Heterogeneity in meta-analysis can be caused by chance, methodological or clinical
variations between the included primary studies. To identify a clinical variable as a cause of …

Meta-analysis is a statistical method for combining the results of studies included in the
systematic review. It is justified only when the potentially eligible studies are similar enough …

In meta-analysis, when the difference in results between studies is greater than would be
expected by chance, one needs to investigate whether the observed variation in results …

ContextA recent meta-analysis found calcium supplementation to be highly effective in
preventing preeclampsia but a large National Institutes of Health trial (Calcium for …

Meta-analyses overcome the limitation of small sample sizes or rare outcomes by pooling
results from a number of individual studies to generate a single best estimate. As long as a …

For meta‐analysis, substantial uncertainty remains about the most appropriate statistical
methods for combining the results of separate trials. An important issue for meta‐analysis is …

Abstract Background and Objectives Meta-analyses sometimes summarize results in the
presence of substantial unexplained between-study heterogeneity. As GRADE criteria …

Background It remains unclear when standard systematic reviews and meta-analyses that
rely on published aggregate data (AD) can provide robust clinical conclusions. We aimed to …

Background Recently developed measures such as I 2 and H allow the evaluation of the
impact of heterogeneity in conventional meta-analyses. There has been no examination of …

Biases in systematic reviews and meta‐analyses may be examined in 'meta‐
epidemiological'studies, in which the influence of trial characteristics such as measures of …