Does age modify the cost-effectiveness of community-based physical activity interventions?

BACKGROUND Community-based efforts to promote physical activity (PA) in adults have been found to be cost-effective in general, but it is unknown if this is true in middle-age specifically. Age group-specific economic evaluations could help inform the design and delivery of better and more tailored PA promotion. METHODS A Markov model was developed to estimate the cost-effectiveness (CE) of 7 exemplar community-level interventions to promote PA recommended by the Guide to Community Preventive Services, over a 20-year horizon. The CE of these interventions in 25- to 64-year-old adults was compared with their CE in middle-aged adults, aged 50 to 64 years. The robustness of the results was examined through sensitivity analyses. RESULTS Cost/QALY (quality-adjusted life year) of the evaluated interventions in 25- to 64-year-olds ranged from $42,456/QALY to $145,868/QALY. Interventions were more cost-effective in middle-aged adults, with CE ratios 38% to 47% lower than in 25- to 64-year-old adults. Sensitivity analyses showed greater than a 90% probability that the true CE of 4 of the 7 interventions was below $125,000/QALY in adults aged 50 to 64 years. CONCLUSION The exemplar PA promotion interventions evaluated appeared to be especially cost-effective for middle-aged adults. Prioritizing such efforts to this age group is a good use of societal resources.