Characteristics and quality of systematic reviews and meta-analyses of observational nutritional epidemiology: a cross-sectional study

Ref ID	835
First Author	D. Zeraatkar
Journal	AMERICAN JOURNAL OF CLINICAL NUTRITION
Year Of Publishing	2021
URL	https://academic.oup.com/ajcn/article/113/6/1578/6178917?login=true#256988075
Keywords	Nutrition Observational studies Heterogeneity Epidemiology Certainty
Problem(s)	Grey literature excluded Search strategy not provided Single reviewer / lack of double checking Lack of statistical expertise in handling of quantitative data Inadequate analysis of heterogeneity Poor execution of narrative synthesis
Number of systematic reviews included	150
Summary of Findings	From150 systematic reviews published in MEDLINE (January 2018–August 2019), EMBASE (January 2018–August 2019), and the Cochrane Database of Systematic Reviews (January 2018–February 2019). Of the 150 included systematic reviews of nutritional epidemiology studies less than one-quarter (n = 30; 20.0%) reported preregistration of a protocol and almost one-third (n = 42; 28.0%) did not report a replicable search strategy. Suboptimal practices and errors in the synthesis of results were common: one-quarter of meta-analyses (n = 30; 26.1%) selected the meta-analytic model based on statistical indicators of heterogeneity and almost half of meta-analyses (n = 50; 43.5%) did not consider dose–response associations even when it was appropriate to do so. Only 16 (10.7%) reviews used an established system to evaluate the certainty of evidence.
Did the article find that the problem(s) led to qualitative changes in interpretation of the results?	Not Applicable
Are the methods of the article described in enough detail to replicate the study?	Yes