Several reasons explained the variation in the results of 22 meta-analyses addressing the same question

Ref ID	615
First Author	A. M. Khamis
Journal	JOURNAL OF CLINICAL EPIDEMIOLOGY
Year Of Publishing	2019
URL	https://www.jclinepi.com/article/S0895-4356(18)30929-6/fulltext
Keywords	• Cardiology • Error • Expertise • Statistical • Spin
Problem(s)	• Spin or subjective interpretation of findings • Errors in study inclusion or omission of relevant studies • Errors in effect estimate calculations or data synthesis • Lack of statistical expertise in handling of quantitative data
Number of systematic reviews included	21
Summary of Findings	The percentage of absolute difference between each of the 22 pooled effect estimates (included odds ratio, risk ratio, hazard ratio) and their median value had an average of 3.2%. Most of the reviews did not clearly report which effect measures they used for the trials included in their meta-analysis; some reviews used for one or more trials an effect measure different than the one used in the meta-analysis, which led to pooling of HR and RR or HR and OR within the same meta-analysis. AMSTAR does not address in enough details the statistical methods used in systematic reviews and subsequently is not sensitive to these methods’ variations as described in this study.
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