An index of the quality of evidence in meta-analysis of randomized controlled trials

Abstract

The quality of evidence in meta-analysis of randomized controlled trials is the degree to which the estimated effect represents the \"truth.\" Current approaches to assessing the quality of evidence focus on trial design and methods. I describe a new quality of evidence index composed of four sub-indexes that measure pre-registration, independent replication, data availability, and trial design and methods, respectively. This index is systematic, objective, and quantitative. I illustrate the index with an empirical example and provide a spreadsheet for easy calculation.\n\nO_QD\"...when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind.\"\n\n-Lord Kelvin (William Thompson), 1824-1907\n\nC_QD