How are systematic reviews of prevalence conducted? A methodological study

Celina Borges Migliavaca,Zachary Munn,Verônica Colpani,Cinara Stein,Timothy Hugh Barker,Maicon Falavigna

doi:10.1186/s12874-020-00975-3

Abstract

BackgroundThere is a notable lack of methodological and reporting guidance for systematic reviews of prevalence data. This information void has the potential to result in reviews that are inconsistent and inadequate to inform healthcare policy and decision making. The aim of this meta-epidemiological study is to describe the methodology of recently published prevalence systematic reviews.MethodsWe searched MEDLINE (via PubMed) from February 2017 to February 2018 for systematic reviews of prevalence studies. We included systematic reviews assessing the prevalence of any clinical condition using patients as the unit of measurement and we summarized data related to reporting and methodology of the reviews.ResultsA total of 235 systematic reviews of prevalence were analyzed. The median number of authors was 5 (interquartile range [IQR] 4–7), the median number of databases searched was 4 (3–6) and the median number of studies included in each review was 24 (IQR 15–41.5). Search strategies were presented for 68% of reviews. Forty five percent of reviews received external funding, and 24% did not provide funding information. Twenty three percent of included reviews had published or registered the systematic review protocol. Reporting guidelines were used in 72% of reviews. The quality of included studies was assessed in 80% of reviews. Nine reviews assessed the overall quality of evidence (4 using GRADE). Meta-analysis was conducted in 65% of reviews; 1% used Bayesian methods. Random effect meta-analysis was used in 94% of reviews; among them, 75% did not report the variance estimator used. Among the reviews with meta-analysis, 70% did not report how data was transformed; 59% percent conducted subgroup analysis, 38% conducted meta-regression and 2% estimated prediction interval; I2 was estimated in 95% of analysis. Publication bias was examined in 48%. The most common software used was STATA (55%).ConclusionsOur results indicate that there are significant inconsistencies regarding how these reviews are conducted. Many of these differences arose in the assessment of methodological quality and the formal synthesis of comparable data. This variability indicates the need for clearer reporting standards and consensus on methodological guidance for systematic reviews of prevalence data.

Highlights

There is a notable lack of methodological and reporting guidance for systematic reviews of prevalence data
Methodological guidance from the Joanna Briggs Institute (JBI) exists for these review types, [5] there currently appears to be little other discussion on how these reviews should be prepared, performed and reported. This is an important consideration, as standards of reporting and conduct for traditional systematic reviews [6] are considered commonplace, and even endorsed by journal editors. Even though such standards and guidelines could be adapted for systematic reviews of prevalence, they do not comprehend specific issues for this type of study, and have not been as readily adopted
Letters, narrative reviews, systematic reviews of interventions or diagnostic accuracy, systematic reviews assessing the association between variables and systematic reviews of prevalence that did not use patients as the unit of measurement, as well as studies not published in English

Summary

Introduction

There is a notable lack of methodological and reporting guidance for systematic reviews of prevalence data This information void has the potential to result in reviews that are inconsistent and inadequate to inform healthcare policy and decision making. Methodological guidance from the Joanna Briggs Institute (JBI) exists for these review types, [5] there currently appears to be little other discussion on how these reviews should be prepared, performed (including when and how results can be pooled using meta-analytical methods) and reported This is an important consideration, as standards of reporting and conduct for traditional systematic reviews (i.e. systematic reviews of interventions) [6] are considered commonplace, and even endorsed by journal editors. This is despite the fact that there is general acceptance that there needs to be different types of approaches for systematic reviews looking at different types of evidence [6,7,8]

Methods

Results

Discussion

Conclusion