382,193 papers found

The quantile approximation method has recently been proposed as a simple method for deriving confidence intervals for the treatment effect in a random effects meta-analysis. Although easily implemented, the quantiles used to construct intervals are derived from a single simulation study. Here it is shown that altering…

The methylenetetrahydrofolate reductase (MTHFR) gene variant C677T is suspected to be a risk factor for psychiatric disorders, but it remains uncertain whether the MTHFR C677T variant is associated with bipolar disorders. To investigate possible association, unrelated controls (n=461) with no history of psychiatric dis…

Rare cardiovascular events of commonly used drugs are important to document and investigate, but single trials are notoriously underpowered to provide conclusive evidence. Recently, meta-analyses have been used to improve on the power. A recent rosiglitazone meta-analysis heightened the debate about the usefulness and…

Meta-analysis offers the opportunity to combine evidence from retrospectively accumulated or prospectively generated data. Meta-analyses may provide summary estimates and can help in detecting and addressing potential inconsistency between the combined datasets. Application of meta-analysis in genetic associations pres…

The combination of results from different large-scale datasets of multidimensional biological signals (such as gene expression profiling) presents a major challenge. Methodologies are needed that can efficiently combine diverse datasets, but can also test the extent of diversity (heterogeneity) across the combined stud…

Meta-analysis of population-based genetic association studies is often challenged by obstacles associated with the underlying inheritance model. For a simple genetic variant with two alleles, a recessive, dominant or co-dominant model is typically assumed. In the absence of a strong biological rationale for a particula…

OBJECTIVE: To predict the screening performance for 17 policies currently in use or being considered for the near future. METHODS: Multivariate Gaussian modeling using parameters derived from published meta-analyses and new meta-analyses for gestation-specific nuchal translucency and between trimester correlations. R…

This study reports an activation likelihood estimation (ALE) meta-analysis of imaging studies of chronic developmental stuttering in adults. Two parallel meta-analyses were carried out: (1) stuttered production in the stutterers; (2) fluent production in the control subjects. The control subjects' data replicated previ…

BACKGROUND: Wise et al. introduced a rank-based statistical technique for meta-analysis of genome scans, the Genome Scan Meta-Analysis (GSMA) method. Levinson et al. recently described two generalizations of the GSMA statistic: (i) a weighted version of the GSMA statistic, so that different studies could be ascribed di…

Possible solutions to the problems of clinical heterogeneity of outcome measures and inadequate reporting of results for randomized controlled trials (RCTs) on carpal tunnel syndrome (CTS) are presented. Meta-analysis was impeded by these problems in 2 systematic reviews concerning conservative and surgical treatment o…

The intricate nature of complex genetic traits dictates that novel methodologies be developed and utilized to achieve better power, better accuracy, and more favorable balance between type I and type II errors than could be achieved by the traditional methods as they are used in mapping Mendelian traits. Meta-analysis…

There exists a variety of situations in which a random effects meta-analysis might be undertaken using a small number of clinical trials. A problem associated with small meta-analyses is estimating the heterogeneity between trials. To overcome this problem, information from other related studies may be incorporated int…

The use of meta-analysis in environmental epidemiology can enhance the value of epidemiologic data in debates about environmental health risks. Meta-analysis may be particularly useful to formally examine sources of heterogeneity, to clarify the relationship between environmental exposures and health effects, and to ge…

Many meta-analyses use a random-effects model to account for heterogeneity among study results, beyond the variation associated with fixed effects. A random-effects regression approach for the synthesis of 2 x 2 tables allows the inclusion of covariates that may explain heterogeneity. A simulation study found that the…