Women's representation in clinical trials of patients with chronic kidney disease

Lay Summary Using a sample of 192 trials of patients with chronic kidney disease (CKD) published between 1995 and 2022, this study showed that women's participation in those trials was lower than their representation in the population of patients with CKD worldwide. Only one in five trials reported efficacy outcomes separately for women and men and no trial reported safety outcomes separately for women and men. The underrepresentation of women in clinical trials and lack of sex-specific analyses prevents understanding whether there are important differences in response to treatments for CKD between women and men. Background Sex and gender differences in chronic kidney disease (CKD), including epidemiology and response to treatment, remain poorly understood. This study aimed to investigate how women are represented in CKD clinical trials and whether sex- and gender-disaggregated outcomes were reported. Methods Clinical trials on CKD were identified from ClinicalTrials.gov. Randomised, phase 3/4 trials with >= 100 participants were selected to quantify women's representation among participants by computing the participation:prevalence ratio (PPR) and investigating whether sex-disaggregated analyses had been performed. Results In total, 192 CKD trials registered on ClinicalTrials.gov and published between 1995 and 2022 were included. Overall, women accounted for 66 875 (45%) of the 147 136 participants. Women's participation in clinical trials was lower than their representation in the underlying CKD population globally (55%). The PPR was 0.75 (95% confidence interval 0.72-0.78), with no significant variation irrespective of mean age, CKD stage, dialysis, location, type of intervention or funding agency. A total of 39 (20%) trials reported sex-disaggregated efficacy outcomes and none reported sex-disaggregated safety outcomes. Conclusion Women's participation in CKD clinical trials was lower than their representation in the underlying CKD population. Sex-disaggregated efficacy and safety outcomes were rarely reported. Improving women's enrolment into clinical trials is crucial to enable sex- and gender-disaggregated analysis and thus identify potential differences in treatment response between women and men.