provides the basis for analyzing the complexity of MS and outcomes of a personalized rehabilitation. Methods/Design Patients with MS referred to hospital rehabilitation services will be randomized to either early admission (within two months) or usual admission (after an average waiting time of eight months). They will complete a battery of standardized health outcome instruments prior to randomization, and again six and twelve months after randomization, and a battery of goal-related outcome measures at admission and discharge, and again one, six and twelve months after randomization. Discussion The results of the study are expected to contribute to further development of MS rehabilitation services and to discussions about the design and content of such services. The results will also provide additional information to health authorities responsible for providing and financing rehabilitation services. Trial registration Current Controlled Trials (ISRCTN05245917) PMID:22954027

Do observational studies using propensity score methods agree with randomized trials? A systematic comparison of studies on acute coronary syndromes

PubMed Central

Dahabreh, Issa J.; Sheldrick, Radley C.; Paulus, Jessica K.; Chung, Mei; Varvarigou, Vasileia; Jafri, Haseeb; Rassen, Jeremy A.; Trikalinos, Thomas A.; Kitsios, Georgios D.

2012-01-01

Aims Randomized controlled trials (RCTs) are the gold standard for assessing the efficacy of therapeutic interventions because randomization protects from biases inherent in observational studies. Propensity score (PS) methods, proposed as a potential solution to confounding of the treatment–outcome association, are widely used in observational studies of therapeutic interventions for acute coronary syndromes (ACS). We aimed to systematically assess agreement between observational studies using PS methods and RCTs on therapeutic interventions for ACS. Methods and results We searched for observational studies of interventions for ACS that used PS methods to estimate treatment effects on short- or long-term mortality. Using a standardized algorithm, we matched observational studies to RCTs based on patients’ characteristics, interventions, and outcomes (‘topics’), and we compared estimates of treatment effect between the two designs. When multiple observational studies or RCTs were identified for the same topic, we performed a meta-analysis and used the summary relative risk for comparisons. We matched 21 observational studies investigating 17 distinct clinical topics to 63 RCTs (median = 3 RCTs per observational study) for short-term (7 topics) and long-term (10 topics) mortality. Estimates from PS analyses differed statistically significantly from randomized evidence in two instances; however, observational studies reported more extreme beneficial treatment effects compared with RCTs in 13 of 17 instances (P = 0.049). Sensitivity analyses limited to large RCTs, and using alternative meta-analysis models yielded similar results. Conclusion For the treatment of ACS, observational studies using PS methods produce treatment effect estimates that are of more extreme magnitude compared with those from RCTs, although the differences are rarely statistically significant. PMID:22711757

Rational and design of a stepped-wedge cluster randomized trial evaluating quality improvement initiative for reducing cardiovascular events among patients with acute coronary syndromes in resource-constrained hospitals in China.

PubMed

Li, Shenshen; Wu, Yangfeng; Du, Xin; Li, Xian; Patel, Anushka; Peterson, Eric D; Turnbull, Fiona; Lo, Serigne; Billot, Laurent; Laba, Tracey; Gao, Runlin

2015-03-01

Acute coronary syndromes (ACSs) are a major cause of morbidity and mortality, yet effective ACS treatments are frequently underused in clinical practice. Randomized trials including the CPACS-2 study suggest that quality improvement initiatives can increase the use of effective treatments, but whether such programs can impact hard clinical outcomes has never been demonstrated in a well-powered randomized controlled trial. The CPACS-3 study is a stepped-wedge cluster-randomized trial conducted in 104 remote level 2 hospitals without PCI facilities in China. All hospitalized ACS patients will be recruited consecutively over a 30-month period to an anticipated total study population of more than 25,000 patients. After a 6-month baseline period, hospitals will be randomized to 1 of 4 groups, and a 6-component quality improvement intervention will be implemented sequentially in each group every 6months. These components include the following: establishment of a quality improvement team, implementation of a clinical pathway, training of physicians and nurses, hospital performance audit and feedback, online technical support, and patient education. All patients will be followed up for 6months postdischarge. The primary outcome will be the incidence of in-hospital major adverse cardiovascular events comprising all-cause mortality, myocardial infarction or reinfarction, and nonfatal stroke. The CPACS-3 study will be the first large randomized trial with sufficient power to assess the effects of a multifaceted quality of care improvement initiative on hard clinical outcomes, in patients with ACS. Copyright © 2014 Elsevier Inc. All rights reserved.

Recruitment of healthy participants for studies on risks for alcoholism: effectiveness of random digit dialling.

PubMed

Sorocco, Kristen H; Vincent, Andrea S; Collins, Frank L; Johnson, Christine A; Lovallo, William R

2006-01-01

To compare the effectiveness of two strategies for recruiting healthy research volunteers. Demographic characteristics and recruitment costs of participants who completed a laboratory study examining risk factors for alcoholism recruited through random digit dialling (N = 11) and community advertisements (N = 102) were compared. Advertisement yielded a more representative sample [76% Caucasian, less well educated (M = 15.2 years, SEM = 0.2; P < 0.05), more equally divided by family history of alcoholism (43% FH- and 57% FH+), and lower in SES (M = 42.8, SEM = 1.3; P < 0.05)] and was more cost effective (72 dollars vs 2272 dollars per participant) than random digit dialling. Findings are relevant to alcohol researchers trying to determine the recruitment strategy that will yield the most representative sample at the lowest cost.

Breastfeeding and intelligence: a systematic review and meta-analysis.

PubMed

Horta, Bernardo L; Loret de Mola, Christian; Victora, Cesar G

2015-12-01

This study was aimed at systematically reviewing evidence of the association between breastfeeding and performance in intelligence tests. Two independent searches were carried out using Medline, LILACS, SCIELO and Web of Science. Studies restricted to infants and those where estimates were not adjusted for stimulation or interaction at home were excluded. Fixed- and random-effects models were used to pool the effect estimates, and a random-effects regression was used to assess potential sources of heterogeneity. We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model, breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression, none of the study characteristics explained the heterogeneity among the studies. Breastfeeding is related to improved performance in intelligence tests. A positive effect of breastfeeding on cognition was also observed in a randomised trial. This suggests that the association is causal. ©2015 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.

A Comparison of Single Sample and Bootstrap Methods to Assess Mediation in Cluster Randomized Trials

ERIC Educational Resources Information Center

Pituch, Keenan A.; Stapleton, Laura M.; Kang, Joo Youn

2006-01-01

A Monte Carlo study examined the statistical performance of single sample and bootstrap methods that can be used to test and form confidence interval estimates of indirect effects in two cluster randomized experimental designs. The designs were similar in that they featured random assignment of clusters to one of two treatment conditions and…

Game-Based Learning as a Vehicle to Teach First Aid Content: A Randomized Experiment

ERIC Educational Resources Information Center

Charlier, Nathalie; De Fraine, Bieke

2013-01-01

Background: Knowledge of first aid (FA), which constitutes lifesaving treatments for injuries or illnesses, is important for every individual. In this study, we have set up a group-randomized controlled trial to assess the effectiveness of a board game for learning FA. Methods: Four class groups (120 students) were randomly assigned to 2…

Cognitive remediation therapy (CRT) as a treatment enhancer of eating disorders and obsessive compulsive disorders: study protocol for a randomized controlled trial.

PubMed

van Passel, Boris; Danner, Unna; Dingemans, Alexandra; van Furth, Eric; Sternheim, Lot; van Elburg, Annemarie; van Minnen, Agnes; van den Hout, Marcel; Hendriks, Gert-Jan; Cath, Daniëlle

2016-11-10

Anorexia nervosa (AN) and Obsessive Compulsive Disorder (OCD) are among the most incapacitating and costly of mental disorders. Cognitive Behaviour Therapy (CBT), medication, and combination regimens, to which in AN personalised guidance on weight control is added, are moderately successful, leaving room for more effective treatment algorithms. An underlying deficit which the two disorders share is cognitive inflexibility, a trait that is likely to impede treatment engagement and reduce patients' ability to benefit from treatment. Cognitive remediation therapy (CRT) is an easy-to-use intervention aimed at reducing cognitive inflexibility and thereby enhancing treatment outcome, which we aim to test in a controled study. In a randomized-controlled multicenter clinical trial 64 adult patients with AN and 64 with OCD are randomized to 10 bi-weekly sessions with either CRT or a control condition, after which Treatment As Usual (TAU) is started. All patients are evaluated during single-blind assessments at baseline, post-CRT/control intervention, and after 6 months. Indices of treatment effect are disorder-specific symptom severity, quality of life, and cost-effectivity. Also, moderators and mediators of treatment effects will be studied. To our knowledge, this is the first randomized controlled trial using an control condition evaluating the efficacy and effectiveness of CRT as a treatment enhancer preceding TAU for AN, and the first study to investigate CRT in OCD, moreover taking cost-effectiveness of CRT in AN and OCD into account. The Netherlands Trial Register NTR3865 . Registered 20 february 2013.

Quenched bond randomness: Superfluidity in porous media and the strong violation of universality

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

Falicov, A.; Berker, A.N.

1997-04-01

The effects of quenched bond randomness are most readily studied with superfluidity immersed in a porous medium. A lattice model for {sup 3}He-{sup 4}He mixtures and incomplete {sup 4}He fillings in aerogel yields the signature effect of bond randomness, namely the conversion of symmetry-breaking first-order phase transitions into second-order phase transitions, the A-line reaching zero temperature, and the elimination of non-symmetry-breaking first-order phase transitions. The model recognizes the importance of the connected nature of aerogel randomness and thereby yields superfluidity at very low {sup 4}He concentrations, a phase separation entirely within the superfluid phase, and the order-parameter contrast between mixturesmore » and incomplete fillings, all in agreement with experiments. The special properties of the helium mixture/aerogel system are distinctly linked to the aerogel properties of connectivity, randomness, and tenuousness, via the additional study of a regularized {open_quote}jungle-gym{close_quotes} aerogel. Renormalization-group calculations indicate that a strong violation of the empirical universality principle of critical phenomena occurs under quenched bond randomness. It is argued that helium/aerogel critical properties reflect this violation and further experiments are suggested. Renormalization-group analysis also shows that, adjoiningly to the strong universality violation (which hinges on the occurrence or non-occurrence of asymptotic strong coupling-strong randomness under resealing), there is a new {open_quotes}hyperuniversality{close_quotes} at phase transitions with asymptotic strong coupling-strong randomness behavior, for example assigning the same critical exponents to random-bond tricriticality and random-field criticality.« less

Mixed models approaches for joint modeling of different types of responses.

PubMed

Ivanova, Anna; Molenberghs, Geert; Verbeke, Geert

2016-01-01

In many biomedical studies, one jointly collects longitudinal continuous, binary, and survival outcomes, possibly with some observations missing. Random-effects models, sometimes called shared-parameter models or frailty models, received a lot of attention. In such models, the corresponding variance components can be employed to capture the association between the various sequences. In some cases, random effects are considered common to various sequences, perhaps up to a scaling factor; in others, there are different but correlated random effects. Even though a variety of data types has been considered in the literature, less attention has been devoted to ordinal data. For univariate longitudinal or hierarchical data, the proportional odds mixed model (POMM) is an instance of the generalized linear mixed model (GLMM; Breslow and Clayton, 1993). Ordinal data are conveniently replaced by a parsimonious set of dummies, which in the longitudinal setting leads to a repeated set of dummies. When ordinal longitudinal data are part of a joint model, the complexity increases further. This is the setting considered in this paper. We formulate a random-effects based model that, in addition, allows for overdispersion. Using two case studies, it is shown that the combination of random effects to capture association with further correction for overdispersion can improve the model's fit considerably and that the resulting models allow to answer research questions that could not be addressed otherwise. Parameters can be estimated in a fairly straightforward way, using the SAS procedure NLMIXED.

Inference for binomial probability based on dependent Bernoulli random variables with applications to meta‐analysis and group level studies

PubMed Central

Bakbergenuly, Ilyas; Morgenthaler, Stephan

2016-01-01

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group‐level studies or in meta‐analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log‐odds and arcsine transformations of the estimated probability p^, both for single‐group studies and in combining results from several groups or studies in meta‐analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta‐analysis and result in abysmal coverage of the combined effect for large K. We also propose bias‐correction for the arcsine transformation. Our simulations demonstrate that this bias‐correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta‐analyses of prevalence. PMID:27192062

Randomized Trials Built on Sand: Examples from COPD, Hormone Therapy, and Cancer

PubMed Central

Suissa, Samy

2012-01-01

The randomized controlled trial is the fundamental study design to evaluate the effectiveness of medications and receive regulatory approval. Observational studies, on the other hand, are essential to address post-marketing drug safety issues but have also been used to uncover new indications or new benefits for already marketed drugs. Hormone replacement therapy (HRT) for instance, effective for menopausal symptoms, was reported in several observational studies during the 1980s and 1990s to also significantly reduce the incidence of coronary heart disease. This claim was refuted in 2002 by the large-scale Women’s Health Initiative randomized trial. An example of a new indication for an old drug is that of metformin, an anti-diabetic medication, which is being hailed as a potential anti-cancer agent, primarily on the basis of several recent observational studies that reported impressive reductions in cancer incidence and mortality with its use. These observational studies have now sparked the conduct of large-scale randomized controlled trials currently ongoing in cancer. We show in this paper that the spectacular effects on new indications or new outcomes reported in many observational studies in chronic obstructive pulmonary disease (COPD), HRT, and cancer are the result of time-related biases, such as immortal time bias, that tend to seriously exaggerate the benefits of a drug and that eventually disappear with the proper statistical analysis. In all, while observational studies are central to assess the effects of drugs, their proper design and analysis are essential to avoid bias. The scientific evidence on the potential beneficial effects in new indications of existing drugs will need to be more carefully assessed before embarking on long and expensive unsubstantiated trials. PMID:23908838

Comparative Evaluation of the Efficacy of Probiotic, Herbal and Chlorhexidine Mouthwash on Gingival Health: A Randomized Clinical Trial

PubMed Central

Dodamani, Arun Suresh; Karibasappa, Gundabaktha; Khairnar, Mahesh Ravindra; Naik, Rahul Gaybarao; Jadhav, Harish Chaitram

2017-01-01

Introduction Due to inherent limitations of Chlorhexidine (CHX), search for an effective and potentially safe anti-plaque agent has led to emergence of alternative products. Aim The present study evaluated the comparative efficacy of probiotic, herbal and CHX mouthwashes on gingival health of healthy individuals. Materials and Methods The present study was randomized parallel group controlled trial. A group of 45 healthy subjects in the age group of 18-21 years received complete supragingival scaling at baseline and study variables viz., Oral Hygiene Index – Simplified (OHI-S), Plaque Index (PI) and Gingival Index (GI) were recorded. Subjects were then randomly divided into three groups (15 in each group) and were randomly intervened with three different mouthwashes i.e., HiOra mouthwash, CHX mouthwash and Probiotic mouthwash. Variables were again recorded on the seventh and 14th day after use of mouthwashes and data obtained was subjected to statistical analysis. Results There was no significant difference in the efficacy of CHX, HiOra regular and probiotic mouthwashes on plaque accumulation, gingival health and oral hygiene status. Conclusion Herbal and probiotic mouthwashes can prove to be effective alternatives to CHX with minimal side effects. PMID:28511500

Modeling and Predicting the Stress Relaxation of Composites with Short and Randomly Oriented Fibers

PubMed Central

Obaid, Numaira; Sain, Mohini

2017-01-01

The addition of short fibers has been experimentally observed to slow the stress relaxation of viscoelastic polymers, producing a change in the relaxation time constant. Our recent study attributed this effect of fibers on stress relaxation behavior to the interfacial shear stress transfer at the fiber-matrix interface. This model explained the effect of fiber addition on stress relaxation without the need to postulate structural changes at the interface. In our previous study, we developed an analytical model for the effect of fully aligned short fibers, and the model predictions were successfully compared to finite element simulations. However, in most industrial applications of short-fiber composites, fibers are not aligned, and hence it is necessary to examine the time dependence of viscoelastic polymers containing randomly oriented short fibers. In this study, we propose an analytical model to predict the stress relaxation behavior of short-fiber composites where the fibers are randomly oriented. The model predictions were compared to results obtained from Monte Carlo finite element simulations, and good agreement between the two was observed. The analytical model provides an excellent tool to accurately predict the stress relaxation behavior of randomly oriented short-fiber composites. PMID:29053601

Random regression analyses using B-spline functions to model growth of Nellore cattle.

PubMed

Boligon, A A; Mercadante, M E Z; Lôbo, R B; Baldi, F; Albuquerque, L G

2012-02-01

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.

Effect of Metformin on Plasma Fibrinogen Concentrations: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials.

PubMed

Simental-Mendia, Luis E; Pirro, Matteo; Atkin, Stephen L; Banach, Maciej; Mikhailidis, Dimitri P; Sahebkar, Amirhossein

2018-01-01

Fibrinogen is a key mediator of thrombosis and it has been implicated in the pathogenesis of atherosclerosis. Because metformin has shown a potential protective effect on different atherothrombotic risk factors, we assessed in this meta-analysis its effect on plasma fibrinogen concentrations. A systematic review and meta-analysis was carried out to identify randomized placebo-controlled trials evaluating the effect of metformin administration on fibrinogen levels. The search included PubMed-Medline, Scopus, ISI Web of Knowledge and Google Scholar databases (by June 2, 2017) and quality of studies was performed according to Cochrane criteria. Quantitative data synthesis was conducted using a random-effects model and sensitivity analysis by the leave-one-out method. Meta-regression analysis was performed to assess the modifiers of treatment response. Meta-analysis of data from 9 randomized placebo-controlled clinical trials with 2302 patients comprising 10 treatment arms did not suggest a significant change in plasma fibrinogen concentrations following metformin therapy (WMD: -0.25 g/L, 95% CI: -0.53, 0.04, p = 0.092). The effect size was robust in the leave-one-out sensitivity analysis and remained non-significant after omission of each single study from the meta-analysis. No significant effect of metformin on plasma fibrinogen concentrations was demonstrated in the current meta-analysis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Human norovirus inactivation in oysters by high hydrostatic pressure processing: A randomized double-blinded study

USDA-ARS?s Scientific Manuscript database

This randomized, double-blinded, clinical trial assessed the effect of high hydrostatic pressure processing (HPP) on genogroup I.1 human norovirus (HuNoV) inactivation in virus-seeded oysters when ingested by subjects. The safety and efficacy of HPP treatments were assessed in three study phases wi...

Melatonin Treatment in Individuals with Intellectual Disability and Chronic Insomnia: A Randomized Placebo-Controlled Study

ERIC Educational Resources Information Center

Braam, W.; Didden, R.; Smits, M.; Curfs, L.

2008-01-01

Background: While several small-number or open-label studies suggest that melatonin improves sleep in individuals with intellectual disabilities (ID) with chronic sleep disturbance, a larger randomized control trial is necessary to validate these promising results. Methods: The effectiveness of melatonin for the treatment of chronic sleep…

Cognitive Behavioral Principles within Group Mentoring: A Randomized Pilot Study

ERIC Educational Resources Information Center

Jent, Jason F.; Niec, Larissa N.

2009-01-01

This study evaluated the effectiveness of a group mentoring program that included components of empirically supported mentoring and cognitive behavioral techniques for children served at a community mental health center. Eighty-six 8- to 12-year-old children were randomly assigned to either group mentoring or a wait-list control group. Group…

Acupuncture for Children with Autism Spectrum Disorders: A Systematic Review of Randomized Clinical Trials

ERIC Educational Resources Information Center

Lee, Myeong Soo; Choi, Tae-Young; Shin, Byung-Cheul; Ernst, Edzard

2012-01-01

This study aimed to assess the effectiveness of acupuncture as a treatment for autism spectrum disorders (ASD). We searched the literature using 15 databases. Eleven randomized clinical trials (RCTs) met our inclusion criteria. Most had significant methodological weaknesses. The studies' statistical and clinical heterogeneity prevented us from…

Effects of diet on carcass quality and consumer taste panel acceptance of intact or castrated hair lambs

USDA-ARS?s Scientific Manuscript database

Forty hair-type lambs were examined in a 70-d study to determine the effects of gender (castrate; C vs. intact; I) and forage type on carcass traits and sensory acceptability. Lambs were procured from a single source in Missouri and one-half were randomly castrated. Lambs were randomly assigned to t...

Alcohol-Specific Parenting within a Cluster-Randomized Effectiveness Trial of a Swedish Primary Prevention Program

ERIC Educational Resources Information Center

Strandberg, Anna K.; Bodin, Maria C.

2011-01-01

Purpose: Within the framework of an ongoing cluster-randomized effectiveness trial of a parental prevention program, the aim of the present study is to investigate attitudes towards under-age drinking and use of program components, i.e. alcohol-specific parenting behaviors, in parents who did and did not take part in the programme.…

Counterintuitive Effects of Online Feedback in Middle School Math: Results from a Randomized Controlled Trial in ASSISTments

ERIC Educational Resources Information Center

McGuire, Patrick; Tu, Shihfen; Logue, Mary Ellin; Mason, Craig A.; Ostrow, Korinn

2017-01-01

This study compared the effects of three different feedback formats provided to sixth grade mathematics students within a web-based online learning platform, ASSISTments. A sample of 196 students were randomly assigned to one of three conditions: (1) text-based feedback; (2) image-based feedback; and (3) correctness only feedback. Regardless of…

Extensions of Existing Methods for Use with a New Class of Experimental Designs Useful when There Is Treatment Effect Contamination

ERIC Educational Resources Information Center

Rhoads, Christopher

2011-01-01

Researchers planning a randomized field trial to evaluate the effectiveness of an educational intervention often face the following dilemma. They plan to recruit schools to participate in their study. The question is, "Should the researchers randomly assign individuals (either students or teachers, depending on the intervention) within schools to…

Evaluation of a 2-Year Physical Activity and Healthy Eating Intervention in Middle School Children

ERIC Educational Resources Information Center

Haerens, Leen; Deforche, Benedicte; Maes, Lea; Cardon, Greet; Stevens, Veerle; De Bourdeaudhuij, Ilse

2006-01-01

The aim of the present study was to evaluate the effects of a middle school physical activity and healthy eating intervention, including an environmental and computer-tailored component, and to investigate the effects of parental involvement. A random sample of 15 schools with seventh and eight graders was randomly assigned to one of three…

Effects of Aerobic Exercise on Overweight Children's Cognitive Functioning: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Davis, Catherine L.; Tomporowski, Phillip D.; Boyle, Colleen A.; Waller, Jennifer L.; Miller, Patricia H.; Naglieri, Jack A.; Gregoski, Mathew

2007-01-01

The study tested the effect of aerobic exercise training on executive function in overweight children. Ninety-four sedentary, overweight but otherwise healthy children (mean age = 9.2 years, body mass index [greater than or equal to] 85th percentile) were randomized to a low-dose (20 min/day exercise), high-dose (40 min/day exercise), or control…

The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

ERIC Educational Resources Information Center

Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

2011-01-01

The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

The Effect of Teacher-Family Communication on Student Engagement: Evidence from a Randomized Field Experiment

ERIC Educational Resources Information Center

Kraft, Matthew A.; Dougherty, Shaun M.

2013-01-01

In this study, we evaluate the efficacy of teacher communication with parents and students as a means of increasing student engagement. We estimate the causal effect of teacher communication by conducting a randomized field experiment in which sixth- and ninth-grade students were assigned to receive a daily phone call home and a text/written…

Using Multisite Experiments to Study Cross-Site Variation in Treatment Effects: A Hybrid Approach with Fixed Intercepts and A Random Treatment Coefficient

ERIC Educational Resources Information Center

Bloom, Howard S.; Raudenbush, Stephen W.; Weiss, Michael J.; Porter, Kristin

2017-01-01

The present article considers a fundamental question in evaluation research: "By how much do program effects vary across sites?" The article first presents a theoretical model of cross-site impact variation and a related estimation model with a random treatment coefficient and fixed site-specific intercepts. This approach eliminates…

Is Homeopathy Effective for Hot Flashes and Other Estrogen-Withdrawl Symptoms in Breast Cancer Survivors? A Preliminary Randomized Controlled Trial

DTIC Science & Technology

2001-09-01

symptoms for more than 100 years. To carry out a pilot study to determine whether there is evidence that homeopathy is an effective treatment to improve the...one month, with at least 3 hot flashes per day. Subjects have been randomized to one of three treatment arms: classical homeopathy , a combination

Effects of Animation on Naming and Identification across Two Graphic Symbol Sets Representing Verbs and Prepositions

ERIC Educational Resources Information Center

Schlosser, Ralf W.; Koul, Rajinder; Shane, Howard; Sorce, James; Brock, Kristofer; Harmon, Ashley; Moerlein, Dorothy; Hearn, Emilia

2014-01-01

Purpose: The effects of animation on naming and identification of graphic symbols for verbs and prepositions were studied in 2 graphic symbol sets in preschoolers. Method: Using a 2 × 2 × 2 × 3 completely randomized block design, preschoolers across three age groups were randomly assigned to combinations of symbol set (Autism Language Program…

Using a Random Dependent Group Contingency to Increase On-Task Behaviors of High School Students with High Incidence Disabilities

ERIC Educational Resources Information Center

Williamson, Brenda D.; Campbell-Whatley, Gloria D.; Lo, Ya-yu

2009-01-01

Group contingencies have the advantages of encouraging individual students to collectively feel responsible for appropriate and inappropriate classroom behaviors and have shown effectiveness in improving students' behavior. The purpose of this study was to investigate the effects of a random dependent group contingency on the on-task behaviors of…

Hypnosis versus diazepam for embryo transfer: a randomized controlled study.

PubMed

Catoire, Patrick; Delaunay, Laurent; Dannappel, Thomas; Baracchini, Dominique; Marcadet-Fredet, Sabine; Moreau, Olivier; Pacaud, Luc; Przyrowski, Daniel; Marret, Emmanuel

2013-04-01

Levitas et al. (2006) showed in a cohort study that hypnosis during embryo transfer (ET) increased pregnancy ratio by 76%. In order to evaluate hypnosis during ET in a general population, the authors performed a randomized prospective controlled study comparing diazepam (usual premedication) administered before ET plus muscle relaxation versus hypnosis plus placebo in 94 patients. Additionally, the authors studied anxiety pre and post ET. Anxiety scores were not different in the two groups before and after ET. No difference in pregnancy and birth ratio was found in the two groups. Hypnosis during ET is as effective as diazepam in terms of pregnancy ratio and anxiolytic effects, but with fewer side effects and should be routinely available.

META-ANALYSIS OF ACUTE EXERCISE EFFECTS ON STATE ANXIETY: AN UPDATE OF RANDOMIZED CONTROLLED TRIALS OVER THE PAST 25 YEARS.

PubMed

Ensari, Ipek; Greenlee, Tina A; Motl, Robert W; Petruzzello, Steven J

2015-08-01

One prominent and well-cited meta-analysis published nearly 25 years ago reported that an acute or single bout of exercise reduced state anxiety by approximately ¼ standard deviation. We conducted a meta-analysis of randomized controlled trials (RCTs) published after that meta-analysis for updating our understanding of the acute effects of exercise on state anxiety. We searched PubMed, EBSCOHost, Medline, PsycINFO, ERIC, and ScienceDirect for RCTs of acute exercise and state anxiety as an outcome. There were 36 RCTs that met inclusion criteria and yielded data for effect size (ES) generation (Cohen's d). An overall ES was calculated using a random effects model and expressed as Hedge's g. The weighted mean ES was small (Hedge's g = 0.16, standard error (SE) = 0.06), but statistically significant (P < 0.05), and indicated that a single bout of exercise resulted in an improvement in state anxiety compared with control. The overall ES was heterogeneous and post hoc, exploratory analyses using both random- and fixed-effects models identified several variables as moderators including sample age, sex and health status, baseline activity levels, exercise intensity, modality and control condition, randomization, overall study quality, and the anxiety measure (P < 0.05). The cumulative evidence from high quality studies indicates that acute bouts of exercise can yield a small reduction in state anxiety. The research is still plagued by floor effects associated with recruiting persons with normal or lower levels of state anxiety, and this should be overcome in subsequent trials. © 2015 Wiley Periodicals, Inc.

Likelihood-Based Random-Effect Meta-Analysis of Binary Events.

PubMed

Amatya, Anup; Bhaumik, Dulal K; Normand, Sharon-Lise; Greenhouse, Joel; Kaizar, Eloise; Neelon, Brian; Gibbons, Robert D

2015-01-01

Meta-analysis has been used extensively for evaluation of efficacy and safety of medical interventions. Its advantages and utilities are well known. However, recent studies have raised questions about the accuracy of the commonly used moment-based meta-analytic methods in general and for rare binary outcomes in particular. The issue is further complicated for studies with heterogeneous effect sizes. Likelihood-based mixed-effects modeling provides an alternative to moment-based methods such as inverse-variance weighted fixed- and random-effects estimators. In this article, we compare and contrast different mixed-effect modeling strategies in the context of meta-analysis. Their performance in estimation and testing of overall effect and heterogeneity are evaluated when combining results from studies with a binary outcome. Models that allow heterogeneity in both baseline rate and treatment effect across studies have low type I and type II error rates, and their estimates are the least biased among the models considered.

Metacognitive therapy versus cognitive behavioural therapy for depression: a randomized pilot study.

PubMed

Jordan, Jennifer; Carter, Janet D; McIntosh, Virginia V W; Fernando, Kumari; Frampton, Christopher M A; Porter, Richard J; Mulder, Roger T; Lacey, Cameron; Joyce, Peter R

2014-10-01

Metacognitive therapy (MCT) is one of the newer developments within cognitive therapy. This randomized controlled pilot study compared independently applied MCT with cognitive behavioural therapy (CBT) in outpatients with depression to explore the relative speed and efficacy of MCT, ahead of a planned randomized controlled trial. A total of 48 participants referred for outpatient therapy were randomized to up to 12 weeks of MCT or CBT. Key outcomes were reduction in depressive symptoms at week 4 and week 12, measured using the independent-clinician-rated Quick Inventory of Depressive Symptomatology16. Intention-to-treat and completer analyses as well as additional methods of reporting outcome of depression are presented. Both therapies were effective in producing clinically significant change in depressive symptoms, with moderate-to-large effect sizes obtained. No differences were detected between therapies in overall outcome or early change on clinician-rated or self-reported measures. Post-hoc analyses suggest that MCT may have been adversely affected by greater comorbidity. In this large pilot study conducted independently of MCT's developers, MCT was an effective treatment for outpatients with depression, with similar results overall to CBT. Insufficient power and imbalanced comorbidity limit conclusions regarding comparative efficacy so further studies of MCT and CBT are required. © The Royal Australian and New Zealand College of Psychiatrists 2014.

Effects of soy isoflavone supplements on bone turnover markers in menopausal women: systematic review and meta-analysis of randomized controlled trials.

PubMed

Taku, Kyoko; Melby, Melissa K; Kurzer, Mindy S; Mizuno, Shoichi; Watanabe, Shaw; Ishimi, Yoshiko

2010-08-01

Effects of soy isoflavone supplements on bone turnover markers remain unclear. This up-to-date systematic review and meta-analysis of randomized controlled trials (RCTs) was performed primarily to more completely and precisely clarify the effects on urinary deoxypyridinoline (DPD) and serum bone alkaline phosphatase (BAP) and secondarily to evaluate the effects on other bone turnover markers, compared with placebo in menopausal women. PubMed, CENTRAL, ICHUSHI, and CNKI were searched in June 2009 for relevant studies of RCTs. Data on study design, participants, interventions, and outcomes were extracted and methodological quality of each included trial was assessed. From 3740 identified relevant articles, 10 (887 participants), 10 (1210 participants), and 8 (380 participants) RCTs were selected for meta-analysis of effects on DPD, BAP, and serum osteocalcin (OC), respectively, using Review Manager 5.0.22. Daily ingestion of an average 56 mg soy isoflavones (aglycone equivalents) for 10 weeks to 12 months significantly decreased DPD by 14.1% (95% CI: -26.8% to -1.5%; P=0.03) compared to baseline (heterogeneity: P<0.00001; I(2)=93%; random effects model). The overall effect of soy isoflavones on DPD compared with placebo was a significant decrease of -18.0% (95% CI: -28.4% to -7.7%, P=0.0007; heterogeneity: P=0.0001; I(2)=73%; random effects model). Subgroup analyses and meta-regressions revealed that isoflavone dose and intervention duration did not significantly relate to the variable effects on DPD. Daily supplementation of about 84 mg and 73 mg of soy isoflavones for up to 12 months insignificantly increased BAP by 8.0% (95% CI: -4.2% to 20.2%, P=0.20; heterogeneity: P<0.00001; I(2)=98%) and OC by 10.3% (95% CI: -3.1% to 23.7%, P=0.13; heterogeneity: P=0.002; I(2)=69%) compared with placebo (random effects model), respectively. Soy isoflavone supplements moderately decreased the bone resorption marker DPD, but did not affect bone formation markers BAP and OC in menopausal women. The effects varied between studies, and further studies are needed to address factors relating to the observed effects of soy isoflavones on DPD and to verify effects on other bone turnover markers. Copyright 2010 Elsevier Inc. All rights reserved.

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study

PubMed Central

Churilov, Leonid

2018-01-01

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting. PMID:29659631

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study.

PubMed

Chiam, Elizabeth; Bellomo, Rinaldo; Churilov, Leonid; Weinberg, Laurence

2018-01-01

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting.

Comparing three knowledge communication strategies - Diffusion, Dissemination and Translation - through randomized controlled studies.

PubMed

Lane, Joseph P; Stone, Vathsala I

2015-01-01

This paper describes a series of three randomized controlled case studies comparing the effectiveness of three strategies for communicating new research-based knowledge (Diffusion, Dissemination, Translation), to different Assistive Technology (AT) stakeholder groups. Pre and post intervention measures for level of knowledge use (unaware, aware, interested, using) via the LOKUS instrument, assessed the relative effectiveness of the three strategies. The latter two approaches were both more effective than diffusion but also equally effective. The results question the value added by tailoring research findings to specific audiences, and instead supports the critical yet neglected role for relevance in determining knowledge use by stakeholders.

Theory-based self-management educational interventions on patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Zhao, Fang-Fang; Suhonen, Riitta; Koskinen, Sanna; Leino-Kilpi, Helena

2017-04-01

To synthesize the effects of theory-based self-management educational interventions on patients with type 2 diabetes (T2DM) in randomized controlled trials. Type 2 diabetes is a common chronic disease causing complications that put a heavy burden on society and reduce the quality of life of patients. Good self-management of diabetes can prevent complications and improve the quality of life of T2DM patients. Systematic review with meta-analysis of randomized controlled trials following Cochrane methods. A literature search was carried out in the MEDLINE, EMBASE, CINAHL, PSYCINFO, and Web of Science databases (1980-April 2015). The risk of bias of these eligible studies was assessed independently by two authors using the Cochrane Collaboration's tool. The Publication bias of the main outcomes was examined. Statistical heterogeneity and random-effects model were used for meta-analysis. Twenty studies with 5802 participants met the inclusion criteria. The interventions in the studies were based on one or more theories which mostly belong to mid-range theories. The pooled main outcomes by random-effects model showed significant improvements in HbA1c, self-efficacy, and diabetes knowledge, but not in BMI. As for quality of life, no conclusions can be drawn as the pooled outcome became the opposite with reduced heterogeneity after one study was excluded. No significant publication bias was found in the main outcomes. To get theory-based interventions to produce more effects, the role of patients should be more involved and stronger and the education team should be trained beyond the primary preparation for the self-management education program. © 2016 John Wiley & Sons Ltd.

Can We Increase Psychological Well-Being? The Effects of Interventions on Psychological Well-Being: A Meta-Analysis of Randomized Controlled Trials

PubMed Central

Westerhof, Gerben J.; Bohlmeijer, Ernst T.

2016-01-01

Background There is a rapidly growing interest in psychological well-being (PWB) as outcome of interventions. Ryff developed theory-based indicators of PWB that are consistent with a eudaimonic perspective of happiness. Numerous interventions have been developed with the aim to increase PWB. However, the effects on PWB measured as coherent outcome have not been examined across studies yet. This meta-analysis of randomized controlled trials of behavioral interventions aims to answer the question whether it is possible to enhance PWB. Methods A systematic literature search was performed in PsycINFO, Cochrane and Web of Science. To be included, studies had to be randomized controlled trials of behavioral interventions with psychological well-being as primary or secondary outcome measure, measured with either Ryff’s Psychological Well-Being Scales or the Mental Health Continuum—Short Form. The meta-analysis was performed using a random effects model. From the 2,298 articles found, 27 met the inclusion criteria. The included studies involved 3,579 participants. Results We found a moderate effect (Cohen’s d = 0.44; z = 5.62; p < .001). Heterogeneity between the studies was large (Q (26) = 134.12; p < .001; I2 = 80.62). At follow-up after two to ten months, a small but still significant effect size of 0.22 was found. There was no clear indication of publication bias. Interventions were more effective in clinical groups and when they were delivered individually. Effects were larger in studies of lower quality. Conclusions It appears to be possible to improve PWB with behavioral interventions. The results are promising for the further development and implementation of interventions to promote PWB. Delivering interventions face-to-face seems to be the most promising option. We recommend to keep including clinical groups in the research of psychological well-being. Heterogeneity is a limitation of the study and there is need for more high-quality studies. PMID:27328124

'Scared Straight' and other juvenile awareness programs for preventing juvenile delinquency.

