Factors that influence time to prosthesis receipt after lower limb amputation: A Cox proportional hazard model regression

Abstract

Background: Early mobility, functional independence, and ambulation are associated benefits after lower limb amputation (LLA), whereas an increased risk of clinical complications is associated with no prosthesis. Objective: To describe time to prosthesis receipt after amputation and to assess the impact of patient demographic and health factors on the rate of prosthesis receipt within 12 months post LLA. Design: A retrospective cohort analysis using commercial administrative claims data. Kaplan-Meier and Cox proportional-hazards models were applied to assess time to prosthesis receipt. Setting: Watson/Truven administrative database 2014-2016. Participants: Adults aged 18-64 years with LLA who maintained their current insurance enrollment for 12 months after amputation. Interventions: Independent variables included diabetes/vascular disease status, amputation level, age, gender, and region. Main Outcome Measures: Prosthesis receipt was defined based on the presence of codes billed for prosthesis services. Time was measured in days from date of amputation surgery. Results: Among the sample, 510 individuals maintained insurance enrollment for 12 months after amputation, of which 443 individuals received a prosthesis within that period (79% below knee and 21% above knee). The adjusted average rate of time to prosthesis receipt was 138 (95% confidence interval [CI]: 113–185) days. Individuals with diabetes/vascular disease were 22% (hazard ratio: 1.22, 95% CI: 1.02–1.49) more likely to receive a prosthesis earlier than individuals without diabetes/vascular disease and women received a prosthesis later than men at 141 (95% CI: 126–162) days versus 106 (95% CI: 96–119) days, respectively. Conclusions: This study expands the understanding of factors that influence the likelihood of receiving a prosthesis along with the timing of prosthesis receipt after LLA among commercially insured adults. At least half of this sample received a prosthesis within 5 months or less. Disparities in timing and access to a prosthesis based on amputation level and gender were noted; future efforts are needed to address these issues.