In 1987, Cynthia Mulrow examined for the first time the methodological quality of a sample of 50 review articles published in four leading medical journals between 1985 and 1986. She found that none met a set of eight explicit scientific criteria, and that the lack of quality assessment of primary studies was a major pitfall in these reviews.[3] In 1987, Sacks and colleagues[4] evaluated the quality of 83 meta-analyses, using a scoring method that considered 23 items in six major areas: study design, combinability, control of bias, statistical analysis, sensitivity analysis, and application of results. Results of this research showed that reporting was generally poor; and pointed out an urgent need for improved methods in literature searching, quality evaluation of trials, and synthesizing of the results.
In 1996, an international group of 30 clinical epidemiologists, clinicians, statisticians, editors, and researchers convened The Quality of Reporting of Meta-analyses [QUOROM] conference to address standards for improving the quality of reporting of meta-analyses of clinical randomized controlled trials [RCTs].[5]
The conference resulted in the QUOROM, a checklist, and a flow diagram that described the preferred way to present the abstract, introduction, methods, results, and discussion sections of a report of a systematic review or a meta-analysis. Eight of the original 18 items formed the basis of the QUOROM reporting. Evaluation of reporting was organized into headings and subheadings regarding searches, selection, validity assessment, data abstraction, study characteristics, and quantitative data synthesis.
In 2009, the QUOROM was updated to address several conceptual and practical advances in the science of systematic reviews, and was renamed PRISMA [Preferred Reporting Items of Systematic reviews and Meta-Analyses].[2] Another update was underway as of March 2018.[6]