392,317 papers found

This research reports an investigation of the use of standardized regression (beta) coefficients in meta-analyses that use correlation coefficients as the effect-size metric. The investigation consisted of analyzing more than 1,700 corresponding beta coefficients and correlation coefficients harvested from published st…

This commentary article reviews a recent meta-analysis of genetic influences on antisocial behavior by Rhee and Waldman (2002). The authors combined the results of 51 twin and adoption studies and concluded that antisocial behavior has an important genetic component. However, twin and adoption studies contain several m…

In this article, the calculation of effect size measures in single-case research and the use of hierarchical linear models for combining these measures are discussed. Special attention is given to meta-analyses that take into account a possible linear trend in the data. We show that effect size measures that have been…

Concurrent with the recent enthusiasm for qualitative research in the health fields, an energetic call for methods by which to synthesize the knowledge has been generated on various substantive topics. Although there is an emerging literature on meta-analysis and metasynthesis, many authors overestimate the simplicity…

Lander and Kruglyak [1995] gave guidelines for interpreting linkage results based on estimating how often a particular threshold for significance would be exceeded by chance in a single genome scan. What is unknown is how often two or more genome scans would exceed a particular threshold within the same region. We deve…

To monitor the performance of the approved generic copies of a brand-name drug, we propose some methods in assessing bioequivalence among generic copies and the brand-name drug, and among generic copies themselves, using data from several bioequivalence studies adopting the standard 2 x 2 crossover design without carry…

A multiplicative random effects model is constructed for combining results from different studies. An EM algorithm is developed for the maximum likelihood estimator under the Empirical Bayes framework. The method is applied to estimation of the admixture component in admixed populations. The admixture estimates can be…

Evaluation of clinical prediction models across multiple clusters, whether centers or datasets, is becoming increasingly common. A comprehensive evaluation includes an assessment of the agreement between the estimated risks and the observed outcomes, also known as calibration. Calibration is of utmost importance for cl…

Network meta-analysis (NMA) facilitates the comparison of multiple treatments by integrating both direct and indirect evidence. Applications of NMA in medical decision making have grown exponentially. However, the validity of NMA findings depends on key assumptions: homogeneity, transitivity, and consistency. A lack of…

BACKGROUND: Maternal periodontitis has been consistently linked to adverse birth outcomes (ABOs). However, a causal relationship is not established due to potential unmeasured confounding factors in observational studies and inconclusive results from randomized controlled trials. This study aimed to assess the impact o…

Network meta-analysis (NMA) combines evidence from multiple trials to compare the effectiveness of a set of interventions. In many areas of research, interventions are often complex, made up of multiple components or features. This makes it difficult to define a common set of interventions on which to perform the analy…

PURPOSE: Han et al. (J Int Soc Sports Nutr 16:55, 2019) sought to quantify the effects of vitamin D supplementation on strength outcomes among athletes in a meta-analysis. The authors reported a pooled effect size (standardized mean difference; SMD) of -0.75 (95% CI: -1.82 to 0.32, p = 0.17) in favor of supplementation…

INTRODUCTION: Tracheostomy is a common emergency procedure for critically ill patients to secure their airway. The speaking valve is a one-way ventilation valve that is attached to the end of the tracheostomy tube to help the patient remodel subglottic pressure. However, the efficacy and safety of speaking valves in ad…

Meta-analysis is a widely used tool for synthesizing results from multiple studies. The collected studies are deemed heterogeneous when they do not share a common underlying effect size; thus, the factors attributable to the heterogeneity need to be carefully considered. A critical problem in meta-analyses and systemat…

OBJECTIVES: An umbrella review is a systematic review of systematic reviews, which provides a tertiary level of evidence. This umbrella review of systematic reviews and meta-analysis (SR-MA) aimed to determine the proportion of oral cancer (OC) development in oral submucous fibrosis (OSF) patients. MATERIALS AND METHO…

BACKGROUND: Selective or non-reporting of study outcomes results in outcome reporting bias. OBJECTIVE: We sought to develop and assess tools for detecting and adjusting for outcome reporting bias. DESIGN: Using data from a previously published systematic review, we abstracted whether outcomes were reported as collect…

PURPOSE: The previous analysis of systematic reviews and meta-analyses have illustrated that obstructive sleep apnea (OSA) is correlated with multiple health outcomes. In the present research, our main aim was to execute an umbrella review to assess the available evidence for the associations between OSA and health out…