Empirical Evidence of Study Design Biases in Randomized Trials: Systematic Review of Meta-Epidemiological Studies.

ABSTRACT:

Objective

To synthesise evidence on the average bias and heterogeneity associated with reported methodological features of randomized trials.

Design

Systematic review of meta-epidemiological studies.

Methods

We retrieved eligible studies included in a recent AHRQ-EPC review on this topic (latest search September 2012), and searched Ovid MEDLINE and Ovid EMBASE for studies indexed from Jan 2012-May 2015. Data were extracted by one author and verified by another. We combined estimates of average bias (e.g. ratio of odds ratios (ROR) or difference in standardised mean differences (dSMD)) in meta-analyses using the random-effects model. Analyses were stratified by type of outcome ("mortality" versus "other objective" versus "subjective"). Direction of effect was standardi

SUBMITTER: Page MJ 

PROVIDER: S-EPMC4939945 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature