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

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.

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.

We excluded 5 Cochrane reviews because they were withdrawn or published and updated within the same time period as well as 4 Campbell reviews and 114 Cochrane reviews which only included studies focused on a single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.

Our study indicates that sex/gender reporting in Campbell and Cochrane reviews is inadequate.