PubMed

Petrosino, Anthony; Turpin-Petrosino, Carolyn; Hollis-Peel, Meghan E; Lavenberg, Julia G

2013-04-30

'Scared Straight' and other similar programs involve organized visits to prison by juvenile delinquents or children at risk for criminal behavior. Programs are designed to deter participants from future offending through first hand observation of prison life and interaction with adult inmates. These programs remain in use despite research questioning their effectiveness. This is an update of a 2002 review. To assess the effects of programs comprising organized visits to prisons by juvenile delinquents (officially adjudicated, that is, convicted by a juvenile court) or pre-delinquents (children in trouble but not officially adjudicated as delinquents), aimed at deterring them from delinquency. To update this review, we searched 22 electronic databases, including CENTRAL, MEDLINE, PsycINFO, and Criminal Justice Abstracts, in December 2011. In addition, we searched clinical trials registries, consulted experts, conducted Google Scholar searches,and followed up on all relevant citations. We included studies that tested programs involving the organized visits of delinquents or children at risk for delinquency to penal institutions such as prisons or re formatives. Studies that had overlapping samples of juvenile and young adults (for example, ages 14 to 20 years) were included. We only considered studies that assigned participants to conditions randomly or quasi-randomly (that is,by odd/even assignment to conditions). Each study had to have a no-treatment control condition and at least one outcome measure of 'post-visit' criminal behavior. The search methods for the original review generated 487 citations, most of which had abstracts. The lead review author screened these citations, determining that 30 were evaluation reports. Two review authors independently examined these citations and agreed that 11 were potential randomized trials. All reports were obtained. Upon inspection of the full-text reports, two review authors independently agreed to exclude two studies, resulting in nine randomized trials. The lead review author extracted data from each of the nine study reports using a specially designed instrument. In cases in which outcome information was missing from the original reports, we made attempts via correspondence to retrieve the data for the analysis from the original investigators. Outcome data were independently checked by a second review author (CTP).In this review, we report the results of each of the nine trials narratively.We conducted two meta-analyses of seven studies that provided post intervention offending rates using official data. Information from other sources (for example, self-report) was either missing from some studies or critical information was omitted (for example, standard deviations).We examined the immediate post-treatment effects(that is, 'first-effects') by computing odds ratios (OR) for data on proportions of each group re offending, and assumed both fixed-effect and random-effects models in our analyses. We have included nine studies in this review. All were part of the original systematic review; no new trials meeting eligibility criteria were identified through our updated searches. The studies were conducted in eight different states of the USA, during the years 1967 to 1992. Nearly 1000 (946) juveniles or young adults of different races participated, almost all males. The average age of the participants in each study ranged from 15 to 17 years.Meta-analyses of seven studies show the intervention to be more harmful than doing nothing. The OR (fixed-effect) for effects on first post-treatment effect on officially measured criminal behavior indicated a negative program effect (OR 1.68, 95% confidence interval (CI) 1.20 to 2.36) and nearly identical regardless of the meta-analytic strategy (random-effectsOR 1.72, 95%CI 1.13 to 2.62).Sensitivity analyses (random-effects) showed the findings were robust even when removing one study with an inadequate randomization strategy (OR 1.47, 95% CI 1.03 to 2.11), or when removing one study with high attrition (OR 1.96, 95% CI 1.25 to 3.08), or both(OR 1.68, 95% CI 1.10 to 2.58). We conclude that programs such as 'cared Straight' increase delinquency relative to doing nothing at all to similar youths. Given these results, we cannot recommend this program as a crime prevention strategy. Agencies that permit such programs, therefore, must rigorously evaluate them, to ensure that they do not cause more harm than good to the very citizens they pledge to protect.

The effect of endometrial scratch on natural-cycle cryopreserved embryo transfer outcomes: a randomized controlled study.

PubMed

Mak, Jennifer Sze Man; Chung, Cathy Hoi Sze; Chung, Jacqueline Pui Wah; Kong, Grace Wing Shan; Saravelos, Sotirios H; Cheung, Lai Ping; Li, Tin-Chiu

2017-07-01

The benefit of endometrial scratch (ES) prior to embryo transfer is controversial. Systemic analysis has confirmed its potential benefit, especially in women with repeated IVF failures, yet most studies have focused on fresh embryo transfer, and its effect on vitrified-warmed embryo transfer (FET) cycles is yet to be explored. We hereby present our prospective, double-blind, randomized controlled study on the evaluation of the implantation and pregnancy rate after ES prior to natural-cycle FET. A total of 299 patients underwent natural-cycle FET and were randomized to receive ES (n = 115) or endocervical manipulation as control (n = 114) prior to FET cycle, and a total of 196 patients had embryo transfer (93 patients in each group). Our study showed no significant difference in the implantation and pregnancy rate, as well as the clinical and ongoing pregnancy or live birth rates between the two groups. It appears that ES does not have any beneficial effect on an unselected group of women undergoing FET in natural cycles. Further studies on its effect in women with recurrent implantation failure after IVF are warranted. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Sativex oromucosal spray as adjunctive therapy in advanced cancer patients with chronic pain unalleviated by optimized opioid therapy: two double-blind, randomized, placebo-controlled phase 3 studies.

PubMed

Fallon, Marie T; Albert Lux, Eberhard; McQuade, Robert; Rossetti, Sandro; Sanchez, Raymond; Sun, Wei; Wright, Stephen; Lichtman, Aron H; Kornyeyeva, Elena

2017-08-01

Opioids are critical for managing cancer pain, but may provide inadequate relief and/or unacceptable side effects in some cases. To assess the analgesic efficacy of adjunctive Sativex (Δ 9 -tetrahydrocannabinol (27 mg/mL): cannabidiol (25 mg/mL)) in advanced cancer patients with chronic pain unalleviated by optimized opioid therapy. This report describes two phase 3, double-blind, randomized, placebo-controlled trials. Eligible patients had advanced cancer and average pain numerical rating scale (NRS) scores ≥4 and ≤8 at baseline, despite optimized opioid therapy. In Study-1, patients were randomized to Sativex or placebo, and then self-titrated study medications over a 2-week period per effect and tolerability, followed by a 3-week treatment period. In Study-2, all patients self-titrated Sativex over a 2-week period. Patients with a ≥15% improvement from baseline in pain score were then randomized 1:1 to Sativex or placebo, followed by 5-week treatment period (randomized withdrawal design). The primary efficacy endpoint (percent improvement (Study-1) and mean change (Study-2) in average daily pain NRS scores) was not met in either study. Post hoc analyses of the primary endpoints identified statistically favourable treatment effect for Sativex in US patients <65 years (median treatment difference: 8.8; 95% confidence interval (CI): 0.00-17.95; p = 0.040) that was not observed in patients <65 years from the rest of the world (median treatment difference: 0.2; 95% CI: -5.00 to 7.74; p = 0.794). Treatment effect in favour of Sativex was observed on quality-of-life questionnaires, despite the fact that similar effects were not observed on NRS score. The safety profile of Sativex was consistent with earlier studies, and no evidence of abuse or misuse was identified. Sativex did not demonstrate superiority to placebo in reducing self-reported pain NRS scores in advanced cancer patients with chronic pain unalleviated by optimized opioid therapy, although further exploration of differences between United States and patients from the rest of the world is warranted.

Approaches to answering critical CER questions.

PubMed

Kinnier, Christine V; Chung, Jeanette W; Bilimoria, Karl Y

2015-01-01

While randomized controlled trials (RCTs) are the gold standard for research, many research questions cannot be ethically and practically answered using an RCT. Comparative effectiveness research (CER) techniques are often better suited than RCTs to address the effects of an intervention under routine care conditions, an outcome otherwise known as effectiveness. CER research techniques covered in this section include: effectiveness-oriented experimental studies such as pragmatic trials and cluster randomized trials, treatment response heterogeneity, observational and database studies including adjustment techniques such as sensitivity analysis and propensity score analysis, systematic reviews and meta-analysis, decision analysis, and cost effectiveness analysis. Each section describes the technique and covers the strengths and weaknesses of the approach.

Effects of unstratified and centre-stratified randomization in multi-centre clinical trials.

PubMed

Anisimov, Vladimir V

2011-01-01

This paper deals with the analysis of randomization effects in multi-centre clinical trials. The two randomization schemes most often used in clinical trials are considered: unstratified and centre-stratified block-permuted randomization. The prediction of the number of patients randomized to different treatment arms in different regions during the recruitment period accounting for the stochastic nature of the recruitment and effects of multiple centres is investigated. A new analytic approach using a Poisson-gamma patient recruitment model (patients arrive at different centres according to Poisson processes with rates sampled from a gamma distributed population) and its further extensions is proposed. Closed-form expressions for corresponding distributions of the predicted number of the patients randomized in different regions are derived. In the case of two treatments, the properties of the total imbalance in the number of patients on treatment arms caused by using centre-stratified randomization are investigated and for a large number of centres a normal approximation of imbalance is proved. The impact of imbalance on the power of the study is considered. It is shown that the loss of statistical power is practically negligible and can be compensated by a minor increase in sample size. The influence of patient dropout is also investigated. The impact of randomization on predicted drug supply overage is discussed. Copyright © 2010 John Wiley & Sons, Ltd.

Study of Tomography Of Nephrolithiasis Evaluation (STONE): methodology, approach and rationale.

PubMed

Valencia, Victoria; Moghadassi, Michelle; Kriesel, Dana R; Cummings, Steve; Smith-Bindman, Rebecca

2014-05-01

Urolithiasis (kidney stones) is a common reason for Emergency Department (ED) visits, accounting for nearly 1% of all visits in the United States. Computed tomography (CT) has become the most common imaging test for these patients but there are few comparative effectiveness data to support its use in comparison to ultrasound. This paper describes the rationale and methods of STONE (Study of Tomography Of Nephrolithiasis Evaluation), a pragmatic randomized comparative effectiveness trial comparing different imaging strategies for patients with suspected urolithiasis. STONE is a multi-center, non-blinded pragmatic randomized comparative effectiveness trial of patients between ages 18 and 75 with suspected nephrolithiasis seen in an ED setting. Patients were randomized to one of three initial imaging examinations: point-of-care ultrasound, ultrasound performed by a radiologist or CT. Participants then received diagnosis and treatment per usual care. The primary aim is to compare the rate of severe SAEs (Serious Adverse Events) between the three arms. In addition, a broad range of secondary outcomes was assessed at baseline and regularly for six months post-baseline using phone, email and mail questionnaires. Excluding 17 patients who withdrew after randomization, a total of 2759 patients were randomized and completed a baseline questionnaire (n=908, 893 and 958 in the point-of-care ultrasound, radiology ultrasound and radiology CT arms, respectively). Follow-up is complete, and full or partial outcomes were assessed on over 90% of participants. The detailed methodology of STONE will provide a roadmap for comparative effectiveness studies of diagnostic imaging conducted in an ED setting. Published by Elsevier Inc.

Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride).

PubMed

Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

2013-01-02

Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively.

Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride)

PubMed Central

Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

2012-01-01

Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively. PMID:24958543

Physical activity measurements affected participants' behavior in a randomized controlled trial.

PubMed

van Sluijs, Esther M F; van Poppel, Mireille N M; Twisk, Jos W R; van Mechelen, Willem

2006-04-01

Assessing levels and determinants of physical activity as outcome measurements might have an independent effect on participant's physical activity behavior. The objective is to study this effect in a randomized controlled trial (RCT) promoting regular physical activity in Dutch general practice. Using a Solomon four-group design, participants were randomized twice. After randomization to a control or intervention-condition at general practice level (N = 29), participants were randomized to a group participating in measurements at baseline, 2 and 6 months (3M-group, N = 361), or a group only participating in measurements at 6 months (1M-group, N = 356). Outcome measures assessed at 6 months included: level of physical activity (self-reported and objectively measured with accelerometry), meeting ACSM/CDC guideline for regular physical activity, stage of change, and determinants of physical activity. Follow-up data on 635 participants (89%) was collected. Statistically significant measurement effects were found for meeting the ACSM/CDC guideline (self-reported), self-efficacy for resisting relapse, knowledge, and on awareness. Other outcome measures showed positive trends, except stages of change. Measurements of physical activity affect participant's physical activity behavior, possibly triggered by a raised awareness about their own physical activity level. Implications for future research are discussed, as well as methodologic limitations of the study design.

Preference option randomized design (PORD) for comparative effectiveness research: Statistical power for testing comparative effect, preference effect, selection effect, intent-to-treat effect, and overall effect.

PubMed

Heo, Moonseong; Meissner, Paul; Litwin, Alain H; Arnsten, Julia H; McKee, M Diane; Karasz, Alison; McKinley, Paula; Rehm, Colin D; Chambers, Earle C; Yeh, Ming-Chin; Wylie-Rosett, Judith

2017-01-01

Comparative effectiveness research trials in real-world settings may require participants to choose between preferred intervention options. A randomized clinical trial with parallel experimental and control arms is straightforward and regarded as a gold standard design, but by design it forces and anticipates the participants to comply with a randomly assigned intervention regardless of their preference. Therefore, the randomized clinical trial may impose impractical limitations when planning comparative effectiveness research trials. To accommodate participants' preference if they are expressed, and to maintain randomization, we propose an alternative design that allows participants' preference after randomization, which we call a "preference option randomized design (PORD)". In contrast to other preference designs, which ask whether or not participants consent to the assigned intervention after randomization, the crucial feature of preference option randomized design is its unique informed consent process before randomization. Specifically, the preference option randomized design consent process informs participants that they can opt out and switch to the other intervention only if after randomization they actively express the desire to do so. Participants who do not independently express explicit alternate preference or assent to the randomly assigned intervention are considered to not have an alternate preference. In sum, preference option randomized design intends to maximize retention, minimize possibility of forced assignment for any participants, and to maintain randomization by allowing participants with no or equal preference to represent random assignments. This design scheme enables to define five effects that are interconnected with each other through common design parameters-comparative, preference, selection, intent-to-treat, and overall/as-treated-to collectively guide decision making between interventions. Statistical power functions for testing all these effects are derived, and simulations verified the validity of the power functions under normal and binomial distributions.

Finite-range Coulomb gas models of banded random matrices and quantum kicked rotors

NASA Astrophysics Data System (ADS)

Pandey, Akhilesh; Kumar, Avanish; Puri, Sanjay

2017-11-01

Dyson demonstrated an equivalence between infinite-range Coulomb gas models and classical random matrix ensembles for the study of eigenvalue statistics. We introduce finite-range Coulomb gas (FRCG) models via a Brownian matrix process, and study them analytically and by Monte Carlo simulations. These models yield new universality classes, and provide a theoretical framework for the study of banded random matrices (BRMs) and quantum kicked rotors (QKRs). We demonstrate that, for a BRM of bandwidth b and a QKR of chaos parameter α , the appropriate FRCG model has the effective range d =b2/N =α2/N , for large N matrix dimensionality. As d increases, there is a transition from Poisson to classical random matrix statistics.

Finite-range Coulomb gas models of banded random matrices and quantum kicked rotors.

PubMed

Pandey, Akhilesh; Kumar, Avanish; Puri, Sanjay

2017-11-01

Dyson demonstrated an equivalence between infinite-range Coulomb gas models and classical random matrix ensembles for the study of eigenvalue statistics. We introduce finite-range Coulomb gas (FRCG) models via a Brownian matrix process, and study them analytically and by Monte Carlo simulations. These models yield new universality classes, and provide a theoretical framework for the study of banded random matrices (BRMs) and quantum kicked rotors (QKRs). We demonstrate that, for a BRM of bandwidth b and a QKR of chaos parameter α, the appropriate FRCG model has the effective range d=b^{2}/N=α^{2}/N, for large N matrix dimensionality. As d increases, there is a transition from Poisson to classical random matrix statistics.

The Prevention Program for Externalizing Problem Behavior (PEP) Improves Child Behavior by Reducing Negative Parenting: Analysis of Mediating Processes in a Randomized Controlled Trial

ERIC Educational Resources Information Center

Hanisch, Charlotte; Hautmann, Christopher; Plück, Julia; Eichelberger, Ilka; Döpfner, Manfred

2014-01-01

Background: Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify…

Sham transcranial electrical stimulation and its effects on corticospinal excitability: a systematic review and meta-analysis.

PubMed

Dissanayaka, Thusharika D; Zoghi, Maryam; Farrell, Michael; Egan, Gary F; Jaberzadeh, Shapour

2018-02-23

Sham stimulation is used in randomized controlled trials (RCTs) to assess the efficacy of active stimulation and placebo effects. It should mimic the characteristics of active stimulation to achieve blinding integrity. The present study was a systematic review and meta-analysis of the published literature to identify the effects of sham transcranial electrical stimulation (tES) - including anodal and cathodal transcranial direct current stimulation (a-tDCS, c-tDCS), transcranial alternating current stimulation (tACS), transcranial random noise stimulation (tRNS) and transcranial pulsed current stimulation (tPCS) - on corticospinal excitability (CSE), compared to baseline in healthy individuals. Electronic databases - PubMed, CINAHL, Scopus, Science Direct and MEDLINE (Ovid) - were searched for RCTs of tES from 1990 to March 2017. Thirty RCTs were identified. Using a random-effects model, meta-analysis of a-tDCS, c-tDCS, tACS, tRNS and tPCS studies showed statistically non-significant pre-post effects of sham interventions on CSE. This review found evidence for statically non-significant effects of sham tES on CSE.

Do Evidence-Based Youth Psychotherapies Outperform Usual Clinical Care? A Multilevel Meta-Analysis

PubMed Central

Weisz, John R.; Kuppens, Sofie; Eckshtain, Dikla; Ugueto, Ana M.; Hawley, Kristin M.; Jensen-Doss, Amanda

2013-01-01

Context Research across four decades has produced numerous empirically-tested evidence-based psychotherapies (EBPs) for youth psychopathology, developed to improve upon usual clinical interventions. Advocates argue that these should replace usual care; but do the EBPs produce better outcomes than usual care? Objective This question was addressed in a meta-analysis of 52 randomized trials directly comparing EBPs to usual care. Analyses assessed the overall effect of EBPs vs. usual care, and candidate moderators; multilevel analysis was used to address the dependency among effect sizes that is common but typically unaddressed in psychotherapy syntheses. Data Sources The PubMed, PsychINFO, and Dissertation Abstracts International databases were searched for studies from January 1, 1960 – December 31, 2010. Study Selection 507 randomized youth psychotherapy trials were identified. Of these, the 52 studies that compared EBPs to usual care were included in the meta-analysis. Data Extraction Sixteen variables (participant, treatment, and study characteristics) were extracted from each study, and effect sizes were calculated for all EBP versus usual care comparisons. Data Synthesis EBPs outperformed usual care. Mean effect size was 0.29; the probability was 58% that a randomly selected youth receiving an EBP would be better off after treatment than a randomly selected youth receiving usual care. Three variables moderated treatment benefit: Effect sizes decreased for studies conducted outside North America, for studies in which all participants were impaired enough to qualify for diagnoses, and for outcomes reported by people other than the youths and parents in therapy. For certain key groups (e.g., studies using clinically referred samples and diagnosed samples), significant EBP effects were not demonstrated. Conclusions EBPs outperformed usual care, but the EBP advantage was modest and moderated by youth, location, and assessment characteristics. There is room for improvement in EBPs, both in the magnitude and range of their benefit, relative to usual care. PMID:23754332

Inflammatory Biomarkers and Risk of Schizophrenia: A 2-Sample Mendelian Randomization Study.

PubMed

Hartwig, Fernando Pires; Borges, Maria Carolina; Horta, Bernardo Lessa; Bowden, Jack; Davey Smith, George

2017-12-01

Positive associations between inflammatory biomarkers and risk of psychiatric disorders, including schizophrenia, have been reported in observational studies. However, conventional observational studies are prone to bias, such as reverse causation and residual confounding, thus limiting our understanding of the effect (if any) of inflammatory biomarkers on schizophrenia risk. To evaluate whether inflammatory biomarkers have an effect on the risk of developing schizophrenia. Two-sample mendelian randomization study using genetic variants associated with inflammatory biomarkers as instrumental variables to improve inference. Summary association results from large consortia of candidate gene or genome-wide association studies, including several epidemiologic studies with different designs, were used. Gene-inflammatory biomarker associations were estimated in pooled samples ranging from 1645 to more than 80 000 individuals, while gene-schizophrenia associations were estimated in more than 30 000 cases and more than 45 000 ancestry-matched controls. In most studies included in the consortia, participants were of European ancestry, and the prevalence of men was approximately 50%. All studies were conducted in adults, with a wide age range (18 to 80 years). Genetically elevated circulating levels of C-reactive protein (CRP), interleukin-1 receptor antagonist (IL-1Ra), and soluble interleukin-6 receptor (sIL-6R). Risk of developing schizophrenia. Individuals with schizophrenia or schizoaffective disorders were included as cases. Given that many studies contributed to the analyses, different diagnostic procedures were used. The pooled odds ratio estimate using 18 CRP genetic instruments was 0.90 (random effects 95% CI, 0.84-0.97; P = .005) per 2-fold increment in CRP levels; consistent results were obtained using different mendelian randomization methods and a more conservative set of instruments. The odds ratio for sIL-6R was 1.06 (95% CI, 1.01-1.12; P = .02) per 2-fold increment. Estimates for IL-1Ra were inconsistent among instruments, and pooled estimates were imprecise and centered on the null. Under mendelian randomization assumptions, our findings suggest a protective effect of CRP and a risk-increasing effect of sIL-6R (potentially mediated at least in part by CRP) on schizophrenia risk. It is possible that such effects are a result of increased susceptibility to early life infection.

Electronic prompts significantly increase response rates to postal questionnaires: a randomized trial within a randomized trial and meta-analysis.

PubMed

Clark, Laura; Ronaldson, Sarah; Dyson, Lisa; Hewitt, Catherine; Torgerson, David; Adamson, Joy

2015-12-01

To assess the effectiveness of sending electronic prompts to randomized controlled trial participants to return study questionnaires. A "trial within a trial" embedded within a study determining the effectiveness of chronic obstructive pulmonary disease (DOC) screening on smoking cessation. Those participants taking part in DOC who provided a mobile phone number and/or an electronic mail address were randomized to either receive an electronic prompt or no electronic prompt to return a study questionnaire. The results were combined with two previous studies in a meta-analysis. A total of 437 participants were randomized: 226 to the electronic prompt group and 211 to the control group. A total of 285 (65.2%) participants returned the follow-up questionnaire: 157 (69.5%) in the electronic prompt group and 128 (60.7%) in the control group [difference 8.8%; 95% confidence interval (CI): -0.11%, 17.7%; P = 0.05]. The mean time to response was 23 days in the electronic prompt group and 33 days in the control group (hazard ratio = 1.27; 95% CI: 1.105, 1.47). The meta-analysis of all three studies showed an increase in response rate of 7.1% (95% CI: 0.8%, 13.3%). The use of electronic prompts increased response rates and reduces the time to response. Copyright © 2015 Elsevier Inc. All rights reserved.

Random walk study of electron motion in helium in crossed electromagnetic fields

NASA Technical Reports Server (NTRS)

Englert, G. W.

1972-01-01

Random walk theory, previously adapted to electron motion in the presence of an electric field, is extended to include a transverse magnetic field. In principle, the random walk approach avoids mathematical complexity and concomitant simplifying assumptions and permits determination of energy distributions and transport coefficients within the accuracy of available collisional cross section data. Application is made to a weakly ionized helium gas. Time of relaxation of electron energy distribution, determined by the random walk, is described by simple expressions based on energy exchange between the electron and an effective electric field. The restrictive effect of the magnetic field on electron motion, which increases the required number of collisions per walk to reach a terminal steady state condition, as well as the effect of the magnetic field on electron transport coefficients and mean energy can be quite adequately described by expressions involving only the Hall parameter.

The effects of Bifidobacterium animalis ssp. lactis B94 on gastrointestinal wellness in adults with Prader-Willi syndrome: study protocol for a randomized controlled trial.

PubMed

Alyousif, Zainab; Miller, Jennifer L; Sandoval, Mariana Y; MacPherson, Chad W; Nagulesapillai, Varuni; Dahl, Wendy J

2018-04-27

Constipation is a frequent problem in adults with Prader-Willi syndrome. Certain probiotics have been shown to improve transit and gastrointestinal symptoms of adults with functional constipation. The aim of this study is to determine the effect of daily consumption of Bifidobacterium animalis ssp. lactis B94 (B. lactis B94) on stool frequency, stool form, and gastrointestinal symptoms in adults with Prader-Willi syndrome. Adults with Prader-Willi syndrome (18-75 years old, n = 36) will be recruited and enrolled in a 20-week, randomized, double-blind, placebo-controlled, crossover study. Study subjects will be randomized to B. lactis B94 or placebo each for a 4-week period, preceded by a 4-week baseline and followed by 4-week washouts. Subjects will complete daily records of stool frequency and stool form (a proxy of transit time). Dietary intake data also will be collected. Stools, one in each period, will be collected for exploratory microbiota analyses. To our knowledge, this is the first randomized controlled trial evaluating the effectiveness of B. lactis in adults with Prader-Willi syndrome. The results of this study will provide evidence of efficacy for future clinical trials in patient populations with constipation. ClinicalTrials.gov ( NCT03277157 ). Registered on 08 September 2017.

Professional opinion concerning the effectiveness of bracing relative to observation in adolescent idiopathic scoliosis.

PubMed

Dolan, Lori A; Donnelly, Melanie J; Spratt, Kevin F; Weinstein, Stuart L

2007-01-01

To determine if community equipoise exists concerning the effectiveness of bracing in adolescent idiopathic scoliosis. Bracing is the standard of care for adolescent idiopathic scoliosis despite the lack of strong reasearch evidence concerning its effectiveness. Thus, some researchers support the idea of a randomized trial, whereas others think that randomization in the face of a standard of care would be unethical. A random of Scoliosis Research Society and Pediatric Orthopaedic Society of North America members were asked to consider 12 clinical profiles and to give their opinion concerning the radiographic outcomes after observation and bracing. An expert panel was created from the respondents. They expressed a wide array of opinions concerning the percentage of patients within each scenario who would benefit from bracing. Agreement was noted concerning the risk due to bracing for post-menarchal patients only. : This study found a high degree of variability in opinion among clinicians concerning the effectiveness of bracing, suggesting that a randomized trial of bracing would be ethical.

Effectiveness of the clinical teaching associate model to improve clinical learning outcomes: a randomized controlled trial.

PubMed

Parchebafieh, Samaneh; Gholizadeh, Leila; Lakdizaji, Sima; Ghiasvandiyan, Shahrzad; Davoodi, Arefeh

2014-01-01

This study examined the effectiveness of the clinical teaching associate (CTA) model to improve clinical learning outcomes in nursing students. Students were randomly allocated to either the CTA (n = 28) or traditional training group (n = 32), and their clinical knowledge, skills, and satisfaction with the learning experience were assessed and compared. The results showed that the CTA model was equally effective in improving clinical knowledge, skills, and satisfaction of nursing students.

Packet Randomized Experiments for Eliminating Classes of Confounders

PubMed Central

Pavela, Greg; Wiener, Howard; Fontaine, Kevin R.; Fields, David A.; Voss, Jameson D.; Allison, David B.

2014-01-01

Background Although randomization is considered essential for causal inference, it is often not possible to randomize in nutrition and obesity research. To address this, we develop a framework for an experimental design—packet randomized experiments (PREs), which improves causal inferences when randomization on a single treatment variable is not possible. This situation arises when subjects are randomly assigned to a condition (such as a new roommate) which varies in one characteristic of interest (such as weight), but also varies across many others. There has been no general discussion of this experimental design, including its strengths, limitations, and statistical properties. As such, researchers are left to develop and apply PREs on an ad hoc basis, limiting its potential to improve causal inferences among nutrition and obesity researchers. Methods We introduce PREs as an intermediary design between randomized controlled trials and observational studies. We review previous research that used the PRE design and describe its application in obesity-related research, including random roommate assignments, heterochronic parabiosis, and the quasi-random assignment of subjects to geographic areas. We then provide a statistical framework to control for potential packet-level confounders not accounted for by randomization. Results PREs have successfully been used to improve causal estimates of the effect of roommates, altitude, and breastfeeding on weight outcomes. When certain assumptions are met, PREs can asymptotically control for packet-level characteristics. This has the potential to statistically estimate the effect of a single treatment even when randomization to a single treatment did not occur. Conclusions Applying PREs to obesity-related research will improve decisions about clinical, public health, and policy actions insofar as it offers researchers new insight into cause and effect relationships among variables. PMID:25444088

Neurorehabilitation in Parkinson's Disease: A Critical Review of Cognitive Rehabilitation Effects on Cognition and Brain.

PubMed

Díez-Cirarda, María; Ibarretxe-Bilbao, Naroa; Peña, Javier; Ojeda, Natalia

2018-01-01

Parkinson's disease (PD) patients experience cognitive impairment which has been related to reduced quality of life and functional disability. These symptoms usually progress until dementia occurs. Some studies have been published assessing the efficacy of cognitive treatments on improving cognition, functional outcome, and producing changes in brain activity. A critical review was performed to present up-to-date neurorehabilitation effects of cognitive rehabilitation in PD, with special emphasis on the efficacy on cognition, quality of life aspects, brain changes, and the longitudinal maintenance of these changes. After exclusions, 13 studies were reviewed, including 6 randomized controlled trials for the efficacy on cognition, 2 randomized controlled trials regarding the brain changes after cognitive training, and 5 studies which evaluated the long-term effects of cognitive treatments. Cognitive rehabilitation programs have demonstrated to be effective on improving cognitive functions, but more research is needed focusing on the efficacy on improving behavioral aspects and producing brain changes in patients with PD. Moreover, there is a need of randomized controlled trials with long-term follow-up periods.

Iterative Usage of Fixed and Random Effect Models for Powerful and Efficient Genome-Wide Association Studies

PubMed Central

Liu, Xiaolei; Huang, Meng; Fan, Bin; Buckler, Edward S.; Zhang, Zhiwu

2016-01-01

False positives in a Genome-Wide Association Study (GWAS) can be effectively controlled by a fixed effect and random effect Mixed Linear Model (MLM) that incorporates population structure and kinship among individuals to adjust association tests on markers; however, the adjustment also compromises true positives. The modified MLM method, Multiple Loci Linear Mixed Model (MLMM), incorporates multiple markers simultaneously as covariates in a stepwise MLM to partially remove the confounding between testing markers and kinship. To completely eliminate the confounding, we divided MLMM into two parts: Fixed Effect Model (FEM) and a Random Effect Model (REM) and use them iteratively. FEM contains testing markers, one at a time, and multiple associated markers as covariates to control false positives. To avoid model over-fitting problem in FEM, the associated markers are estimated in REM by using them to define kinship. The P values of testing markers and the associated markers are unified at each iteration. We named the new method as Fixed and random model Circulating Probability Unification (FarmCPU). Both real and simulated data analyses demonstrated that FarmCPU improves statistical power compared to current methods. Additional benefits include an efficient computing time that is linear to both number of individuals and number of markers. Now, a dataset with half million individuals and half million markers can be analyzed within three days. PMID:26828793

Peer Influence, Genetic Propensity, and Binge Drinking: A Natural Experiment and a Replication.

PubMed

Guo, Guang; Li, Yi; Wang, Hongyu; Cai, Tianji; Duncan, Greg J

2015-11-01

The authors draw data from the College Roommate Study (ROOM) and the National Longitudinal Study of Adolescent Health to investigate gene-environment interaction effects on youth binge drinking. In ROOM, the environmental influence was measured by the precollege drinking behavior of randomly assigned roommates. Random assignment safeguards against friend selection and removes the threat of gene-environment correlation that makes gene-environment interaction effects difficult to interpret. On average, being randomly assigned a drinking peer as opposed to a nondrinking peer increased college binge drinking by 0.5-1.0 episodes per month, or 20%-40% the average amount of binge drinking. However, this peer influence was found only among youths with a medium level of genetic propensity for alcohol use; those with either a low or high genetic propensity were not influenced by peer drinking. A replication of the findings is provided in data drawn from Add Health. The study shows that gene-environment interaction analysis can uncover social-contextual effects likely to be missed by traditional sociological approaches.

Effect of berberine on insulin resistance in women with polycystic ovary syndrome: study protocol for a randomized multicenter controlled trial.

PubMed

Li, Yan; Ma, Hongli; Zhang, Yuehui; Kuang, Hongying; Ng, Ernest Hung Yu; Hou, Lihui; Wu, Xiaoke

2013-07-18

Insulin resistance and hyperinsulinemia play a key role in the pathogenesis of polycystic ovary syndrome (PCOS), which is characterized by hyperandrogenism, ovulatory dysfunction, and presence of polycystic ovaries on pelvic scanning. Insulin resistance is significantly associated with the long-term risks of metabolic syndrome and cardiovascular disease. Berberine has effects on insulin resistance but its use in women with PCOS has not been fully investigated. In this paper, we present a research design evaluating the effects of berberine on insulin resistance in women with PCOS. This is a multicenter, randomized, placebo-controlled and double-blind trial. A total of 120 patients will be enrolled in this study and will be randomized into two groups. Berberine or placebo will be taken orally for 12 weeks. The primary outcome is the whole body insulin action assessed with the hyperinsulinemic-euglycemic clamp. We postulate that women with PCOS will have improved insulin resistance following berberine administration. This study is registered at ClinicalTrials.gov, NCT01138930.

Effects of exercises on Bell's palsy: systematic review of randomized controlled trials.

PubMed

Cardoso, Jefferson Rosa; Teixeira, Elsie Cobra; Moreira, Michelle Damasceno; Fávero, Francis Meire; Fontes, Sissy Veloso; Bulle de Oliveira, Acary Souza

2008-06-01

This study examined the effects of facial exercises associated either with mirror or electromyogram (EMG) biofeedback with respect to complications of delayed recovery in Bell's palsy. Patients with unilateral idiopathic facial palsy were included in this review. Facial exercises associated with mirror and/or EMG biofeedback as treatment. Report of facial symmetry, synkinesis, lip mobility, and physical and social aspects. Four studies of 132 met the eligibility criteria. The studies described mime therapy versus control (n = 50), mirror biofeedback exercise versus control (n = 27), "small" mirror movements versus conventional neuromuscular retraining (n = 10), and EMG biofeedback + mirror training versus mirror training alone. The treatment length varied from 1 to 12 months. Because of the small number of randomized controlled trials, it was not possible to analyze if the exercises, associated either with mirror or EMG biofeedback, were effective. In summary, the available evidence from randomized controlled trials is not yet strong enough to become integrated into clinical practice.

Group versus individual family planning counseling in Ghana: a randomized, noninferiority trial.

PubMed

Schwandt, Hilary M; Creanga, Andreea A; Danso, Kwabena A; Adanu, Richard M K; Agbenyega, Tsiri; Hindin, Michelle J

2013-08-01

Group, rather than individual, family planning counseling has the potential to increase family planning knowledge and use through more efficient use of limited human resources. A randomized, noninferiority study design was utilized to identify whether group family planning counseling is as effective as individual family planning counseling in Ghana. Female gynecology patients were enrolled from two teaching hospitals in Ghana in June and July 2008. Patients were randomized to receive either group or individual family planning counseling. The primary outcome in this study was change in modern contraceptive method knowledge. Changes in family planning use intention before and after the intervention and intended method type were also explored. Comparisons between the two study arms suggest that randomization was successful. The difference in change in modern contraceptive methods known from baseline to follow-up between the two study arms (group-individual), adjusted for study site, was -0.21, (95% confidence interval: -0.53 to 0.12) suggesting no difference between the two arms. Group family planning counseling was as effective as individual family planning counseling in increasing modern contraceptive knowledge among female gynecology patients in Ghana. Copyright © 2013 Elsevier Inc. All rights reserved.

Effectiveness of anisodamine for the treatment of critically ill patients with septic shock (ACIdoSIS study): study protocol for randomized controlled trial

PubMed Central

Zhou, Jiancang; Shang, You; Wang, Xin’an; Yin, Rui; Zhu, Zhenhua; Chen, Wensen; Tian, Xin; Yu, Yuetian; Zuo, Xiangrong; Chen, Kun; Ji, Xuqing; Ni, Hongying

2015-01-01

Background Septic shock is an important contributor of mortality in the intensive care unit (ICU). Although strenuous effort has been made to improve its outcome, the mortality rate is only marginally decreased. The present study aimed to investigate the effectiveness of anisodamine in the treatment of septic shock, in the hope that the drug will provide alternatives to the treatment of septic shock. Methods The study is a multi-center randomized controlled clinical trial. Study population will include critically ill patients with septic shock requiring vasopressor use. Blocked randomization was performed where anisodamine and control treatments were allocated at random in a ratio of 1:1 in blocks of sizes 2, 4, 6, 8, and 10 to 354 subjects. Interim analysis will be performed. The primary study end point is the hospital mortality, and other secondary study endpoints include ICU mortality, length of stay in ICU and hospital, organ failure free days. Adverse events including new onset psychosis, urinary retention, significant hypotension and tachycardia will be reported. Discussion The study will provide new insight into the treatment of septic shock and can help to reduce mortality rate of septic shock. Trial registration NCT02442440 (https://register.clinicaltrials.gov/). PMID:26605292

Acupuncture treatment for insulin sensitivity of women with polycystic ovary syndrome and insulin resistance: a study protocol for a randomized controlled trial.

PubMed

Li, Juan; Ng, Ernest Hung Yu; Stener-Victorin, Elisabet; Hu, Zhenxing; Shao, Xiaoguang; Wang, Haiyan; Li, Meifang; Lai, Maohua; Xie, Changcai; Su, Nianjun; Yu, Chuyi; Liu, Jia; Wu, Taixiang; Ma, Hongxia

2017-03-09

Our prospective pilot study of acupuncture affecting insulin sensitivity on polycystic ovary syndrome (PCOS) combined with insulin resistance (IR) showed that acupuncture had a significant effect on improving the insulin sensitivity of PCOS. But there is still no randomized controlled trial to determine the effect of acupuncture on the insulin sensitivity in women with PCOS and IR. In this article, we present the protocol of a randomized controlled trial to compare the effect of true acupuncture on the insulin sensitivity of these patients compared with metformin and sham acupuncture. Acupuncture may be an effective therapeutic alternative that is superior to metformin and sham acupuncture in improving the insulin sensitivity of PCOS combined with IR. This study is a multi-center, controlled, double-blind, and randomized clinical trial aiming to evaluate the effect of acupuncture on the insulin sensitivity in PCOS combined with IR. In total 342 patients diagnosed with PCOS and IR will be enrolled. Participants will be randomized to one of the three groups: (1) true acupuncture + metformin placebo; (2) sham acupuncture + metformin, and (3) sham acupuncture + metformin placebo. Participants and assessors will be blinded. The acupuncture intervention will be given 3 days per week for a total of 48 treatment sessions during 4 months. Metformin (0.5 g per pill) or placebo will be given, three times per day, and for 4 months. Primary outcome measures are changes in homeostasis model assessment of insulin resistance (HOMA-IR) and improvement rate of HOMA-IR by oral glucose tolerance test (OGTT) and insulin releasing test (Ins). Secondary outcome measures are homeostasis model assessment-β (HOMA-β), area under the curve for glucose and insulin, frequency of regular menstrual cycles and ovulation, body composition, metabolic profile, hormonal profile, questionnaires, side effect profile, and expectation and credibility of treatment. Outcome measures are collected at baseline, at the end of treatments, and 3 months after the last acupuncture treatment. On completion of the screening visit, randomization will be conducted using a central randomization system. This study will investigate the effects of acupuncture on the insulin sensitivity of PCOS and IR women compared with metformin and sham acupuncture. We will test whether true acupuncture with needles placed in skeletal muscles and stimulated manually and by electrical stimulation is more effective than metformin and sham acupuncture with superficial needle placement with no manual or electrical stimulation in improving the insulin sensitivity in PCOS women with IR. ClinicalTrials.gov, NCT02491333 ; Chinese Clinical Trial Registry, ChiCTR-ICR-15006639. Registered on 24 June 2015.

Clinical effectiveness, quality of life and cost-effectiveness of Flaminal® versus Flamazine® in the treatment of partial thickness burns: study protocol for a randomized controlled trial.

