Variability in 30-day major amputation rates following endovascular peripheral vascular intervention for critical limb ischemia.

Patients with critical limb ischemia (CLI) can undergo endovascular peripheral vascular intervention (PVI) to restore blood flow and decrease risk of amputation. As a potential indicator of quality for CLI care, we sought to describe 30-day major amputation rates following PVI. We also examined rate variability, and patient-level and site-level factors predicting amputations, using a national electronic health record (EHR) database. Using the Cerner Health Facts de-identified EHR database, patients with CLI diagnosis codes undergoing PVI were identified. The rate of amputation within 30 days of PVI was calculated. Risk ratios predicting amputation were derived using a mixed effects Poisson regression model adjusting for 16 patient and clinical factors. Median risk ratios (MRRs) were calculated to quantify site-level variability in amputations. A total of 20,204 PVI procedures for CLI from 179 healthcare sites were identified. Mean age at procedure was 69.0 ± 12.6 years, 58.0% were male, and 29.6% were persons of color. Amputation within 30 days of PVI occurred after 570 (2.8%) procedures. Malnutrition, previous amputation, diabetes, and being of Black race were predictors of amputation. Amputation rates across sites ranged from 0.0% to 10.0%. The unadjusted MRR was 1.40 (95% CI 1.35-1.46), which was attenuated after adjusting for patient-level factors (MRR 1.30, 95% CI 1.26-1.34) and site characteristics (MRR 1.11, 95% CI 1.09-1.13). Among PVI procedures for CLI treatment, 30-day amputation rates varied across institutions. Although patient-level factors explained some variability, site-level factors explained most variation in the rates of these outcomes.