Cost-Effectiveness Analysis of Implementing Bike Paths to Promote Leisure-Time Physical Activity Among Adults in São Paulo City, Brazil

BACKGROUND: The study aimed to conduct a cost-effectiveness analysis of bike path implementation to promote leisure-time physical activity (LTPA) among adults in São Paulo, Brazil. METHODS: The economic evaluation was conducted using the societal perspective, based on data from 1434 participants with complete records in 2 waves of the ISA-Physical Activity and Environment survey (2014-2015 and 2020-2021). Changes in LTPA and direct costs of bike paths implemented during follow-up were used to estimate the cost-effectiveness analysis. Participants completed the International Physical Activity Questionnaire in person during the first wave and were interviewed via telephone in the second wave. Geographic information systems were used to conduct participants' exposure to bike paths within a 1-km buffer around their households. The Municipal Department of Traffic and the Traffic Engineering Company provided data on costs for the implementation of bike paths from 2014 to 2016, which were used to estimate direct costs through 2021. The incremental cost-effectiveness ratio was calculated by comparing weekly direct costs per person according to exposure to bike paths in relation to the probability of improvement in physical activity. RESULTS: The direct cost of bike path implementation from 2014 to 2021 per person per week was approximately US$ 0.21 (95% CI, 0.18-0.24). The incremental cost-effectiveness ratio was US$ 115.59 per unit increase in the odds ratio of LTPA over the follow-up period among adults with exposure to bike paths. CONCLUSION: The findings indicate that the implementation of bike paths is a highly cost-effective intervention for promoting LTPA among adults in São Paulo City, Brazil.