PubMed

Rashaan, Zjir M; Krijnen, Pieta; van den Akker-van Marle, M Elske; van Baar, Margriet E; Vloemans, Adrianus F P; Dokter, Jan; Tempelman, Fenike R H; van der Vlies, Cees H; Breederveld, Roelf S

2016-03-05

Partial thickness burns are painful, difficult to manage and can have a negative effect on quality of life through scarring, permanent disfigurement and loss of function. The aim of burn treatment in partial thickness burns is to save lives, stimulate wound healing by creating an optimumly moist wound environment, to have debriding and analgesic effects, protect the wound from infection and be convenient for the patient and caregivers. However, there is no consensus on the optimal treatment of partial thickness wounds. Flaminal® and Flamazine® are two standard treatment options that provide the above mentioned properties in burn treatment. Nevertheless, no randomized controlled study has yet compared these two common treatment modalities in partial thickness burns. Thus, the aim of this study is to evaluate the clinical effectiveness, quality of life and cost-effectiveness of Flaminal® versus Flamazine® in the treatment of partial thickness burns. In this two-arm open multi-center randomized controlled trial, 90 patients will be randomized between Flaminal® and Flamazine® and followed for 12 months. The study population will consist of competent or temporarily non-competent (because of sedation and/or intubation) patients, 18 years of age or older, with acute partial thickness burns and a total body surface area (TBSA) of less than 30 %. The main study outcome is time to complete re-epithelialization (greater than 95 %). Secondary outcome measures include need for grafting, wound colonization/infection, number of dressing changes, pain and anxiety, scar formation, health-related quality of life (HRQoL), and costs. This study will contribute to the optimal treatment of patients with partial thickness burn wounds and will provide evidence on the (cost-)effectiveness and quality of life of Flaminal® versus Flamazine® in the treatment of partial thickness burns. Netherlands Trial Register NTR4486 , registered on 2 April 2014.

Limited Effects of a 2-Year School-Based Physical Activity Intervention on Body Composition and Cardiorespiratory Fitness in 7-Year-Old Children

ERIC Educational Resources Information Center

Magnusson, Kristjan Thor; Hrafnkelsson, Hannes; Sigurgeirsson, Ingvar; Johannsson, Erlingur; Sveinsson, Thorarinn

2012-01-01

The aim of this study was to assess the effects of a 2-year cluster-randomized physical activity and dietary intervention program among 7-year-old (at baseline) elementary school participants on body composition and objectively measured cardiorespiratory fitness. Three pairs of schools were selected and matched, then randomly selected as either an…

The Relative Effects and Equity of Inquiry-Based and Commonplace Science Teaching on Students' Knowledge, Reasoning, and Argumentation

ERIC Educational Resources Information Center

Wilson, Christopher D.; Taylor, Joseph A.; Kowalski, Susan M.; Carlson, Janet

2010-01-01

We conducted a laboratory-based randomized control study to examine the effectiveness of inquiry-based instruction. We also disaggregated the data by student demographic variables to examine if inquiry can provide equitable opportunities to learn. Fifty-eight students aged 14-16 years old were randomly assigned to one of two groups. Both groups of…

Effects of a Randomized Couple-Based Intervention on Quality of Life of Breast Cancer Patients and Their Partners

ERIC Educational Resources Information Center

Kayser, Karen; Feldman, Barry N.; Borstelmann, Nancy A.; Daniels, Ann A.

2010-01-01

The purpose of this study was to determine the effectiveness of a couple-based intervention on the quality of life (QOL) of early-stage breast cancer patients and their partners. A randomized controlled design was used to assign couples to either the hospital standard social work services (SSWS) or a couple-based intervention, the Partners in…

Effects of a Web-Based Decision Aid Regarding Diagnostic Self-Testing. A Single-Blind Randomized Controlled Trial

ERIC Educational Resources Information Center

Ickenroth, Martine H. P.; Grispen, J. E. J.; de Vries, N. K.; Dinant, G. J.; Ronda, G.; van der Weijden, T.

2016-01-01

Currently, there are many diagnostic self-tests on body materials available to consumers. The aim of this study was to assess the effect of an online decision aid on diagnostic self-testing for cholesterol and diabetes on knowledge among consumers with an intention to take these tests. A randomized controlled trial was designed. A total of 1259…

Cluster-Randomized Controlled Trial Evaluating the Effectiveness of Computer-Assisted Intervention Delivered by Educators for Children with Speech Sound Disorders

ERIC Educational Resources Information Center

McLeod, Sharynne; Baker, Elise; McCormack, Jane; Wren, Yvonne; Roulstone, Sue; Crowe, Kathryn; Masso, Sarah; White, Paul; Howland, Charlotte

2017-01-01

Purpose: The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD). Method: The Sound Start Study was a cluster-randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 parents and educators of 4- and…

School-Based Prevention of Depressive Symptoms: A Randomized Controlled Study of the Effectiveness and Specificity of the Penn Resiliency Program

ERIC Educational Resources Information Center

Gillham, Jane E.; Reivich, Karen J.; Freres, Derek R.; Chaplin, Tara M.; Shatte, Andrew J.; Samuels, Barbra; Elkon, Andrea G. L.; Litzinger, Samantha; Lascher, Marisa; Gallop, Robert; Seligman, Martin E. P.

2007-01-01

The authors investigated the effectiveness and specificity of the Penn Resiliency Program (PRP; J. E. Gillham, L. H. Jaycox, K. J. Reivich, M. E. P. Seligman, & T. Silver, 1990), a cognitive-behavioral depression prevention program. Children (N = 697) from 3 middle schools were randomly assigned to PRP, Control (CON), or the Penn Enhancement …

Effects of a Cognitive Behavioral Self-Help Program on Emotional Problems for People with Acquired Hearing Loss: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Garnefski, Nadia; Kraaij, Vivian

2012-01-01

The aim of the study was to examine whether a cognitive-behavioral self-help program was effective in improving depressed mood and anxiety in people with acquired deafness. Participants were 45 persons with acquired deafness, randomly allocated to the Cognitive-Behavioral Self-help (CBS) group or the Waiting List Control (WLC) group. Depression…

The Effectiveness of a Group Triple P with Chinese Parents Who Have a Child with Developmental Disabilities: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Leung, Cynthia; Fan, Angel; Sanders, Matthew R.

2013-01-01

The study examined the effectiveness of Group Triple P, a Level 4 variant of the Triple P multilevel system of parenting support, with Chinese parents who had a preschool aged child with a developmental disability, using randomized controlled trial design. Participants (Intervention group: 42; Waitlist Control group: 39) completed measures on…

The Effects of a STEM Professional Development Intervention on Elementary Teachers' Science Process Skills

ERIC Educational Resources Information Center

Cotabish, Alicia; Dailey, Deborah; Hughes, Gail D.; Robinson, Ann

2011-01-01

In order to increase the quality and quantity of science instruction, elementary teachers must receive professional development in science learning processes. The current study was part of a larger randomized field study of teacher and student learning in science. In two districts in a southern state, researchers randomly assigned teacher…

Social Skills Training for Young Adults with High-Functioning Autism Spectrum Disorders: A Randomized Controlled Pilot Study

ERIC Educational Resources Information Center

Gantman, Alexander; Kapp, Steven K.; Orenski, Kaely; Laugeson, Elizabeth A.

2012-01-01

Despite the psychosocial difficulties common among young adults with autism spectrum disorders (ASD), little to no evidence-based social skills interventions exist for this population. Using a randomized controlled trial (RCT) design, the current study tested the effectiveness of an evidence-based, caregiver-assisted social skills intervention…

Working Memory Training in Young Children with ADHD: A Randomized Placebo-Controlled Trial

ERIC Educational Resources Information Center

Dongen-Boomsma, Martine; Vollebregt, Madelon A.; Buitelaar, Jan K.; Slaats-Willemse, Dorine

2014-01-01

Background: Until now, working memory training has not reached sufficient evidence as effective treatment for ADHD core symptoms in children with ADHD; for young children with ADHD, no studies are available. To this end, a triple-blind, randomized, placebo-controlled study was designed to assess the efficacy of Cogmed Working Memory Training…

A Randomized Control Study of Responsive Teaching with Young Turkish Children and Their Mothers

ERIC Educational Resources Information Center

Karaaslan, Ozcan; Diken, Ibrahim H.; Mahoney, Gerald

2013-01-01

A randomized control study was conducted to evaluate the effectiveness of responsive teaching (RT) with a sample of 19 Turkish preschool-age children with disabilities and their mothers over a 6-months period. RT is an early intervention curriculum that attempts to promote children's development by encouraging parents to engage in highly…

Building Kindergartners' Number Sense: A Randomized Controlled Study

ERIC Educational Resources Information Center

Jordan, Nancy C.; Glutting, Joseph; Dyson, Nancy; Hassinger-Das, Brenna; Irwin, Casey

2012-01-01

Math achievement in elementary school is mediated by performance and growth in number sense during kindergarten. The aim of the present study was to test the effectiveness of a targeted small-group number sense intervention for high-risk kindergartners from low-income communities. Children were randomly assigned to 1 of 3 groups (n = 44 in each…

A Randomized Controlled Study Evaluating a Brief, Bystander Bullying Intervention with Junior High School Students

ERIC Educational Resources Information Center

Midgett, Aida; Doumas, Diana; Trull, Rhiannon; Johnston, April D.

2017-01-01

A randomized controlled study evaluated a brief, bystander bullying intervention for junior high school students. Students in both groups reported an increase in knowledge and confidence to act as defenders and to utilize strategies to intervene on behalf of victims of bullying. Findings suggest possible carry-over effects from the intervention…

Random matrix approach to plasmon resonances in the random impedance network model of disordered nanocomposites

NASA Astrophysics Data System (ADS)

Olekhno, N. A.; Beltukov, Y. M.

2018-05-01

Random impedance networks are widely used as a model to describe plasmon resonances in disordered metal-dielectric and other two-component nanocomposites. In the present work, the spectral properties of resonances in random networks are studied within the framework of the random matrix theory. We have shown that the appropriate ensemble of random matrices for the considered problem is the Jacobi ensemble (the MANOVA ensemble). The obtained analytical expressions for the density of states in such resonant networks show a good agreement with the results of numerical simulations in a wide range of metal filling fractions 0

Analyzing crash frequency in freeway tunnels: A correlated random parameters approach.

PubMed

Hou, Qinzhong; Tarko, Andrew P; Meng, Xianghai

2018-02-01

The majority of past road safety studies focused on open road segments while only a few focused on tunnels. Moreover, the past tunnel studies produced some inconsistent results about the safety effects of the traffic patterns, the tunnel design, and the pavement conditions. The effects of these conditions therefore remain unknown, especially for freeway tunnels in China. The study presented in this paper investigated the safety effects of these various factors utilizing a four-year period (2009-2012) of data as well as three models: 1) a random effects negative binomial model (RENB), 2) an uncorrelated random parameters negative binomial model (URPNB), and 3) a correlated random parameters negative binomial model (CRPNB). Of these three, the results showed that the CRPNB model provided better goodness-of-fit and offered more insights into the factors that contribute to tunnel safety. The CRPNB was not only able to allocate the part of the otherwise unobserved heterogeneity to the individual model parameters but also was able to estimate the cross-correlations between these parameters. Furthermore, the study results showed that traffic volume, tunnel length, proportion of heavy trucks, curvature, and pavement rutting were associated with higher frequencies of traffic crashes, while the distance to the tunnel wall, distance to the adjacent tunnel, distress ratio, International Roughness Index (IRI), and friction coefficient were associated with lower crash frequencies. In addition, the effects of the heterogeneity of the proportion of heavy trucks, the curvature, the rutting depth, and the friction coefficient were identified and their inter-correlations were analyzed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Peer-Led Team Learning (PLTL) on Student Achievement, Attitude, and Self-Concept in College General Chemistry in Randomized and Quasi Experimental Designs

ERIC Educational Resources Information Center

Chan, Julia Y. K.; Bauer, Christopher F.

2015-01-01

This study investigated exam achievement and affective characteristics of students in general chemistry in a fully-randomized experimental design, contrasting Peer-Led Team Learning (PLTL) participation with a control group balanced for time-on-task and study activity. This study population included two independent first-semester courses with…

Does Increased Exercise or Physical Activity Alter Ad-Libitum Daily Energy Intake or Macronutrient Composition in Healthy Adults? A Systematic Review

PubMed Central

Donnelly, Joseph E.; Herrmann, Stephen D.; Lambourne, Kate; Szabo, Amanda N.; Honas, Jeffery J.; Washburn, Richard A.

2014-01-01

Background The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. Objective To address the question: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? Data Sources PubMed and Embase were searched (January 1990–January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Study Eligibility Criteria Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18–64 years). Study Appraisal and Synthesis Methods Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. Results No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. Limitations The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. Conclusions We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake. PMID:24454704

A randomized and placebo-controlled study to compare the skin-lightening efficacy and safety of lignin peroxidase cream vs. 2% hydroquinone cream.

PubMed

Mauricio, Tess; Karmon, Yoram; Khaiat, Alain

2011-12-01

  Historically, the most effective treatments for skin lightening have contained hydroquinone. However, there is a need for an effective alternative.   The purpose of this study was to evaluate the skin-lightening efficacy and safety of lignin peroxidase (LIP) creams using a regimen of both day and night products compared with twice-daily application of 2% hydroquinone cream and placebo in Asian women.   This was a randomized, double-blind, placebo-controlled, split-face, single-center study of 51 patients. Patients were randomized to receive day and night LIP cream on one randomly selected side of their face and either 2% hydroquinone cream or placebo on the other.   A statistically significant change from baseline in the melanin index was observed in LIP-treated skin, with a mean reduction of 7.6% (P < 0.001) on Day 31. Conversely, hydroquinone and placebo did not provide a statistically significant lightening effect when instrumentally measured. Dermatologist scoring demonstrated a significant improvement in overall fairness as early as 8 days after treatment initiation in the LIP-treated group, which was not observed in the other groups. Overall, patients preferred the LIP creams.   The application of day/night LIP cream provided a significantly more rapid and observable skin-lightening effect than hydroquinone 2% cream or placebo. © 2011 Wiley Periodicals, Inc.

Interventions for reducing fear of childbirth: A systematic review and meta-analysis of clinical trials.

PubMed

MoghaddamHosseini, Vahideh; Nazarzadeh, Milad; Jahanfar, Shayesteh

2017-11-07

Fear of childbirth is a problematic mental health issue during pregnancy. But, effective interventions to reduce this problem are not well understood. To examine effective interventions for reducing fear of childbirth. The Cochrane Central Register of Controlled Trials, PubMed, Embase and PsycINFO were searched since inception till September 2017 without any restriction. Randomised controlled trials and quasi-randomised controlled trials comparing interventions for treatment of fear of childbirth were included. The standardized mean differences were pooled using random and fixed effect models. The heterogeneity was determined using the Cochran's test and I 2 index and was further explored in meta-regression model and subgroup analyses. Ten studies inclusive of 3984 participants were included in the meta-analysis (2 quasi-randomized and 8 randomized clinical trials). Eight studies investigated education and two studies investigated hypnosis-based intervention. The pooled standardized mean differences of fear for the education intervention and hypnosis group in comparison with control group were -0.46 (95% CI -0.73 to -0.19) and -0.22 (95% CI -0.34 to -0.10), respectively. Both types of interventions were effective in reducing fear of childbirth; however our pooled results revealed that educational interventions may reduce fear with double the effect of hypnosis. Further large scale randomized clinical trials and individual patient data meta-analysis are warranted for assessing the association. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

A randomized controlled pilot study of the effectiveness of occupational therapy for children with sensory modulation disorder.

PubMed

Miller, Lucy Jane; Coll, Joseph R; Schoen, Sarah A

2007-01-01

A pilot randomized controlled trial (RCT) of the effectiveness of occupational therapy using a sensory integration approach (OT-SI) was conducted with children who had sensory modulation disorders (SMDs). This study evaluated the effectiveness of three treatment groups. In addition, sample size estimates for a large scale, multisite RCT were calculated. Twenty-four children with SMD were randomly assigned to one of three treatment conditions; OT-SI, Activity Protocol, and No Treatment. Pretest and posttest measures of behavior, sensory and adaptive functioning, and physiology were administered. The OT-SI group, compared to the other two groups, made significant gains on goal attainment scaling and on the Attention subtest and the Cognitive/Social composite of the Leiter International Performance Scale-Revised. Compared to the control groups, OT-SI improvement trends on the Short Sensory Profile, Child Behavior Checklist, and electrodermal reactivity were in the hypothesized direction. Findings suggest that OT-SI may be effective in ameliorating difficulties of children with SMD.

Effects of combination oral care on oral health, dry mouth and salivary pH of intubated patients: A randomized controlled trial.

PubMed

Jang, Chun Sun; Shin, Yong Soon

2016-10-01

Intubated patients are at risk of oral health problems. Although a variety of oral care regimens for intubated patients have been studied, there is a lack of research on the effects of combination oral care that includes tooth brushing, chlorhexidine and cold water. This open-labelled, randomized, controlled trial aimed to evaluate the effects of combination oral care on oral health status. Participants aged 20 years and older were recruited on the first day after intubation through convenience sampling in a medical intensive care unit. Random assignment was performed using an internet randomization service. The primary outcome was oral health status. Data were collected during May and June 2013. Participants were randomized to one of two groups (23 intervention and 21 control). The final analysis included 18 patients with combination oral care and 17 in the control group. The intervention group had better oral health (effect size = 1.56), less dry mouth and higher salivary pH than the control group. Any additional burden of providing combination oral care to patients who are mechanically ventilated is worthwhile in terms of clinical outcomes. © 2016 John Wiley & Sons Australia, Ltd.

Analyzing social experiments as implemented: A reexamination of the evidence from the HighScope Perry Preschool Program

PubMed Central

Heckman, James; Moon, Seong Hyeok; Pinto, Rodrigo; Savelyev, Peter; Yavitz, Adam

2012-01-01

Social experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. “Significant” effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study. PMID:23255883

Breathing exercises in upper abdominal surgery: a systematic review and meta-analysis.

PubMed

Grams, Samantha T; Ono, Lariane M; Noronha, Marcos A; Schivinski, Camila I S; Paulin, Elaine

2012-01-01

There is currently no consensus on the indication and benefits of breathing exercises for the prevention of postoperative pulmonary complications PPCs and for the recovery of pulmonary mechanics. To undertake a systematic review of randomized and quasi-randomized studies that assessed the effects of breathing exercises on the recovery of pulmonary function and prevention of PCCs after upper abdominal surgery UAS. We searched the Physiotherapy Evidence Database PEDro, Scientific Electronic Library Online SciELO, MEDLINE, and Cochrane Central Register of Controlled Trials. We included randomized controlled trials and quasi-randomized controlled trials on pre- and postoperative UAS patients, in which the primary intervention was breathing exercises without the use of incentive inspirometers. The methodological quality of the studies was rated according to the PEDro scale. Data on maximal respiratory pressures MIP and MEP, spirometry, diaphragm mobility, and postoperative complications were extracted and analyzed. Data were pooled in fixed-effect meta-analysis whenever possible. Six studies were used for analysis. Two meta-analyses including 66 participants each showed that, on the first day post-operative, the breathing exercises were likely to have induced MEP and MIP improvement treatment effects of 11.44 mmH2O (95%CI 0.88 to 22) and 11.78 mmH2O (95%CI 2.47 to 21.09), respectively. Breathing exercises are likely to have a beneficial effect on respiratory muscle strength in patients submitted to UAS, however the lack of good quality studies hinders a clear conclusion on the subject.

Melatonin for Atypical Antipsychotic-Induced Metabolic Adverse Effects: A Meta-Analysis of Randomized Controlled Trials.

PubMed

Kamath, Ashwin; Rather, Zahoor Ahmad

2018-01-01

The objective of our study was to determine the effect of melatonin administration on atypical antipsychotic-induced metabolic adverse effects in patients with psychiatric disorders. A systematic search was performed in PUBMED, Cochrane Library, Scopus, Web of Science, and EBSCOhost electronic databases. Randomized controlled trials studying the effect of melatonin on antipsychotic-induced metabolic adverse effects were identified and subjected to meta-analysis. Four studies were included in the meta-analysis, including 57 patients on melatonin and 61 patients on placebo. Melatonin produced a significant decrease in the diastolic blood pressure compared with placebo (mean difference = -4.44 [95% CI, -7.00 to -1.88]; p = 0.0007; I 2 = 13%), but not the systolic blood pressure (mean difference = -4.23 [95% CI, -8.11 to -0.36]; p = 0.03; I 2 = 0%). Although a decrease in the body mass index was seen in the melatonin group, the difference was not significant in the random-effects analysis model. To conclude, in patients on atypical antipsychotics, melatonin at a dose of up to 5 mg/day for a treatment duration of up to 12 weeks attenuated the rise in diastolic blood pressure compared with placebo but had no significant effects on other metabolic parameters.

Photodynamic Therapy for Actinic Keratoses: A Randomized Prospective Non-sponsored Cost-effectiveness Study of Daylight-mediated Treatment Compared with Light-emitting Diode Treatment.

PubMed

Neittaanmäki-Perttu, Noora; Grönroos, Mari; Karppinen, Toni; Snellman, Erna; Rissanen, Pekka

2016-02-01

Daylight-mediated photodynamic therapy (DL-PDT) is considered as effective as conventional PDT using artificial light (light-emitting diode (LED)-PDT) for treatment of actinic keratoses (AK). This randomized prospective non-sponsored study assessed the cost-effectiveness of DL-PDT compared with LED-PDT. Seventy patients with 210 AKs were randomized to DL-PDT or LED-PDT groups. Effectiveness was assessed at 6 months. The costs included societal costs and private costs, including the time patients spent in treatment. Results are presented as incremental cost-effectiveness ratio (ICER). The total costs per patient were significantly lower for DL-PDT (€132) compared with LED-PDT (€170), giving a cost saving of €38 (p = 0.022). The estimated probabilities for patients' complete response were 0.429 for DL-PDT and 0.686 for LED-PDT; a difference in probability of being healed of 0.257. ICER showed a monetary gain of €147 per unit of effectiveness lost. DL-PDT is less costly and less effective than LED-PDT. In terms of cost-effectiveness analysis, DL-PDT provides lower value for money compared with LED-PDT.

Timing and Characteristics of Cumulative Evidence Available on Novel Therapeutic Agents Receiving Food and Drug Administration Accelerated Approval.

PubMed

Naci, Huseyin; Wouters, Olivier J; Gupta, Radhika; Ioannidis, John P A

2017-06-01

Policy Points: Randomized trials-the gold standard of evaluating effectiveness-constitute a small minority of existing evidence on agents given accelerated approval. One-third of randomized trials are in therapeutic areas outside of FDA approval and less than half evaluate the therapeutic benefits of these agents but use them instead as common backbone treatments. Agents receiving accelerated approval are often tested concurrently in several therapeutic areas. For most agents, no substantial time lag is apparent between the average start dates of randomized trials evaluating their effectiveness and those using them as part of background therapies. There appears to be a tendency for therapeutic agents receiving accelerated approval to quickly become an integral component of standard treatment, despite potential shortcomings in their evidence base. Therapeutic agents treating serious conditions are eligible for Food and Drug Administration (FDA) accelerated approval. The clinical evidence accrued on agents receiving accelerated approval has not been systematically evaluated. Our objective was to assess the timing and characteristics of available studies. We first identified clinical studies of novel therapeutic agents receiving accelerated approval. We then (1) categorized those studies as randomized or nonrandomized, (2) explored whether they evaluated the FDA-approved indications, and (3) documented the available treatment comparisons. We also meta-analyzed the difference in start times between randomized studies that (1) did or did not evaluate approved indications and (2) were or were not designed to evaluate the agent's effectiveness. In total, 37 novel therapeutic agents received accelerated approval between 2000 and 2013. Our search of ClinicalTrials.gov identified 7,757 studies, which included 1,258,315 participants. Only one-third of identified studies were randomized controlled trials. Of 1,631 randomized trials with advanced recruitment status, 906 were conducted in therapeutic areas for which agents received initial accelerated approval, 202 were in supplemental indications, and 523 were outside approved indications. Only 411 out of 906 (45.4%) trials were designed to test the effectiveness of agents that received accelerated approval ("evaluation" trials); others used these agents as common background treatment in both arms ("background" trials). There was no detectable lag between average start times of trials conducted within and outside initially approved indications. Evaluation trials started on average 1.52 years (95% CI: 0.87 to 2.17) earlier than background trials. Cumulative evidence on agents with accelerated approvals has major limitations. Most clinical studies including these agents are small and nonrandomized, and about a third are conducted in unapproved areas, typically concurrently with those conducted in approved areas. Most randomized trials including these therapeutic agents are not designed to directly evaluate their clinical benefits but to incorporate them as standard treatment. © 2017 Milbank Memorial Fund.

Effectiveness of Quality Improvement Strategies for the Management of CKD: A Meta-Analysis.

PubMed

Silver, Samuel A; Bell, Chaim M; Chertow, Glenn M; Shah, Prakesh S; Shojania, Kaveh; Wald, Ron; Harel, Ziv

2017-10-06

Quality improvement interventions have enhanced care for other chronic illnesses, but their effectiveness for patients with CKD is unknown. We sought to determine the effects of quality improvement strategies on clinical outcomes in adult patients with nondialysis-requiring CKD. We conducted a systematic review of randomized trials, searching Medline and the Cochrane Effective Practice and Organization of Care database from January of 2003 to April of 2015. Eligible studies evaluated one or more of 11 prespecified quality improvement strategies, and prespecified study outcomes included at least one process of care measure, surrogate outcome, or hard clinical outcome. We used a random effects model to estimate the pooled risk ratio (RR; dichotomous data) or the mean difference (continuous data). We reviewed 15 patient-level randomized trials ( n =3298 patients), and six cluster-randomized trials ( n =30,042 patients). Quality improvement strategies reduced dialysis incidence (seven trials; RR, 0.85; 95% confidence interval [95% CI], 0.74 to 0.97) and LDL cholesterol concentrations (four trials; mean difference, -17.6 mg/dl; 95% CI, -28.7 to -6.5), and increased the likelihood that patients received renin-angiotensin-aldosterone system inhibitors (nine trials; RR, 1.16; 95% CI, 1.06 to 1.27). We did not observe statistically significant effects on mortality, cardiovascular events, eGFR, glycated hemoglobin, and systolic or diastolic BP. Quality improvement interventions yielded significant beneficial effects on three elements of CKD care. Estimates of the effectiveness of quality improvement strategies were limited by study number and adherence to quality improvement principles. This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_09_06_CJASNPodcast_17_10.mp3. Copyright © 2017 by the American Society of Nephrology.

Which is your choice for prolonging the analgesic duration of single-shot interscalene brachial blocks for arthroscopic shoulder surgery? intravenous dexamethasone 5 mg vs. perineural dexamethasone 5 mg randomized, controlled, clinical trial.

PubMed

Chun, Eun Hee; Kim, Youn Jin; Woo, Jae Hee

2016-06-01

The aim of this study was to compare the effect of intravenous (I.V.) dexamethasone with that of perineural dexamethasone on the prolongation of analgesic duration of single-shot interscalene brachial plexus blocks (SISB) in patients undergoing arthroscopic shoulder surgery. We performed a prospective, randomized, double-blind, placebo-controlled study. Patients undergoing elective arthroscopic shoulder surgery with ultrasound-guided SISB were enrolled and randomized into 2 groups. A total volume of 12 mL of the study drug was prepared with a final concentration of 0.5% ropivacaine. In the I.V. group, patients received SISB using ropivacaine 5 mg mL with normal saline (control) with dexamethasone 5 mg I.V. injection. In the perineural group, patients received SISB using ropivacaine 5 mg mL with dexamethasone 5 mg, with normal saline 1 mL I.V. injection. The primary outcome was the time to the first analgesic request, defined as the time between the end of the operation and the first request of analgesics by the patient. The secondary outcomes included patient satisfaction scores, side effects, and neurological symptoms. Patients were randomly assigned to 1 of the 2 groups using a computer-generated randomization table. An anesthesiologist blinded to the group assignments prepared the solutions for injection. The patients and the investigator participating in the study were also blinded to the group assignments. One hundred patients were randomized. Data were analyzed for 99 patients. One case in the I.V. group was converted to open surgery and was therefore not included in the study. Perineural dexamethasone significantly prolonged analgesic duration (median, standard error: 1080 minutes, 117.5 minutes) compared with I.V. dexamethasone (810 minutes, 48.1 minutes) (P = 0.02). There were no significant differences in side effects, neurological symptoms, or changes in blood glucose values between the 2 groups. Our results show that perineural dexamethasone 5 mg is more effective than I.V. dexamethasone 5 mg with regard to analgesic duration of SISB for arthroscopic shoulder surgery.

Assessing the effectiveness and cost-effectiveness of audit and feedback on physician’s prescribing indicators: study protocol of a randomized controlled trial with economic evaluation

PubMed Central

2012-01-01

Background Physician prescribing is the most frequent medical intervention with a highest impact on healthcare costs and outcomes. Therefore improving and promoting rational drug use is a great interest. We aimed to assess the effectiveness and cost-effectiveness of two forms of conducting prescribing audit and feedback interventions and a printed educational material intervention in improving physician prescribing. Method/design A four-arm randomized trial with economic evaluation will be conducted in Tehran. Three interventions (routine feedback, revised feedback, and printed educational material) and a no intervention control arm will be compared. Physicians working in outpatient practices are randomly allocated to one of the four arms using stratified randomized sampling. The interventions are developed based on a review of literature, physician interviews, current experiences in Iran and with theoretical insights from the Theory of Planned Behavior. Effects of the interventions on improving antibiotics and corticosteroids prescribing will be assessed in regression analyses. Cost data will be assessed from a health care provider’s perspective and incremental cost-effectiveness ratios will be calculated. Discussion This study will determine the effectiveness and cost-effectiveness of three interventions and allow us to determine the most effective interventions in improving prescribing pattern. If the interventions are cost-effective, they will likely be applied nationwide. Trial registration Iranian Registry of Clinical Trials Registration Number: IRCT201106086740N1Pharmaceutical Sciences Research Center of TUMS Ethics Committee Registration Number: 90-02-27-07 PMID:23351564

Does ascorbic acid protect against contrast-induced acute kidney injury in patients undergoing coronary angiography: a systematic review with meta-analysis of randomized, controlled trials.

PubMed

Sadat, Umar; Usman, Ammara; Gillard, Jonathan H; Boyle, Jonathan R

2013-12-10

This study sought to perform a systematic review with meta-analysis of randomized controlled trials comparing the use of ascorbic acid with placebo or other treatment options for the treatment of contrast induced-acute kidney injury (CI-AKI) in patients undergoing coronary angiography. CI-AKI remains the most widely discussed and debated topic in cardiovascular medicine, with its incidence increasing due to an increasing number of contrast media-enhanced radiological procedures being performed. MEDLINE, Embase, and Cochrane central databases were searched from inception to May 2013, without language restrictions. For a study to be selected, it had to report the incidence of CI-AKI as an outcome measure. Studies were excluded if at least 1 study arm did not have ascorbic acid administered alone or with saline solution hydration. Data were extracted by 1 author, and random checks were made by another author. Nine randomized, controlled trials reported data on the incidence of CI-AKI in 1,536 patients who had completed the trial and were included in the final analysis. Patients receiving ascorbic acid had 33% less risk of CI-AKI compared with patients receiving placebo or an alternate pharmacological treatment (risk ratio by random-effects model: 0.672; 95% confidence interval, 0.466 to 0.969; p = 0.034). Ascorbic acid provides effective nephroprotection against CI-AKI and may form a part of effective prophylactic pharmacological regimens. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Effect of study design on the reported effect of cardiac resynchronization therapy (CRT) on quantitative physiological measures: stratified meta-analysis in narrow-QRS heart failure and implications for planning future studies.

PubMed

Jabbour, Richard J; Shun-Shin, Matthew J; Finegold, Judith A; Afzal Sohaib, S M; Cook, Christopher; Nijjer, Sukhjinder S; Whinnett, Zachary I; Manisty, Charlotte H; Brugada, Josep; Francis, Darrel P

2015-01-06

Biventricular pacing (CRT) shows clear benefits in heart failure with wide QRS, but results in narrow QRS have appeared conflicting. We tested the hypothesis that study design might have influenced findings. We identified all reports of CRT-P/D therapy in subjects with narrow QRS reporting effects on continuous physiological variables. Twelve studies (2074 patients) met these criteria. Studies were stratified by presence of bias-resistance steps: the presence of a randomized control arm over a single arm, and blinded outcome measurement. Change in each endpoint was quantified using a standardized effect size (Cohen's d). We conducted separate meta-analyses for each variable in turn, stratified by trial quality. In non-randomized, non-blinded studies, the majority of variables (10 of 12, 83%) showed significant improvement, ranging from a standardized mean effect size of +1.57 (95%CI +0.43 to +2.7) for ejection fraction to +2.87 (+1.78 to +3.95) for NYHA class. In the randomized, non-blinded study, only 3 out of 6 variables (50%) showed improvement. For the randomized blinded studies, 0 out of 9 variables (0%) showed benefit, ranging from -0.04 (-0.31 to +0.22) for ejection fraction to -0.1 (-0.73 to +0.53) for 6-minute walk test. Differences in degrees of resistance to bias, rather than choice of endpoint, explain the variation between studies of CRT in narrow-QRS heart failure addressing physiological variables. When bias-resistance features are implemented, it becomes clear that these patients do not improve in any tested physiological variable. Guidance from studies without careful planning to resist bias may be far less useful than commonly perceived. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Theory-Based Interventions Combining Mental Simulation and Planning Techniques to Improve Physical Activity: Null Results from Two Randomized Controlled Trials.

PubMed

Meslot, Carine; Gauchet, Aurélie; Allenet, Benoît; François, Olivier; Hagger, Martin S

2016-01-01

Interventions to assist individuals in initiating and maintaining regular participation in physical activity are not always effective. Psychological and behavioral theories advocate the importance of both motivation and volition in interventions to change health behavior. Interventions adopting self-regulation strategies that foster motivational and volitional components may, therefore, have utility in promoting regular physical activity participation. We tested the efficacy of an intervention adopting motivational (mental simulation) and volitional (implementation intentions) components to promote a regular physical activity in two studies. Study 1 adopted a cluster randomized design in which participants ( n = 92) were allocated to one of three conditions: mental simulation plus implementation intention, implementation intention only, or control. Study 2 adopted a 2 (mental simulation vs. no mental simulation) × 2 (implementation intention vs. no implementation intention) randomized controlled design in which fitness center attendees ( n = 184) were randomly allocated one of four conditions: mental simulation only, implementation intention only, combined, or control. Physical activity behavior was measured by self-report (Study 1) or fitness center attendance (Study 2) at 4- (Studies 1 and 2) and 19- (Study 2 only) week follow-up periods. Findings revealed no statistically significant main or interactive effects of the mental simulation and implementation intention conditions on physical activity outcomes in either study. Findings are in contrast to previous research which has found pervasive effects for both intervention strategies. Findings are discussed in light of study limitations including the relatively small sample sizes, particularly for Study 1, deviations in the operationalization of the intervention components from previous research and the lack of a prompt for a goal intention. Future research should focus on ensuring uniformity in the format of the intervention components, test the effects of each component alone and in combination using standardized measures across multiple samples, and systematically explore effects of candidate moderators.

Theory-Based Interventions Combining Mental Simulation and Planning Techniques to Improve Physical Activity: Null Results from Two Randomized Controlled Trials

PubMed Central

Meslot, Carine; Gauchet, Aurélie; Allenet, Benoît; François, Olivier; Hagger, Martin S.

2016-01-01

Interventions to assist individuals in initiating and maintaining regular participation in physical activity are not always effective. Psychological and behavioral theories advocate the importance of both motivation and volition in interventions to change health behavior. Interventions adopting self-regulation strategies that foster motivational and volitional components may, therefore, have utility in promoting regular physical activity participation. We tested the efficacy of an intervention adopting motivational (mental simulation) and volitional (implementation intentions) components to promote a regular physical activity in two studies. Study 1 adopted a cluster randomized design in which participants (n = 92) were allocated to one of three conditions: mental simulation plus implementation intention, implementation intention only, or control. Study 2 adopted a 2 (mental simulation vs. no mental simulation) × 2 (implementation intention vs. no implementation intention) randomized controlled design in which fitness center attendees (n = 184) were randomly allocated one of four conditions: mental simulation only, implementation intention only, combined, or control. Physical activity behavior was measured by self-report (Study 1) or fitness center attendance (Study 2) at 4- (Studies 1 and 2) and 19- (Study 2 only) week follow-up periods. Findings revealed no statistically significant main or interactive effects of the mental simulation and implementation intention conditions on physical activity outcomes in either study. Findings are in contrast to previous research which has found pervasive effects for both intervention strategies. Findings are discussed in light of study limitations including the relatively small sample sizes, particularly for Study 1, deviations in the operationalization of the intervention components from previous research and the lack of a prompt for a goal intention. Future research should focus on ensuring uniformity in the format of the intervention components, test the effects of each component alone and in combination using standardized measures across multiple samples, and systematically explore effects of candidate moderators. PMID:27899904

Multifamily psychoeducation for improvement of mental health among relatives of patients with major depressive disorder lasting more than one year: study protocol for a randomized controlled trial.

PubMed

Katsuki, Fujika; Takeuchi, Hiroshi; Watanabe, Norio; Shiraishi, Nao; Maeda, Tohru; Kubota, Yosuke; Suzuki, Masako; Yamada, Atsurou; Akechi, Tatsuo

2014-08-12

Major depressive disorder (MDD) is a long-lasting disorder with frequent relapses that have significant effects on the patient's family. Family psychoeducation is recognized as part of the optimal treatment for patients with psychotic disorder. A previous randomized controlled trial has found that family psychoeducation is effective in enhancing the treatment of MDD. Although MDD can easily become a chronic illness, there has been no intervention study on the families of patients with chronic depression. In the present study, we design a randomized controlled trial to examine the effectiveness of family psychoeducation in improving the mental health of relatives of patients with MDD lasting more than one year. Participants are patients with MDD lasting more than one year and their relatives. Individually randomized, parallel-group trial design will be employed. Participants will be allocated to one of two treatment conditions: relatives will receive (a) family psychoeducation (four, two-hour biweekly multifamily psychoeducation sessions) plus treatment-as-usual for the patient (consultation by physicians), or (b) counseling for the family (one counseling session from a nurse) plus treatment-as-usual for the patient. The primary outcome measure will be relatives' mental health as measured by K6 that was developed to screen for DSM-IV depressive and anxiety disorder. Additionally, the severity of depressive symptoms in patients measured by the Beck Depression Inventory-II (BDI-II) scale will be assessed. Data from the intention-to-treat sample will be analyzed 16 weeks after randomization. This is the first study to evaluate the effectiveness of family psychoeducation for relatives of patients with MDD lasting more than one year. If this type of intervention is effective, it could be a new method of rehabilitation for patients with MDD lasting more than one year. Clinical Trials.gov NCT01734291 (registration date: 18 October 2012).

