OBJECTIVES: Growing evidence suggests that individuals with transfemoral amputation or knee disarticulation who use a prosthesis equipped with a microprocessor-controlled knee (MPK) benefit from enhanced mobility and safety. In elderly individuals, high mortality rates are assumed to reduce the expected useful life of MPKs and concerns have been raised regarding their economic effectiveness in this group of individuals. The objective of this study was to investigate the cost-effectiveness and budget impact of a MPK, designed for low-active users, compared to non-microprocessor-controlled knee (NMPK) in individuals aged +65 at the time of amputation.

METHODS: A decision-analytic model was developed to perform cost-effectiveness and budget impact analyses from a Swedish payer perspective. Two cohorts, surviving 6 months after amputation, were compared: firstly, prosthesis users (PU) with amputations due to diabetes mellitus and/or peripheral vascular disease (DM/PVD) and secondly, PU with other etiologies. Input parameters were derived from two Swedish databases(SwedeAmp/Socialstyrelsen) and published literature. Univariate and probabilistic sensitivity analyses were performed to explore parameter uncertainty.

RESULTS: Compared with NMPKs, the MPK would prevent 141 hospitalizations and 19 fatal-falls/1,000 person years (PY) in PU with DM/PVD and 129 hospitalizations and 17 fatal-falls/1,000 PY in PU with other etiologies. Over a time horizon of 25 years, the incremental cost-effectiveness ratio for PU with DM/PVD was SEK138,003(€11,138)/quality adjusted life years (QALY) gained and SEK114,772(€9,263)/QALY gained for PU with other etiologies. The probability of the MPK being cost-effective at a threshold of SEK500,000(€40,355)/QALY gained was above 99% in both cohorts. For the period of 2020-2024, the model predicted an increase in payer’s expenditures of SEK21.3(€1.72)million if all new PU received the MPK and 50% of prevalent NMPK users are re-fitted with the MPK.

CONCLUSIONS:

The results indicate that an MPK for low-active users may provide additional benefits and is likely to be cost-effective even for older individuals.