Anesthesiology systematic reviews: Too heterogeneous?
Many systematic reviews (SR) in anesthesiology do not provide sufficient detail regarding heterogeneity, say US-American researchers at the Oklahoma State University Center for Health Science. The authors conducted a metaanalysis of 207 anesthesiology SRs published in highly ranked anesthesiology journals and Cochrane reviews, and evaluated the heterogeneity practices these studies reported.
According to the analysis, 150 SRs reported a test for statistical heterogeneity, while 138 reviews used plots to display heterogeneity. Subgroup analyses were the most commonly reported analysis (used in more than half the studies); meta-regression and sensitivity analyses were conducted in 25 and 23 % of cases, respectively. A random effects model was most commonly reported (33 %). The majority of studies (55 %) did not present sufficient heterogeneity to be of great concern. In addition, the authors analyzed 58 Cochrane reviews; here, plots were used in 88 %, subgroup analysis was used in 59 %, and sensitivity analysis was used in 62 %.
The authors call for improvement to reporting practices, as many reviews currently do not provide sufficient detail with respect to heterogeneity.