Sex/gender reporting and analysis in Campbell and Cochrane systematic reviews: a cross-sectional methods study

Background: The importance of sex and gender considerations in research is being increasingly recognized. Evidence indicates that sex and gender can influence intervention effectiveness. We assessed the extent to which sex/gender is reported and analyzed in Campbell and Cochrane systematic reviews. Methods: We screened all the systematic reviews in the Campbell Library (n = 137) and a sample of systematic reviews from 2016 to 2017 in the Cochrane Library (n = 674). We documented the frequency of sex/gender terms used in each section of the reviews. Results: We excluded 5 Cochrane reviews because they were withdrawn or published and updated within the same time period as well as 4 Campbell reviews and 114 Cochrane reviews which only included studies focused on a single sex. Our analysis includes 133 Campbell reviews and 555 Cochrane reviews. We assessed reporting of sex/gender considerations for each section of the systematic review (Abstract, Background, Methods, Results, Discussion). In the methods section, 83% of Cochrane reviews (95% CI 80-86%) and 51% of Campbell reviews (95% CI 42-59%) reported on sex/gender. In the results section, less than 30% of reviews reported on sex/gender. Of these, 37% (95% CI 29-45%) of Campbell and 75% (95% CI 68-82%) of Cochrane reviews provided a descriptive report of sex/gender and 63% (95% CI 55-71%) of Campbell reviews and 25% (95% CI 18-32%) of Cochrane reviews reported analytic approaches for exploring sex/gender, such as subgroup analyses, exploring heterogeneity, or presenting disaggregated data by sex/gender. Conclusion: Our study indicates that sex/gender reporting in Campbell and Cochrane reviews is inadequate.