A systematic survey of 200 systematic reviews with network meta-analysis (published 2020-2021) reveals that few reviews report structured evidence summaries

Abstract

Objectives - To map whether and how systematic reviews (SRs) with network meta-analysis (NMA) use presentation formats to report (a) structured evidence summaries – here defined as reporting of effects estimates in absolute effects with certainty ratings and with a method to rate interventions across one or more outcome(s) – and (b) NMA results in general.<p>

<p>Study Design and Setting - We conducted a systematic survey, searching MEDLINE (Ovid) for SRs with NMA published between January 1, 2020, and December 31, 2021. We planned to include a random sample of publications, with predefined mechanisms in place for saturation, and included SRs that met prespecified quality criteria and extracted data on presentation formats that reported: (a) estimates of effects, (b) certainty of the evidence, or (c) rating of interventions.<p>

<p>Results - The 200 eligible SRs, from 158 unique Journals, utilized 1133 presentation formats. We found structured evidence summaries in 10 publications (5.0%), with 3 (1.5%) reporting structured evidence summaries across all outcomes, including benefits and harms. Sixteen of the 133 SRs (11.7%) reporting dichotomous outcomes included estimates of absolute effects. Seventy-six SRs (38.0%) reported both benefits and harms and 26 SRs (13.0%) reported certainty ratings in presentation formats, 20 (76.9%) used Grading of Recommendations Assessment, Development and Evaluation and 6 (23.1%) used Confidence In Network Meta-analysis. Surface Under the Cumulative Ranking Curve was the most common method to rate interventions (69 SRs, 34.5%). NMA results were most often reported using forest plots (108 SRs, 54.0%) and league tables (93 SRs, 46.5%).<p>

<p>Conclusion - Most SRs with NMA do not report structured evidence summaries and only rarely do such summaries include reporting of both benefits and harms; those that do offer effective user-friendly communication and provide models for optimal NMA presentation practice.