Sex Differences in Management and Outcomes of Critical Limb Ischemia in the Medicare Population

Background: Evidence about sex differences in management and outcomes of critical limb ischemia (CLI) is conflicting. Methods: We identified Fee-For-Service Medicare patients within the 5% enhanced sample file who were diagnosed with new incident CLI between 2015 and 2017. For each beneficiary, we identified all hospital admissions, outpatient encounters and procedures, and pharmacy prescriptions. Outcomes included 90-day mortality and major amputation. Results: Incidence of CLI declined from 2.80 (95% CI, 2.72-2.88) to 2.47 (95% CI, 2.40-2.54) per 1000 person from 2015 to 2017, P<0.01. Incidence was lower in women compared with men (2.19 versus 3.11 per 1000) but declined in both groups. Women had a lower prevalence of prescription of any statin (48.4% versus 52.9%, P<0.001) or high-intensity statins (15.3% versus 19.8%, P<0.01) compared with men. Overall, 90-day revascularization rate was 52%, and women were less likely to undergo revascularization (50.1% versus 53.6%, P<0.01) compared with men. Women had a similar unadjusted (9.9% versus 10.3%, P=0.5) and adjusted 90-day mortality (adjusted rate ratio, 0.98 [95% CI, 0.85-1.12], P=0.7) compared with men. Over the study period, unadjusted 90-day mortality remained unchanged for men (10.4% in 2015 to 9.9% in 2017, P^{for trend}=0.3), and women (9.5% in 2015 to 10.6% in 2017, P^{for trend}=0.2). Men had higher unadjusted (12.9% versus 8.9%, P<0.001) and adjusted risk of 90-day major amputation (adjusted rate ratio, 1.30 [95% CI, 1.14-1.48], P<0.001). One-third of patients with CLI underwent major amputation without a diagnostic angiogram or trial of revascularization in the preceding 90 days regardless of the sex. Conclusions: Women with new incident CLI are less likely to receive statin or undergo revascularization at 90 days compared with men. However, the differences were small. There was no difference in risk of 90-day mortality between both sexes.