Meta-analysis in otolaryngology

Objective: To examine the results of meta-analyses in otolaryngology and co mpare these results with;he individual component studies that constitute ea ch metaanalysis. Design: A retrospective review of the literature. Main Outcome Measures: Studies that conducted pooled statistical systematic analyses indexed on MEDLINE for the 10-year period from January 1989 to Ja nuary 1999 were selected for keyword or subject headings of meta-analysis a nd otolaryngology (N=22). Analysis consisted of a modified funnel graph dep iction of the individual studies that made up each meta-analysis. Each meta -analysis was evaluated for consistency among these individual studies and comparison, of the median result with the weighted mean meta-analysis resul t. In addition, the methodologic quality of each meta-analysis was assessed in terms of the rigor with which component studies were evaluated. Results: Ten (46%) of the 22 meta-analyses did not provide the individual s tudy results that made up their meta-analyses. The results of 10 studies (4 6%) were similar to the median result of their individual component studies . The results of 2 studies (9%) differed from this median result, with wide ly heterogeneous component study results. Conclusions: A large proportion of meta-analyses in otolaryngology (46%) fa il to provide the individual study results necessary to analyze the meta-an alysis result critically, Most remaining studies do provide results that ac curately compare with the median of their component study results. Only a s mall proportion of meta-analyses were found to have disparate results, and each appropriately discusses the heterogeneity of the individual studies th at comprise their meta-analysis.