A study of the influence of conductive paths and their directions in randomly generated conductor network.

NASA Astrophysics Data System (ADS)

Mandolesi, E.; Moorkamp, M.; Jones, A. G.

2014-12-01

Most electromagnetic (EM) geophysical methods focus on the electrical conductivity of rocks and sediments to determine the geological structure of the subsurface. Electric conductivity itself is measured in the laboratory with a wide range of instruments and techniques. These measurements seldom return a compatible result. The presence of partially-interconnected random pathways of electrically conductive materials in resistive hosts has been studied for decades, and recently with increasing interest. To comprehend which conductive mechanism scales from the microstructures up to field electrical conductivity measurements, two main branch of studies have been undertaken: statistical probability of having a conductive pathways and mixing laws. Several numerical approaches have been tested to understand the effects of interconnected pathways of conductors at field scale. Usually these studies were restricted in two ways: the sources are considered constant in time (i.e., DC) and the domain is, with few exception, two-dimensional. We simulated the effects of time-varying EM sources on the conductivity measured on the surface of a three-dimensional randomly generated body embedded in an uniform host by using electromagnetic induction equations. We modelled a two-phase mixture of resistive and conductive elements with the goal of comparing the conductivity measured on field scale with the one proper of the elements constituting the random rock, and to test how the internal structures influence the directionality of the responses. Moreover, we modelled data from randomly generated bodies characterized by coherent internal structures, to check the effect of the named structures on the anisotropy of the effective conductivity. We compared these values with the electrical conductivity limits predicted by Hashin-Shtrikman bounds and the effective conductivity predicted by the Archie's law, both cast in its classic form and in an updated that allow to take in account two materials. The same analysis was done for both the resistive and the conductive conductivity values for the anisotropic case.

Hospital recruitment for a pragmatic cluster-randomized clinical trial: Lessons learned from the COMPASS study.

PubMed

Johnson, Anna M; Jones, Sara B; Duncan, Pamela W; Bushnell, Cheryl D; Coleman, Sylvia W; Mettam, Laurie H; Kucharska-Newton, Anna M; Sissine, Mysha E; Rosamond, Wayne D

2018-01-26

Pragmatic randomized clinical trials are essential to determine the effectiveness of interventions in "real-world" clinical practice. These trials frequently use a cluster-randomized methodology, with randomization at the site level. Despite policymakers' increased interest in supporting pragmatic randomized clinical trials, no studies to date have reported on the unique recruitment challenges faced by cluster-randomized pragmatic trials. We investigated key challenges and successful strategies for hospital recruitment in the Comprehensive Post-Acute Stroke Services (COMPASS) study. The COMPASS study is designed to compare the effectiveness of the COMPASS model versus usual care in improving functional outcomes, reducing the numbers of hospital readmissions, and reducing caregiver strain for patients discharged home after stroke or transient ischemic attack. This model integrates early supported discharge planning with transitional care management, including nurse-led follow-up phone calls after 2, 30, and 60 days and an in-person clinic visit at 7-14 days involving a functional assessment and neurological examination. We present descriptive statistics of the characteristics of successfully recruited hospitals compared with all eligible hospitals, reasons for non-participation, and effective recruitment strategies. We successfully recruited 41 (43%) of 95 eligible North Carolina hospitals. Leading, non-exclusive reasons for non-participation included: insufficient staff or financial resources (n = 33, 61%), lack of health system support (n = 16, 30%), and lack of support of individual decision-makers (n = 11, 20%). Successful recruitment strategies included: building and nurturing relationships, engaging team members and community partners with a diverse skill mix, identifying gatekeepers, finding mutually beneficial solutions, having a central institutional review board, sharing published pilot data, and integrating contracts and review board administrators. Although we incorporated strategies based on the best available evidence at the outset of the study, hospital recruitment required three times as much time and considerably more staff than anticipated. To reach our goal, we tailored strategies to individuals, hospitals, and health systems. Successful recruitment of a sufficient number and representative mix of hospitals requires considerable preparation, planning, and flexibility. Strategies presented here may assist future trial organizers in implementing cluster-randomized pragmatic trials. Clinicaltrials.gov, NCT02588664 . Registered on 23 October 2015.

Prebiotics, Prosynbiotics and Synbiotics: Can They Reduce Plasma Oxidative Stress Parameters? A Systematic Review.

PubMed

Salehi-Abargouei, Amin; Ghiasvand, Reza; Hariri, Mitra

2017-03-01

This study assessed the effectiveness of presybiotics, prosybiotics and synbiotics on reducing serum oxidative stress parameters. PubMed/Medline, Ovid, Google Scholar, ISI Web of Science and SCOPUS were searched up to September 2016. English language randomized clinical trials reporting the effect of presybiotics, prosybiotics or synbiotic interventions on serum oxidative stress parameters in human adults were included. Twenty-one randomized clinical trials met the inclusion criteria for systematic review. Two studies investigated prebiotics, four studies synbiotics and fifteen studies probiotics. According to our systematic review, prebiotic could decrease malondialdehyde and increase superoxidative dismutase, but evidence is not enough. In comparison with fructo-oligosaccharide, inulin is much more useful for oxidative stress reduction. Using probiotics with dairy products could reduce oxidative stress significantly, but probiotic in form of supplementation did not have any effect on oxidative stress. There is limited but supportive evidence that presybiotics, prosybiotics and synbiotics are effective for reducing oxidative stress parameters. Further randomized clinical trials with longer duration of intervention especially on population with increased oxidative stress are needed to provide more definitive results before any recommendation for clinical use of these interventions.

Positive effects of resistant starch supplementation on bowel function in healthy adults: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Shen, Deqiang; Bai, Hao; Li, Zhaoping; Yu, Yue; Zhang, Huanhuan; Chen, Liyong

2017-03-01

Animal experimental studies have found that resistant starch can significantly improve bowel function, but the outcomes are mixed while conducting human studies. Thus, we conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the relationship between resistant starch supplementation and large intestinal function. Three electronic databases (PubMed, Embase, Scopus) were searched to identify eligible studies. The standardized mean difference (SMD) or weighted mean difference (WMD) was calculated using a fixed-effects model or a random-effects model. The pooled findings revealed that resistant starch significantly increased fecal wet weight (WMD 35.51 g/d, 95% CI 1.21, 69.82) and butyrate concentration (SMD 0.61, 95% CI 0.32, 0.89). Also, it significantly reduced fecal PH (WMD -0.19, 95% CI -0.35, -0.03), but the increment of defecation frequency were not statistically significant (WMD 0.04stools/g, 95% CI -0.08, 0.16). To conclude, our study found that resistant starch elicited a beneficial effect on the function of large bowel in healthy adults.[Formula: see text].

Quantifying the impact of fixed effects modeling of clusters in multiple imputation for cluster randomized trials

PubMed Central

Andridge, Rebecca. R.

2011-01-01

In cluster randomized trials (CRTs), identifiable clusters rather than individuals are randomized to study groups. Resulting data often consist of a small number of clusters with correlated observations within a treatment group. Missing data often present a problem in the analysis of such trials, and multiple imputation (MI) has been used to create complete data sets, enabling subsequent analysis with well-established analysis methods for CRTs. We discuss strategies for accounting for clustering when multiply imputing a missing continuous outcome, focusing on estimation of the variance of group means as used in an adjusted t-test or ANOVA. These analysis procedures are congenial to (can be derived from) a mixed effects imputation model; however, this imputation procedure is not yet available in commercial statistical software. An alternative approach that is readily available and has been used in recent studies is to include fixed effects for cluster, but the impact of using this convenient method has not been studied. We show that under this imputation model the MI variance estimator is positively biased and that smaller ICCs lead to larger overestimation of the MI variance. Analytical expressions for the bias of the variance estimator are derived in the case of data missing completely at random (MCAR), and cases in which data are missing at random (MAR) are illustrated through simulation. Finally, various imputation methods are applied to data from the Detroit Middle School Asthma Project, a recent school-based CRT, and differences in inference are compared. PMID:21259309

Does higher education protect against obesity? Evidence using Mendelian randomization.

PubMed

Böckerman, Petri; Viinikainen, Jutta; Pulkki-Råback, Laura; Hakulinen, Christian; Pitkänen, Niina; Lehtimäki, Terho; Pehkonen, Jaakko; Raitakari, Olli T

2017-08-01

The aim of this explorative study was to examine the effect of education on obesity using Mendelian randomization. Participants (N=2011) were from the on-going nationally representative Young Finns Study (YFS) that began in 1980 when six cohorts (aged 30, 33, 36, 39, 42 and 45 in 2007) were recruited. The average value of BMI (kg/m 2 ) measurements in 2007 and 2011 and genetic information were linked to comprehensive register-based information on the years of education in 2007. We first used a linear regression (Ordinary Least Squares, OLS) to estimate the relationship between education and BMI. To identify a causal relationship, we exploited Mendelian randomization and used a genetic score as an instrument for education. The genetic score was based on 74 genetic variants that genome-wide association studies (GWASs) have found to be associated with the years of education. Because the genotypes are randomly assigned at conception, the instrument causes exogenous variation in the years of education and thus enables identification of causal effects. The years of education in 2007 were associated with lower BMI in 2007/2011 (regression coefficient (b)=-0.22; 95% Confidence Intervals [CI]=-0.29, -0.14) according to the linear regression results. The results based on Mendelian randomization suggests that there may be a negative causal effect of education on BMI (b=-0.84; 95% CI=-1.77, 0.09). The findings indicate that education could be a protective factor against obesity in advanced countries. Copyright © 2017 Elsevier Inc. All rights reserved.

A note on variance estimation in random effects meta-regression.

PubMed

Sidik, Kurex; Jonkman, Jeffrey N

2005-01-01

For random effects meta-regression inference, variance estimation for the parameter estimates is discussed. Because estimated weights are used for meta-regression analysis in practice, the assumed or estimated covariance matrix used in meta-regression is not strictly correct, due to possible errors in estimating the weights. Therefore, this note investigates the use of a robust variance estimation approach for obtaining variances of the parameter estimates in random effects meta-regression inference. This method treats the assumed covariance matrix of the effect measure variables as a working covariance matrix. Using an example of meta-analysis data from clinical trials of a vaccine, the robust variance estimation approach is illustrated in comparison with two other methods of variance estimation. A simulation study is presented, comparing the three methods of variance estimation in terms of bias and coverage probability. We find that, despite the seeming suitability of the robust estimator for random effects meta-regression, the improved variance estimator of Knapp and Hartung (2003) yields the best performance among the three estimators, and thus may provide the best protection against errors in the estimated weights.

Cardiac effects of granisetron in a prospective crossover randomized dose comparison trial.

PubMed

Cakir, F B; Yapar, O; Canpolat, C; Akalin, F; Berrak, S G

2012-10-01

Cardiac side effects of granisetron have been studied mostly in adult patients that are using cardiotoxic chemotherapeutics. There is limited evidence in pediatric age group and no information in pediatric oncology patients with non-cardiotoxic chemotherapeutics. In this prospective, crossover randomized study, the cardiac side effects of granisetron are compared in pediatric oncology patients who had carboplatin based chemotherapy. They were randomized to receive either 10 or 40 μg kg(-1) dose(-1) of granisetron before each cycle of chemotherapy. We drew blood for creatine phosphokinase (CPK), CPK-muscle band (MB) and Troponin-T before and 24 h after administering granisetron. Electrocardiography (ECG) tracings were taken at 0, 1, 2, 3, 6 and 24 h of granisetron. Twenty-four hours Holter ECG monitorisation was performed after each granisetron infusion. A total of 16 patients (median 8.7 years of age) were treated with weekly consecutive courses of carboplatin. There was bradycardia (p = 0.000) in patients that had granisetron at 40 μg/kg and PR interval was shortened in patients that had granisetron at 10 μg/kg dose (p = 0.021). At both doses of granisetron, QTc interval and dispersion were found to be similar. CPK, CK-MB and Troponin-T values were found to be normal before and 24 h after granisetron infusion. As the first study that has studied cardiac side effects of granisetron in patients that are not using cardiotoxic chemotherapeutics, we conclude that granisetron at 40 μg kg(-1) dose(-1) causes bradycardia only. We have also demonstrated that granisetron does not cause any clinically cardiac side effects either at 10 or 40 μg kg(-1) dose(-1). However, our results should be supported by prospective randomized studies with larger samples of patient groups.

Continuous intra-articular infusion anesthesia for pain control after total knee arthroplasty: study protocol for a randomized controlled trial.

PubMed

Guo, Da; Cao, Xue-Wei; Liu, Jin-Wen; Ouyang, Wen-Wei; Pan, Jian-Ke; Liu, Jun

2014-06-23

Postoperative pain control after total knee arthroplasty (TKA) remains a great challenge. The management of pain in the immediate postoperative period is one of the most critical aspects to allow speedier rehabilitation and reduce the risk of postoperative complications. Recently, periarticular infiltration anesthesia has become popular, but the outcome is controversial. Some studies have shown transient effects, "rebound pain", or no effectiveness in pain control. Continuous intra-articular infusion technique has been introduced to improve these transient effects, but more clinical studies are needed. Furthermore, the potential risk of early periprosthetic joint infection is causing concerning. We plan to compare continuous intra-articular infusion anesthesia with epidural infusion anesthesia after TKA to assess the effectiveness of this technique in reducing pain, in improving postoperative function, and to look at the evidence for risk of early infection. This trial is a randomized, controlled study. Patients (n = 214) will be randomized into two groups: to receive continuous intra-articular infusion anesthesia (group C); and epidural infusion anesthesia (group E). For the first 3 postoperative days, pain at rest, active range of motion (A-ROM), rescue analgesia and side effects will be recorded. At 3-month and 6-month follow-up, A-ROM, C-reactive protein, erythrocyte sedimentation rate, and synovial fluid cell count and culture will be analyzed. The results from this study will provide clinical evidence on the efficacy of a continuous intra-articular infusion technique in reducing pain, postoperative functional improvement and safety. It will be the first randomized controlled trial to investigate infection risk with local anesthesia after TKA. ClinicalTrials.gov identifier: ChiCTR-TRC-13003999.

Wrist-ankle acupuncture (WAA) for primary dysmenorrhea (PD) of young females: study protocol for a randomized controlled trial.

PubMed

Chen, Yingfan; Tian, Sinan; Tian, Jing; Shu, Shi

2017-08-22

Primary dysmenorrhea (PD) is one of the most common health complaints all over the world, specifically among young females. Acupuncture has been employed to relieve the pain-based symptoms and to avoid the side effects of conventional medication, and wrist-ankle acupuncture (WAA) has confirmed analgesic efficacy for various types of pain. The aim of this study is to evaluate the immediate analgesia effect of WAA on PD of young females. This study will carry out a randomized parallel controlled single-blind trial to observe the immediate analgesia effect of WAA in PD of young females. Sixty participants who meet inclusion criteria will be recruited from September 2016 to September 2017 in Changhai hospital of China. They are randomly assigned to WAA therapy or sham acupuncture groups (30 patients for each group), and then receive real or sham acupuncture treatment, respectively. In this trial, the primary outcome measure is simple form of McGill pain questionnaire (SF-MPQ), while expectation and treatment credibility scale (ETCS), safety assessment, the COX menstrual symptom scale (CMSS), questionnaire about the feeling of being punctured are included in the secondary outcomes. This trial will be the first study protocol designed to evaluate the immediate analgesia effect of WAA in PD of young females. The strengths in methodology, including rigorous randomized, sham-controlled, participants-blinded and assessors-blinded, will guarantee the quality of this study. WAA doesn't require any needling sensation, so non-penetrating sham acupuncture can serve as an effective placebo intervention in this trial. Chinese Clinical Trial Registry (identifier: ChiCTR-IOR-16008546 ; registration date: 27 May 2016).

Effect of estrogen replacement therapy on bone and cardiovascular outcomes in women with turner syndrome: a systematic review and meta-analysis.

PubMed

Cintron, Dahima; Rodriguez-Gutierrez, Rene; Serrano, Valentina; Latortue-Albino, Paula; Erwin, Patricia J; Murad, Mohammad Hassan

2017-02-01

Patients with Turner syndrome have adverse bone and cardiovascular outcomes from chronic estrogen deficiency. Hence, long-term estrogen replacement therapy is the cornerstone treatment. The estimates of its effect and optimal use, however, remain uncertain. We aimed to summarize the benefits and harms of estrogen replacement therapy on bone, cardiovascular, vasomotor and quality of life outcomes in patients with Turner syndrome. A comprehensive search of four databases was performed from inception through January 2016. Randomized clinical trials and observational cohort studies studying the effect of estrogen replacement therapy in patients with Turner syndrome under the age of 40 were included. Independently and in duplicate reviewers selected studies, extracted data and assessed risk of bias. Subgroup analyses were based on route of administration and type of estrogen formulation. Twenty-five studies at moderate to high risk of bias (12 randomized trials, 13 cohort studies) with 771 patients were included. Using random-effects models, estrogen replacement therapy showed an increase in bone mineral density [weighted mean change from baseline 0.09 g/cm2 (0.04-0.14)] that differed by type of estrogen but not route of administration. Oral estrogen replacement therapy showed a higher increase in high density lipoprotein cholesterol levels when compared to transdermal [weighted mean difference 9.33 mg/dl (4.82-13.85)] with no significant effect on other lipid fractions. The current evidence suggests possible benefit of estrogen replacement therapy on bone mineral density and high density lipoprotein cholesterol. Whether this improvement translates into changes in patient important outcomes (cardiovascular events or fractures) remains uncertain. Larger randomized clinical trials with direct comparisons on patient important outcomes are necessary.

Effects of statins on bone mineral density: a meta-analysis of clinical studies.

PubMed

Uzzan, Bernard; Cohen, Régis; Nicolas, Patrick; Cucherat, Michel; Perret, Gérard-Yves

2007-06-01

Statins inhibit HMG-CoA reductase, preventing synthesis of mevalonate but also of isoprenoids, which affect osteoclast activity. Amino-bisphosphonates share this effect. In vitro and in vivo, statins show convincing anabolic and anti-resorptive bone effects. However, in a clinical meta-analysis (MA), they did not prevent hip fractures. Our meta-analysis studied the impact of statins on bone mineral density (BMD) at various sites and compared the effects of lipophilic and more hydrophilic statins. Our PubMed and Embase queries using two keywords (statins, BMD) were updated to October 2006. Two readers independently collected BMDs from studies. Twenty-one studies, mostly observational (three randomized controlled trials and one pseudo-randomized study), were assessed. Two studies were excluded (no control groups). Three studies could not be analyzed. The sixteen studies analyzed mainly included postmenopausal osteopenic women (2971 patients under statins). Statins significantly increased BMD at total hip (TH) and femoral neck (FN). Effect sizes (ESs) were modest: 0.21 at TH (95% confidence interval [CI]: 0.16-0.25) and 0.20 at FN (CI: 0.08-0.28). Among women, statins acted similarly (ES: 0.20 for TH and 0.18 for FN; CI: 0.14-0.25 and 0.06-0.31 respectively); lipophilic statins (simvastatin, lovastatin) almost entirely caused this effect, at both TH (ES: 0.20; CI: 0.15-0.26) and FN (ES: 0.22; CI: 0.06-0.37). Our findings of modest but statistically significant beneficial effects of statins on hip BMD should promote large double-blind randomized controlled trials on their bone effects, in view of their major beneficial cardiovascular effects with excellent safety profile.

Resistance training for hot flushes in postmenopausal women: Randomized controlled trial protocol.

PubMed

Berin, Emilia; Hammar, Mats L; Lindblom, Hanna; Lindh-Åstrand, Lotta; Spetz Holm, Anna-Clara E

2016-03-01

Hot flushes and night sweats affect 75% of all women after menopause and is a common reason for decreased quality of life in mid-aged women. Hormone therapy is effective in ameliorating symptoms but cannot be used by all women due to contraindications and side effects. Engagement in regular exercise is associated with fewer hot flushes in observational studies, but aerobic exercise has not proven effective in randomized controlled trials. It remains to be determined whether resistance training is effective in reducing hot flushes and improves quality of life in symptomatic postmenopausal women. The aim of this study is to investigate the effect of standardized resistance training on hot flushes and other health parameters in postmenopausal women. This is an open, parallel-group, randomized controlled intervention study conducted in Linköping, Sweden. Sixty symptomatic and sedentary postmenopausal women with a mean of at least four moderate to severe hot flushes per day or 28 per week will be randomized to an exercise intervention or unchanged physical activity (control group). The intervention consists of 15 weeks of standardized resistance training performed three times a week under supervision of a physiotherapist. The primary outcome is hot flush frequency assessed by self-reported hot flush diaries, and the difference in change from baseline to week 15 will be compared between the intervention group and the control group. The intention is that this trial will contribute to the evidence base regarding effective treatment for hot flushes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Causal mediation analysis for longitudinal data with exogenous exposure

PubMed Central

Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. PMID:26272993

A randomized trial of blood donor recruitment strategies.

PubMed

Reich, Pascale; Roberts, Paula; Laabs, Nancy; Chinn, Artina; McEvoy, Patrick; Hirschler, Nora; Murphy, Edward L

2006-07-01

Improvement in donor return rates, especially among first-time donors, may significantly improve the blood supply. There are few rigorous studies of the effectiveness of various approaches to donor recruitment, however. By use of a single-blind, randomized trial design, 6919 post-September 11, 2001, first-time donors were randomly assigned into the following intervention arms: T-shirt incentive versus none, recruitment scripts with a patient story (Script A) versus a complimentary message including the donor's blood type (Script B), and telephone versus e-mail recruitment. Our primary outcome was a second donation within 6 months. Rate ratios (RRs) and 95 percent confidence intervals (95% CIs) were calculated with Taylor series methods. A total of 1421 (20.5%) first-time donors returned within the 6 months, including 1252 with a second and 169 with both second and third donations. The T-shirt incentive was not effective in increasing returns compared to no incentive (20.5% vs. 20.6%; RR, 0.99; 95% CI, 0.91-1.09). Script A was significantly more effective than Script B (22.2% vs. 18.9%; RR, 1.18; 95% CI, 1.07-1.29). E-mail was substantially less effective than telephone recruitment (13.2% vs. 27.8%; RR, 0.48; 95% CI, 0.40-0.57). A T-shirt incentive had no apparent effect, but an empathetic message significantly improved the return donation rate. E-mail recruitment was substantially less effective than telephone recruitment, perhaps due to technical problems. The study illustrates the utility of the randomized clinical trial study design for testing donor recruitment strategies.

Effectiveness of a new health care organization model in primary care for chronic cardiovascular disease patients based on a multifactorial intervention: the PROPRESE randomized controlled trial.

PubMed

Orozco-Beltran, Domingo; Ruescas-Escolano, Esther; Navarro-Palazón, Ana Isabel; Cordero, Alberto; Gaubert-Tortosa, María; Navarro-Perez, Jorge; Carratalá-Munuera, Concepción; Pertusa-Martínez, Salvador; Soler-Bahilo, Enrique; Brotons-Muntó, Francisco; Bort-Cubero, Jose; Nuñez-Martinez, Miguel Angel; Bertomeu-Martinez, Vicente; Gil-Guillen, Vicente Francisco

2013-08-02

To evaluate the effectiveness of a new multifactorial intervention to improve health care for chronic ischemic heart disease patients in primary care. The strategy has two components: a) organizational for the patient/professional relationship and b) training for professionals. Experimental study. Randomized clinical trial. Follow-up period: one year. primary care, multicenter (15 health centers). For the intervention group 15 health centers are selected from those participating in ESCARVAL study. Once the center agreed to participate patients are randomly selected from the total amount of patients with ischemic heart disease registered in the electronic health records. For the control group a random sample of patients with ischemic heart disease is selected from all 72 health centers electronic records. This study aims to evaluate the efficacy of a multifactorial intervention strategy involving patients with ischemic heart disease for the improvement of the degree of control of the cardiovascular risk factors and of the quality of life, number of visits, and number of hospitalizations. NCT01826929.

Random quaternary ammonium Diels-Alder poly(phenylene) copolymers for improved vanadium redox flow batteries

NASA Astrophysics Data System (ADS)

Largier, Timothy D.; Cornelius, Chris J.

2017-06-01

This study analyzes the effect of quaternary ammonium homopolymer (AmPP) and ionic and non-ionic random unit copolymerization (AmPP-PP) of Diels-Alder poly(phenylene)s on electrochemical and transport properties, vanadium redox flow battery performance, and material stability. AmPP-PP materials were synthesized with IEC's up to 2.2 meq/g, displaying a carbonate form ion conductivity of 17.3 mS/cm and water uptake of 57.3%. Vanadium ion permeability studies revealed that the random copolymers possess superior charge carrier selectivity. For materials of comparable ion content, at 10 mA/cm2 the random copolymer displayed a 14% increase in coulombic efficiency (CE) corresponding to a 7% increase in energy efficiency. All quaternary ammonium materials displayed ex situ degradation in a 0.5 M V5+ + 5 M H2SO4 solution, with the rate of degradation appearing to increase with IEC. Preliminary studies reveal that the neutralizing counter-ion has a significant effect on VRB performance, proportional to changes in vanadium ion molecular diffusion.

Parent-only interventions in the treatment of childhood obesity: a systematic review of randomized controlled trials.

PubMed

Ewald, H; Kirby, J; Rees, K; Robertson, W

2014-09-01

An effective and cost-effective treatment is required for the treatment of childhood obesity. Comparing parent-only interventions with interventions including the child may help determine this. A systematic review of published and ongoing studies until 2013, using electronic database and manual searches. randomized controlled trials, overweight/obese children aged 5-12 years, parent-only intervention compared with an intervention that included the child, 6 months or more follow-up. Outcomes included measures of overweight. Ten papers from 6 completed studies, and 2 protocols for ongoing studies, were identified. Parent-only groups are either more effective than or similarly effective as child-only or parent-child interventions, in the change in degree of overweight. Most studies were at unclear risk of bias for randomization, allocation concealment and blinding of outcome assessors. Two trials were at high risk of bias for incomplete outcome data. Four studies showed higher dropout from parent-only interventions. One study examined programme costs and found parent-only interventions to be cheaper. Parent-only interventions appear to be as effective as parent-child interventions in the treatment of childhood overweight/obesity, and may be less expensive. Reasons for higher attrition rates in parent-only interventions need further investigation. © The Author 2013. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estimating the optimal dynamic antipsychotic treatment regime: Evidence from the sequential multiple assignment randomized CATIE Schizophrenia Study

PubMed Central

Shortreed, Susan M.; Moodie, Erica E. M.

2012-01-01

Summary Treatment of schizophrenia is notoriously difficult and typically requires personalized adaption of treatment due to lack of efficacy of treatment, poor adherence, or intolerable side effects. The Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) Schizophrenia Study is a sequential multiple assignment randomized trial comparing the typical antipsychotic medication, perphenazine, to several newer atypical antipsychotics. This paper describes the marginal structural modeling method for estimating optimal dynamic treatment regimes and applies the approach to the CATIE Schizophrenia Study. Missing data and valid estimation of confidence intervals are also addressed. PMID:23087488

Transcranial direct current stimulation (tDCS) for idiopathic Parkinson's disease.

PubMed

Elsner, Bernhard; Kugler, Joachim; Pohl, Marcus; Mehrholz, Jan

2016-07-18

Idiopathic Parkinson's disease (IPD) is a neurodegenerative disorder, with the severity of the disability usually increasing with disease duration. IPD affects patients' health-related quality of life, disability, and impairment. Current rehabilitation approaches have limited effectiveness in improving outcomes in patients with IPD, but a possible adjunct to rehabilitation might be non-invasive brain stimulation by transcranial direct current stimulation (tDCS) to modulate cortical excitability, and hence to improve these outcomes in IPD. To assess the effectiveness of tDCS in improving motor and non-motor symptoms in people with IPD. We searched the following databases (until February 2016): the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library ; 2016 , Issue 2), MEDLINE, EMBASE, CINAHL, AMED, Science Citation Index, the Physiotherapy Evidence Database (PEDro), Rehabdata, and Inspec. In an effort to identify further published, unpublished, and ongoing trials, we searched trial registers and reference lists, handsearched conference proceedings, and contacted authors and equipment manufacturers. We included only randomised controlled trials (RCTs) and randomised controlled cross-over trials that compared tDCS versus control in patients with IPD for improving health-related quality of life , disability, and impairment. Two review authors independently assessed trial quality (JM and MP) and extracted data (BE and JM). If necessary, we contacted study authors to ask for additional information. We collected information on dropouts and adverse events from the trial reports. We included six trials with a total of 137 participants. We found two studies with 45 participants examining the effects of tDCS compared to control (sham tDCS) on our primary outcome measure, impairment, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS). There was very low quality evidence for no effect of tDCS on change in global UPDRS score ( mean difference (MD) -7.10 %, 95% confidence interval (CI -19.18 to 4.97; P = 0.25, I² = 21%, random-effects model). However, there was evidence of an effect on UPDRS part III motor subsection score at the end of the intervention phase (MD -14.43%, 95% CI -24.68 to -4.18; P = 0.006, I² = 2%, random-effects model; very low quality evidence). One study with 25 participants measured the reduction in off and on time with dyskinesia, but there was no evidence of an effect (MD 0.10 hours, 95% CI -0.14 to 0.34; P = 0.41, I² = 0%, random-effects model; and MD 0.00 hours, 95% CI -0.12 to 0.12; P = 1, I² = 0%, random- effects model, respectively; very low quality evidence).Two trials with a total of 41 participants measured gait speed using measures of timed gait at the end of the intervention phase, revealing no evidence of an effect ( standardised mean difference (SMD) 0.50, 95% CI -0.17 to 1.18; P = 0.14, I² = 11%, random-effects model; very low quality evidence). Another secondary outcome was health-related quality of life and we found one study with 25 participants reporting on the physical health and mental health aspects of health-related quality of life (MD 1.00 SF-12 score, 95% CI -5.20 to 7.20; I² = 0%, inverse variance method with random-effects model; very low quality evidence; and MD 1.60 SF-12 score, 95% CI -5.08 to 8.28; I² = 0%, inverse variance method with random-effects model; very low quality evidence, respectively). We found no study examining the effects of tDCS for improving activities of daily living. In two of six studies, dropouts , adverse events, or deaths occurring during the intervention phase were reported. There was insufficient evidence that dropouts , adverse effects, or deaths were higher with intervention (risk difference (RD) 0.04, 95% CI -0.05 to 0.12; P = 0.40, I² = 0%, random-effects model; very low quality evidence).We found one trial with a total of 16 participants examining the effects of tDCS plus movement therapy compared to control (sham tDCS) plus movement therapy on our secondary outcome, gait speed at the end of the intervention phase, revealing no evidence of an effect (MD 0.05 m/s, 95% CI -0.15 to 0.25; inverse variance method with random-effects model; very low quality evidence). We found no evidence of an effect regarding differences in dropouts and adverse effects between intervention and control groups (RD 0.00, 95% CI -0.21 to 0.21; Mantel-Haenszel method with random-effects model; very low quality evidence). There is insufficient evidence to determine the effects of tDCS for reducing off time ( when the symptoms are not controlled by the medication) and on time with dyskinesia ( time that symptoms are controlled but the person still experiences involuntary muscle movements ) , and for improving health- related quality of life, disability, and impairment in patients with IPD. Evidence of very low quality indicates no difference in dropouts and adverse events between tDCS and control groups.

Bias, Confounding, and Interaction: Lions and Tigers, and Bears, Oh My!

PubMed

Vetter, Thomas R; Mascha, Edward J

2017-09-01

Epidemiologists seek to make a valid inference about the causal effect between an exposure and a disease in a specific population, using representative sample data from a specific population. Clinical researchers likewise seek to make a valid inference about the association between an intervention and outcome(s) in a specific population, based upon their randomly collected, representative sample data. Both do so by using the available data about the sample variable to make a valid estimate about its corresponding or underlying, but unknown population parameter. Random error in an experiment can be due to the natural, periodic fluctuation or variation in the accuracy or precision of virtually any data sampling technique or health measurement tool or scale. In a clinical research study, random error can be due to not only innate human variability but also purely chance. Systematic error in an experiment arises from an innate flaw in the data sampling technique or measurement instrument. In the clinical research setting, systematic error is more commonly referred to as systematic bias. The most commonly encountered types of bias in anesthesia, perioperative, critical care, and pain medicine research include recall bias, observational bias (Hawthorne effect), attrition bias, misclassification or informational bias, and selection bias. A confounding variable is a factor associated with both the exposure of interest and the outcome of interest. A confounding variable (confounding factor or confounder) is a variable that correlates (positively or negatively) with both the exposure and outcome. Confounding is typically not an issue in a randomized trial because the randomized groups are sufficiently balanced on all potential confounding variables, both observed and nonobserved. However, confounding can be a major problem with any observational (nonrandomized) study. Ignoring confounding in an observational study will often result in a "distorted" or incorrect estimate of the association or treatment effect. Interaction among variables, also known as effect modification, exists when the effect of 1 explanatory variable on the outcome depends on the particular level or value of another explanatory variable. Bias and confounding are common potential explanations for statistically significant associations between exposure and outcome when the true relationship is noncausal. Understanding interactions is vital to proper interpretation of treatment effects. These complex concepts should be consistently and appropriately considered whenever one is not only designing but also analyzing and interpreting data from a randomized trial or observational study.

Prophylactic intra-peritoneal drain placement following pancreaticoduodenectomy: A systematic review and meta-analysis

PubMed Central

Wang, Yi-Chao; Szatmary, Peter; Zhu, Jing-Qiang; Xiong, Jun-Jie; Huang, Wei; Gomatos, Ilias; Nunes, Quentin M; Sutton, Robert; Liu, Xu-Bao

2015-01-01

AIM: To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy (PD) with or without prophylactic drainage. METHODS: Relevant comparative randomized and non-randomized studies were systemically searched based on specific inclusion and exclusion criteria. Postoperative outcomes were compared between patients with and those without routine drainage. Pooled odds ratios (OR) with 95%CI were calculated using either fixed effects or random effects models. RESULTS: One randomized controlled trial and four non-randomized comparative studies recruiting 1728 patients were analyzed. Patients without prophylactic drainage after PD had significantly higher mortality (OR = 2.32, 95%CI: 1.11-4.85; P = 0.02), despite the fact that they were associated with fewer overall complications (OR = 0.62, 95%CI: 0.48-0.82; P = 0.00), major complications (OR = 0.75, 95%CI: 0.60-0.93; P = 0.01) and readmissions (OR = 0.77, 95%CI: 0.60-0.98; P = 0.04). There were no significant differences in the rates of pancreatic fistula, intra-abdominal abscesses, postpancreatectomy hemorrhage, biliary fistula, delayed gastric emptying, reoperation or radiologic-guided drains between the two groups. CONCLUSION: Indiscriminate abandonment of intra-abdominal drainage following PD is associated with greater mortality, but lower complication rates. Future randomized trials should compare routine vs selective drainage. PMID:25741162

Movement-Pattern Training to Improve Function in People With Chronic Hip Joint Pain: A Feasibility Randomized Clinical Trial.

PubMed

Harris-Hayes, Marcie; Czuppon, Sylvia; Van Dillen, Linda R; Steger-May, Karen; Sahrmann, Shirley; Schootman, Mario; Salsich, Gretchen B; Clohisy, John C; Mueller, Michael J

2016-06-01

Study Design Feasibility randomized clinical trial. Background Rehabilitation may be an appropriate treatment strategy for patients with chronic hip joint pain; however, the evidence related to the effectiveness of rehabilitation is limited. Objectives To assess feasibility of performing a randomized clinical trial to investigate the effectiveness of movement-pattern training (MPT) to improve function in people with chronic hip joint pain. Methods Thirty-five patients with chronic hip joint pain were randomized into a treatment (MPT) group or a control (wait-list) group. The MPT program included 6 one-hour supervised sessions and incorporated (1) task-specific training for basic functional tasks and symptom-provoking tasks, and (2) strengthening of hip musculature. The wait-list group received no treatment. Primary outcomes for feasibility were patient retention and adherence. Secondary outcomes to assess treatment effects were patient-reported function (Hip disability and Osteoarthritis Outcome Score), lower extremity kinematics, and hip muscle strength. Results Retention rates did not differ between the MPT (89%) and wait-list groups (94%, P = 1.0). Sixteen of the 18 patients (89%) in the MPT group attended at least 80% of the treatment sessions. For the home exercise program, 89% of patients reported performing their home program at least once per day. Secondary outcomes support the rationale for conduct of a superiority randomized clinical trial. Conclusion Based on retention and adherence rates, a larger randomized clinical trial appears feasible and warranted to assess treatment effects more precisely. Data from this feasibility study will inform our future clinical trial. Level of Evidence Therapy, level 2b-. J Orthop Sports Phys Ther 2016;46(6):452-461. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6279.

A novel comparative effectiveness study of Tai Chi versus aerobic exercise for fibromyalgia: study protocol for a randomized controlled trial.

PubMed

Wang, Chenchen; McAlindon, Timothy; Fielding, Roger A; Harvey, William F; Driban, Jeffrey B; Price, Lori Lyn; Kalish, Robert; Schmid, Anna; Scott, Tammy M; Schmid, Christopher H

2015-01-30

Fibromyalgia is a chronic musculoskeletal pain syndrome that causes substantial physical and psychological impairment and costs the US healthcare system over $25 billion annually. Current pharmacological therapies may cause serious adverse effects, are expensive, and fail to effectively improve pain and function. Finding new and effective non-pharmacological treatments for fibromyalgia patients is urgently needed. We are currently conducting the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise (a recommended component of the current standard of care) in a large fibromyalgia population. This article describes the design and conduct of this trial. A single-center, 52-week, randomized controlled trial of Tai Chi versus aerobic exercise is being conducted at an urban tertiary medical center in Boston, Massachusetts. We plan to recruit 216 patients with fibromyalgia. The study population consists of adults ≥21 years of age with fibromyalgia who meet American College of Rheumatology 1990 and 2010 diagnostic criteria. Participants are randomized to one of four Tai Chi intervention groups: 12 or 24 weeks of supervised Tai Chi held once or twice per week, or a supervised aerobic exercise control held twice per week for 24 weeks. The primary outcome is the change in Revised Fibromyalgia Impact Questionnaire total score from baseline to 24 weeks. Secondary outcomes include measures of widespread pain, symptom severity, functional performance, balance, muscle strength and power, psychological functioning, sleep quality, self-efficacy, durability effects, and health-related quality of life at 12, 24, and 52 week follow-up. This study is the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise in a large fibromyalgia population with long-term follow up. We present here a robust and well-designed trial to determine the optimal frequency and duration of a supervised Tai Chi intervention with regard to short- and long-term effectiveness. The trial also explores multiple outcomes to elucidate the potential mechanisms of Tai Chi and aerobic exercise and the generalizability of these interventions across instructors. Results of this study are expected to have important public health implications for patients with a major disabling disease that incurs substantial health burdens and economic costs. ClinicalTrials.gov identifier: NCT01420640 , registered 18 August 2011.

