Under-representation of Women and Ethnic Minorities in Vascular Surgery Randomized Controlled Trials

ABSTRACT
Objectives: Gender and ethnicity are factors affecting the incidence of vascular disease and subsequent treatment outcomes. Though robustly studied in other fields, balanced enrollment of patients with relevant demographic characteristics in vascular surgery randomized-control trials (RCT) is not known. This study describes the reporting of gender and ethnicity data in vascular surgery RCT and analyzes whether these groups are adequately represented.
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 (2006) was analyzed to obtain sub-population incidence of these procedures.
Results: Seventy-seven studies were reviewed and 42 met our inclusion criteria. Of these, only 83% reported gender and 24% reported ethnicity. Reporting of ethnicity was strongly associated with larger (>250 subjects), multi-center, government-funded trials (P<0.001 for all). Women and minorities were disproportionately under-represented in RCT compared to the population incidence, with the exception of LER where minorities were over-represented (Table 1).
Conclusions: Minority ethnicity and female gender are under-represented and under-reported 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 population in RCT may yield more applicable results.
Table 1. Gender and ethnicity enrollment rates vs. population procedural rates