Ann Vasc Surg. 2026 Sep 4:S0890-5096(26)00648-5. doi: 10.1016/j.avsg.2026.08.051. Online ahead of print.
ABSTRACT
OBJECTIVES: Despite the recent improvement in female recruitment to randomized controlled medical research trials (RCTs), males continue to predominate in cardiovascular trials due to multiple structural barriers. Scarce data are available on female representation in peripheral artery disease (PAD) trials. This study aimed to analyze the reporting of gender and quantify female enrollment rates in PAD RCTs, the impact of trial funding sources, and geographic factors over two decades.
METHODS: A systematic literature search across multiple databases was performed to retrieve PAD RCTs conducted in the United States or Canada from 2001 through June 2021. Extracted data included the trial year, country, geographic region, number of recruitment sites, sample size, sex reporting/composition, follow-up duration, and funding source. A pooled estimate of the female percentages across studies was performed using the random effects meta-analysis with inverse variance pooling.
RESULTS: A total of 103 RCTs were included. 98 (95.1%) trials reported their participants' sex. 40 (40.8%) trials were published in 2001-2010, while the rest, 58 (59.2%), were published over the second decade. 75,776 participants were enrolled, 48,120 females, corresponding to an aggregate female enrollment proportion of 63.5%. The random-effects pooled proportion of female participants was 0.30 [95% CI, 0.21-0.40], with substantial heterogeneity. There were no significant differences in overall female proportions across different trial types. Studies that were sponsored by non-NIH, federal, or state governmental agencies demonstrated disproportionately lower rates of female enrollment [8% vs. 35% in NIH, 0.30 industry-sponsored RCTs; P<.01].
CONCLUSIONS: The enrollment of women was disproportionately low in this systematic analysis of PAD clinical trials, regardless of trial purpose, funding source, or geographic site, when compared to men. The analyzed trials occurred for two decades following non-enforceable federal mandates to improve female and minority trial enrollment. As a result, the current purported evidence-based treatment of PAD interventions in women is based upon data disproportionately extrapolated from observations of PAD in men. These findings suggest that the evidence base supporting PAD interventions may have limited generalizability to women as they remain underrepresented among PAD trial participants. A coordinated effort on behalf of investigators, professional societies, industry, and government sponsors is necessary to overcome this research enrollment finding, which calls into question the fidelity of contemporary PAD treatment strategies.
PMID:42697326 | DOI:10.1016/j.avsg.2026.08.051