Experimental evaluation of the effects of drug information on antibiotic prescribing: a study in outpatient care in an area of Sri lanka.

PubMed

Angunawela, I I; Diwan, V K; Tomson, G

1991-06-01

The intervention level of epidemiology is useful for studying effects in health systems research. Due to practical and ethical reasons, it is often difficult to apply experimental methods such as classical randomized clinical trials in the field. However with alternative approaches such as 'randomization by group' some of these problems can be overcome. Drug information has since long been considered as an instrument to influence physicians, however evaluation of its effects is a new field of research. In the present study the impact of drug information on prescribing behaviour was evaluated in an outpatient setting in Sri Lanka. The study included 15 state health institutions (45 prescribers) with a common drug formulary. Groups of prescribers were randomized into two interventions; newsletters and newsletters reinforced by a group seminar, and one control group. The target topic was 'rational prescribing of antibiotics'. Some 18,766 randomly selected outpatient drug prescriptions were studied. Antibiotics (and sulphonamides) were prescribed to 33.2% of the patients. An overall trend towards a decrease in proportion of patients prescribed antibiotics in the two intervention groups was seen, although the difference was not significant (p greater than 0.05) compared to the control group. This is similar to the effect of written information on prescribing in other studies. A mean difference of -7.4% in written, -7.3% in written + seminar and -0.4% in the control group was shown. The general antibiotic prescribing pattern did not change in any of the three groups. Penicillin was the most commonly prescribed antibiotic and tetracycline was only rarely prescribed to children. This experiment indicates the feasibility of drug information intervention studies in developing countries.(ABSTRACT TRUNCATED AT 250 WORDS)

Health effects of cow's milk consumption in infants up to 3 years of age: a systematic review and meta-analysis.

PubMed

Griebler, Ursula; Bruckmüller, Melanie U; Kien, Christina; Dieminger, Birgit; Meidlinger, Bettina; Seper, Katrin; Hitthaller, Ariane; Emprechtinger, Robert; Wolf, Alexandra; Gartlehner, Gerald

2016-02-01

To summarize the best available evidence regarding the short- and long-term health effects of cow's milk intake in healthy, full-term infants up to 3 years of age. We conducted a systematic review and meta-analysis. We searched MEDLINE (via PubMed), EMBASE and the Cochrane Library between 1960 and July 2013 and manually reviewed reference lists of pertinent articles. Two researchers independently reviewed abstracts and full-text articles and extracted relevant data. We included (randomized/non-randomized) controlled trials and observational studies. We included data from twenty-three studies (one randomized controlled trial, four non-randomized controlled trials, eight case-control studies and ten cohort studies) for the evidence synthesis. Pooled results of four studies revealed a higher risk of Fe-deficiency anaemia for infants consuming cow's milk compared with those consuming follow-on formula (relative risk=3·76; 95 % CI 2·73, 5·19). For type 1 diabetes mellitus, six out of seven case-control studies did not show a difference in the risk of developing this disease based on the age of introduction of cow's milk. We did not find negative associations for other health effects. Cow's milk consumption in infancy is associated with an increased risk of developing Fe-deficiency anaemia. Limiting cow's milk consumption may be important to ensure an adequate Fe intake for infants and toddlers. High-quality patient information for caregivers is needed on how infants' Fe requirements can be met.

Design of healthy hearts in the heartland (H3): A practice-randomized, comparative effectiveness study.

PubMed

Ciolino, Jody D; Jackson, Kathryn L; Liss, David T; Brown, Tiffany; Walunas, Theresa L; Murakami, Linda; Chung, Isabel; Persell, Stephen D; Kho, Abel N

2018-06-02

The Healthy Hearts in the Heartland (H3) study is part of a nationwide effort, EvidenceNOW, seeking to better understand the ability of small primary care practices to improve "ABCS" clinical quality measures: appropriate Aspirin therapy, Blood pressure control, Cholesterol management, and Smoking cessation. H3 aimed to assess feasibility of implementing Point-of-Care (POC) or POC plus Population Management (POC + PM) quality improvement (QI) strategies to improve ABCS at practices in Illinois, Indiana, and Wisconsin. We describe the design and randomization of the H3 study. We conducted a two-arm (1:1, POC:POC + PM), practice-randomized, comparative effectiveness study in 226 primary care practices across four "waves" of randomization with a 12-month intervention period, followed by a six-month sustainability period. Randomization controlled imbalance in nine baseline variables through a modified constrained algorithm. Among others, we used initial, unverified estimates of baseline ABCS values. We randomized 112 and 114 practices to POC and POC + PM arms, respectively. Randomization ensured baseline comparability for all nine key variables, including the ABCS measures indicating proportion of patients at the practice level meeting each quality measure. Median(Inner Quartile Range) values were A: 0.78(0.66-0.86) in POC arm vs. 0.77(0.63-0.86) in POC + PM arm, B: 0.64(0.53-0.73) vs. 0.64(0.53-0.75), C: 0.78(0.63-0.86) vs. 0.75(0.64-0.81), S: 0.80(0.65-0.81) vs. 0.79(0.61-0.91). Surrogate estimates for the true ABCS at baseline coupled with the unique randomization logic achieved adequate baseline balance on these outcomes. Similar practice- or cluster-randomized trials may consider adaptations of this design. Final analyses on 12- and 18-month ABCS outcomes for the H3 study are forthcoming. This trial is registered on ClinicalTrials.gov (Initial post: 11/05/2015; identifier: NCT02598284; https://clinicaltrials.gov/ct2/show/NCT02598284?term=NCT02598284&rank=1). Copyright © 2018 Elsevier Inc. All rights reserved.

Undermining position effects in choices from arrays, with implications for police lineups.

PubMed

Palmer, Matthew A; Sauer, James D; Holt, Glenys A

2017-03-01

Choices from arrays are often characterized by position effects, such as edge-aversion. We investigated position effects when participants attempted to pick a suspect from an array similar to a police photo lineup. A reanalysis of data from 2 large-scale field studies showed that choices made under realistic conditions-closely matching eyewitness identification decisions in police investigations-displayed edge-aversion and bias to choose from the top row (Study 1). In a series of experiments (Studies 2a-2c and 3), participants guessing the location of a suspect exhibited edge-aversion regardless of whether the lineup was constructed to maximize the chances of the suspect being picked, to ensure the suspect did not stand out, or randomly. Participants favored top locations only when the lineup was constructed to maximize the chances of the suspect being picked. In Studies 4 and 5, position effects disappeared when (a) response options were presented in an array with no obvious center, edges, or corners, and (b) instructions stated that the suspect was placed randomly. These findings show that position effects are influenced by a combination of task instructions and array shape. Randomizing the location of the suspect and modifying the shape of the lineup array may reduce misidentification. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Context-dependent effects of background colour in free recall with spatially grouped words.

PubMed

Sakai, Tetsuya; Isarida, Toshiko K; Isarida, Takeo

2010-10-01

Three experiments investigated context-dependent effects of background colour in free recall with groups of items. Undergraduates (N=113) intentionally studied 24 words presented in blocks of 6 on a computer screen with two different background colours. The two background colours were changed screen-by-screen randomly (random condition) or alternately (alternation condition) during the study period. A 30-second filled retention interval was imposed before an oral free-recall test. A signal for free recall was presented throughout the test on one of the colour background screens presented at study. Recalled words were classified as same- or different-context words according to whether the background colours at study and test were the same or different. The random condition produced significant context-dependent effects, whereas the alternation condition showed no context-dependent effects, regardless of whether the words were presented once or twice. Furthermore, the words presented on the same screen were clustered in recall, whereas the words presented against the same background colour but on different screens were not clustered. The present results imply: (1) background colours can cue spatially massed words; (2) background colours act as temporally local context; and (3) predictability of the next background colour modulates the context-dependent effect.

The effects of aquatic therapy on mobility of individuals with neurological diseases: a systematic review.

PubMed

Marinho-Buzelli, Andresa R; Bonnyman, Alison M; Verrier, Mary C

2015-08-01

To summarize evidence on the effects of aquatic therapy on mobility in individuals with neurological diseases. MEDLINE, EMBASE, PsycInfo, CENTRAL, CINAHL, SPORTDiscus, PEDro, PsycBITE and OT Seeker were searched from inception to 15 September 2014. Hand-searching of reference lists was performed in the selected studies. The search included randomized controlled trials and quasi-experimental studies that investigated the use of aquatic therapy and its effect on mobility of adults with neurological diseases. One reviewer screened titles and abstracts of retrieved studies from the search strategy. Two reviewers independently examined the full texts and conducted the study selection, data extraction and quality assessment. A narrative synthesis of data was applied to summarize information from included studies. The Downs and Black Scale was used to assess methodological quality. A total of 116 articles were obtained for full text eligibility. Twenty studies met the specified inclusion criteria: four Randomized Controlled Trials (RCTs), four non-randomized studies and 12 before-and-after tests. Two RCTs (30 patients with stroke in the aquatic therapy groups), three non-randomized studies and three before-and-after studies showed "fair" evidence that aquatic therapy increases dynamic balance in participants with some neurological disorders. One RCT (seven patients with stroke in the aquatic therapy group) and two before-and-after tests (20 patients with multiple sclerosis) demonstrated "fair" evidence on improvement of gait speed after aquatic therapy. Our synthesis showed "fair" evidence supporting the use of aquatic therapy to improve dynamic balance and gait speed in adults with certain neurological conditions. © The Author(s) 2014.

Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies

PubMed Central

Meyer, Katie A.; Shea, Jonathan W.

2017-01-01

Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). We conducted a systematic review and random-effects meta-analysis to quantify a summary estimated effect of dietary choline and betaine on hard CVD outcomes (incidence and mortality). Eligible studies were prospective studies in adults with comprehensive diet assessment and follow-up for hard CVD endpoints. We identified six studies that met our criteria, comprising 18,076 incident CVD events, 5343 CVD deaths, and 184,010 total participants. In random effects meta-analysis, incident CVD was not associated with choline (relative risk (RR): 1.00; 95% CI: 0.98, 1.02) or betaine (RR: 0.99; 95% CI: 0.98, 1.01) intake. Results did not vary by study outcome (incident coronary heart disease, stroke, total CVD) and there was no evidence for heterogeneity among studies. Only two studies provided data on phosphatidylcholine and CVD mortality. Random effects meta-analysis did not support an association between choline and CVD mortality (RR: 1.09, 95% CI: 0.89, 1.35), but one study supported a positive association and there was significant heterogeneity (I2 = 84%, p-value < 0.001). Our findings do not support an association between dietary choline/betaine with incident CVD, but call for further research into choline and CVD mortality. PMID:28686188

Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies.

PubMed

Meyer, Katie A; Shea, Jonathan W

2017-07-07

Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). We conducted a systematic review and random-effects meta-analysis to quantify a summary estimated effect of dietary choline and betaine on hard CVD outcomes (incidence and mortality). Eligible studies were prospective studies in adults with comprehensive diet assessment and follow-up for hard CVD endpoints. We identified six studies that met our criteria, comprising 18,076 incident CVD events, 5343 CVD deaths, and 184,010 total participants. In random effects meta-analysis, incident CVD was not associated with choline (relative risk (RR): 1.00; 95% CI: 0.98, 1.02) or betaine (RR: 0.99; 95% CI: 0.98, 1.01) intake. Results did not vary by study outcome (incident coronary heart disease, stroke, total CVD) and there was no evidence for heterogeneity among studies. Only two studies provided data on phosphatidylcholine and CVD mortality. Random effects meta-analysis did not support an association between choline and CVD mortality (RR: 1.09, 95% CI: 0.89, 1.35), but one study supported a positive association and there was significant heterogeneity ( I ² = 84%, p -value < 0.001). Our findings do not support an association between dietary choline/betaine with incident CVD, but call for further research into choline and CVD mortality.

Treatment with GLP1 receptor agonists reduce serum CRP concentrations in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials.

PubMed

Mazidi, Mohsen; Karimi, Ehsan; Rezaie, Peyman; Ferns, Gordon A

2017-07-01

To undertake a systematic review and meta-analysis of randomized controlled trials of the effect of glucagon-like peptide-1 receptor agonist (GLP-1 RAs) therapy on serum C-reactive protein (CRP) concentrations. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched for the period up until March 16, 2016. Prospective studies evaluating the impact of GLP-1 RAs on serum CRP were identified. A random effects model (using the DerSimonian-Laird method) and generic inverse variance methods were used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I 2 index. Random effects meta-regression was performed using unrestricted maximum likelihood method to evaluate the impact of potential moderator. International Prospective Register for Systematic Reviews (PROSPERO) number CRD42016036868. Meta-analysis of the data from 7 treatment arms revealed a significant reduction in serum CRP concentrations following treatment with GLP-1 RAs (WMD -2.14 (mg/dL), 95% CI -3.51, -0.78, P=0.002; I 2 96.1%). Removal of one study in the meta-analysis did not change the result in the sensitivity analysis (WMD -2.14 (mg/dL), 95% CI -3.51, -0.78, P=0.002; I 2 96.1%), indicating that our results could not be solely attributed to the effect of a single study. Random effects meta-regression was performed to evaluate the impact of potential moderator on the estimated effect size. Changes in serum CRP concentration were associated with the duration of treatment (slope -0.097, 95% CI -0.158, -0.042, P<0.001). This meta-analysis suggests that GLP-1 RAs therapy causes a significant reduction in CRP. Copyright © 2016 Elsevier Inc. All rights reserved.

Mechanisms for an effect of acetylcysteine on renal function after exposure to radio-graphic contrast material: study protocol

PubMed Central

2012-01-01

Background Contrast-induced nephropathy is a common complication of contrast administration in patients with chronic kidney disease and diabetes. Its pathophysiology is not well understood; similarly the role of intravenous or oral acetylcysteine is unclear. Randomized controlled trials to date have been conducted without detailed knowledge of the effect of acetylcysteine on renal function. We are conducting a detailed mechanistic study of acetylcysteine on normal and impaired kidneys, both with and without contrast. This information would guide the choice of dose, route, and appropriate outcome measure for future clinical trials in patients with chronic kidney disease. Methods/Design We designed a 4-part study. We have set up randomised controlled cross-over studies to assess the effect of intravenous (50 mg/kg/hr for 2 hrs before contrast exposure, then 20 mg/kg/hr for 5 hrs) or oral acetylcysteine (1200 mg twice daily for 2 days, starting the day before contrast exposure) on renal function in normal and diseased kidneys, and normal kidneys exposed to contrast. We have also set up a parallel-group randomized controlled trial to assess the effect of intravenous or oral acetylcysteine on patients with chronic kidney disease stage III undergoing elective coronary angiography. The primary outcome is change in renal blood flow; secondary outcomes include change in glomerular filtration rate, tubular function, urinary proteins, and oxidative balance. Discussion Contrast-induced nephropathy represents a significant source of hospital morbidity and mortality. Over the last ten years, acetylcysteine has been administered prior to contrast to reduce the risk of contrast-induced nephropathy. Randomized controlled trials, however, have not reliably demonstrated renoprotection; a recent large randomized controlled trial assessing a dose of oral acetylcysteine selected without mechanistic insight did not reduce the incidence of contrast-induced nephropathy. Our study should reveal the mechanism of effect of acetylcysteine on renal function and identify an appropriate route for future dose response studies and in time randomized controlled trials. Trial registration Clinical Trials.gov: NCT00558142; EudraCT: 2006-003509-18. PMID:22305183

Hawthorne effect with transient behavioral and biochemical changes in a randomized controlled sleep extension trial of chronically short-sleeping obese adults: implications for the design and interpretation of clinical studies.

PubMed

Cizza, Giovanni; Piaggi, Paolo; Rother, Kristina I; Csako, Gyorgy

2014-01-01

To evaluate the effects of study participation per se at the beginning of a sleep extension trial between screening, randomization, and the run-in visit. Subjects were screened, returned for randomization (Comparison vs. Intervention) after 81 days (median), and attended run-in visit 121 days later. Outpatient. Obese (N = 125; M/F, 30/95; Blacks/Whites/Other, N = 73/44/8), mean weight 107.6±19.7 kg, <6.5 h sleep/night. Non-pharmacological sleep extension. Sleep duration (diaries and actigraphy watch), sleep quality (Pittsburgh Sleep Quality Index), daily sleepiness (Epworth Sleepiness Scale), fasting glucose, insulin and lipids. Prior to any intervention, marked improvements occurred between screening and randomization. Sleep duration increased (diaries: 357.4 ±51.2 vs. 388.1±48.6 min/night; mean±SD; P<0.001 screening vs. randomization; actigraphy: 344.3 ±41.9 vs. 358.6±48.2 min/night; P<0.001) sleep quality improved (9.1±3.2 vs. 8.2±3.0 PSQI score; P<0.001), sleepiness tended to improve (8.9±4.6 vs. 8.3±4.5 ESS score; P = 0.06), insulin resistance decreased (0.327±0.038 vs. 0.351±0.045; Quicki index; P<0.001), and lipids improved, except for HDL-C. Abnormal fasting glucose (25% vs. 11%; P = 0.007), and metabolic syndrome (42% vs. 29%; P = 0.007) both decreased. In absence of intervention, the earlier metabolic improvements disappeared at the run-in visit. Relatively small sample size. Improvements in biochemical and behavioral parameters between screening and randomization changed the "true" study baseline, thereby potentially affecting outcome. While regression to the mean and placebo effect were considered, these findings are most consistent with the "Hawthorne effect", according to which behavior measured in the setting of an experimental study changes in response to the attention received from study investigators. This is the first time that biochemical changes were documented with respect to the Hawthorne effect. The findings have implications for the design and conduct of clinical research. ClinicalTrials.gov NCT00261898.

Tunable random lasing behavior in plasmonic nanostructures

NASA Astrophysics Data System (ADS)

Yadav, Ashish; Zhong, Liubiao; Sun, Jun; Jiang, Lin; Cheng, Gary J.; Chi, Lifeng

2017-01-01

Random lasing is desired in plasmonics nanostructures through surface plasmon amplification. In this study, tunable random lasing behavior was observed in dye molecules attached with Au nanorods (NRs), Au nanoparticles (NPs) and Au@Ag nanorods (NRs) respectively. Our experimental investigations showed that all nanostructures i.e., Au@AgNRs, AuNRs & AuNPs have intensive tunable spectral effects. The random lasing has been observed at excitation wavelength 532 nm and varying pump powers. The best random lasing properties were noticed in Au@AgNRs structure, which exhibits broad absorption spectrum, sufficiently overlapping with that of dye Rhodamine B (RhB). Au@AgNRs significantly enhance the tunable spectral behavior through localized electromagnetic field and scattering. The random lasing in Au@AgNRs provides an efficient coherent feedback for random lasers.

Analgesic effects of treatments for non-specific low back pain: a meta-analysis of placebo-controlled randomized trials.

PubMed

Machado, L A C; Kamper, S J; Herbert, R D; Maher, C G; McAuley, J H

2009-05-01

Estimates of treatment effects reported in placebo-controlled randomized trials are less subject to bias than those estimates provided by other study designs. The objective of this meta-analysis was to estimate the analgesic effects of treatments for non-specific low back pain reported in placebo-controlled randomized trials. Medline, Embase, Cinahl, PsychInfo and Cochrane Central Register of Controlled Trials databases were searched for eligible trials from earliest records to November 2006. Continuous pain outcomes were converted to a common 0-100 scale and pooled using a random effects model. A total of 76 trials reporting on 34 treatments were included. Fifty percent of the investigated treatments had statistically significant effects, but for most the effects were small or moderate: 47% had point estimates of effects of <10 points on the 100-point scale, 38% had point estimates from 10 to 20 points and 15% had point estimates of >20 points. Treatments reported to have large effects (>20 points) had been investigated only in a single trial. This meta-analysis revealed that the analgesic effects of many treatments for non-specific low back pain are small and that they do not differ in populations with acute or chronic symptoms.

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

A randomized trial on folic acid supplementation and risk of recurrent colorectal adenoma

USDA-ARS?s Scientific Manuscript database

Background: Evidence from observational studies suggests that inadequate folate status enhances colorectal carcinogenesis, but results from some randomized trials do not support this hypothesis. Objective: To assess the effect of folic acid supplementation on recurrent colorectal adenoma, we conduc...

Effects of the TCARE® intervention on caregiver burden and depressive symptoms: preliminary findings from a randomized controlled study.

PubMed

Montgomery, Rhonda J V; Kwak, Jung; Kosloski, Karl; O'Connell Valuch, Katharine

2011-09-01

We examined the effects of a manualized care management protocol specifically designed for care managers working with caregivers, the Tailored Caregiver Assessment and Referral® (TCARE®) protocol, on caregiver identity discrepancy, burden, and depressive symptoms. Preliminary data from a longitudinal, randomized, controlled intervention study with 266 family caregivers served by 52 care managers in 4 states were analyzed using repeated measures random effects regression procedures. Caregivers in the intervention and control groups were repeatedly assessed for up to 9 months on caregiver identity discrepancy, 3 areas of caregiving burden-objective, relationship, and stress burdens; depression; and intention for nursing home placement. We found significant group by time interaction effects for caregiver identity discrepancy, relationship burden, stress burden, depression, and intention for nursing home placement. Caregivers in the intervention group experienced significant improvement on these measures, whereas caregivers in the control group worsened on these measures over time. The preliminary findings provide strong support for effectiveness of the TCARE® protocol on improving caregiver well-being and mental health outcomes.

Effects of the TCARE® Intervention on Caregiver Burden and Depressive Symptoms: Preliminary Findings From a Randomized Controlled Study

PubMed Central

Kwak, Jung; Kosloski, Karl; O’Connell Valuch, Katharine

2011-01-01

Objectives. We examined the effects of a manualized care management protocol specifically designed for care managers working with caregivers, the Tailored Caregiver Assessment and Referral® (TCARE®) protocol, on caregiver identity discrepancy, burden, and depressive symptoms. Methods. Preliminary data from a longitudinal, randomized, controlled intervention study with 266 family caregivers served by 52 care managers in 4 states were analyzed using repeated measures random effects regression procedures. Caregivers in the intervention and control groups were repeatedly assessed for up to 9 months on caregiver identity discrepancy, 3 areas of caregiving burden—objective, relationship, and stress burdens; depression; and intention for nursing home placement. Results. We found significant group by time interaction effects for caregiver identity discrepancy, relationship burden, stress burden, depression, and intention for nursing home placement. Caregivers in the intervention group experienced significant improvement on these measures, whereas caregivers in the control group worsened on these measures over time. Discussion. The preliminary findings provide strong support for effectiveness of the TCARE® protocol on improving caregiver well-being and mental health outcomes. PMID:21840840

Inference for binomial probability based on dependent Bernoulli random variables with applications to meta-analysis and group level studies.

PubMed

Bakbergenuly, Ilyas; Kulinskaya, Elena; Morgenthaler, Stephan

2016-07-01

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group-level studies or in meta-analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log-odds and arcsine transformations of the estimated probability p̂, both for single-group studies and in combining results from several groups or studies in meta-analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta-analysis and result in abysmal coverage of the combined effect for large K. We also propose bias-correction for the arcsine transformation. Our simulations demonstrate that this bias-correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta-analyses of prevalence. © 2016 The Authors. Biometrical Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Prospective, randomized assessment of transfer of training (ToT) and transfer effectiveness ratio (TER) of virtual reality simulation training for laparoscopic skill acquisition.

PubMed

Gallagher, Anthony G; Seymour, Neal E; Jordan-Black, Julie-Anne; Bunting, Brendan P; McGlade, Kieran; Satava, Richard Martin

2013-06-01

We assessed the effectiveness of ToT from VR laparoscopic simulation training in 2 studies. In a second study, we also assessed the TER. ToT is a detectable performance improvement between equivalent groups, and TER is the observed percentage performance differences between 2 matched groups carrying out the same task but with 1 group pretrained on VR simulation. Concordance between simulated and in-vivo procedure performance was also assessed. Prospective, randomized, and blinded. In Study 1, experienced laparoscopic surgeons (n = 195) and in Study 2 laparoscopic novices (n = 30) were randomized to either train on VR simulation before completing an equivalent real-world task or complete the real-world task only. Experienced laparoscopic surgeons and novices who trained on the simulator performed significantly better than their controls, thus demonstrating ToT. Their performance showed a TER between 7% and 42% from the virtual to the real tasks. Simulation training impacted most on procedural error reduction in both studies (32-42%). The correlation observed between the VR and real-world task performance was r > 0·96 (Study 2). VR simulation training offers a powerful and effective platform for training safer skills.

The Minicommunity Design to Assess Indirect Effects of Vaccination.

PubMed

Halloran, M Elizabeth

2012-08-01

We propose the minicommunity design to estimate indirect effects of vaccination. Establishing indirect effects of vaccination in unvaccinated subpopulations could have important implications for global vaccine policies. In the minicommunity design, the household or other small transmission unit serves as the cluster in which to estimate indirect effects of vaccination, similar to studies in larger communities to estimate indirect, total, and overall effects. Examples from the literature include studies in small transmission units to estimate indirect effects of pertussis, pneumococcal, influenza, and cholera vaccines. We characterize the minicommunity design by several methodologic considerations, including the assignment mechanism, ascertainment, the role of transmission outside the transmission unit, and the relation of the size of the transmission unit to number of people vaccinated. The minicommunity study for indirect effects is contrasted with studies to estimate vaccine effects on infectiousness and protective effects under conditions of household exposure within small transmission units. The minicommunity design can be easily implemented in individually randomized studies by enrolling and following-up members of households of the randomized individuals. The methodology for the minicommunity design for estimating indirect effects of vaccination deserves much future research.

Stochastic stability of parametrically excited random systems

NASA Astrophysics Data System (ADS)

Labou, M.

2004-01-01

Multidegree-of-freedom dynamic systems subjected to parametric excitation are analyzed for stochastic stability. The variation of excitation intensity with time is described by the sum of a harmonic function and a stationary random process. The stability boundaries are determined by the stochastic averaging method. The effect of random parametric excitation on the stability of trivial solutions of systems of differential equations for the moments of phase variables is studied. It is assumed that the frequency of harmonic component falls within the region of combination resonances. Stability conditions for the first and second moments are obtained. It turns out that additional parametric excitation may have a stabilizing or destabilizing effect, depending on the values of certain parameters of random excitation. As an example, the stability of a beam in plane bending is analyzed.

A comparison of methods for estimating the random effects distribution of a linear mixed model.

PubMed

Ghidey, Wendimagegn; Lesaffre, Emmanuel; Verbeke, Geert

2010-12-01

This article reviews various recently suggested approaches to estimate the random effects distribution in a linear mixed model, i.e. (1) the smoothing by roughening approach of Shen and Louis,(1) (2) the semi-non-parametric approach of Zhang and Davidian,(2) (3) the heterogeneity model of Verbeke and Lesaffre( 3) and (4) a flexible approach of Ghidey et al. (4) These four approaches are compared via an extensive simulation study. We conclude that for the considered cases, the approach of Ghidey et al. (4) often shows to have the smallest integrated mean squared error for estimating the random effects distribution. An analysis of a longitudinal dental data set illustrates the performance of the methods in a practical example.

Bayesian random-effect model for predicting outcome fraught with heterogeneity--an illustration with episodes of 44 patients with intractable epilepsy.

PubMed

Yen, A M-F; Liou, H-H; Lin, H-L; Chen, T H-H

2006-01-01

The study aimed to develop a predictive model to deal with data fraught with heterogeneity that cannot be explained by sampling variation or measured covariates. The random-effect Poisson regression model was first proposed to deal with over-dispersion for data fraught with heterogeneity after making allowance for measured covariates. Bayesian acyclic graphic model in conjunction with Markov Chain Monte Carlo (MCMC) technique was then applied to estimate the parameters of both relevant covariates and random effect. Predictive distribution was then generated to compare the predicted with the observed for the Bayesian model with and without random effect. Data from repeated measurement of episodes among 44 patients with intractable epilepsy were used as an illustration. The application of Poisson regression without taking heterogeneity into account to epilepsy data yielded a large value of heterogeneity (heterogeneity factor = 17.90, deviance = 1485, degree of freedom (df) = 83). After taking the random effect into account, the value of heterogeneity factor was greatly reduced (heterogeneity factor = 0.52, deviance = 42.5, df = 81). The Pearson chi2 for the comparison between the expected seizure frequencies and the observed ones at two and three months of the model with and without random effect were 34.27 (p = 1.00) and 1799.90 (p < 0.0001), respectively. The Bayesian acyclic model using the MCMC method was demonstrated to have great potential for disease prediction while data show over-dispersion attributed either to correlated property or to subject-to-subject variability.

Application of Poisson random effect models for highway network screening.

PubMed

Jiang, Ximiao; Abdel-Aty, Mohamed; Alamili, Samer

2014-02-01

In recent years, Bayesian random effect models that account for the temporal and spatial correlations of crash data became popular in traffic safety research. This study employs random effect Poisson Log-Normal models for crash risk hotspot identification. Both the temporal and spatial correlations of crash data were considered. Potential for Safety Improvement (PSI) were adopted as a measure of the crash risk. Using the fatal and injury crashes that occurred on urban 4-lane divided arterials from 2006 to 2009 in the Central Florida area, the random effect approaches were compared to the traditional Empirical Bayesian (EB) method and the conventional Bayesian Poisson Log-Normal model. A series of method examination tests were conducted to evaluate the performance of different approaches. These tests include the previously developed site consistence test, method consistence test, total rank difference test, and the modified total score test, as well as the newly proposed total safety performance measure difference test. Results show that the Bayesian Poisson model accounting for both temporal and spatial random effects (PTSRE) outperforms the model that with only temporal random effect, and both are superior to the conventional Poisson Log-Normal model (PLN) and the EB model in the fitting of crash data. Additionally, the method evaluation tests indicate that the PTSRE model is significantly superior to the PLN model and the EB model in consistently identifying hotspots during successive time periods. The results suggest that the PTSRE model is a superior alternative for road site crash risk hotspot identification. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sugar-sweetened beverages and weight gain in children and adults: a systematic review and meta-analysis123

PubMed Central

Pan, An; Willett, Walter C; Hu, Frank B

2013-01-01

Background: The relation between sugar-sweetened beverages (SSBs) and body weight remains controversial. Objective: We conducted a systematic review and meta-analysis to summarize the evidence in children and adults. Design: We searched PubMed, EMBASE, and Cochrane databases through March 2013 for prospective cohort studies and randomized controlled trials (RCTs) that evaluated the SSB-weight relation. Separate meta-analyses were conducted in children and adults and for cohorts and RCTs by using random- and fixed-effects models. Results: Thirty-two original articles were included in our meta-analyses: 20 in children (15 cohort studies, n = 25,745; 5 trials, n = 2772) and 12 in adults (7 cohort studies, n = 174,252; 5 trials, n = 292). In cohort studies, one daily serving increment of SSBs was associated with a 0.06 (95% CI: 0.02, 0.10) and 0.05 (95% CI: 0.03, 0.07)-unit increase in BMI in children and 0.22 kg (95% CI: 0.09, 0.34 kg) and 0.12 kg (95% CI: 0.10, 0.14 kg) weight gain in adults over 1 y in random- and fixed-effects models, respectively. RCTs in children showed reductions in BMI gain when SSBs were reduced [random and fixed effects: −0.17 (95% CI: −0.39, 0.05) and −0.12 (95% CI: −0.22, −0.2)], whereas RCTs in adults showed increases in body weight when SSBs were added (random and fixed effects: 0.85 kg; 95% CI: 0.50, 1.20 kg). Sensitivity analyses of RCTs in children showed more pronounced benefits in preventing weight gain in SSB substitution trials (compared with school-based educational programs) and among overweight children (compared with normal-weight children). Conclusion: Our systematic review and meta-analysis of prospective cohort studies and RCTs provides evidence that SSB consumption promotes weight gain in children and adults. PMID:23966427

Changing friend selection in middle school: A social network analysis of a randomized intervention study designed to prevent adolescent problem behavior

PubMed Central

DeLay, Dawn; Ha, Thao; Van Ryzin, Mark; Winter, Charlotte; Dishion, Thomas J.

2015-01-01

Adolescent friendships that promote problem behavior are often chosen in middle school. The current study examines the unintended impact of a randomized school based intervention on the selection of friends in middle school, as well as on observations of deviant talk with friends five years later. Participants included 998 middle school students (526 boys and 472 girls) recruited at the onset of middle school (age 11-12 years) from three public middle schools participating in the Family Check-up model intervention. The current study focuses only on the effects of the SHAPe curriculum—one level of the Family Check-up model—on friendship choices. Participants nominated friends and completed measures of deviant peer affiliation. Approximately half of the sample (n=500) was randomly assigned to the intervention and the other half (n=498) comprised the control group within each school. The results indicate that the SHAPe curriculum affected friend selection within School 1, but not within Schools 2 or 3. The effects of friend selection in School 1 translated into reductions in observed deviancy training five years later (age 16-17 years). By coupling longitudinal social network analysis with a randomized intervention study the current findings provide initial evidence that a randomized public middle school intervention can disrupt the formation of deviant peer groups and diminish levels of adolescent deviance five years later. PMID:26377235

Effectiveness of Functional Progressive Resistance Exercise Training on Walking Ability in Children with Cerebral Palsy: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Scholtes, Vanessa A.; Becher, Jules G.; Janssen-Potten, Yvonne J.; Dekkers, Hurnet; Smallenbroek, Linda; Dallmeijer, Annet J.

2012-01-01

The objective of the study was to evaluate the effectiveness of functional progressive resistance exercise (PRE) training on walking ability in children with cerebral palsy (CP). Fifty-one ambulant children with spastic CP (mean age 10 years 5 months, 29 boys) were randomized to an intervention (n=26) or control group (n=25, receiving usual care).…

Determining the Effects That the Order of Abstraction and Type of Reflection Have on Content Knowledge When Teaching Experientially: An Exploratory Experiment

ERIC Educational Resources Information Center

Baker, Marshall A.; Brown, Nicholas R.; Blackburn, J. Joey; Robinson, J. Shane

2014-01-01

The purpose of this experimental study was to determine the effects of order of abstraction and type of reflection on student knowledge acquisition. Students were assigned randomly to one of four treatment combinations in the completely randomized 2 x 2 design which included either abstraction prior to or directly after an experience, and either…

Social Stories: Mechanisms of Effectiveness in Increasing Game Play Skills in Children Diagnosed with Autism Spectrum Disorder Using a Pretest Posttest Repeated Measures Randomized Control Group Design

ERIC Educational Resources Information Center

Quirmbach, Linda M.; Lincoln, Alan J.; Feinberg-Gizzo, Monica J.; Ingersoll, Brooke R.; Andrews, Siri M.

2009-01-01

An increasing body of literature has indicated that social stories are an effective way to teach individuals diagnosed with autism appropriate social behavior. This study compared two formats of a social story targeting the improvement of social skills during game play using a pretest posttest repeated measures randomized control group design. A…

The Effects of Total Physical Response by Storytelling and the Traditional Teaching Styles of a Foreign Language in a Selected High School

ERIC Educational Resources Information Center

Kariuki, Patrick N. K.; Bush, Elizabeth Danielle

2008-01-01

The purpose of this study was to examine the effects of Total Physical Response by Storytelling and the traditional teaching method on a foreign language in a selected high school. The sample consisted of 30 students who were randomly selected and randomly assigned to experimental and control group. The experimental group was taught using Total…

The Effectiveness of Conflict Maps and the V-Shape Teaching Method in Science Conceptual Change among Eighth-Grade Students in Jordan

ERIC Educational Resources Information Center

Bawaneh, Ali Khalid Ali; Zain, Ahmad Nurulazam Md; Ghazali, Munirah

2010-01-01

The purpose of the present study is to investigate the effectiveness of Conflict Maps and the V-Shape method as teaching methods in bringing about conceptual change in science among primary eighth-grade students in Jordan. A randomly selected sample (N = 63) from the Bani Kenana region North of Jordan was randomly assigned to the two teaching…

Population-Level Cost-Effectiveness of Implementing Evidence-Based Practices into Routine Care

PubMed Central

Fortney, John C; Pyne, Jeffrey M; Burgess, James F

2014-01-01

Objective The objective of this research was to apply a new methodology (population-level cost-effectiveness analysis) to determine the value of implementing an evidence-based practice in routine care. Data Sources/Study Setting Data are from sequentially conducted studies: a randomized controlled trial and an implementation trial of collaborative care for depression. Both trials were conducted in the same practice setting and population (primary care patients prescribed antidepressants). Study Design The study combined results from a randomized controlled trial and a pre-post-quasi-experimental implementation trial. Data Collection/Extraction Methods The randomized controlled trial collected quality-adjusted life years (QALYs) from survey and medication possession ratios (MPRs) from administrative data. The implementation trial collected MPRs and intervention costs from administrative data and implementation costs from survey. Principal Findings In the randomized controlled trial, MPRs were significantly correlated with QALYs (p = .03). In the implementation trial, patients at implementation sites had significantly higher MPRs (p = .01) than patients at control sites, and by extrapolation higher QALYs (0.00188). Total costs (implementation, intervention) were nonsignificantly higher ($63.76) at implementation sites. The incremental population-level cost-effectiveness ratio was $33,905.92/QALY (bootstrap interquartile range −$45,343.10/QALY to $99,260.90/QALY). Conclusions The methodology was feasible to operationalize and gave reasonable estimates of implementation value. PMID:25328029

The feasibility and acceptability of conducting a trial of specialist medical care and the Lightning Process in children with chronic fatigue syndrome: feasibility randomized controlled trial (SMILE study)

PubMed Central

2013-01-01

Background Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is relatively common in children with limited evidence for treatment. The Phil Parker Lightning Process (LP) is a trademarked intervention, which >250 children use annually. There are no reported studies investigating the effectiveness or possible side effects of LP. Methods The trial population was drawn from the Bath and Bristol NHS specialist paediatric CFS or ME service. The study was designed as a pilot randomized trial with children (aged 12 to 18 years) comparing specialist medical care with specialist medical care plus the Lightning Process. Integrated qualitative methodology was used to explore the feasibility and acceptability of the recruitment, randomization and interventions. Results A total of 56 children were recruited from 156 eligible children (1 October 2010 to 16 June 2012). Recruitment, randomization and both interventions were feasible and acceptable. Participants suggested changes to improve feasibility and acceptability and we incorporated the following in the trial protocol: stopped collecting 6-week outcomes; introduced a second reminder letter; used phone calls to collect primary outcomes from nonresponders; informed participants about different approaches of each intervention and changed our recommendation for the primary outcome for the full study from school attendance to disability (SF-36 physical function subscale) and fatigue (Chalder Fatigue Scale). Conclusions Conducting randomized controlled trials (RCTs) to investigate an alternative treatment such as LP is feasible and acceptable for children with CFS or ME. Feasibility studies that incorporate qualitative methodology enable changes to be made to trial protocols to improve acceptability to participants. This is likely to improve recruitment rate and trial retention. Trial registration Feasibility study first randomization: 29 September 2010. Trial registration: Current Controlled Trials ISRCTN81456207 (31 July 2012). Full trial first randomization: 19 September 2012. PMID:24304689

The Effect of Omega-3 on Circulating Adiponectin in Adults with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PubMed

Bahreini, Mehdi; Ramezani, Amir-Hossein; Shishehbor, Farideh; Mansoori, Anahita

2018-01-04

Whether consumption of omega-3 affects circulating adiponectin has not been established. The objective of this study was to evaluate the effect of omega-3 (food or supplement) on circulating adiponectin in patients with type 2 diabetes through a systematic review of meta-analyses of randomized controlled trials. PubMed, Scopus and Web of Science were searched for relevant studies through May 2016. Two researchers screened and abstracted the literature independently. Pooled estimates were obtained using the random-effects models. Overall, omega-3 increased adiponectin by 0.57 µg/mL (95% confidence interval [CI] 0.15 to 1.31; p=0.01, I-square=74.2% p for heterogeneity <0.001). The source of observed heterogeneity was explored by subgroup analyses. In subgroup analyses, adiponectin levels increased only in those who had consumed omega-3 for more than 8 weeks. This systematic review and meta-analysis of randomized, placebo-controlled clinical trials suggests that omega-3 in patients with type 2 diabetes increases circulating adiponectin. These findings support the potentially beneficial effects of dietary omega-3 in patients with type 2 diabetes on pathways related to adiponectin metabolism. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Effects of music therapy on self- and experienced stigma in patients on an acute care psychiatric unit: a randomized three group effectiveness study.

