COST-EFFECTIVENESS OF MICROPROCESSOR-CONTROLLED PROSTHETIC KNEES IN THE DUTCH HEALTHCARE SYSTEM: THE IMPACT OF STUDY DURATION ON OUTCOMES

A previous health-utility analysis of microprocessor-controlled prosthetic knees (MPKs) in the Netherlands used a very short evaluation period of only 6 months resulting in an extremely high incremental cost-utility ratio (ICUR) of €457,063 per quality-adjusted life year (QALY) gained. However, for proper health-economic analyses, an appropriate time horizon, usually the useful life of an intervention, must be chosen to avoid biased results. Therefore, we performed a basic cost-utility analysis (CUA) extrapolating and properly discounting the utility and cost data reported by that article over the useful lifetime of MPKs of 6 years and found an ICUR of €17,945 per QALY. To further refine the CUA, we conducted a modeling study of the ICUR of the MPKs over a timeframe from 6 months to 25 years using existing and published population models for Germany and Sweden. In the modeling study, the ICUR was higher for the Netherlands with €37,567 per QALY than for Germany (€18,276 per QALY) or Sweden (€11,147 per QALY) but below the Dutch threshold for willingness to pay of €50,000 per QALY for people with a lower-limb amputation. Thus, the MPKs were cost-effective for the Dutch healthcare system in all scenarios of the cost-utility analysis. Our analysis showed that time had a much bigger impact on the ICUR than utility with the MPKs becoming cost-effective with the ICUR falling below the €50,000-per-QALY threshold after 4-5 years of use. Thus, a proper time horizon covering the useful lifetime of an intervention is key for health-economic analyses to prevent potentially misleading results and unjustified detrimental decisions for patients. Layman's Abstract A previous analysis of utility and costs of microprocessor-controlled prosthetic knees (MPKs) compared to non-microprocessor controlled prosthetic knees (NMPKs) for users with above-knee amputation in the Netherlands used a very short evaluation period of 6 months only and found extremely high costs of €457,063 per quality-adjusted life year gained by the MPKs. However, proper health-economic analyses require an appropriate time horizon, which is usually the useful lifetime of the medical device studied. Therefore, we performed a basic cost-utility analysis that extrapolated and properly discounted the utility and cost reported in that study over the useful lifetime of MPKs (6 years) and found costs of only €17,945 per quality-adjusted life year gained. To further refine the analysis, we also conducted a modeling study analyzing MPKs use over a timeframe from 6 months to 25 years using established and published population models for countries comparable to the Netherlands, such as Germany and Sweden. In the modeling study, the cost for the MPKs was higher for the Netherlands (€37,567 per quality-adjusted life year gained) than for Germany (€18,276) or Sweden (€11,147) but below the threshold for what the Dutch healthcare system would be willing to pay for people with above-knee amputations of €50,000 per quality-adjusted life year gained. Thus, the MPKs can be considered cost-effective for the Dutch healthcare system, and their cost starts falling below the willingness-to-pay threshold after 4-5 years of use. Our analysis showed that an appropriate time horizon of health-economic analyses must be chosen to avoid potentially misleading results and detrimental decisions for patients based on too-short evaluation periods. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/46669/34863 How To Cite: Kuhlmann A, Kannenberg A. Cost-effectiveness of microprocessor-controlled prosthetic knees in the Dutch healthcare system: The impact of study duration on outcomes. Canadian Prosthetics & Orthotics Journal. 2026; Volume 9, Issue 1, No. 2. https://doi.org/10.33137/cpoj.v9i1.46669 Corresponding Author: Andreas Kannenberg, PhDAffiliation: Clinical Research & Services, Ottobock Healthcare LP, Austin, TX, USA.E-Mail: [email protected] ID: https://orcid.org/0000-0001-7983-1744