Systematic reviews that include only published data may overestimate the effectiveness of analgesic medicines for low back pain: a systematic review and meta-analysis

Ref ID 587
First Author M. K. Bagg
Journal JOURNAL OF CLINICAL EPIDEMIOLOGY
Year Of Publishing 2020
URL https://www.jclinepi.com/article/S0895-4356(19)30841-8/fulltext
Keywords Grey literature
Pain
Problem(s) Grey literature excluded
Number of systematic reviews included 5
Summary of Findings Two of the five source systematic review' meta-analyses were re-calculated. Including unpublished trial registry data for muscle relaxant medicines resulted in a 89% decrease in effect size for muscle relaxant medicines.
Did the article find that the problem(s) led to qualitative changes in interpretation of the results? Yes
Are the methods of the article described in enough detail to replicate the study? Yes