UC Davis

BACKGROUND:To examine the associations between objective physical activity measures and subsequent health care utilization. METHODS:We studied 1,283 men (mean age 79.1 years, SD 5.3) participating in the Osteoporotic Fractures in Men Study. Participants wore a SenseWear® Pro Armband monitor for 1 week. Data was summarized as daily (i) step counts, (ii) total energy expenditure, (iii) active energy expenditure, and (iv) activity time (sedentary, ≥ light, ≥ moderate). The outcome measures of 1-year hospitalizations/duration of stay from Medicare data were analyzed with a two-part hurdle model. Covariates included age, clinical center, body mass index, marital status, depressive symptoms, medical conditions, cognitive function, and prior hospitalization. RESULTS:Each 1 SD = 3,092 step increase in daily step count was associated with a 34% (95% confidence interval [CI]: 19%-46%) lower odds of hospitalization in base model (age and center) and 21% (95% CI: 4%-35%) lower odds of hospitalization in fully adjusted models. Similar but smaller associations held for other physical activity measures, but these associations were not significant in fully adjusted models. Among those hospitalized, higher step count was associated with shorter total duration of acute/postacute care stays in the base model only. There was a fourfold significant difference (from model-based estimates) in predicted care days comparing those with 2,000 versus 10,000 daily steps in the base model, but only a twofold difference (not significant) in the full model. CONCLUSION:Daily step count is an easily determined measure of physical activity that may be useful in assessment of future health care burden in older men.