Older Adults' Physical Activity and Healthcare Costs, 2003-2014.

Introduction: Research has documented the health benefits of physical activity among older adults, but the relationship between physical activity and healthcare costs remains unexplored at the population level. Using data from 50 U.S. states and the District of Columbia, this study investigates the extent to which physical activity prevalence is associated with healthcare costs among older adults.

Methods: Twelve-year state-level data (2003-2014) were obtained from 5 secondary sources (n=611). Healthcare costs were captured by Medicare Parts A and B spending. Fixed-effect models were estimated in 2019 to assess the relationship between the state-level physical activity prevalence and Medicare costs. The potential lagged associations were captured by lagged variables of physical activity prevalence (i.e., t-1, t-2, and t-3).

Results: Physical activity prevalence was not associated with Medicare costs occurring in the concurrent and subsequent year (p>0.05); however, the 2-year lagged variable (p=0.03) and the 3-year lagged variable (p=0.01) for physical activity prevalence were negatively associated with Medicare costs, indicating a time-lagged relationship. It was estimated that a 10 percentage point increase in physical activity prevalence in each state is associated with reduced Medicare Parts A and B costs of 0.4% after 2 years and 1.0% after 3 years.

Conclusions: Results revealed a time lag effect highlighted by a delayed inverse relationship between state-level physical activity prevalence and healthcare costs among older adults. This evidence offers governments and communities new insights to guide policymaking on long-term public investment in physical activity intervention programs.