Determinants of Long-Term Outcomes and Costs in the Management of Critical Limb Ischemia: A Population-Based Cohort Study

Abstract

Background The optimal treatment for critical limb ischemia remains controversial owing to conflicting conclusions from previous studies. Methods and Results We obtained administrative claims on Medicare beneficiaries with initial critical limb ischemia diagnosis in 2011. Clinical outcomes and healthcare costs over 4 years were estimated among all patients and by first treatment (endovascular revascularization, surgical revascularization, or major amputation) in unmatched and propensity-score-matched samples. Among 72 199 patients with initial primary critical limb ischemia diagnosis in 2011, survival was 46% (median survival, 3.5 years) and freedom from major amputation was 87%. Among 9942 propensity-score-matched patients (8% rest pain, 26% ulcer, and 66% gangrene), survival was 38% with endovascular revascularization (median survival, 2.7 years), 40% with surgical revascularization (median survival, 2.9 years), and 23% with major amputation (median survival, 1.3 years; P<0.001 for each revascularization procedure versus major amputation). Corresponding major amputation rates were 6.5%, 9.6%, and 10.6%, respectively ( P<0.001 for all pair-wise comparisons). The cost per patient year during follow-up was $49 700, $49 200, and $55 700, respectively ( P<0.001 for each revascularization procedure versus major amputation). Conclusions Long-term survival and cost in critical limb ischemia management is comparable between revascularization techniques, with lower major amputation rates following endovascular revascularization. Primary major amputation results in shorter survival, higher risk of subsequent major amputation, and higher healthcare costs versus revascularization. Results from this observational research may be susceptible to bias because of the influence of unmeasured confounders.

Keywords: Medicare; amputation; cost; critical limb ischemia; peripheral artery disease; revascularization.

Figure 1

Patient survival over 4 years following diagnosis of critical limb ischemia by clinical presentation in entire sample. *P<0.001 vs ulcer; ^† P<0.001 vs gangrene; ^‡ P<0.001 vs rest pain.

Figure 2

Freedom from major amputation over 4 years following diagnosis of critical limb ischemia by clinical presentation in entire sample. *P<0.001 vs ulcer; ^† P<0.001 vs gangrene; ^‡ P<0.001 vs rest pain.

Figure 3

Patient survival over 4 years following first major therapy for critical limb ischemia in matched patients. *P<0.001 vs major amputation.

Figure 4

Patient survival over 4 years following first major therapy for critical limb ischemia by clinical presentation (A, rest pain; B, ulcer; C, gangrene) in matched patients. Amp indicates major amputation; endo, endovascular; surg, surgical. *P<0.001 vs major amputation within each clinical presentation category.