PubMed

Silverman, Michael J

2013-10-01

Stigma is a major social barrier that can restrict access to and willingness to seek psychiatric care. Psychiatric consumers may use secrecy and withdrawal in an attempt to cope with stigma. The purpose of this study was to determine the effects of music therapy on self- and experienced stigma in acute care psychiatric inpatients using a randomized design with wait-list control. Participants (N=83) were randomly assigned by cluster to one of three single-session group-based conditions: music therapy, education, or wait-list control. Participants in the music therapy and education conditions completed only posttests while participants in the wait-list control condition completed only pretests. The music therapy condition was a group songwriting intervention wherein participants composed lyrics for "the stigma blues." Results indicated significant differences in measures of discrimination (experienced stigma), disclosure (self-stigma), and total stigma between participants in the music therapy condition and participants in the wait-list control condition. From the results of this randomized controlled investigation, music therapy may be an engaging and effective psychosocial technique to treat stigma. Limitations, suggestions for future research, and implications for clinical practice and psychiatric music therapy research are provided. © 2013.

Relapse prevention interventions for smoking cessation.

PubMed

Hajek, Peter; Stead, Lindsay F; West, Robert; Jarvis, Martin; Hartmann-Boyce, Jamie; Lancaster, Tim

2013-08-20

A number of treatments can help smokers make a successful quit attempt, but many initially successful quitters relapse over time. Several interventions have been proposed to help prevent relapse. To assess whether specific interventions for relapse prevention reduce the proportion of recent quitters who return to smoking. We searched the Cochrane Tobacco Addiction Group trials register in May 2013 for studies mentioning relapse prevention or maintenance in title, abstracts or keywords. Randomized or quasi-randomized controlled trials of relapse prevention interventions with a minimum follow-up of six months. We included smokers who quit on their own, were undergoing enforced abstinence, or were participating in treatment programmes. We included trials that compared relapse prevention interventions with a no intervention control, or that compared a cessation programme with additional relapse prevention components with a cessation programme alone. Studies were screened and data extracted by one review author, and checked by a second. Disagreements were resolved by discussion or by referral to a third review author. Sixty-three studies met inclusion criteria but were heterogeneous in terms of populations and interventions. We considered 41 studies that randomly assigned abstainers separately from studies that randomly assigned participants before their quit date.Upon looking at studies of behavioural interventions that randomly assigned abstainers, we detected no benefit of brief and 'skills-based' relapse prevention methods for women who had quit smoking because of pregnancy, or for smokers undergoing a period of enforced abstinence during hospitalisation or military training. We also failed to detect significant effects of behavioural interventions in trials in unselected groups of smokers who had quit on their own or through a formal programme. Amongst trials randomly assigning smokers before their quit date and evaluating the effects of additional relapse prevention components, we found no evidence of benefit of behavioural interventions or combined behavioural and pharmacotherapeutic interventions in any subgroup. Overall, providing training in skills thought to be needed for relapse avoidance did not reduce relapse, but most studies did not use experimental designs best suited to the task and had limited power to detect expected small differences between interventions. For pharmacological interventions, extended treatment with varenicline significantly reduced relapse in one trial (risk ratio (RR) 1.18, 95% confidence interval (CI) 1.03 to 1.36). Pooling of six studies of extended treatment with bupropion failed to detect a significant effect (RR 1.15, 95% CI 0.98 to 1.35). Two small trials of oral nicotine replacement treatment (NRT) failed to detect an effect, but treatment compliance was low, and in two other trials of oral NRT in which short-term abstainers were randomly assigned, a significant effect of intervention was noted. At the moment, there is insufficient evidence to support the use of any specific behavioural intervention to help smokers who have successfully quit for a short time to avoid relapse. The verdict is strongest for interventions focused on identifying and resolving tempting situations, as most studies were concerned with these. Little research is available regarding other behavioural approaches.Extended treatment with varenicline may prevent relapse. Extended treatment with bupropion is unlikely to have a clinically important effect. Studies of extended treatment with nicotine replacement are needed.

Competency-Based Training and Worker Turnover in Community Supports for People with IDD: Results from a Group Randomized Controlled Study

ERIC Educational Resources Information Center

Bogenschutz, Matthew; Nord, Derek; Hewitt, Amy

2015-01-01

Turnover among direct support professionals (DSPs) in community support settings for individuals with intellectual and developmental disabilities (IDD) has been regarded as a challenge since tracking of this workforce began in the 1980s. This study utilized a group randomized controlled design to test the effects of a competency-based training…

WWC Review of the Report "Evaluation of the College Possible Program: Results from a Randomized Controlled Trial." What Works Clearinghouse Single Study Review

ERIC Educational Resources Information Center

What Works Clearinghouse, 2014

2014-01-01

The 2013 study, "Evaluation of the College Possible Program: Results From a Randomized Controlled Trial", investigated the effect of the "College Possible" program, which is designed to serve low-income high school students by providing SAT/ACT test preparation, financial aid consulting, and college admissions guidance in an…

Effects of the Caregiver Interaction Profile Training on Caregiver-Child Interactions in Dutch Child Care Centers: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Helmerhorst, Katrien O.; Riksen-Walraven, J. Marianne; Fukkink, Ruben G.; Tavecchio, Louis W. C.; Gevers Deynoot-Schaub, Mirjam J. J. M.

2017-01-01

Background: Previous studies underscore the need to improve caregiver-child interactions in early child care centers. Objective: In this study we used a randomized controlled trial to examine whether a 5-week video feedback training can improve six key interactive skills of caregivers in early child care centers: Sensitive responsiveness, respect…

Design of the Physical exercise during Adjuvant Chemotherapy Effectiveness Study (PACES): a randomized controlled trial to evaluate effectiveness and cost-effectiveness of physical exercise in improving physical fitness and reducing fatigue.

PubMed

van Waart, Hanna; Stuiver, Martijn M; van Harten, Wim H; Sonke, Gabe S; Aaronson, Neil K

2010-12-07

Cancer chemotherapy is frequently associated with a decline in general physical condition, exercise tolerance, and muscle strength and with an increase in fatigue. While accumulating evidence suggests that physical activity and exercise interventions during chemotherapy treatment may contribute to maintaining cardiorespiratory fitness and strength, the results of studies conducted to date have not been consistent. Additional research is needed to determine the optimal intensity of exercise training programs in general and in particular the relative effectiveness of supervised, outpatient (hospital- or physical therapy practice-based) versus home-based programs. This multicenter, prospective, randomized trial will evaluate the effectiveness of a low to moderate intensity, home-based, self-management physical activity program, and a high intensity, structured, supervised exercise program, in maintaining or enhancing physical fitness (cardiorespiratory fitness and muscle strength), in minimizing fatigue and in enhancing the health-related quality of life (HRQoL). Patients receiving adjuvant chemotherapy for breast or colon cancer (n = 360) are being recruited from twelve hospitals in the Netherlands, and randomly allocated to one of the two treatment groups or to a 'usual care' control group. Performance-based and self-reported outcomes are assessed at baseline, at the end of chemotherapy and at six month follow-up. This large, multicenter, randomized clinical trial will provide additional empirical evidence regarding the effectiveness of physical exercise during adjuvant chemotherapy in enhancing physical fitness, minimizing fatigue, and maintaining or enhancing patients' quality of life. If demonstrated to be effective, exercise intervention programs will be a welcome addition to the standard program of care offered to patients with cancer receiving chemotherapy. This study is registered at the Netherlands Trial Register (NTR 2159).

Online Alcohol Assessment and Feedback for Hazardous and Harmful Drinkers: Findings From the AMADEUS-2 Randomized Controlled Trial of Routine Practice in Swedish Universities.

PubMed

Bendtsen, Preben; Bendtsen, Marcus; Karlsson, Nadine; White, Ian R; McCambridge, Jim

2015-07-09

Previous research on the effectiveness of online alcohol interventions for college students has shown mixed results. Small benefits have been found in some studies and because online interventions are inexpensive and possible to implement on a large scale, there is a need for further study. This study evaluated the effectiveness of national provision of a brief online alcohol intervention for students in Sweden. Risky drinkers at 9 colleges and universities in Sweden were invited by mail and identified using a single screening question. These students (N=1605) gave consent and were randomized into a 2-arm parallel group randomized controlled trial consisting of immediate or delayed access to a fully automated online assessment and intervention with personalized feedback. After 2 months, there was no strong evidence of effectiveness with no statistically significant differences in the planned analyses, although there were some indication of possible benefit in sensitivity analyses suggesting an intervention effect of a 10% reduction (95% CI -30% to 10%) in total weekly alcohol consumption. Also, differences in effect sizes between universities were seen with participants from a major university (n=365) reducing their weekly alcohol consumption by 14% (95% CI -23% to -4%). However, lower recruitment than planned and differential attrition in the intervention and control group (49% vs 68%) complicated interpretation of the outcome data. Any effects of current national provision are likely to be small and further research and development work is needed to enhance effectiveness. International Standard Randomized Controlled Trial Number (ISRCTN): 02335307; http://www.isrctn.com/ISRCTN02335307 (Archived by WebCite at http://www.webcitation.org/6ZdPUh0R4).

Comparative effectiveness and cost-effectiveness of Chuna manual therapy versus conventional usual care for nonacute low back pain: study protocol for a pilot multicenter, pragmatic randomized controlled trial (pCRN study).

PubMed

Shin, Byung-Cheul; Kim, Me-Riong; Cho, Jae-Heung; Jung, Jae-Young; Kim, Koh-Woon; Lee, Jun-Hwan; Nam, Kibong; Lee, Min Ho; Hwang, Eui-Hyoung; Heo, Kwang-Ho; Kim, Namkwen; Ha, In-Hyuk

2017-01-17

While Chuna manual therapy is a Korean manual therapy widely used primarily for low back pain (LBP)-related disorders in Korea, well-designed studies on the comparative effectiveness of Chuna manual therapy are scarce. This study is the protocol for a three-armed, multicenter, pragmatic randomized controlled pilot trial. Sixty severe nonacute LBP patients (pain duration of at least 3 weeks, Numeric Rating Scale (NRS) ≥5) will be recruited at four Korean medicine hospitals. Participants will be randomly allocated to the Chuna group (n = 20), usual care group (n = 20), or Chuna plus usual care group (n = 20) for 6 weeks of treatment. Usual care will consist of orally administered conventional medicine, physical therapy, and back pain care education. The trial will be conducted with outcome assessor and statistician blinding. The primary endpoint will be NRS of LBP at week 7 post randomization. Secondary outcomes include NRS of leg pain, the Oswestry Disability Index (ODI), the Patient Global Impression of Change (PGIC), the Credibility and Expectancy Questionnaire, lumbar range of motion (ROM), the EuroQol-5 Dimension (EQ-5D) health survey, the Health Utility Index III (HUI-III), and economic evaluation and safety data. Post-treatment follow-ups will be conducted at 1, 4, and 10 weeks after conclusion of treatment. This study will assess the comparative effectiveness of Chuna manual therapy compared to conventional usual care. Costs and effectiveness (utility) data will be analyzed for exploratory cost-effectiveness analysis. If this pilot study does not reach a definite conclusion due to its small sample size, these results will be used as preliminary results to calculate sample size for future large-scale clinical trials and contribute in the assessment of feasibility of a full-scale multicenter trial. Clinical Research Information Service (CRIS), KCT0001850 . Registered on 17 March 2016.

Human comfort response to dominant random motions in longitudinal modes of aircraft motion

NASA Technical Reports Server (NTRS)

Stone, R. W., Jr.

1980-01-01

The effects of random vertical and longitudinal accelerations and pitching velocity passenger ride comfort responses were examined on the NASA Langley Visual Motion Simulator. Effects of power spectral density shape were studied for motions where the peak was between 0 and 2 Hz. The subjective rating data and the physical motion data obtained are presented without interpretation or detailed analysis. There existed motions in all other degrees of freedom as well as the particular pair of longitudinal airplane motions studied. These unwanted motions, caused by the characteristics of the simulator may have introduced some interactive effects on passenger responses.

Bias in Observational Studies of Prevalent Users: Lessons for Comparative Effectiveness Research From a Meta-Analysis of Statins

PubMed Central

Danaei, Goodarz; Tavakkoli, Mohammad; Hernán, Miguel A.

2012-01-01

Randomized clinical trials (RCTs) are usually the preferred strategy with which to generate evidence of comparative effectiveness, but conducting an RCT is not always feasible. Though observational studies and RCTs often provide comparable estimates, the questioning of observational analyses has recently intensified because of randomized-observational discrepancies regarding the effect of postmenopausal hormone replacement therapy on coronary heart disease. Reanalyses of observational data that excluded prevalent users of hormone replacement therapy led to attenuated discrepancies, which begs the question of whether exclusion of prevalent users should be generally recommended. In the current study, the authors evaluated the effect of excluding prevalent users of statins in a meta-analysis of observational studies of persons with cardiovascular disease. The pooled, multivariate-adjusted mortality hazard ratio for statin use was 0.77 (95% confidence interval (CI): 0.65, 0.91) in 4 studies that compared incident users with nonusers, 0.70 (95% CI: 0.64, 0.78) in 13 studies that compared a combination of prevalent and incident users with nonusers, and 0.54 (95% CI: 0.45, 0.66) in 13 studies that compared prevalent users with nonusers. The corresponding hazard ratio from 18 RCTs was 0.84 (95% CI: 0.77, 0.91). It appears that the greater the proportion of prevalent statin users in observational studies, the larger the discrepancy between observational and randomized estimates. PMID:22223710

The internal validity of arthroscopic simulators and their effectiveness in arthroscopic education.

PubMed

Slade Shantz, Jesse Alan; Leiter, Jeff R S; Gottschalk, Tania; MacDonald, Peter Benjamin

2014-01-01

The purpose of this systematic review was to identify standard procedures for the validation of arthroscopic simulators and determine whether simulators improve the surgical skills of users. Arthroscopic simulator validation studies and randomized trials assessing the effectiveness of arthroscopic simulators in education were identified from online databases, as well as, grey literature and reference lists. Only validation studies and randomized trials were included for review. Study heterogeneity was calculated and where appropriate, study results were combined employing a random effects model. Four hundred and thirteen studies were reviewed. Thirteen studies met the inclusion criteria assessing the construct validity of simulators. A pooled analysis of internal validation studies determined that simulators could discriminate between novice and experts, but not between novice and intermediate trainees on time of completion of a simulated task. Only one study assessed the utility of a knee simulator in training arthroscopic skills directly and demonstrated that the skill level of simulator-trained residents was greater than non-simulator-trained residents. Excessive heterogeneity exists in the literature to determine the internal and transfer validity of arthroscopic simulators currently available. Evidence suggests that simulators can discriminate between novice and expert users, but discrimination between novice and intermediate trainees in surgical education should be paramount. International standards for the assessment of arthroscopic simulator validity should be developed to increase the use and effectiveness of simulators in orthopedic surgery.

Theory of Mind training in children with autism: a randomized controlled trial.

PubMed

Begeer, Sander; Gevers, Carolien; Clifford, Pamela; Verhoeve, Manja; Kat, Kirstin; Hoddenbach, Elske; Boer, Frits

2011-08-01

Many children with Autism Spectrum Disorders (ASD) participate in social skills or Theory of Mind (ToM) treatments. However, few studies have shown evidence for their effectiveness. The current study used a randomized controlled design to test the effectiveness of a 16-week ToM treatment in 8-13 year old children with ASD and normal IQs (n = 40). The results showed that, compared to controls, the treated children with ASD improved in their conceptual ToM skills, but their elementary understanding, self reported empathic skills or parent reported social behaviour did not improve. Despite the effects on conceptual understanding, the current study does not indicate strong evidence for the effectiveness of a ToM treatment on the daily life mindreading skills.

Statins as antiarrhythmics: a systematic review part I: effects on risk of atrial fibrillation.

PubMed

Abuissa, Hussam; O'Keefe, James H; Bybee, Kevin A

2009-10-01

Recent studies have demonstrated that statins may possess antiarrhythmic properties in addition to their lipid-lowering effects. Studies which reported the association of statins with the incidence of atrial arrhythmias were identified through a systematic review of published literature. One randomized, placebo-controlled trial of 200 patients undergoing cardiac surgery showed that atorvastatin decreased the incidence of postoperative atrial fibrillation by 61%. Observational studies in patients with stable coronary disease, left ventricular dysfunction, or those undergoing cardiac or noncardiac surgery show that statin therapy is associated with an approximately 50% lower rate of atrial fibrillation. Two small randomized trials reported conflicting results: one showing that atorvastatin reduced the recurrence of AF after electrical cardioversion and the other finding that pravastatin did not. Published data suggests that statins may possess antiarrhythmic properties that reduce the propensity for atrial fibrillation. Most of this data is observational; more randomized, placebo-controlled trials are needed.

The effects of office ergonomic training on musculoskeletal complaints, sickness absence, and psychological well-being: a cluster randomized control trial.

PubMed

Mahmud, Norashikin; Kenny, Dianna T; Md Zein, Raemy; Hassan, Siti Nurani

2015-03-01

This study explored whether musculoskeletal complaints can be reduced by the provision of ergonomics education. A cluster randomized controlled trial study was conducted in which 3 units were randomized to intervention and received training and 3 units were given a leaflet. The effect of intervention on knowledge, workstation practices, musculoskeletal complaints, sickness absence, and psychological well-being were assessed at 6 and 12 months. Although there was no increment of knowledge among workers, significant improvements in workstation practices in the use of monitor, keyboard, and chair were observed. There were significant reductions in neck and upper and lower back complaints among workers but these did not translate into fewer days lost from work. Workers' stress was found to be significantly reduced across the studies. In conclusion, office ergonomics training can be beneficial in reducing musculoskeletal risks and stress among workers. © 2011 APJPH.

Worksite Environmental Interventions for Obesity Prevention and Control: Evidence from Group Randomized Trials.

PubMed

Fernandez, Isabel Diana; Becerra, Adan; Chin, Nancy P

2014-06-01

Worksites provide multiple advantages to prevent and treat obesity and to test environmental interventions to tackle its multiple causal factors. We present a literature review of group-randomized and non-randomized trials that tested worksite environmental, multiple component interventions for obesity prevention and control paying particular attention to the conduct of formative research prior to intervention development. The evidence on environmental interventions on measures of obesity appears to be strong since most of the studies have a low (4/8) and unclear (2/8) risk of bias. Among the studies reviewed whose potential risk of bias was low, the magnitude of the effect was modest and sometimes in the unexpected direction. None of the four studies describing an explicit formative research stage with clear integration of findings into the intervention was able to demonstrate an effect on the main outcome of interest. We present alternative explanation for the findings and recommendations for future research.

The effect of parent education program for preschool children with developmental disabilities: A randomized controlled trial.

PubMed

Leung, Cynthia; Chan, Stanley; Lam, Tiney; Yau, Sharon; Tsang, Sandra

2016-09-01

This study aimed to evaluate the efficacy of a parent education program, the Happy Parenting program, for Chinese preschool children with developmental disabilities. This study adopted randomized controlled trial design without blinding. Participants were randomized into intervention group (n=62) who were offered the Happy Parenting program delivered by educational psychologists and trainee educational psychologists, and a control group (n=57) who were offered a parent talk after the intervention group had completed treatment. Parent participants were requested to complete questionnaires on their children's behavior, their parenting stress, and discipline strategies. Analysis was by intention-to-treat. The results indicated significant decrease in child problem behaviors, parenting stress and dysfunctional discipline strategies in the intervention group at post-intervention. This study provided promising evidence on the effectiveness of a parent education program, the Happy Parenting program, for Chinese preschool children with developmental disabilities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mediation and spillover effects in group-randomized trials: a case study of the 4Rs educational intervention

PubMed Central

VanderWeele, Tyler J.; Hong, Guanglei; Jones, Stephanie M.; Brown, Joshua L.

2013-01-01

Peer influence and social interactions can give rise to spillover effects in which the exposure of one individual may affect outcomes of other individuals. Even if the intervention under study occurs at the group or cluster level as in group-randomized trials, spillover effects can occur when the mediator of interest is measured at a lower level than the treatment. Evaluators who choose groups rather than individuals as experimental units in a randomized trial often anticipate that the desirable changes in targeted social behaviors will be reinforced through interference among individuals in a group exposed to the same treatment. In an empirical evaluation of the effect of a school-wide intervention on reducing individual students’ depressive symptoms, schools in matched pairs were randomly assigned to the 4Rs intervention or the control condition. Class quality was hypothesized as an important mediator assessed at the classroom level. We reason that the quality of one classroom may affect outcomes of children in another classroom because children interact not simply with their classmates but also with those from other classes in the hallways or on the playground. In investigating the role of class quality as a mediator, failure to account for such spillover effects of one classroom on the outcomes of children in other classrooms can potentially result in bias and problems with interpretation. Using a counterfactual conceptualization of direct, indirect and spillover effects, we provide a framework that can accommodate issues of mediation and spillover effects in group randomized trials. We show that the total effect can be decomposed into a natural direct effect, a within-classroom mediated effect and a spillover mediated effect. We give identification conditions for each of the causal effects of interest and provide results on the consequences of ignoring “interference” or “spillover effects” when they are in fact present. Our modeling approach disentangles these effects. The analysis examines whether the 4Rs intervention has an effect on children's depressive symptoms through changing the quality of other classes as well as through changing the quality of a child's own class. PMID:23997375

A preliminary double-blind, placebo-controlled randomized study of baclofen effects in alcoholic smokers

PubMed Central

Zywiak, William H.; Edwards, Steven M.; Tidey, Jennifer W.; Swift, Robert M.; Kenna, George A.

2014-01-01

Rationale There is presently no approved single treatment for dual alcohol and nicotine dependencies. Objective This pilot study investigated baclofen effects in alcoholic smokers. Methods This was a preliminary double-blind placebo-controlled randomized clinical study with 30 alcoholic smokers randomized to baclofen at 80 mg/day or placebo. A subgroup (n=18) participated in an alcohol cue-reactivity experiment. Results Baclofen, compared with placebo, significantly decreased the percent days of abstinence from alcohol-tobacco co-use (p=0.004). Alcohol dependence severity moderated baclofen effects, with the higher severity group having the greater baclofen response (p<0.001). Although the percent days of alcohol-tobacco co-use declined in both groups, this decline was greater after placebo than baclofen (p<0.001). Secondary analyses on alcohol or tobacco use alone suggested that the increase in percent days of co-abstinence was driven by the medication differences on heavy drinking days and on percent days smoking. In the cue-reactivity substudy, baclofen slightly decreased alcohol urge (p=0.058) and significantly reduced salivation (p=0.001), but these effects were not related to cue type. Conclusions This study provides preliminary evidence suggesting a possible role of baclofen in the treatment of alcoholic smokers. However, the mixed results and the small sample require larger confirmatory studies. PMID:24973894

Nutritively Sweetened Beverage Consumption and Body Weight: A Systematic Review and Meta-Analysis of Randomized Experiments

PubMed Central

Mattes, Richard D; Shikany, James M; Kaiser, Kathryn A; Allison, David B

2010-01-01

Nutritively sweetened beverages (NSBs) may play a role in the obesity epidemic. We abstracted data from randomized controlled trials (RCTs) and evidence-based reviews through January 2009 concerning effects of consumption of NSBs on changes in body weight and adiposity. Studies included were those 1) conducted in humans; 2) lasting at least 3 weeks; 3) incorporating random assignment of subjects to conditions that differed only in the consumption of NSBs; and 4) including an adiposity indicator as an outcome. Twelve studies met the inclusion criteria. Meta-analysis of 6 studies that added NSBs to persons’ diets showed dose-dependent increases in weight. Contrarily, meta-analysis of studies that attempted to reduce NSB consumption consistently showed no effect on BMI when all subjects were considered. Meta-analysis of studies providing access to results separately for subjects overweight at baseline showed a significant effect of a roughly 0.35 standard deviations lesser BMI change (i.e., more weight loss or less weight gain) relative to controls. The current evidence does not demonstrate conclusively that NSB consumption has uniquely contributed to obesity or that reducing NSB consumption will reduce BMI levels in general. We recommend an adequately powered RCT among overweight persons, among whom there is suggestive evidence of an effect. PMID:20524996

Nicotine patches and quitline counseling to help hospitalized smokers stay quit: study protocol for a randomized controlled trial.

PubMed

Cummins, Sharon; Zhu, Shu-Hong; Gamst, Anthony; Kirby, Carrie; Brandstein, Kendra; Klonoff-Cohen, Hillary; Chaplin, Edward; Morris, Timothy; Seymann, Gregory; Lee, Joshua

2012-08-01

Hospitalized smokers often quit smoking, voluntarily or involuntarily; most relapse soon after discharge. Extended follow-up counseling can help prevent relapse. However, it is difficult for hospitals to provide follow-up and smokers rarely leave the hospital with quitting aids (for example, nicotine patches). This study aims to test a practical model in which hospitals work with a state cessation quitline. Hospital staff briefly intervene with smokers at bedside and refer them to the quitline. Depending on assigned condition, smokers may receive nicotine patches at discharge or extended quitline telephone counseling post-discharge. This project establishes a practical model that lends itself to broader dissemination, while testing the effectiveness of the interventions in a rigorous randomized trial. This randomized clinical trial (N = 1,640) tests the effect of two interventions on long-term quit rates of hospitalized smokers in a 2 x 2 factorial design. The interventions are (1) nicotine patches (eight-week, step down program) dispensed at discharge and (2) proactive telephone counseling provided by the state quitline after discharge. Subjects are randomly assigned into: usual care, nicotine patches, telephone counseling, or both patches and counseling. It is hypothesized that patches and counseling have independent effects and their combined effect is greater than either alone. The primary outcome measure is thirty-day abstinence at six months; a secondary outcome is biochemically validated smoking status. Cost-effectiveness analysis is conducted to compare each intervention condition (patch alone, counseling alone, and combined interventions) against the usual care condition. Further, this study examines whether smokers' medical diagnosis is a moderator of treatment effect. Generalized linear (binomial) mixed models will be used to study the effect of treatment on abstinence rates. Clustering is accounted for with hospital-specific random effects. If this model is effective, quitlines across the U.S. could work with interested hospitals to set up similar systems. Hospital accreditation standards related to tobacco cessation performance measures require follow-up after discharge and provide additional incentive for hospitals to work with quitlines. The ubiquity of quitlines, combined with the consistency of quitline counseling delivery as centralized state operations, make this partnership attractive. Smoking cessation in hospitalized smokers NCT01289275. Date of registration February 1, 2011; date of first patient August 3, 2011.

Do federal and state audits increase compliance with a grant program to improve municipal infrastructure (AUDIT study): study protocol for a randomized controlled trial.

PubMed

De La O, Ana L; Martel García, Fernando

2014-09-03

Poor governance and accountability compromise young democracies' efforts to provide public services critical for human development, including water, sanitation, health, and education. Evidence shows that accountability agencies like superior audit institutions can reduce corruption and waste in federal grant programs financing service infrastructure. However, little is know about their effect on compliance with grant reporting and resource allocation requirements, or about the causal mechanisms. This study protocol for an exploratory randomized controlled trial tests the hypothesis that federal and state audits increase compliance with a federal grant program to improve municipal service infrastructure serving marginalized households. The AUDIT study is a block randomized, controlled, three-arm parallel group exploratory trial. A convenience sample of 5 municipalities in each of 17 states in Mexico (n=85) were block randomized to be audited by federal auditors (n=17), by state auditors (n=17), and a control condition outside the annual program of audits (n=51) in a 1:1:3 ratio. Replicable and verifiable randomization was performed using publicly available lottery numbers. Audited municipalities were included in the national program of audits and received standard audits on their use of federal public service infrastructure grants. Municipalities receiving moderate levels of grant transfers were recruited, as these were outside the auditing sampling frame--and hence audit program--or had negligible probabilities of ever being audited. The primary outcome measures capture compliance with the grant program and markers for the causal mechanisms, including deterrence and information effects. Secondary outcome measure include differences in audit reports across federal and state auditors, and measures like career concerns, political promotions, and political clientelism capturing synergistic effects with municipal accountability systems. The survey firm and research assistants assessing outcomes were blind to treatment status. This study will improve our understanding of local accountability systems for public service delivery in the 17 states under study, and may have downstream policy implications. The study design also demonstrates the use of verifiable and replicable randomization, and of sequentially partitioned hypotheses to reduce the Type I error rate in multiple hypothesis tests. Controlled-trials.com Identifier ISRCTN22381841: Date registered 02/11/2012.

Low level laser therapy and hair regrowth: an evidence-based review.

PubMed

Zarei, Mina; Wikramanayake, Tongyu C; Falto-Aizpurua, Leyre; Schachner, Lawrence A; Jimenez, Joaquin J

2016-02-01

Despite the current treatment options for different types of alopecia, there is a need for more effective management options. Recently, low-level laser therapy (LLLT) was evaluated for stimulating hair growth. Here, we reviewed the current evidence on the LLLT effects with an evidence-based approach, focusing more on randomized controlled studies by critically evaluating them. In order to investigate whether in individuals presenting with hair loss (male pattern hair loss (MPHL), female pattern hair loss (FPHL), alopecia areata (AA), and chemotherapy-induced alopecia (CIA)) LLLT is effective for hair regrowth, several databases including PubMed, Google Scholar, Medline, Embase, and Cochrane Database were searched using the following keywords: Alopecia, Hair loss, Hair growth, Low level laser therapy, Low level light therapy, Low energy laser irradiation, and Photobiomodulation. From the searches, 21 relevant studies were summarized in this review including 2 in vitro, 7 animal, and 12 clinical studies. Among clinical studies, only five were randomized controlled trials (RCTs), which evaluated LLLT effect on male and female pattern hair loss. The RCTs were critically appraised using the created checklist according to the Critical Appraisal for Therapy Articles Worksheet created by the Center of Evidence-Based Medicine, Oxford. The results demonstrated that all the performed RCTs have moderate to high quality of evidence. However, only one out of five studies performed intention-to-treat analysis, and only another study reported the method of randomization and subsequent concealment of allocation clearly; all other studies did not include this very important information in their reports. None of these studies reported the treatment effect of factors such as number needed to treat. Based on this review on all the available evidence about effect of LLLT in alopecia, we found that the FDA-cleared LLLT devices are both safe and effective in patients with MPHL and FPHL who did not respond or were not tolerant to standard treatments. Future randomized controlled trials of LLLT are strongly encouraged to be conducted and reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement to facilitate analysis and comparison.

Leveraging contact network structure in the design of cluster randomized trials.

PubMed

Harling, Guy; Wang, Rui; Onnela, Jukka-Pekka; De Gruttola, Victor

2017-02-01

In settings like the Ebola epidemic, where proof-of-principle trials have provided evidence of efficacy but questions remain about the effectiveness of different possible modes of implementation, it may be useful to conduct trials that not only generate information about intervention effects but also themselves provide public health benefit. Cluster randomized trials are of particular value for infectious disease prevention research by virtue of their ability to capture both direct and indirect effects of intervention, the latter of which depends heavily on the nature of contact networks within and across clusters. By leveraging information about these networks-in particular the degree of connection across randomized units, which can be obtained at study baseline-we propose a novel class of connectivity-informed cluster trial designs that aim both to improve public health impact (speed of epidemic control) and to preserve the ability to detect intervention effects. We several designs for cluster randomized trials with staggered enrollment, in each of which the order of enrollment is based on the total number of ties (contacts) from individuals within a cluster to individuals in other clusters. Our designs can accommodate connectivity based either on the total number of external connections at baseline or on connections only to areas yet to receive the intervention. We further consider a "holdback" version of the designs in which control clusters are held back from re-randomization for some time interval. We investigate the performance of these designs in terms of epidemic control outcomes (time to end of epidemic and cumulative incidence) and power to detect intervention effect, by simulating vaccination trials during an SEIR-type epidemic outbreak using a network-structured agent-based model. We compare results to those of a traditional Stepped Wedge trial. In our simulation studies, connectivity-informed designs lead to a 20% reduction in cumulative incidence compared to comparable traditional study designs, but have little impact on epidemic length. Power to detect intervention effect is reduced in all connectivity-informed designs, but "holdback" versions provide power that is very close to that of a traditional Stepped Wedge approach. Incorporating information about cluster connectivity in the design of cluster randomized trials can increase their public health impact, especially in acute outbreak settings. Using this information helps control outbreaks-by minimizing the number of cross-cluster infections-with very modest cost in terms of power to detect effectiveness.

Randomized clinical trial of bright light therapy for antepartum depression: preliminary findings.

PubMed

Epperson, C Neill; Terman, Michael; Terman, Jiuan Su; Hanusa, Barbara H; Oren, Dan A; Peindl, Kathleen S; Wisner, Katherine L

2004-03-01

Bright light therapy was shown to be a promising treatment for depression during pregnancy in a recent open-label study. In an extension of this work, we report findings from a double-blind placebo-controlled pilot study. Ten pregnant women with DSM-IV major depressive disorder were randomly assigned from April 2000 to January 2002 to a 5-week clinical trial with either a 7000 lux (active) or 500 lux (placebo) light box. At the end of the randomized controlled trial, subjects had the option of continuing in a 5-week extension phase. The Structured Interview Guide for the Hamilton Depression Scale-Seasonal Affective Disorder Version was administered to assess changes in clinical status. Salivary melatonin was used to index circadian rhythm phase for comparison with antidepressant results. Although there was a small mean group advantage of active treatment throughout the randomized controlled trial, it was not statistically significant. However, in the longer 10-week trial, the presence of active versus placebo light produced a clear treatment effect (p =.001) with an effect size (0.43) similar to that seen in antidepressant drug trials. Successful treatment with bright light was associated with phase advances of the melatonin rhythm. These findings provide additional evidence for an active effect of bright light therapy for antepartum depression and underscore the need for an expanded randomized clinical trial.

Implementation of a guideline for low back pain management in primary care: a cost-effectiveness analysis.

PubMed

Becker, Annette; Held, Heiko; Redaelli, Marcus; Chenot, Jean F; Leonhardt, Corinna; Keller, Stefan; Baum, Erika; Pfingsten, Michael; Hildebrandt, Jan; Basler, Heinz-Dieter; Kochen, Michael M; Donner-Banzhoff, Norbert; Strauch, Konstantin

2012-04-15

Cost-effectiveness analysis alongside a cluster randomized controlled trial. To study the cost-effectiveness of 2 low back pain guideline implementation (GI) strategies. Several evidence-based guidelines on management of low back pain have been published. However, there is still no consensus on the effective implementation strategy. Especially studies on the economic impact of different implementation strategies are lacking. This analysis was performed alongside a cluster randomized controlled trial on the effectiveness of 2 GI strategies (physician education alone [GI] or physician education in combination with motivational counseling [MC] by practice nurses)--both compared with the postal dissemination of the guideline (control group, C). Sociodemographic data, pain characteristics, and cost data were collected by interview at baseline and after 6 and 12 months. low back pain-related health care costs were valued for 2004 from the societal perspective. For the cost analysis, 1322 patients from 126 general practices were included. Both interventions showed lower direct and indirect costs as well as better patient outcomes during follow-up compared with controls. In addition, both intervention arms showed superiority of cost-effectiveness to C. The effects attenuated when adjusting for differences of health care utilization prior to patient recruitment and for clustering of data. Trends in cost-effectiveness are visible but need to be confirmed in future studies. Researchers performing cost-evaluation studies should test for baseline imbalances of health care utilization data instead of judging on the randomization success by reviewing non-cost parameters like clinical data alone.

Hypothesis testing in clinical trials.

PubMed

Green, S B

2000-08-01

In designing and analyzing any clinical trial, two issues related to patient heterogeneity must be considered: (1) the effect of chance and (2) the effect of bias. These issues are addressed by enrolling adequate numbers of patients in the study and using randomization for treatment assignment. An "intention-to-treat" analysis of outcome data includes all individuals randomized and counted in the group to which they are randomized. There is an increased risk of spurious results with a greater number of subgroup analyses, particularly when these analyses are data derived. Factorial designs are sometimes appropriate and can lead to efficiencies by addressing more than one comparison of interventions in a single trial.

