#3436 Representation of women and sex-disaggregated outcomes of trials in ANCA-associated vasculitis

Abstract Background and Aims Women are generally underrepresented in randomized controlled trials (RCTs). No data exists on potential differential outcomes in ANCA-associated vasculitis (AAV) between women and men. Thus we sought to evaluate representation of women and reporting of sex-disaggregated outcomes in RCTs of AAV. Method A PubMed search was carried out for RCTs published from beginning of indexation to May 2024 on granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis. RCT quality was assessed using modified Jadad 8-point scale (mJS) Representation of women was expressed as participation-to-prevalence ratio (PPR) calculated as the ratio between enrollment of women and prevalence of AAV in women (data on prevalence was obtained from a recently published FAIRVASC study). A PPR of less than 0.8 indicates underrepresentation and 1.2 or higher indicates overrepresentation. Results A total of 572 publications were identified, of which 56 original (main) RCTs were included. Of 5,336 enrolled patients 2,415 were women (45.3 ± 10.7%; min-max: 21.9% to 69.8%, with a PPR of 0.94 (min-max: 0.46 to 1.45). Even after exclusion of RCTs in EGPA (n = 12), there were no changes to percentage of women enrolled or PPR (44.1% and 0.92, respectively). Women were underrepresented (PPR < 0.8) in 13 (25%) and overrepresented (PPR ≥ 1.2) in 7 (13%) RCTs. There was a geographical imbalance with women more frequently recruited in RCTs based in Australasia (61.2%) compared to Europe (41.8%) and globally (defined as RCT which enrolled patients from two or more continents) (47.7%) (P < 0.001) (Fig. 1A). Enrollment of women increased over time (Beta = 0.003, P = 0.05) (Fig. 1B), and was not associated with RCT size or study quality. Most studies reported sex of participants (96%), but none compared baseline characteristics between women and men. Only three studies (5%) reported sex-disaggregated outcomes: two for the primary efficacy outcome and one for the primary safety outcome and of these just one RCT reported sex-disaggregated outcomes in the main text. Conclusion Women are generally not underrepresented in AAV RCTs. However, trials almost never report sex-disaggregated outcomes or discuss on any differences between women and men.