Background: there is a great need to promote health and reduce health inequities. Since systematic reviews, and overviews of reviews, are important sources for health policy, it is important to ensure that they reflect upon equity and diversity issues.
Objectives: to investigate whether Cochrane overviews of reviews reflect upon factors related to health equity and diversity.
Methods: we initially searched the Cochrane Library for overviews of reviews of interventions, published from 2009 up to March 2019. We then searched the abstracts of identified overviews, as well as the full texts, using the following search terms: marginalized, equity/inequity, minority/minorities, disadvantaged, underserved, vulnerable, diverse/diversity, socioeconomic status, social capital, social gradient, sexuality, and disability.
Results: the initial search yielded 48 overviews of reviews published between 2009 and 2019, covering a variety of health topics. We searched the abstracts and found that only two contained any of the search terms, while 15 of the 48 full texts did. However, only eight of the 15 overviews either discussed equity and related factors, or included references suggesting that they could have. We excluded seven of the overviews that included one or more of the search terms, since they did not actually report on equity. Of the eight remaining, the main aim of five reviews was equity-related.
Discussion: MECIR standards specify that it is highly desirable to consider equity issues. Nevertheless, only five of 48 overviews initially identified, explicitly discussed factors related to equity. One explanation may be that original reviews (or the original studies) do not report equity-related factors. However, if, for example, socioeconomic status (SES) was relevant for the effect of an intervention, overview authors should have stated that this information was missing. In one overview, SES was mentioned as a risk factor in the background, but was not discussed further. In two other overviews, disadvantaged populations were described in the titles of references, indicating that it might have been reported in original studies, but their disadvantage was not discussed in the overview. In one overview, the importance of SES for the health issue under study was stated in the background, but was not discussed further.
Conclusions: few Cochrane overviews of reviews reflect on factors related to equity or diversity, or both, despite the recommendation of the MECIR standards. At a minimum, authors should state whether equity or diversity, or both, is likely to be an issue for the health topic under investigation, and whether it was reported in the included reviews.
Patient or healthcare consumer involvement: one overview involved consumers in the work on the overview.