Cost utility analysis of physical activity counselling in general practice

Objective: To evaluate the economic performance of the 'Green Prescription' physical activity counselling program in general practice. Methods: Cost utility analysis using a Markov model was used to estimate the cost utility of the Green Prescription program over full life expectancy. Program effectiveness was based on published trial data (878 inactive patients presenting to NZ general practice). Costs were based on detailed costing information and were discounted at 5% per anum. The main outcome measure is cost per quality adjusted life year (QALY) gained. Extensive one-way sensitivity analyses were performed along with probabilistic (stochastic) analysis. Results: Incremental, modelled cost utility of the Green Prescription program compared with 'usual care' was $NZ2,053 per QALY gained over full life expectancy (range $NZ827 to $NZ37,516 per QALY). Based on the probabilistic sensitivity analysis, 90% of ICERs fell below $NZ7,500 per QALY. Conclusions: Based on a plausible and conservative set of assumptions, if decision makers are willing to pay at least $NZ2,000 per QALY gained the Green Prescription program is likely to represent better value for money than 'usual care'. Implications: The Green Prescription program performs well, representing a good buy relative to other published cost effectiveness estimates. Policy makers should consider encouraging general practitioners to prescribe physical activity advice in the primary care setting, in association with support from exercise specialists.