Does variation in either age at start of therapy or duration of therapy make chemoprevention with finasteride cost-effective?

BACKGROUND: Incremental cost-effectiveness ratios (ICERs) of finasteride for prostate cancer prevention are consistent with estimates beyond $100 000 per quality-adjusted life-year (QALY). The majority of these analyses are based on chemoprevention starting in men aged 50-55 years. We sought to evaluate the impact of varying both age at commencement of therapy and length of therapy on the cost-effectiveness of finasteride.
METHODS: A probabilistic Markov model was designed to estimate lifetime prostate health-related costs and quality-adjusted survival for men receiving or not receiving chemoprevention with finasteride. ICERs across scenarios varying age at start of therapy and duration of chemoprevention were compared.
RESULTS: The ICER for men starting chemoprevention at age 50 and continuing to age 75 was $88 800 per QALY when assuming finasteride causes a constant risk reduction across all tumor grades (base case 1) and $142 300 per QALY when assuming a differential treatment effect according to Gleason score (base case 2). When starting age is increased, the ICERs trend downward and nadir at 65 years to $64 700 per QALY (base case 1) and $118 600 per QALY (base case 2). Altering duration of therapy had minimal impact. Patient-level experiences with finasteride and BPH significantly influenced the cost-effectiveness of chemoprevention.
CONCLUSIONS: Initiating chemoprevention at ages when prostate cancer incidence is higher improves its cost-effectiveness profile. Only when assuming a constant risk reduction for all tumor grades, did finasteride fall below $100 000 per QALY, but this finding was not upheld when accounting for side effects associated with the drug.