Inclusion of nonrandomized studies in Cochrane systematic reviews was found to be in need of improvement

Ref ID	755
First Author	S. Ijaz
Journal	JOURNAL OF CLINICAL EPIDEMIOLOGY
Year Of Publishing	2014
URL	https://www.ncbi.nlm.nih.gov/pubmed/24725644
Keywords	• Cochrane • Observational studies • Risk of bias
Problem(s)	• Weaknesses identified in some Cochrane reviews • Flawed risk of bias undertaken • Inclusion of observational / non-randomised studies
Number of systematic reviews included	202
Summary of Findings	Of the included 202 included Cochrane reviews that considered non-randomised studies published between 2000-2013 most reviews (n=114; 56%) did not justify including non-randomised studies. When they did, most were not in line with Cochrane recommendations. The reasons were divided into two major categories: non-randomised studies were included because randomized controlled trials are wanted (N 5 81, 92%) but not feasible, lacking, or insufficient alone or because RCTs are not needed (N 5 7, 8%). Risk of bias assessment varied across reviews and needs improvement.
Did the article find that the problem(s) led to qualitative changes in interpretation of the results?	N/A
Are the methods of the article described in enough detail to replicate the study?	Yes