Under-representation of women and ethnic minorities in vascular surgery randomized controlled trials

Abstract

Objectives Gender and ethnicity are factors affecting the incidence and severity of vascular disease as well as subsequent treatment outcomes. Though well-studied in other fields, balanced enrollment of patients with relevant demographic characteristics in vascular surgery randomized-control trials (RCT) is not well known. This study describes the reporting of gender and ethnicity data in vascular surgery RCT and analyzes whether these studies adequately represent our diverse patient population. Methods We conducted a retrospective review of US-based RCT from 1983 through 2007 for three broadly defined vascular procedures: aortic aneurysm repair (AAR), carotid revascularization (CR), and lower extremity revascularization (LER). Included studies were examined for gender and ethnicity data, study parameters, funding source, and geographic region. The Nationwide Inpatient Sample (NIS) database was analyzed to obtain group-specific procedure frequency as an estimate of procedure frequency in the general population. Results Seventy-seven studies were reviewed and 52 met our inclusion criteria. Of these, only 85% reported gender and 21% reported ethnicity. Reporting of ethnicity was strongly associated with larger (>280 subjects), multi-center, government-funded trials (P<0.001 for all). Women are disproportionately under-represented in RCT for all procedure categories (AAR: 9.0% vs 21.5%, CR: 30.0% vs 42.9%, LER: 22.4% vs 41.3%) while minorities are underrepresented in AAR studies (6.0% vs 10.7%) and CR studies (6.9% vs 9.5%) while they are over represented in LER studies (26.0% vs 21.8%, P<.001 for all). Conclusions Minority ethnicity and female gender are under-reported and under-represented in vascular surgery RCT, particularly in small, non-government funded and single-center trials. The generalizability of some trial results may not be applicable to these populations. Greater effort to enroll a balanced study population in RCT may yield more broadly applicable results.

A Call to Action: Women and Peripheral Artery Disease

“…51 Currently, women and ethnic minorities are underrepresented in essentially all PAD prospective randomized controlled trials. 52 There may be a reluctance of women (and possibly also patients in some ethnic groups) to participate in cardiovascular clinical trials. 53 Efforts to enroll women of diverse ethnic groups in such trials should be expanded, because further investigation is needed to determine why these subgroups have higher prevalence and worse outcomes of treatment of PAD.…”

Analysis of large databases in vascular surgery

“…27 The dataset has also been used to demonstrate the underrepresentation of women and ethnic minorities in randomized trials of aortic aneurysm repair, carotid revascularization, and lower extremity revascularization. 28 Because NIS data is based on inpatient encounters, there is no information about outpatient care. Linkage of multiple inpatient encounters for the same patient over time is also not possible.…”

Gender differences in clinical registration trials: is there a real problem?

“…cancer, vascular surgery and cardiovascular trials 9, 10, 11, 12, 13), with the general media continuing to report that large gender gaps are still putting women at a disadvantage 14. This reporting has had serious effects on policy, with large amounts of money being allocated to study gender differences in healthcare 15.…”