Background Well designed randomized controlled trials provide reliable evidence of
treatment effects, but there is no consensus on how best to apply these results to clinical …

Randomized controlled trials or studies are often considered the ideal way to evaluate the
effectiveness of a treatment compared to a control. In such a study, the randomization …

Publication and selection biases in meta-analysis are more likely to affect small studies,
which also tend to be of lower methodological quality. This may lead to “small-study effects,” …

Background For many years it has been claimed that observational studies find stronger
treatment effects than randomized, controlled trials. We compared the results of …

Background Meta-analyses are now widely used to provide evidence to support clinical
strategies. However, large randomized, controlled trials are considered the gold standard in …

In therapeutic research meta-analysis is most commonly used to determine more precisely
the beneficial and/or harmful effects of a given treatment from a collection of randomized …

Purpose: To explore whether reported methodologic quality affects estimated intervention
effects in randomized trials and contributes to discrepancies between the results of large …

Meta-analysis of randomized controlled trials combines information from independent
studies that address a similar question to provide more reliable estimates of treatment …

High-quality randomized clinical trials (RCTs) occupy the highest position on the evidence
pyramid, either as standalone studies or as part of meta-analyses. However, the …

Figure 1 Distinguished statistician Karl Pearson is seen as the first medical researcher to
use formal techniques to combine data from different studies studies are needed. For …