Prevalence, incidence, and outcomes of critical limb ischemia in the US Medicare population

Abstract

Objective. This study aimed to assess annual prevalence and incidence of critical limb ischemia (CLI) and associated outcomes (amputation, leg revascularization, death) in elderly persons in the United States. Method. Medicare beneficiaries ages 65 and older were retrospectively analyzed and compared for demographic and clinical characteristics from January 2007 to December 2008. Using the direct standardization method, year, age, gender, and race, as well as diabetes-specific prevalence and incidence rates were estimated for the CLI burden in the United States. Potential risk factors for CLI outcomes, events, and mortality were selected using Cox proportional hazard regression models. CLI prevalence and incidence was 0.23% and 0.20% respectively. Similar to prevalence, incidence increased sharply among beneficiaries ages 65 to 69 (0.13%) to 85 and older (0.31%). Results. Among black patients, 0.41% had CLI, compared to 0.18% among white patients. Diabetes caused 7.6 times increased CLI risk compared to nondiabetic patients. In the multivariate analysis, younger, male, diabetic (HR 1.21), or proliferative retinopathy (HR 1.112) patients were significantly associated with nontraumatic amputation, while hypertension (HR 1.043), angina pectoris (HR 1.074), myocardial infarction (HR 1.08), or hyperlipidemia (HR 1.1) were significantly related to leg revascularization. Black patients had a lower revascularization probability and a higher amputation probability than white patients (after adjustment for age, gender, CLI severity, comorbidities), and displayed a longer time to first revascularization and shorter time to amputation. Older, male and black patients had higher CLI prevalence. Conclusion. CLI management differs among the US population according to ethnicity, leading to varying outcomes (revascularization, amputation). Since outcome event risk varies, patients should be examined individually. VASCULAR DISEASE MANAGEMENT 2013:10(2):E26-E36