Correlation of Quality Measures With Estimates of Treatment Effect in Meta-analyses of Randomized Controlled Trials

Abstract

Several studies have suggested that specific measures of trial quality, such as concealment of random allocation, blinding of patients and outcome assessors, and handling of dropouts, may significantly influence observed treatment effects in single studies,^1,2 specific clinical areas,^3,4 and meta-analyses from a mixture of clinical areas.^5,6 Proposed quality measures have been incorporated into a growing number of scales that attempt to quantify overall trial quality.⁷ These findings have led to recommendations that investigators conducting meta-analyses should take into account the quality measures and scales when drawing conclusions.^8-12