Random lasing actions in self-assembled perovskite nanoparticles

NASA Astrophysics Data System (ADS)

Liu, Shuai; Sun, Wenzhao; Li, Jiankai; Gu, Zhiyuan; Wang, Kaiyang; Xiao, Shumin; Song, Qinghai

2016-05-01

Solution-based perovskite nanoparticles have been intensively studied in the past few years due to their applications in both photovoltaic and optoelectronic devices. Here, based on the common ground between solution-based perovskite and random lasers, we have studied the mirrorless lasing actions in self-assembled perovskite nanoparticles. After synthesis from a solution, discrete lasing peaks have been observed from optically pumped perovskites without any well-defined cavity boundaries. We have demonstrated that the origin of the random lasing emissions is the scattering between the nanostructures in the perovskite microplates. The obtained quality (Q) factors and thresholds of random lasers are around 500 and 60 μJ/cm2, respectively. Both values are comparable to the conventional perovskite microdisk lasers with polygon-shaped cavity boundaries. From the corresponding studies on laser spectra and fluorescence microscope images, the lasing actions are considered random lasers that are generated by strong multiple scattering in random gain media. In additional to conventional single-photon excitation, due to the strong nonlinear effects of perovskites, two-photon pumped random lasers have also been demonstrated for the first time. We believe this research will find its potential applications in low-cost coherent light sources and biomedical detection.

Exercise, Manual Therapy, and Booster Sessions in Knee Osteoarthritis: Cost-Effectiveness Analysis From a Multicenter Randomized Controlled Trial.

PubMed

Bove, Allyn M; Smith, Kenneth J; Bise, Christopher G; Fritz, Julie M; Childs, John; Brennan, Gerard P; Abbott, J Haxby; Fitzgerald, G Kelley

2018-01-01

Limited information exists regarding the cost-effectiveness of rehabilitation strategies for individuals with knee osteoarthritis (OA). The study objective was to compare the cost-effectiveness of 4 different combinations of exercise, manual therapy, and booster sessions for individuals with knee OA. This economic evaluation involved a cost-effectiveness analysis performed alongside a multicenter randomized controlled trial. The study took place in Pittsburgh, Pennsylvania; Salt Lake City, Utah; and San Antonio, Texas. The study participants were 300 individuals taking part in a randomized controlled trial investigating various physical therapy strategies for knee OA. Participants were randomized into 4 treatment groups: exercise only (EX), exercise plus booster sessions (EX+B), exercise plus manual therapy (EX+MT), and exercise plus manual therapy and booster sessions (EX+MT+B). For the 2-year base case scenario, a Markov model was constructed using the United States societal perspective and a 3% discount rate for costs and quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios were calculated to compare differences in cost per QALY gained among the 4 treatment strategies. In the 2-year analysis, booster strategies (EX+MT+B and EX+B) dominated no-booster strategies, with both lower health care costs and greater effectiveness. EX+MT+B had the lowest total health care costs. EX+B cost ${\\$}$1061 more and gained 0.082 more QALYs than EX+MT+B, for an incremental cost-effectiveness ratio of ${\\$}$12,900/QALY gained. The small number of total knee arthroplasty surgeries received by individuals in this study made the assessment of whether any particular strategy was more successful at delaying or preventing surgery in individuals with knee OA difficult. Spacing exercise-based physical therapy sessions over 12 months using periodic booster sessions was less costly and more effective over 2 years than strategies not containing booster sessions for individuals with knee OA. © 2017 American Physical Therapy Association

Lipid profile changes after pomegranate consumption: A systematic review and meta-analysis of randomized controlled trials.

PubMed

Sahebkar, Amirhossein; Simental-Mendía, Luis E; Giorgini, Paolo; Ferri, Claudio; Grassi, Davide

2016-10-15

Transport of oxidized low-density lipoprotein across the endothelium into the artery wall is considered a fundamental priming step for the atherosclerotic process. Recent studies reported potential therapeutic effects of micronutrients found in natural products, indicating positive applications for controlling the pathogenesis of chronic cardiovascular disease driven by cardiovascular risk factors and oxidative stress. A particular attention has been recently addressed to pomegranate; however findings of clinical studies have been contrasting. To evaluate the effects of pomegranate consumption on plasma lipid concentrations through a systematic review and meta-analysis of randomized controlled trials (RCTs). The study was designed according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. Scopus and Medline databases were searched to identify randomized placebo-controlled trials investigating the impact of pomegranate on plasma lipid concentrations. A fixed-effects model and the generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the one-study remove approach. Random-effects meta-regression was performed to assess the impact of potential confounders on the estimated effect sizes. A total of 545 individuals were recruited from the 12 RCTs. Fixed-effect meta-analysis of data from 12 RCTs (13 treatment arms) did not show any significant effect of pomegranate consumption on plasma lipid concentrations. The results of meta-regression did not suggest any significant association between duration of supplementation and impact of pomegranate on total cholesterol and HDL-C, while an inverse association was found with changes in triglycerides levels (slope: -1.07; 95% CI: -2.03 to -0.11; p = 0.029). There was no association between the amount of pomegranate juice consumed per day and respective changes in plasma total cholesterol, LDL-C, HDL-C and triglycerides. The present meta-analysis of RCTs did not suggest any effect of pomegranate consumption on lipid profile in human. Copyright © 2016. Published by Elsevier GmbH.

Multiple-trait structured antedependence model to study the relationship between litter size and birth weight in pigs and rabbits.

PubMed

David, Ingrid; Garreau, Hervé; Balmisse, Elodie; Billon, Yvon; Canario, Laurianne

2017-01-20

Some genetic studies need to take into account correlations between traits that are repeatedly measured over time. Multiple-trait random regression models are commonly used to analyze repeated traits but suffer from several major drawbacks. In the present study, we developed a multiple-trait extension of the structured antedependence model (SAD) to overcome this issue and validated its usefulness by modeling the association between litter size (LS) and average birth weight (ABW) over parities in pigs and rabbits. The single-trait SAD model assumes that a random effect at time [Formula: see text] can be explained by the previous values of the random effect (i.e. at previous times). The proposed multiple-trait extension of the SAD model consists in adding a cross-antedependence parameter to the single-trait SAD model. This model can be easily fitted using ASReml and the OWN Fortran program that we have developed. In comparison with the random regression model, we used our multiple-trait SAD model to analyze the LS and ABW of 4345 litters from 1817 Large White sows and 8706 litters from 2286 L-1777 does over a maximum of five successive parities. For both species, the multiple-trait SAD fitted the data better than the random regression model. The difference between AIC of the two models (AIC_random regression-AIC_SAD) were equal to 7 and 227 for pigs and rabbits, respectively. A similar pattern of heritability and correlation estimates was obtained for both species. Heritabilities were lower for LS (ranging from 0.09 to 0.29) than for ABW (ranging from 0.23 to 0.39). The general trend was a decrease of the genetic correlation for a given trait between more distant parities. Estimates of genetic correlations between LS and ABW were negative and ranged from -0.03 to -0.52 across parities. No correlation was observed between the permanent environmental effects, except between the permanent environmental effects of LS and ABW of the same parity, for which the estimate of the correlation was strongly negative (ranging from -0.57 to -0.67). We demonstrated that application of our multiple-trait SAD model is feasible for studying several traits with repeated measurements and showed that it provided a better fit to the data than the random regression model.

Full Bayes Poisson gamma, Poisson lognormal, and zero inflated random effects models: Comparing the precision of crash frequency estimates.

PubMed

Aguero-Valverde, Jonathan

2013-01-01

In recent years, complex statistical modeling approaches have being proposed to handle the unobserved heterogeneity and the excess of zeros frequently found in crash data, including random effects and zero inflated models. This research compares random effects, zero inflated, and zero inflated random effects models using a full Bayes hierarchical approach. The models are compared not just in terms of goodness-of-fit measures but also in terms of precision of posterior crash frequency estimates since the precision of these estimates is vital for ranking of sites for engineering improvement. Fixed-over-time random effects models are also compared to independent-over-time random effects models. For the crash dataset being analyzed, it was found that once the random effects are included in the zero inflated models, the probability of being in the zero state is drastically reduced, and the zero inflated models degenerate to their non zero inflated counterparts. Also by fixing the random effects over time the fit of the models and the precision of the crash frequency estimates are significantly increased. It was found that the rankings of the fixed-over-time random effects models are very consistent among them. In addition, the results show that by fixing the random effects over time, the standard errors of the crash frequency estimates are significantly reduced for the majority of the segments on the top of the ranking. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Stochastic Simulation Framework for the Prediction of Strategic Noise Mapping and Occupational Noise Exposure Using the Random Walk Approach

PubMed Central

Haron, Zaiton; Bakar, Suhaimi Abu; Dimon, Mohamad Ngasri

2015-01-01

Strategic noise mapping provides important information for noise impact assessment and noise abatement. However, producing reliable strategic noise mapping in a dynamic, complex working environment is difficult. This study proposes the implementation of the random walk approach as a new stochastic technique to simulate noise mapping and to predict the noise exposure level in a workplace. A stochastic simulation framework and software, namely RW-eNMS, were developed to facilitate the random walk approach in noise mapping prediction. This framework considers the randomness and complexity of machinery operation and noise emission levels. Also, it assesses the impact of noise on the workers and the surrounding environment. For data validation, three case studies were conducted to check the accuracy of the prediction data and to determine the efficiency and effectiveness of this approach. The results showed high accuracy of prediction results together with a majority of absolute differences of less than 2 dBA; also, the predicted noise doses were mostly in the range of measurement. Therefore, the random walk approach was effective in dealing with environmental noises. It could predict strategic noise mapping to facilitate noise monitoring and noise control in the workplaces. PMID:25875019

Estimating overall exposure effects for the clustered and censored outcome using random effect Tobit regression models.

PubMed

Wang, Wei; Griswold, Michael E

2016-11-30

The random effect Tobit model is a regression model that accommodates both left- and/or right-censoring and within-cluster dependence of the outcome variable. Regression coefficients of random effect Tobit models have conditional interpretations on a constructed latent dependent variable and do not provide inference of overall exposure effects on the original outcome scale. Marginalized random effects model (MREM) permits likelihood-based estimation of marginal mean parameters for the clustered data. For random effect Tobit models, we extend the MREM to marginalize over both the random effects and the normal space and boundary components of the censored response to estimate overall exposure effects at population level. We also extend the 'Average Predicted Value' method to estimate the model-predicted marginal means for each person under different exposure status in a designated reference group by integrating over the random effects and then use the calculated difference to assess the overall exposure effect. The maximum likelihood estimation is proposed utilizing a quasi-Newton optimization algorithm with Gauss-Hermite quadrature to approximate the integration of the random effects. We use these methods to carefully analyze two real datasets. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Nitrofurantoin vs other prophylactic agents in reducing recurrent urinary tract infections in adult women: a systematic review and meta-analysis.

PubMed

Price, Jameca Renee; Guran, Larissa A; Gregory, W Thomas; McDonagh, Marian S

2016-11-01

The clinical and financial burden from bladder infections is significant. Daily antibiotic use is the recommended strategy for recurrent urinary tract infection prevention. Increasing antibiotic resistance rates, however, require immediate identification of innovative alternative prophylactic therapies. This systematic review aims to provide guidance on gaps in evidence to guide future research. The objective of this review was to provide current pooled estimates of randomized control trials comparing the effects of nitrofurantoin vs other agents in reducing recurrent urinary tract infections in adult, nonpregnant women and assess relative adverse side effects. Data sources included the following: MEDLINE, Jan. 1, 1946, to Jan. 31, 2015; Cochrane Central Register of Controlled Trials the Cochrane Database of Systematic Reviews, and web sites of the National Institute for Clinical Excellence, and the National Guideline Clearinghouse from 2000 to 2015. Randomized control trials of women with recurrent urinary tract infections comparing nitrofurantoin with any other treatment were included. A protocol for the study was developed a priori. Published guidance was followed for assessment of study quality. All meta-analyses were performed using random-effects models with Stats Direct Software. Dual review was used for all decisions and data abstraction. Twelve randomized control trials involving 1063 patients were included. One study that had a serious flaw was rated poor in quality, one study rated good, and the remainder fair. No significant differences in prophylactic antibiotic treatment with nitrofurantoin and norfloxacin, trimethoprim, sulfamethoxazole/trimethoprim, methamine hippurate, estriol, or cefaclor were found in clinical or microbiological cure in adult nonpregnant women with recurrent urinary tract infections (9 randomized control trials, 673 patients, relative risk ratio, 1.06; 95% confidence interval, 0.89-1.27; I 2 , 65%; and 12 randomized control trials, 1063 patients, relative risk ratio, 1.06; 95% confidence interval, 0.90-1.26; I 2 , 76%, respectively). Duration of prophylaxis also did not have a significant impact on outcomes. There was a statistically significant difference in overall adverse effects, with nitrofurantoin resulting in greater risk than other prophylactic treatments (10 randomized control trials, 948 patients, relative risk ratio, 2.17; 95% confidence interval, 1.34-3.50; I 2 , 61%). Overall, the majority of nitrofurantoin adverse effects were gastrointestinal, with a significant difference for withdrawals (12 randomized control trials, 1063 patients, relative risk ratio, 2.14; 95% confidence interval, 1.28-3.56; I 2 , 8%). Nitrofurantoin had similar efficacy but a greater risk of adverse events than other prophylactic treatments. Balancing the risks of adverse events, particularly gastrointestinal symptoms, with potential benefits of decreasing collateral ecological damage should be considered if selecting nitrofurantoin. Copyright © 2016 Elsevier Inc. All rights reserved.

Covariance functions for body weight from birth to maturity in Nellore cows.

PubMed

Boligon, A A; Mercadante, M E Z; Forni, S; Lôbo, R B; Albuquerque, L G

2010-03-01

The objective of this study was to estimate (co)variance functions using random regression models on Legendre polynomials for the analysis of repeated measures of BW from birth to adult age. A total of 82,064 records from 8,145 females were analyzed. Different models were compared. The models included additive direct and maternal effects, and animal and maternal permanent environmental effects as random terms. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of animal age (cubic regression) were considered as random covariables. Eight models with polynomials of third to sixth order were used to describe additive direct and maternal effects, and animal and maternal permanent environmental effects. Residual effects were modeled using 1 (i.e., assuming homogeneity of variances across all ages) or 5 age classes. The model with 5 classes was the best to describe the trajectory of residuals along the growth curve. The model including fourth- and sixth-order polynomials for additive direct and animal permanent environmental effects, respectively, and third-order polynomials for maternal genetic and maternal permanent environmental effects were the best. Estimates of (co)variance obtained with the multi-trait and random regression models were similar. Direct heritability estimates obtained with the random regression models followed a trend similar to that obtained with the multi-trait model. The largest estimates of maternal heritability were those of BW taken close to 240 d of age. In general, estimates of correlation between BW from birth to 8 yr of age decreased with increasing distance between ages.

Personalized contact strategies and predictors of time to survey completion: analysis of two sequential randomized trials.

PubMed

Dinglas, Victor D; Huang, Minxuan; Sepulveda, Kristin A; Pinedo, Mariela; Hopkins, Ramona O; Colantuoni, Elizabeth; Needham, Dale M

2015-01-09

Effective strategies for contacting and recruiting study participants are critical in conducting clinical research. In this study, we conducted two sequential randomized controlled trials of mail- and telephone-based strategies for contacting and recruiting participants, and evaluated participant-related variables' association with time to survey completion and survey completion rates. Subjects eligible for this study were survivors of acute lung injury who had been previously enrolled in a 12-month observational follow-up study evaluating their physical, cognitive and mental health outcomes, with their last study visit completed at a median of 34 months previously. Eligible subjects were contacted to complete a new research survey as part of two randomized trials, initially using a randomized mail-based contact strategy, followed by a randomized telephone-based contact strategy for non-responders to the mail strategy. Both strategies focused on using either a personalized versus a generic approach. In addition, 18 potentially relevant subject-related variables (e.g., demographics, last known physical and mental health status) were evaluated for association with time to survey completion. Of 308 eligible subjects, 67% completed the survey with a median (IQR) of 3 (2, 5) contact attempts required. There was no significant difference in the time to survey completion for either randomized trial of mail- or phone-based contact strategy. Among all subject-related variables, age ≤40 years and minority race were independently associated with a longer time to survey completion. We found that age ≤40 years and minority race were associated with a longer time to survey completion, but personalized versus generic approaches to mail- and telephone-based contact strategies had no significant effect. Repeating both mail and telephone contact attempts was important for increasing survey completion rate. NCT00719446.

Vaccine Effectiveness - How Well Does the Seasonal Flu Vaccine Work?

MedlinePlus

... to determine the benefits of flu vaccination are “observational studies.” “Observational studies” compare the occurrence of flu illness in ... randomized. The measurement of vaccine effects in an observational study is referred to as “effectiveness.” Top of ...

Two new methods to fit models for network meta-analysis with random inconsistency effects.

PubMed

Law, Martin; Jackson, Dan; Turner, Rebecca; Rhodes, Kirsty; Viechtbauer, Wolfgang

2016-07-28

Meta-analysis is a valuable tool for combining evidence from multiple studies. Network meta-analysis is becoming more widely used as a means to compare multiple treatments in the same analysis. However, a network meta-analysis may exhibit inconsistency, whereby the treatment effect estimates do not agree across all trial designs, even after taking between-study heterogeneity into account. We propose two new estimation methods for network meta-analysis models with random inconsistency effects. The model we consider is an extension of the conventional random-effects model for meta-analysis to the network meta-analysis setting and allows for potential inconsistency using random inconsistency effects. Our first new estimation method uses a Bayesian framework with empirically-based prior distributions for both the heterogeneity and the inconsistency variances. We fit the model using importance sampling and thereby avoid some of the difficulties that might be associated with using Markov Chain Monte Carlo (MCMC). However, we confirm the accuracy of our importance sampling method by comparing the results to those obtained using MCMC as the gold standard. The second new estimation method we describe uses a likelihood-based approach, implemented in the metafor package, which can be used to obtain (restricted) maximum-likelihood estimates of the model parameters and profile likelihood confidence intervals of the variance components. We illustrate the application of the methods using two contrasting examples. The first uses all-cause mortality as an outcome, and shows little evidence of between-study heterogeneity or inconsistency. The second uses "ear discharge" as an outcome, and exhibits substantial between-study heterogeneity and inconsistency. Both new estimation methods give results similar to those obtained using MCMC. The extent of heterogeneity and inconsistency should be assessed and reported in any network meta-analysis. Our two new methods can be used to fit models for network meta-analysis with random inconsistency effects. They are easily implemented using the accompanying R code in the Additional file 1. Using these estimation methods, the extent of inconsistency can be assessed and reported.

Simvastatin as an Adjunct to Conventional Therapy of Non-infectious Uveitis: A Randomized, Open-Label Pilot Study.

PubMed

Shirinsky, Ivan V; Biryukova, Anastasia A; Shirinsky, Valery S

2017-12-01

Statins have been shown to reduce ocular inflammation in animal models of uveitis and to prevent development of uveitis in observational studies. There have been no experimental human studies evaluating statins' efficacy and safety in uveitis. In this study, we aimed to investigate efficacy and safety of simvastatin in patients with uveitis. For this single-center, open-label, randomized study, we enrolled patients with acute non-infectious uveitis. The patients were randomized to receive 40 mg simvastatin per day for 2 months in addition to conventional treatment or conventional treatment alone. The studied outcomes were the rate of steroid-sparing control of ocular inflammation, measures of ocular inflammation, intraocular pressure, and visual acuity. Fifty patients were enrolled in the study. Twenty-five patients were randomly assigned to receive simvastatin with conventional treatment and 25 to conventional treatment alone. Simvastatin was associated with significantly higher rates of steroid-sparing ocular inflammation control, decrease in anterior chamber inflammation, and improvement in visual acuity. The treatment was well tolerated, no serious adverse effects were observed. Our findings suggest that statins may have therapeutic potential in uveitis. These results need to be confirmed in double-blind, randomized, controlled studies.

Stochastic Seismic Response of an Algiers Site with Random Depth to Bedrock

NASA Astrophysics Data System (ADS)

Badaoui, M.; Berrah, M. K.; Mébarki, A.

2010-05-01

Among the important effects of the Boumerdes earthquake (Algeria, May 21st 2003) was that, within the same zone, the destructions in certain parts were more important than in others. This phenomenon is due to site effects which alter the characteristics of seismic motions and cause concentration of damage during earthquakes. Local site effects such as thickness and mechanical properties of soil layers have important effects on the surface ground motions. This paper deals with the effect of the randomness aspect of the depth to bedrock (soil layers heights) which is assumed to be a random variable with lognormal distribution. This distribution is suitable for strictly non-negative random variables with large values of the coefficient of variation. In this case, Monte Carlo simulations are combined with the stiffness matrix method, used herein as a deterministic method, for evaluating the effect of the depth to bedrock uncertainty on the seismic response of a multilayered soil. This study considers a P and SV wave propagation pattern using input accelerations collected at Keddara station, located at 20 km from the epicenter, as it is located directly on the bedrock. A parametric study is conducted do derive the stochastic behavior of the peak ground acceleration and its response spectrum, the transfer function and the amplification factors. It is found that the soil height heterogeneity causes a widening of the frequency content and an increase in the fundamental frequency of the soil profile, indicating that the resonance phenomenon concerns a larger number of structures.

Discrete-element modeling of nacre-like materials: Effects of random microstructures on strain localization and mechanical performance

NASA Astrophysics Data System (ADS)

Abid, Najmul; Mirkhalaf, Mohammad; Barthelat, Francois

2018-03-01

Natural materials such as nacre, collagen, and spider silk are composed of staggered stiff and strong inclusions in a softer matrix. This type of hybrid microstructure results in remarkable combinations of stiffness, strength, and toughness and it now inspires novel classes of high-performance composites. However, the analytical and numerical approaches used to predict and optimize the mechanics of staggered composites often neglect statistical variations and inhomogeneities, which may have significant impacts on modulus, strength, and toughness. Here we present an analysis of localization using small representative volume elements (RVEs) and large scale statistical volume elements (SVEs) based on the discrete element method (DEM). DEM is an efficient numerical method which enabled the evaluation of more than 10,000 microstructures in this study, each including about 5,000 inclusions. The models explore the combined effects of statistics, inclusion arrangement, and interface properties. We find that statistical variations have a negative effect on all properties, in particular on the ductility and energy absorption because randomness precipitates the localization of deformations. However, the results also show that the negative effects of random microstructures can be offset by interfaces with large strain at failure accompanied by strain hardening. More specifically, this quantitative study reveals an optimal range of interface properties where the interfaces are the most effective at delaying localization. These findings show how carefully designed interfaces in bioinspired staggered composites can offset the negative effects of microstructural randomness, which is inherent to most current fabrication methods.

Effect of inspiratory muscle training with load compared with sham training on blood pressure in individuals with hypertension: study protocol of a double-blind randomized clinical trial.

PubMed

Posser, Simone Regina; Callegaro, Carine Cristina; Beltrami-Moreira, Marina; Moreira, Leila Beltrami

2016-08-02

Hypertension is a complex chronic condition characterized by elevated arterial blood pressure. Management of hypertension includes non-pharmacologic strategies, which may include techniques that effectively reduce autonomic sympathetic activity. Respiratory exercises improve autonomic control over cardiovascular system and attenuate muscle metaboreflex. Because of these effects, respiratory exercises may be useful to lower blood pressure in subjects with hypertension. This randomized, double-blind clinical trial will test the efficacy of inspiratory muscle training in reducing blood pressure in adults with essential hypertension. Subjects are randomly allocated to intervention or control groups. Intervention consists of inspiratory muscle training loaded with 40 % of maximum inspiratory pressure, readjusted weekly. Control sham intervention consists of unloaded exercises. Systolic and diastolic blood pressures are co-primary endpoint measures assessed with 24 h ambulatory blood pressure monitoring. Secondary outcome measures include cardiovascular autonomic control, inspiratory muscle metaboreflex, cardiopulmonary capacity, and inspiratory muscle strength and endurance. Previously published work suggests that inspiratory muscle training reduces blood pressure in persons with hypertension, but the effectiveness of this intervention is yet to be established. We propose an adequately sized randomized clinical trial to test this hypothesis rigorously. If an effect is found, this study will allow for the investigation of putative mechanisms to mediate this effect, including autonomic cardiovascular control and metaboreflex. ClinicalTrials.gov NCT02275377 . Registered on 30 September 2014.

The Effectiveness and Cost-Effectiveness of Spinal Cord Stimulation for Refractory Angina (RASCAL Study): A Pilot Randomized Controlled Trial.

PubMed

Eldabe, Sam; Thomson, Simon; Duarte, Rui; Brookes, Morag; deBelder, Mark; Raphael, Jon; Davies, Ed; Taylor, Rod

2016-01-01

Patients with "refractory angina" (RA) unsuitable for coronary revascularization experience high levels of hospitalization and poor health-related quality of life. Randomized trials have shown spinal cord stimulation (SCS) to be a promising treatment for chronic stable angina and RA; however, none has compared SCS with usual care (UC). The aim of this pilot study was to address the key uncertainties of conducting a definitive multicenter trial to assess the clinical and cost-effectiveness of SCS in RA patients, i.e., recruitment and retention of patients, burden of outcome measures, our ability to standardize UC in a UK NHS setting. RA patients deemed suitable were randomized in a 1:1 ratio to SCS plus UC (SCS group) or UC alone (UC group). We sought to assess: recruitment, uptake, and retention of patients; feasibility and acceptability of SCS treatment; the feasibility and acceptability of standardizing UC; and the feasibility and acceptability of the proposed trial outcome measures. Patient outcomes were assessed at baseline (prerandomization) and three and six months postrandomization. We failed to meet our planned recruitment target (45 patients) and randomized 29 patients (15 SCS group, 14 UC group) over a 42-month period across four sites. None of the study participants chose to withdraw following consent and randomization. With exception of two deaths, all completed evaluation at baseline and follow-up. Although the study was not formally powered to compare outcomes between groups, we saw a trend toward larger improvements in both primary and secondary outcomes in the SCS group. While patient recruitment was found to be challenging, levels of participant retention, outcome completion, and acceptability of SCS therapy were high. A number of lessons are presented in order to take forward a future definitive pragmatic randomized trial. © 2015 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals, Inc. on behalf of International Neuromodulation Society.

Tubal anastomosis after previous sterilization: a systematic review.

PubMed

van Seeters, Jacoba A H; Chua, Su Jen; Mol, Ben W J; Koks, Carolien A M

2017-05-01

Female sterilization is one of the most common contraceptive methods. A small number of women, however, opt for reversal of sterilization procedures after they experience regret. Procedures can be performed by laparotomy or laparoscopy, with or without robotic assistance. Another commonly utilized alternative is IVF. The choice between surgery and IVF is often influenced by reimbursement politics for that particular geographic location. We evaluated the fertility outcomes of different surgical methods available for the reversal of female sterilization, compared these to IVF and assessed the prognostic factors for success. Two search strategies were employed. Firstly, we searched for randomized and non-randomized clinical studies presenting fertility outcomes of sterilization reversal up to July 2016. Data on the following outcomes were collected: pregnancy rate, ectopic pregnancy rate, cost of the procedure and operative time. Eligible study designs included prospective or retrospective studies, randomized controlled trials, cohort studies, case-control studies and case series. No age restriction was applied. Exclusion criteria were patients suffering from tubal infertility from any other reason (e.g. infection, endometriosis and adhesions from previous surgery) and studies including <10 participants. The following factors likely to influence the success of sterilization reversal procedures were then evaluated: female age, BMI and duration and method of sterilization. Secondly, we searched for randomized and non-randomized clinical studies that compared reversal of sterilization to IVF and evaluated them for pregnancy outcomes and cost effectiveness. We included 37 studies that investigated a total of 10 689 women. No randomized controlled trials were found. Most studies were retrospective cohort studies of a moderate quality. The pooled pregnancy rate after sterilization reversal was 42-69%, with heterogeneity seen from the different methods utilized. The reported ectopic pregnancy rate was 4-8%. The only prognostic factor affecting the chance of conception was female age. The surgical approach (i.e. laparotomy [microscopic], laparoscopy or robotic) had no impact on the outcome, with the exception of the macroscopic laparotomic technique, which had inferior results and is not currently utilized. For older women, IVF could be a more cost-effective alternative for the reversal of sterilization. However, direct comparative data are lacking and a cut-off age cannot be stated. In sterilized women who suffer regret, surgical tubal re-anastomosis is an effective treatment, especially in younger women. However, there is a need for randomized controlled trials comparing the success rates and costs of surgical reversal with IVF. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Effect of extended-release niacin on plasma lipoprotein(a) levels: A systematic review and meta-analysis of randomized placebo-controlled trials.

PubMed

Sahebkar, Amirhosssein; Reiner, Željko; Simental-Mendía, Luis E; Ferretti, Gianna; Cicero, Arrigo F G

2016-11-01

Lipoprotein(a) (Lp(a)) is a proatherogenic and prothrombotic lipoprotein. Our aim was to quantify the extended-release nicotinic acid Lp(a) reducing effect with a meta-analysis of the available randomized clinical trials. A meta-analysis and random-effects meta-regression were performed on data pooled from 14 randomized placebo-controlled clinical trials published between 1998 and 2015, comprising 17 treatment arms, which included 9013 subjects, with 5362 in the niacin arm. The impact of ER niacin on plasma Lp(a) concentrations was reported in 17 treatment arms. Meta-analysis suggested a significant reduction of Lp(a) levels following ER niacin treatment (weighted mean difference - WMD: -22.90%, 95% CI: -27.32, -18.48, p<0.001). Results also remained similar when the meta-analysis was repeated with standardized mean difference as summary statistic (WMD: -0.66, 95% CI: -0.82, -0.50, p<0.001). When the studies were categorized according to the administered dose, there was a comparable effect between the subsets of studies with administered doses of <2000mg/day (WMD: -21.85%, 95% CI: -30.61, -13.10, p<0.001) and ≥2000mg/day (WMD: -23.21%, 95% CI: -28.41, -18.01, p<0.001). The results of the random-effects meta-regression did not suggest any significant association between the changes in plasma concentrations of Lp(a) with dose (slope: -0.0001; 95% CI: -0.01, 0.01; p=0.983), treatment duration (slope: -0.40; 95% CI: -0.97, 0.17; p=0.166), and percentage change in plasma HDL-C concentrations (slope: 0.44; 95% CI: -0.48, 1.36; p=0.350). In this meta-analysis of randomized placebo-controlled clinical trials, treatment with nicotinic acid was associated with a significant reduction in Lp(a) levels. Copyright © 2016 Elsevier Inc. All rights reserved.

Peer Effects in the Workplace: Evidence from Random Groupings in Professional Golf Tournaments

PubMed Central

Guryan, Jonathan; Kroft, Kory; Notowidigdo, Matthew J.

2010-01-01

This paper uses random assignment in professional golf tournaments to test for peer effects in the workplace. We find no evidence that playing partners’ ability affects performance, contrary to recent evidence on peer effects in the workplace from laboratory experiments, grocery scanners, and soft-fruit pickers. In our preferred specification we can rule out peer effects larger than 0.043 strokes for a one stroke increase in playing partners’ ability. Our results complement existing studies on workplace peer effects and are useful in explaining how social effects vary across labor markets, across individuals, and with the form of incentives faced. PMID:20454555

A new u-statistic with superior design sensitivity in matched observational studies.

PubMed

Rosenbaum, Paul R

2011-09-01

In an observational or nonrandomized study of treatment effects, a sensitivity analysis indicates the magnitude of bias from unmeasured covariates that would need to be present to alter the conclusions of a naïve analysis that presumes adjustments for observed covariates suffice to remove all bias. The power of sensitivity analysis is the probability that it will reject a false hypothesis about treatment effects allowing for a departure from random assignment of a specified magnitude; in particular, if this specified magnitude is "no departure" then this is the same as the power of a randomization test in a randomized experiment. A new family of u-statistics is proposed that includes Wilcoxon's signed rank statistic but also includes other statistics with substantially higher power when a sensitivity analysis is performed in an observational study. Wilcoxon's statistic has high power to detect small effects in large randomized experiments-that is, it often has good Pitman efficiency-but small effects are invariably sensitive to small unobserved biases. Members of this family of u-statistics that emphasize medium to large effects can have substantially higher power in a sensitivity analysis. For example, in one situation with 250 pair differences that are Normal with expectation 1/2 and variance 1, the power of a sensitivity analysis that uses Wilcoxon's statistic is 0.08 while the power of another member of the family of u-statistics is 0.66. The topic is examined by performing a sensitivity analysis in three observational studies, using an asymptotic measure called the design sensitivity, and by simulating power in finite samples. The three examples are drawn from epidemiology, clinical medicine, and genetic toxicology. © 2010, The International Biometric Society.

Effect of psycho-educational interventions on quality of life in patients with implantable cardioverter defibrillators: a meta-analysis of randomized controlled trials.

PubMed

Kao, Chi-Wen; Chen, Miao-Yi; Chen, Ting-Yu; Lin, Pai-Hui

2016-09-30

Implantable cardioverter defibrillators (ICD) were developed for primary and secondary prevention of sudden cardiac death. However, ICD recipients' mortality is significantly predicted by their quality of life (QOL). The aim of this meta-analysis was to evaluate the effects of psycho-educational interventions on QOL in patients with ICDs. We systematically searched PubMed, Medline, Cochrane Library, and CINAHL through April 2015 and references of relevant articles. Studies were reviewed if they met following criteria: (1) randomized controlled trial, (2) participants were adults with an ICD, and (3) data were sufficient to evaluate the effect of psychological or educational interventions on QOL measured by the SF-36 or SF-12. Studies were independently selected and their data were extracted by two reviewers. Study quality was evaluated using a modified Jadad scale. The meta-analysis was conducted using the Cochrane Collaboration's Review Manager Software Package (RevMan 5). Study heterogeneity was assessed by Q statistics and I 2 statistic. Depending on heterogeneity, data were pooled across trials using fixed-effect or random-effect modeling. Seven randomized controlled trials fulfilled the inclusion and exclusion criteria, and included 1017 participants. The psycho-educational interventions improved physical component summary (PCS) scores in the intervention groups more than in control groups (mean difference 2.08, 95 % CI 0.86 to 3.29, p < 0.001), but did not significantly affect mental component summary (MCS) scores (mean difference 0.84, 95 % CI -1.68 to 3.35, p = 0.52). Our meta-analysis demonstrates that psycho-educational interventions improved the physical component, but not the mental component of QOL in patients with ICDs.

The solid fat content of stearic acid-rich fats determines their postprandial effects.

PubMed

Berry, Sarah E E; Miller, George J; Sanders, Thomas A B

2007-06-01

The process of randomization is used commercially to harden fats as an alternative to partial hydrogenation, but its effects on cardiovascular disease risk factors are uncertain. The objective was to compare the chronic and acute effects of randomization of a fat rich in 1,3-distearyl, 2-oleyl glycerol on fasting and postprandial lipids, glucose, insulin, and activated clotting factor VII (FVIIa) concentrations. A crossover design study in 16 men compared fasting and postprandial lipid, glucose, insulin, and FVIIa concentrations at baseline and after a 3-wk diet providing 30 g unrandomized or randomized shea butter and sunflower oil blends (SSOBs), both of which contained approximately 50% stearic acid. Fecal fat excretion was measured during each dietary period. Postprandial changes were assessed after the consumption of meals providing 50 g test fat. A subsequent study compared postprandial changes after the consumption of an oleic acid-rich sunflower oil meal and an unrandomized SSOB meal. Both SSOBs were well digested and absorbed. Randomization did not affect fasting or postprandial lipid, glucose, insulin, or FVIIa concentrations. Compared with the oleic acid-rich meal, the unrandomized SSOB resulted in 53% lower postprandial lipemia, 23% higher hepatic lipase activity, and a 25% lower postprandial increase in FVIIa concentration. The solid fat contents at 37 degrees C were 22%, 41%, and 0% with the unrandomized SSOB, randomized SSOB, and oleic acid-rich meals, respectively. Stearic acid-rich triacylglycerol in both unrandomized and randomized forms does not adversely affect lipid risk factors for cardiovascular disease. The high proportion of solid fat at 37 degrees C may explain the decreased postprandial lipemic response.

An analysis of the effect of funding source in randomized clinical trials of second generation antipsychotics for the treatment of schizophrenia.

PubMed

Montgomery, John H; Byerly, Matthew; Carmody, Thomas; Li, Baitao; Miller, Daniel R; Varghese, Femina; Holland, Rhiannon

2004-12-01

The effect of funding source on the outcome of randomized controlled trials has been investigated in several medical disciplines; however, psychiatry has been largely excluded from such analyses. In this article, randomized controlled trials of second generation antipsychotics in schizophrenia are reviewed and analyzed with respect to funding source (industry vs. non-industry funding). A literature search was conducted for randomized, double-blind trials in which at least one of the tested treatments was a second generation antipsychotic. In each study, design quality and study outcome were assessed quantitatively according to rating scales. Mean quality and outcome scores were compared in the industry-funded studies and non-industry-funded studies. An analysis of the primary author's affiliation with industry was similarly performed. Results of industry-funded studies significantly favored second generation over first generation antipsychotics when compared to non-industry-funded studies. Non-industry-funded studies showed a trend toward higher quality than industry-funded studies; however, the difference between the two was not significant. Also, within the industry-funded studies, outcomes of trials involving first authors employed by industry sponsors demonstrated a trend toward second generation over first generation antipsychotics to a greater degree than did trials involving first authors employed outside the industry (p=0.05). While the retrospective design of the study limits the strength of the findings, the data suggest that industry bias may occur in randomized controlled trials in schizophrenia. There appears to be several sources by which bias may enter clinical research, including trial design, control of data analysis and multiplicity/redundancy of trials.

How informative are open-label studies for youth with bipolar disorder? A meta-analysis comparing open-label versus randomized, placebo-controlled clinical trials.

PubMed

Biederman, Joseph; Petty, Carter R; Woodworth, K Yvonne; Lomedico, Alexandra; O'Connor, Katherine B; Wozniak, Janet; Faraone, Stephen V

2012-03-01

To examine the informativeness of open-label trials toward predicting results in subsequent randomized, placebo-controlled clinical trials of psychopharmacologic treatments for pediatric bipolar disorder. We searched journal articles through PubMed at the National Library of Medicine using bipolar disorder, mania, pharmacotherapy, treatment and clinical trial as keywords. This search was supplemented with scientific presentations at national and international scientific meetings and submitted manuscripts from our group. Selection criteria included (1) enrollment of children diagnosed with DSM-IV bipolar disorder; (2) prospective assessment of at least 3 weeks; (3) monotherapy of a pharmacologic treatment for bipolar disorder; (4) use of a randomized placebo-controlled design or an open-label design for the same therapeutic compound; and (5) repeated use of the Young Mania Rating Scale (YMRS) as an outcome. The following information and data were extracted from 14 studies: study design, name of medication, class of medication, dose of medication, sample size, age, sex, trial length, and YMRS mean and standard deviation baseline and follow-up scores. For both study designs, the pooled effect size was statistically significant (open-label studies, z = 8.88, P < .001; randomized placebo-controlled studies, z = 13.75, P < .001), indicating a reduction in the YMRS from baseline to endpoint in both study designs. In a meta-analysis regression, study design was not a significant predictor of mean change in the YMRS. We found similarities in the treatment effects between open-label and randomized placebo-controlled studies in youth with bipolar disorder indicating that open-label studies are useful predictors of the potential safety and efficacy of a given compound in the treatment of pediatric bipolar disorder. © Copyright 2012 Physicians Postgraduate Press, Inc.

The effects of recall errors and of selection bias in epidemiologic studies of mobile phone use and cancer risk.

PubMed

Vrijheid, Martine; Deltour, Isabelle; Krewski, Daniel; Sanchez, Marie; Cardis, Elisabeth

2006-07-01

This paper examines the effects of systematic and random errors in recall and of selection bias in case-control studies of mobile phone use and cancer. These sensitivity analyses are based on Monte-Carlo computer simulations and were carried out within the INTERPHONE Study, an international collaborative case-control study in 13 countries. Recall error scenarios simulated plausible values of random and systematic, non-differential and differential recall errors in amount of mobile phone use reported by study subjects. Plausible values for the recall error were obtained from validation studies. Selection bias scenarios assumed varying selection probabilities for cases and controls, mobile phone users, and non-users. Where possible these selection probabilities were based on existing information from non-respondents in INTERPHONE. Simulations used exposure distributions based on existing INTERPHONE data and assumed varying levels of the true risk of brain cancer related to mobile phone use. Results suggest that random recall errors of plausible levels can lead to a large underestimation in the risk of brain cancer associated with mobile phone use. Random errors were found to have larger impact than plausible systematic errors. Differential errors in recall had very little additional impact in the presence of large random errors. Selection bias resulting from underselection of unexposed controls led to J-shaped exposure-response patterns, with risk apparently decreasing at low to moderate exposure levels. The present results, in conjunction with those of the validation studies conducted within the INTERPHONE study, will play an important role in the interpretation of existing and future case-control studies of mobile phone use and cancer risk, including the INTERPHONE study.

Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

PubMed

Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

2010-01-01

Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

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

Douillard, Jean-Yves; Rosell, Rafael; De Lena, Mario

Purpose: To study the impact of postoperative radiation therapy (PORT) on survival in the Adjuvant Navelbine International Trialist Association (ANITA) randomized study of adjuvant chemotherapy. Methods and Materials: ANITA is a randomized trial of adjuvant cisplatin and vinorelbine chemotherapy vs. observation in completely resected non-small-cell lung carcinoma (NSCLC) Stages IB to IIIA. Use of PORT was recommended for pN+ disease but was not randomized or mandatory. Each center decided whether to use PORT before initiation of the study. We describe here the survival of patients with and without PORT within each treatment group of ANITA. No statistical comparison of survivalmore » was performed because this was an unplanned subgroup analysis. Results: Overall, 232 of 840 patients received PORT (33.3% in the observation arm and 21.6% in the chemotherapy arm). In univariate analysis, PORT had a deleterious effect on the overall population survival. Patients with pN1 disease had an improved survival from PORT in the observation arm (median survival [MS] 25.9 vs. 50.2 months), whereas PORT had a detrimental effect in the chemotherapy group (MS 93.6 months and 46.6 months). In contrast, survival was improved in patients with pN2 disease who received PORT, both in the chemotherapy (MS 23.8 vs. 47.4 months) and observation arm (median 12.7 vs. 22.7 months). Conclusion: This retrospective evaluation suggests a positive effect of PORT in pN2 disease and a negative effect on pN1 disease when patients received adjuvant chemotherapy. The results support further evaluation of PORT in prospectively randomized studies in completely resected pN2 NSCLC.« less

Transportability of an Evidence-Based Early Childhood Intervention in a Low-Income African Country: Results of a Cluster Randomized Controlled Study.

PubMed

Huang, Keng-Yen; Nakigudde, Janet; Rhule, Dana; Gumikiriza-Onoria, Joy Louise; Abura, Gloria; Kolawole, Bukky; Ndyanabangi, Sheila; Kim, Sharon; Seidman, Edward; Ogedegbe, Gbenga; Brotman, Laurie Miller

2017-11-01

Children in Sub-Saharan Africa (SSA) are burdened by significant unmet mental health needs. Despite the successes of numerous school-based interventions for promoting child mental health, most evidence-based interventions (EBIs) are not available in SSA. This study investigated the implementation quality and effectiveness of one component of an EBI from a developed country (USA) in a SSA country (Uganda). The EBI component, Professional Development, was provided by trained Ugandan mental health professionals to Ugandan primary school teachers. It included large-group experiential training and small-group coaching to introduce and support a range of evidence-based practices (EBPs) to create nurturing and predictable classroom experiences. The study was guided by the Consolidated Framework for Implementation Research, the Teacher Training Implementation Model, and the RE-AIM evaluation framework. Effectiveness outcomes were studied using a cluster randomized design, in which 10 schools were randomized to intervention and wait-list control conditions. A total of 79 early childhood teachers participated. Teacher knowledge and the use of EBPs were assessed at baseline and immediately post-intervention (4-5 months later). A sample of 154 parents was randomly selected to report on child behavior at baseline and post-intervention. Linear mixed effect modeling was applied to examine effectiveness outcomes. Findings support the feasibility of training Ugandan mental health professionals to provide Professional Development for Ugandan teachers. Professional Development was delivered with high levels of fidelity and resulted in improved teacher EBP knowledge and the use of EBPs in the classroom, and child social competence.

Effects of a Physical Education-Based Programme on Health-Related Physical Fitness and Its Maintenance in High School Students: A Cluster-Randomized Controlled Trial

ERIC Educational Resources Information Center

Mayorga-Vega, Daniel; Montoro-Escaño, Jorge; Merino-Marban, Rafael; Viciana, Jesús

2016-01-01

The purpose of this study was to examine the effects of a physical education-based development and maintenance programme on objective and perceived health-related physical fitness in high school students. A sample of 111 students aged 12-14 years old from six classes were cluster-randomly assigned to an experimental group (n = 54) or a control…

Mediating Effects of Home-Related Factors on Fat Intake from Snacks in a School-Based Nutrition Intervention among Adolescents

ERIC Educational Resources Information Center

Van Lippevelde, Wendy; van Stralen, Maartje; Verloigne, Maite; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Brug, Johannes; Maes, Lea; Haerens, Leen

2012-01-01

The purpose of the present study was to investigate if the effects of the parental component of a school-based intervention on dietary fat intake from snacking were mediated by changes in home-related factors. A random sample of 10 schools with 2232 pupils aged 11-15 years was randomly assigned to one of two intervention groups [one with (n =…

Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models.

PubMed

Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J; Zucker, David M

2017-12-01

The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elements of randomization, either by design or by nature (e.g., random inheritance of genes). Instrumental variables estimation of exposure effects is well established for continuous outcomes and to some extent for binary outcomes. It is, however, largely lacking for time-to-event outcomes because of complications due to censoring and survivorship bias. In this article, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies and illustrate it in a Mendelian randomization study to evaluate the effect of diabetes on mortality using data from the Health and Retirement Study. We further use the proposed method to investigate potential benefit from breast cancer screening on subsequent breast cancer mortality based on the HIP-study. © 2017, The International Biometric Society.

Screening large-scale association study data: exploiting interactions using random forests.

PubMed

Lunetta, Kathryn L; Hayward, L Brooke; Segal, Jonathan; Van Eerdewegh, Paul

2004-12-10

Genome-wide association studies for complex diseases will produce genotypes on hundreds of thousands of single nucleotide polymorphisms (SNPs). A logical first approach to dealing with massive numbers of SNPs is to use some test to screen the SNPs, retaining only those that meet some criterion for further study. For example, SNPs can be ranked by p-value, and those with the lowest p-values retained. When SNPs have large interaction effects but small marginal effects in a population, they are unlikely to be retained when univariate tests are used for screening. However, model-based screens that pre-specify interactions are impractical for data sets with thousands of SNPs. Random forest analysis is an alternative method that produces a single measure of importance for each predictor variable that takes into account interactions among variables without requiring model specification. Interactions increase the importance for the individual interacting variables, making them more likely to be given high importance relative to other variables. We test the performance of random forests as a screening procedure to identify small numbers of risk-associated SNPs from among large numbers of unassociated SNPs using complex disease models with up to 32 loci, incorporating both genetic heterogeneity and multi-locus interaction. Keeping other factors constant, if risk SNPs interact, the random forest importance measure significantly outperforms the Fisher Exact test as a screening tool. As the number of interacting SNPs increases, the improvement in performance of random forest analysis relative to Fisher Exact test for screening also increases. Random forests perform similarly to the univariate Fisher Exact test as a screening tool when SNPs in the analysis do not interact. In the context of large-scale genetic association studies where unknown interactions exist among true risk-associated SNPs or SNPs and environmental covariates, screening SNPs using random forest analyses can significantly reduce the number of SNPs that need to be retained for further study compared to standard univariate screening methods.

Role of Statistical Random-Effects Linear Models in Personalized Medicine.

PubMed

Diaz, Francisco J; Yeh, Hung-Wen; de Leon, Jose

2012-03-01

Some empirical studies and recent developments in pharmacokinetic theory suggest that statistical random-effects linear models are valuable tools that allow describing simultaneously patient populations as a whole and patients as individuals. This remarkable characteristic indicates that these models may be useful in the development of personalized medicine, which aims at finding treatment regimes that are appropriate for particular patients, not just appropriate for the average patient. In fact, published developments show that random-effects linear models may provide a solid theoretical framework for drug dosage individualization in chronic diseases. In particular, individualized dosages computed with these models by means of an empirical Bayesian approach may produce better results than dosages computed with some methods routinely used in therapeutic drug monitoring. This is further supported by published empirical and theoretical findings that show that random effects linear models may provide accurate representations of phase III and IV steady-state pharmacokinetic data, and may be useful for dosage computations. These models have applications in the design of clinical algorithms for drug dosage individualization in chronic diseases; in the computation of dose correction factors; computation of the minimum number of blood samples from a patient that are necessary for calculating an optimal individualized drug dosage in therapeutic drug monitoring; measure of the clinical importance of clinical, demographic, environmental or genetic covariates; study of drug-drug interactions in clinical settings; the implementation of computational tools for web-site-based evidence farming; design of pharmacogenomic studies; and in the development of a pharmacological theory of dosage individualization.

Exits in order: How crowding affects particle lifetimes

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

Penington, Catherine J.; Simpson, Matthew J.; Baker, Ruth E.

2016-06-28

Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents inmore » a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.« less

Professional Opinion Concerning the Effectiveness of Bracing Relative to Observation in Adolescent Idiopathic Scoliosis

PubMed Central

Dolan, Lori A.; Donnelly, Melanie J.; Spratt, Kevin F.; Weinstein, Stuart L.

2015-01-01

Objective To determine if community equipoise exists concerning the effectiveness of bracing in adolescent idiopathic scoliosis. Background Data Bracing is the standard of care for adolescent idiopathic scoliosis despite the lack of strong reasearch evidence concerning its effectiveness. Thus, some researchers support the idea of a randomized trial, whereas others think that randomization in the face of a standard of care would be unethical. Methods A random of Scoliosis Research Society and Pediatric Orthopaedic Society of North America members were asked to consider 12 clinical profiles and to give their opinion concerning the radiographic outcomes after observation and bracing. Results An expert panel was created from the respondents. They expressed a wide array of opinions concerning the percentage of patients within each scenario who would benefit from bracing. Agreement was noted concerning the risk due to bracing for post-menarchal patients only. Conclusions This study found a high degree of variability in opinion among clinicians concerning the effectiveness of bracing, suggesting that a randomized trial of bracing would be ethical. PMID:17414008

Effect of flashlight guidance on manual ventilation performance in cardiopulmonary resuscitation: A randomized controlled simulation study.

PubMed

Kim, Ji Hoon; Beom, Jin Ho; You, Je Sung; Cho, Junho; Min, In Kyung; Chung, Hyun Soo

2018-01-01

Several auditory-based feedback devices have been developed to improve the quality of ventilation performance during cardiopulmonary resuscitation (CPR), but their effectiveness has not been proven in actual CPR situations. In the present study, we investigated the effectiveness of visual flashlight guidance in maintaining high-quality ventilation performance. We conducted a simulation-based, randomized, parallel trial including 121 senior medical students. All participants were randomized to perform ventilation during 2 minutes of CPR with or without flashlight guidance. For each participant, we measured mean ventilation rate as a primary outcome and ventilation volume, inspiration velocity, and ventilation interval as secondary outcomes using a computerized device system. Mean ventilation rate did not significantly differ between flashlight guidance and control groups (P = 0.159), but participants in the flashlight guidance group exhibited significantly less variation in ventilation rate than participants in the control group (P<0.001). Ventilation interval was also more regular among participants in the flashlight guidance group. Our results demonstrate that flashlight guidance is effective in maintaining a constant ventilation rate and interval. If confirmed by further studies in clinical practice, flashlight guidance could be expected to improve the quality of ventilation performed during CPR.

A Feasibility Randomized Controlled Crossover Trial of Home-Based Warm Footbath to Improve Sleep in the Chronic Phase of Traumatic Brain Injury.

PubMed

Chiu, Hsiao-Yean; Lin, En-Yuan; Chiu, Hsiao-Ting; Chen, Pin-Yuan

2017-12-01

Sleep disturbance is a common complaint after traumatic brain injury (TBI). The aim of this study was to examine the effects of a home-based warm footbath intervention on sleep in patients with TBI. This was a randomized controlled crossover study, and 23 adults with TBI were recruited and randomized to receive first a 30-minute, 41°C warm footbath and then a usual care, or vice versa, with each lasting 3 days and separated by a 3-day washout. Sleep efficiency, sleep onset latency (SOL), total sleep time, and wake after sleep onset (WASO) were assessed by actigraphy. We found that home-based warm footbath significantly had a reduced SOL (difference, -5.11 minutes) and a suppressed WASO (difference, -2.57 minutes) compared with those of usual care, but not in sleep efficiency and total sleep time. No adverse effect was reported. This study suggested that home-based warm footbath is practical and effective in relieving post-TBI sleep disturbances, particular in SOL and WASO. Nurses can use home-based warm footbath as an effective intervention for management of sleep disturbances after TBI.

Group Matching: Is This a Research Technique to Be Avoided?

ERIC Educational Resources Information Center

Ross, Donald C.; Klein, Donald F.

1988-01-01

The variance of the sample difference and the power of the "F" test for mean differences were studied under group matching on covariates and also under random assignment. Results shed light on systematic assignment procedures advocated to provide more precise estimates of treatment effects than simple random assignment. (TJH)

HIV Interventions to Reduce HIV/AIDS Stigma: A Systematic Review

PubMed Central

Banks, Bahby; Jonas, Dan; Miles, Margaret Shandor; Smith, Giselle Corbie

2011-01-01

We reviewed the literature to determine the effectiveness of HIV-related interventions in reducing HIV/AIDS stigma. Studies selected had randomized controlled trial (RCT), pretest–posttest with a non-randomized control group, or pretest–posttest one group study designs in which HIV-related interventions were being evaluated, and in which HIV/AIDS stigma was one of the outcomes being measured. A checklist was used to extract data from accepted studies, assess their internal validity, and overall quality. Data were extracted from 19 studies, and 14 of these studies demonstrated effectiveness in reducing HIV/ AIDS stigma. Only 2 of these 14 effective studies were considered good studies, based on quality, the extent to which the intervention focused on reducing HIV/AIDS stigma, and the statistics reported to demonstrate effectiveness. Future studies to reduce HIV/AIDS stigma could improve by designing interventions that pay greater attention to internal validity, use validated HIV/AIDS stigma instruments, and achieve both statistical and public health significance. PMID:21088989

HIV interventions to reduce HIV/AIDS stigma: a systematic review.

PubMed

Sengupta, Sohini; Banks, Bahby; Jonas, Dan; Miles, Margaret Shandor; Smith, Giselle Corbie

2011-08-01

We reviewed the literature to determine the effectiveness of HIV-related interventions in reducing HIV/AIDS stigma. Studies selected had randomized controlled trial (RCT), pretest-posttest with a non-randomized control group, or pretest-posttest one group study designs in which HIV-related interventions were being evaluated, and in which HIV/AIDS stigma was one of the outcomes being measured. A checklist was used to extract data from accepted studies, assess their internal validity, and overall quality. Data were extracted from 19 studies, and 14 of these studies demonstrated effectiveness in reducing HIV/AIDS stigma. Only 2 of these 14 effective studies were considered good studies, based on quality, the extent to which the intervention focused on reducing HIV/AIDS stigma, and the statistics reported to demonstrate effectiveness. Future studies to reduce HIV/AIDS stigma could improve by designing interventions that pay greater attention to internal validity, use validated HIV/AIDS stigma instruments, and achieve both statistical and public health significance.

Learning Historical Thinking with Oral History Interviews: A Cluster Randomized Controlled Intervention Study of Oral History Interviews in History Lessons

ERIC Educational Resources Information Center

Bertram, Christiane; Wagner, Wolfgang; Trautwein, Ulrich

2017-01-01

The present study examined the effectiveness of the oral history approach with respect to students' historical competence. A total of 35 ninth-grade classes (N = 900) in Germany were randomly assigned to one of four conditions--live, video, text, or a (nontreated) control group--in a pretest, posttest, and follow-up design. Comparing the three…

Effects of Teaching a Library Usage Unit to Seventh Graders.

ERIC Educational Resources Information Center

Gifford, Vernon; Gifford, Jean

This document reports the results of a study undertaken to determine if teaching a 2-week unit on library usage to 7th graders would increase their use of the library. From three non-ability grouped 7th grade classes, two classes of 26 students each were randomly selected for the study. One class was randomly assigned as the experimental group and…

Review of Three Recent Randomized Trials of School-Based Mentoring: Making Sense of Mixed Findings. Social Policy Report. Volume 24, Number 3

ERIC Educational Resources Information Center

Wheeler, Marc E.; Keller, Thomas E.; DuBois, David L.

2010-01-01

Between 2007 and 2009, reports were released on the results of three separate large-scale random assignment studies of the effectiveness of school-based mentoring programs for youth. The studies evaluated programs implemented by Big Brothers Big Sisters of America (BBBSA) affiliates (Herrera et al., 2007), Communities In Schools of San Antonio,…

Promoting the Development of Preschool Children's Emergent Literacy Skills: A Randomized Evaluation of a Literacy-Focused Curriculum and Two Professional Development Models

ERIC Educational Resources Information Center

Lonigan, Christopher J.; Farver, JoAnn M.; Phillips, Beth M.; Clancy-Menchetti, Jeanine

2011-01-01

To date, there have been few causally interpretable evaluations of the impacts of preschool curricula on the skills of children at-risk for academic difficulties, and even fewer studies have demonstrated statistically significant or educationally meaningful effects. In this cluster-randomized study, we evaluated the impacts of a literacy-focused…

A large-scale cluster randomized trial to determine the effects of community-based dietary sodium reduction--the China Rural Health Initiative Sodium Reduction Study.

PubMed

Li, Nicole; Yan, Lijing L; Niu, Wenyi; Labarthe, Darwin; Feng, Xiangxian; Shi, Jingpu; Zhang, Jianxin; Zhang, Ruijuan; Zhang, Yuhong; Chu, Hongling; Neiman, Andrea; Engelgau, Michael; Elliott, Paul; Wu, Yangfeng; Neal, Bruce

2013-11-01

Cardiovascular diseases are the leading cause of death and disability in China. High blood pressure caused by excess intake of dietary sodium is widespread and an effective sodium reduction program has potential to improve cardiovascular health. This study is a large-scale, cluster-randomized, trial done in five Northern Chinese provinces. Two counties have been selected from each province and 12 townships in each county making a total of 120 clusters. Within each township one village has been selected for participation with 1:1 randomization stratified by county. The sodium reduction intervention comprises community health education and a food supply strategy based upon providing access to salt substitute. Subsidization of the price of salt substitute was done in 30 intervention villages selected at random. Control villages continued usual practices. The primary outcome for the study is dietary sodium intake level estimated from assays of 24-hour urine. The trial recruited and randomized 120 townships in April 2011. The sodium reduction program was commenced in the 60 intervention villages between May and June of that year with outcome surveys scheduled for October to December 2012. Baseline data collection shows that randomisation achieved good balance across groups. The establishment of the China Rural Health Initiative has enabled the launch of this large-scale trial designed to identify a novel, scalable strategy for reduction of dietary sodium and control of blood pressure. If proved effective, the intervention could plausibly be implemented at low cost in large parts of China and other countries worldwide. © 2013.

Characterizing Time to Diagnostic Resolution After an Abnormal Cancer Screening Exam in Older Adult Participants in the Ohio Patient Navigation Research Program.

PubMed

DeSalvo, Jennifer M; Young, Gregory S; Krok-Schoen, Jessica L; Paskett, Electra D

2017-06-01

This study aims to test the effectiveness of a patient navigation (PN) intervention to reduce time to diagnostic resolution among older adults age ≥65 years versus those <65 years with abnormal breast, cervical, or colorectal cancer screening exams participating in the Ohio Patient Navigation Research Program (OPNRP). The OPNRP utilized a nested cohort group-randomized trial design to randomize 862 participants ( n = 67 for ≥65 years; n = 795 for <65 years) to PN or usual care conditions. A shared frailty Cox model tested the effect of PN on time to resolution. Older adult participants randomized to PN achieved a 6-month resolution rate that was 127% higher than those randomized to usual care ( p = .001). This effect was not significantly different from participants <65 years. PN significantly reduced time to diagnostic resolution among older adults beginning 6 months after an abnormal cancer screening exam. Health care systems should include this population in PN programs to reduce cancer disparities.

Cinnamomum zeylanicum (Ceylon cinnamon) as a potential pharmaceutical agent for type-2 diabetes mellitus: study protocol for a randomized controlled trial.

PubMed

Ranasinghe, Priyanga; Galappaththy, Priyadarshani; Constantine, Godwin Roger; Jayawardena, Ranil; Weeratunga, Hasitha Dhananjaya; Premakumara, Sirimal; Katulanda, Prasad

2017-09-29

Previous studies have explored the anti-diabetic effects of Cinnamomum cassia extract in vivo and in vitro. However, there are no studies at present exploring the effects of the indigenous species of Sri Lankan cinnamon (Cinnamomum zeylanicum) in patients with diabetes mellitus. The present study aims to evaluate the potential effects of Cinnamomum zeylanicum extract as a pharmaceutical agent in patients with type-2 diabetes mellitus. The study will be conducted as a randomized, double-blind, placebo-controlled clinical trial for a period of 4 months at the Medical Clinic, University Medical Unit, National Hospital of Sri Lanka. A total of 210 subjects with diabetes, in three equal groups, will be recruited for the study. The patients will be randomized in a 1:1:1 ratio according to the method of block randomization and the subjects will be randomly and equally assigned into two test groups (n = 70 each) and one placebo group (n = 70). The population will be stratified at randomization based on age, gender and disease severity. The treatment drug is a capsule containing Cinnamomum zeylanicum extract as the active ingredient and the placebo capsule will contain lactose monohydrate. Two doses of Cinnamomum zeylanicum extracts (250 mg and 500 mg of the cinnamon extract) will be used. The study drugs will be double blinded to both investigators and participants. The visits and the evaluations will be done as follows: screening (visit 0), 1 month (visit 1), 2 months (visit 2), 3 months (visit 3) and 4 months (visit 4). The following primary outcome measures will be evaluated: glycosylated hemoglobin (HbA 1 c), fasting plasma glucose (FPG) and serum insulin. Secondary outcome measures include: Body Mass Index (BMI) and other anthropometric parameters, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL) and triglycerides (TAG). Data will be analyzed using SPSS version 14. We describe the protocol for a clinical trial design evaluating the effects of Cinnamomum zeylanicum (Ceylon cinnamon) in patients with type-2 diabetes mellitus. The result of the present study, positive or negative, should provide a step change in the evidence guiding current and future policies regarding the use of cinnamon dietary supplementation in patients with diabetes. Sri Lanka Clinical Trials Registry (SLCTR), identifier: SLCTR/2017/010 ( http://slctr.lk/trials/714 ). Registered on 5 April 2017; study protocol version 3.1 21 March 2017.

The Effect of Massage With Lavender Oil on Restless Leg Syndrome in Hemodialysis Patients: A Randomized Controlled Trial.

PubMed

Hashemi, Sayyed Hossein; Hajbagheri, Ali; Aghajani, Mohammad

2015-12-01

Restless leg syndrome (RLS) is a common problem in patients with chronic renal failure. It can reduce the quality of life and sleep disturbances. This disorder is usually treated pharmacologically. Recently, complementary medicine methods have been suggested because of chemical drugs adverse effects. There is not enough evidence about the effect of aromatherapy on RLS. The aim of this study was to determine the effects of massage with lavender oil on RLS symptoms in hemodialysis patients. This randomized clinical trial study included 70 hemodialysis patients with RLS that were randomly assigned into two groups in 2014. The experimental group received effleurage massage using lavender oil and control group received routine care for three weeks. Data was collected with RLS questionnaire and analyzed using independent and paired t-test and Chi-square test. The mean RLS scores were not significantly different in the two groups at the start of study (22.41 ± 7.67 vs. 22.90 ± 4.38, P = 0.76). At the end of study, the mean RLS score significantly decreased in the intervention group, while this score remained relatively un-changed in the control group (12.41 ± 5.49 vs. 23.23 ± 4.52, P < 0.0001). Lavender oil massage was effective to improve RLS in hemodialysis patients. It has no adverse effects, is practical and cost-effective. It is suggested to be used along with routine treatment of RLS in hemodialysis patients.

Effects of Repetitive Transcranial Magnetic Stimulation in the Rehabilitation of Communication and Deglutition Disorders: Systematic Review of Randomized Controlled Trials.

PubMed

Gadenz, Camila Dalbosco; Moreira, Tais de Campos; Capobianco, Dirce Maria; Cassol, Mauriceia

2015-01-01

To systematically review randomized controlled trials that evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on rehabilitation aspects related to communication and swallowing functions. A search was conducted on PubMed, Clinical Trials, Cochrane Library, and ASHA electronic databases. Studies were judged according to the eligibility criteria and analyzed by 2 independent and blinded researchers. We analyzed 9 studies: 4 about aphasia, 3 about dysphagia, 1 about dysarthria in Parkinson's disease and 1 about linguistic deficits in Alzheimer's disease. All aphasia studies used low-frequency rTMS to stimulate Broca's homologous area. High-frequency rTMS was applied over the pharyngoesophageal cortex from the left and/or right hemisphere in the dysphagia studies and over the left dorsolateral prefrontal cortex in the Parkinson's and Alzheimer's studies. Two aphasia and all dysphagia studies showed a significant improvement of the disorder, compared to the sham group. The other 2 studies related to aphasia found a benefit restricted to subgroups with a severe case or injury on the anterior portion of the language cortical area, respectively, whereas the Alzheimer's study demonstrated positive effects specific to auditory comprehension. There were no changes for vocal function in the Parkinson's study. The benefits of the technique and its applicability in neurogenic disorders related to communication and deglutition are still uncertain. Therefore, other randomized controlled trials are needed to clarify the optimal stimulation protocol for each disorder studied and its real effects. © 2015 S. Karger AG, Basel.

Prophylactic intra-aortic balloon pump in high-risk patients undergoing coronary artery bypass surgery: a meta-analysis of randomized controlled trials.

PubMed

Sá, Michel Pompeu B O; Ferraz, Paulo E; Escobar, Rodrigo R; Martins, Wendell N; Nunes, Eliobas O; Vasconcelos, Frederico P; Lima, Ricardo C

2012-11-01

The aim of this study was to assess the efficacy of a prophylactic intra-aortic balloon pump (IABP) in high-risk patients undergoing coronary artery bypass graft surgery. MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar, and reference lists of relevant articles were searched. We included only randomized controlled trials. Assessments for eligibility, relevance, and study validity and data extraction were performed in duplicate using prespecified criteria. Meta-analysis was carried out using fixed-effect and random-effect models. Seven publications fulfilled our eligibility criteria. There was no important statistical heterogeneity or publication bias among included studies. In total, 177 patients received prophylactic IABP and 168 did not. Overall relative risk (RR) for hospital mortality in patients treated with prophylactic IABP was 0.255 [95% confidence interval (CI), 0.122-0.533; P<0.001; same results for both effect models]. Pooled RR for postoperative low cardiac output syndrome was 0.206 (95% CI, 0.109-0.389; P<0.001) for the fixed-effect model and 0.219 (95% CI, 0.095-0.504; P<0.001) for the random-effect model. Patients treated with prophylactic IABP presented an overall difference in means for length of intensive care unit stay and hospital stay, which was lower than that in the control group (P<0.001 for both effect models). Only 7.4% (13/177) of patients who received prophylactic IABP developed complications at an insertion site, with no IABP-related death. This meta-analysis supports the use of prophylactic IABP in high-risk patients to reduce hospital mortality. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Effects of Positive Psychology Interventions on Risk Biomarkers in Coronary Patients: A Randomized, Wait-List Controlled Pilot Trial.

PubMed

Nikrahan, Gholam Reza; Laferton, Johannes A C; Asgari, Karim; Kalantari, Mehrdad; Abedi, Mohammad Reza; Etesampour, Ali; Rezaei, Abbas; Suarez, Laura; Huffman, Jeff C

2016-01-01

Among cardiac patients, positive psychologic factors are consistently linked with superior clinical outcomes and improvement in key markers of inflammation and hypothalamic-pituitary-adrenal axis functioning. Further, positive psychology interventions (PPI) have effectively increased psychologic well-being in a wide variety of populations. However, there has been minimal study of PPIs in cardiac patients, and no prior study has evaluated their effect on key prognostic biomarkers of cardiac outcome. Accordingly, we investigated the effect of 3 distinct PPIs on risk biomarkers in cardiac patients. In an exploratory trial, 69 patients with recent coronary artery bypass graft surgery or percutaneous intervention were randomized to (1) one of three 6-week in-person PPIs (based on the work of Seligman, Lyubomirsky, or Fordyce) or (2) a wait-list control group. Risk biomarkers were assessed at baseline, postintervention (7 weeks), and at 15-week follow-up. Between-group differences in change from baseline biomarker levels were examined via random effects models. Compared with the control group, participants randomized to the Seligman (B = -2.06; p = 0.02) and Fordyce PPI (B = -1.54; p = 0.04) had significantly lower high-sensitivity C-reactive protein levels at 7 weeks. Further, the Lyubomirsky PPI (B = -245.86; p = 0.04) was associated with a significantly lower cortisol awakening response at 7 weeks when compared with control participants. There were no other significant between-group differences. Despite being an exploratory pilot study with multiple between-group comparisons, this initial trial offers the first suggestion that PPIs might be effective in reducing risk biomarkers in high-risk cardiac patients. Copyright © 2016 The Academy of Psychosomatic Medicine. All rights reserved.

Effects of positive psychology interventions on risk biomarkers in coronary patients: A randomized, wait-list controlled pilot trial

PubMed Central

Nikrahan, Gholam Reza; Laferton, Johannes A. C.; Asgari, Karim; Kalantari, Mehrdad; Abedi, Mohammad Reza; Etesampour, Ali; Rezaei, Abbas; Suarez, Laura; Huffman, Jeff C.

2016-01-01

Background Among cardiac patients, positive psychological factors are consistently linked with superior clinical outcomes and improvement in key markers of inflammation and hypothalamic-pituitary-adrenal axis functioning. Further, positive psychology interventions (PPI) have effectively increased psychological well-being in a wide variety of populations. However, there has been minimal study of PPIs in cardiac patients, and no prior study has evaluated their effect on key prognostic biomarkers of cardiac outcome. Accordingly, we investigated the effect of three distinct PPIs on risk biomarkers in cardiac patients. Methods In an exploratory trial, 69 patients with recent coronary artery bypass graft surgery or percutaneous intervention were randomized to a) one of three 6-week in-person PPIs (based on the work of Seligman, Lyubomirsky, or Fordyce) or b) a wait-list control group. Risk biomarkers were assessed at baseline, post-intervention (7 weeks), and at 15 week follow-up. Between-group differences in change from baseline biomarker levels were examined via random effects models. Results Compared to the control group, participants randomized to the Seligman (B= −2.06; p= .02) and Fordyce PPI (B= −1.54; p= .04) had significantly lower high-sensitivity C-reactive protein (hs-CRP) levels at 7 weeks. Further, the Lyubomirsky PPI (B= −245.86; p= .04) was associated with a significantly lower cortisol awakening response (CARg) at 7 weeks compared to control participants. There were no other significant between-group differences. Conclusion Despite being an exploratory pilot study with multiple between-group comparisons, this initial trial offers the first suggestion that PPIs might be effective in reducing risk biomarkers in high-risk cardiac patients. PMID:27129358

Causal mediation analysis for longitudinal data with exogenous exposure.

PubMed

Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An approximate generalized linear model with random effects for informative missing data.

PubMed

Follmann, D; Wu, M

1995-03-01

This paper develops a class of models to deal with missing data from longitudinal studies. We assume that separate models for the primary response and missingness (e.g., number of missed visits) are linked by a common random parameter. Such models have been developed in the econometrics (Heckman, 1979, Econometrica 47, 153-161) and biostatistics (Wu and Carroll, 1988, Biometrics 44, 175-188) literature for a Gaussian primary response. We allow the primary response, conditional on the random parameter, to follow a generalized linear model and approximate the generalized linear model by conditioning on the data that describes missingness. The resultant approximation is a mixed generalized linear model with possibly heterogeneous random effects. An example is given to illustrate the approximate approach, and simulations are performed to critique the adequacy of the approximation for repeated binary data.

Analytical connection between thresholds and immunization strategies of SIS model in random networks

NASA Astrophysics Data System (ADS)

Zhou, Ming-Yang; Xiong, Wen-Man; Liao, Hao; Wang, Tong; Wei, Zong-Wen; Fu, Zhong-Qian

2018-05-01

Devising effective strategies for hindering the propagation of viruses and protecting the population against epidemics is critical for public security and health. Despite a number of studies based on the susceptible-infected-susceptible (SIS) model devoted to this topic, we still lack a general framework to compare different immunization strategies in completely random networks. Here, we address this problem by suggesting a novel method based on heterogeneous mean-field theory for the SIS model. Our method builds the relationship between the thresholds and different immunization strategies in completely random networks. Besides, we provide an analytical argument that the targeted large-degree strategy achieves the best performance in random networks with arbitrary degree distribution. Moreover, the experimental results demonstrate the effectiveness of the proposed method in both artificial and real-world networks.

Randomized trials published in Chinese or Western journals: comparative empirical analysis.

PubMed

Purgato, Marianna; Cipriani, Andrea; Barbui, Corrado

2012-06-01

A major concern to the inclusion in systematic reviews of studies originating in China and published in Chinese journals refers to the quality of study reporting. In this systematic survey of randomized trials, we compared the characteristics of studies published in Chinese journals with those of studies published in Western journals. We included 69 studies comparing citalopram with other antidepressant drugs in the treatment of major depression. Of these, 37 (54%) were published in Chinese journals. The standard of reporting was generally poor in both Western and Chinese studies. In some Chinese studies, the generation of the randomization sequence raised concern about their experimental nature, and in almost all included studies, the concealment of allocation was not properly described. Blinding was seldom adopted in Chinese studies, and the risk of sponsorship bias was uncertain because Chinese studies did not report any financial support. In most Western studies, outcome data were selectively and incompletely reported. Pooling together all trials revealed that citalopram was similarly effective in comparison with all other antidepressant drugs both in Western studies (standardized mean difference, -0.04; 95% confidence interval, -0.15 to 0.06) and in Chinese studies (standardized mean difference, -0.08, 95% confidence interval, -0.18 to 0.02). Randomized controlled trials published in Chinese journals represent most of the studies included in this review. This suggests that omitting to search biomedical databases originating from China would systematically exclude a relevant proportion of randomized trials published in Chinese journals, with a risk of random error or bias. The increasing inclusion of Chinese studies in systematic reviews reinforces the need to check the quality of randomized trials that are meta-analyzed.

A Bayesian ridge regression analysis of congestion's impact on urban expressway safety.

PubMed

Shi, Qi; Abdel-Aty, Mohamed; Lee, Jaeyoung

2016-03-01

With the rapid growth of traffic in urban areas, concerns about congestion and traffic safety have been heightened. This study leveraged both Automatic Vehicle Identification (AVI) system and Microwave Vehicle Detection System (MVDS) installed on an expressway in Central Florida to explore how congestion impacts the crash occurrence in urban areas. Multiple congestion measures from the two systems were developed. To ensure more precise estimates of the congestion's effects, the traffic data were aggregated into peak and non-peak hours. Multicollinearity among traffic parameters was examined. The results showed the presence of multicollinearity especially during peak hours. As a response, ridge regression was introduced to cope with this issue. Poisson models with uncorrelated random effects, correlated random effects, and both correlated random effects and random parameters were constructed within the Bayesian framework. It was proven that correlated random effects could significantly enhance model performance. The random parameters model has similar goodness-of-fit compared with the model with only correlated random effects. However, by accounting for the unobserved heterogeneity, more variables were found to be significantly related to crash frequency. The models indicated that congestion increased crash frequency during peak hours while during non-peak hours it was not a major crash contributing factor. Using the random parameter model, the three congestion measures were compared. It was found that all congestion indicators had similar effects while Congestion Index (CI) derived from MVDS data was a better congestion indicator for safety analysis. Also, analyses showed that the segments with higher congestion intensity could not only increase property damage only (PDO) crashes, but also more severe crashes. In addition, the issues regarding the necessity to incorporate specific congestion indicator for congestion's effects on safety and to take care of the multicollinearity between explanatory variables were also discussed. By including a specific congestion indicator, the model performance significantly improved. When comparing models with and without ridge regression, the magnitude of the coefficients was altered in the existence of multicollinearity. These conclusions suggest that the use of appropriate congestion measure and consideration of multicolilnearity among the variables would improve the models and our understanding about the effects of congestion on traffic safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantum Mechanical Enhancement of the Random Dopant Induced Threshold Voltage Fluctuations and Lowering in Sub 0.1 Micron MOSFETs

NASA Technical Reports Server (NTRS)

Asenov, Asen; Slavcheva, G.; Brown, A. R.; Davies, J. H.; Saini, Subhash

1999-01-01

A detailed study of the influence of quantum effects in the inversion layer on the random dopant induced threshold voltage fluctuations and lowering in sub 0.1 micron MOSFETs has been performed. This has been achieved using a full 3D implementation of the density gradient (DG) formalism incorporated in our previously published 3D 'atomistic' simulation approach. This results in a consistent, fully 3D, quantum mechanical picture which implies not only the vertical inversion layer quantisation but also the lateral confinement effects manifested by current filamentation in the 'valleys' of the random potential fluctuations. We have shown that the net result of including quantum mechanical effects, while considering statistical fluctuations, is an increase in both threshold voltage fluctuations and lowering.