Introduction Men with prostate cancer (PCa) treated with androgen deprivation therapy (ADT) may develop adverse effects that increase their risks of falls and fractures. Exercise medicine reduces these unwanted effects through improved muscle strength, physical function, fatigue and bone health. The purpose of this study was to assess the cost utility of exercise in preventing falls and fractures for this population.
Methods A decision analytic model was constructed to evaluate the cost-effectiveness of an exercise intervention compared to usual care from a healthcare perspective. The intervention comprised two one-hour sessions of supervised exercise per week over one year for men with localised PCa receiving curative therapy and ADT. A Markov model simulated the transition between five health states: 1) at risk of falling; 2) at recurrent risk of falling; 3) fracture; 4) non-fracture injury; and 5) death. Model inputs including transition probabilities and utility scores were obtained from published meta-analyses, and costs were drawn from Australian data sources (e.g., Medical Benefits Schedule). The model time horizon was three years, and costs and effects were discounted at 5% annual rate. Incremental net monetary benefit (iNMB) was calculated, which is the difference in quality-adjusted life years (QALYs) times willingness-to-pay threshold, minus difference in costs. Uncertainty in the results was explored using probabilistic sensitivity analysis (PSA).
Results At a willingness-to-pay of AU$50,000 per QALY, the exercise intervention dominated, as it was less costly and more effective than usual care. The iNMB was $4,636 per patient. The PSA showed a 77% probability the intervention was cost-effective.
Conclusion This is the first modelled economic evaluation of exercise for men with PCa. Our results suggest exercise is cost effective in reducing the risks of fall and fractures in this population. Efforts should be focused on implementation of exercise interventions to realise these economic and health benefits.