Cost-effectiveness of health coaching and financial incentives to promote physical activity after total knee replacement

Abstract

We evaluated the cost-effectiveness of Telephonic Health Coaching and Financial Incentives (THC+FI) to promote physical activity in total knee replacement recipients. We used the Osteoarthritis Policy Model, a computer simulation of knee osteoarthritis, to evaluate the cost-effectiveness of THC+FI compared to usual care. We derived transition probabilities, utilities, and costs from trial data. We conducted lifetime analyses from the healthcare perspective and discounted all cost-effectiveness outcomes by 3% annually. The primary outcome was the Incremental Cost-Effectiveness Ratio (ICER), defined as the ratio of the differences in costs and Quality-Adjusted Life Years (QALYs) between strategies. We considered ICERs <$100,000/QALY to be cost-effective. We conducted one-way sensitivity analyses that varied parameters across their 95% confidence intervals (CI) and limited the efficacy of THC+FI to 1year or to 9months. We also conducted a probabilistic sensitivity analysis (PSA), simultaneously varying cost, utilities, and transition probabilities. THC+FI had an ICER of $57,200/QALY in the base case and an ICER below $100,000/QALY in most deterministic sensitivity analyses. THC+FI cost-effectiveness depended on assumptions about long-term efficacy; when efficacy was limited to 1year or to 9months, the ICER was $93,300/QALY or $121,800/QALY, respectively. In the PSA, THC+FI had an ICER below $100,000/QALY in 70% of iterations. Based on currently available information, THC+FI might be a cost-effective alternative to usual care. However, the uncertainty surrounding this choice is considerable, and further research to reduce this uncertainty may be economically justified.