Excluding non-English publications from evidence-syntheses did not change conclusions: a meta-epidemiological study

Ref ID 363
First Author B. Nussbaumer-Streit
Year Of Publishing 2020
URL https://www.jclinepi.com/article/S0895-4356(19)30657-2/fulltext
Keywords Cochrane
General medical
Problem(s) Language restriction
Number of systematic reviews included 59
Summary of Findings Overall, the exclusion of non-English publications led to the exclusion of 31 studies contributing to 40 outcomes. For 38 of the 40 outcomes, the exclusion of non-English studies did not markedly alter the size or direction of effect estimates or statistical significance. In two outcomes, the statistical significance changed, but authors would have still drawn the same conclusion, albeit with less certainty. Thus, the proportion of changed conclusions in our sample was 0.0% (95% CI 0.0 - 0.6), which indicated the noninferiority of the approach. However, the majority of excluded studies were small.
Did the article find that the problem(s) led to qualitative changes in interpretation of the results? No
Are the methods of the article described in enough detail to replicate the study? Yes