Physical activity, health symptoms, and falls in older adults with different cognition levels: evidence from the Health and Retirement Study.

BACKGROUND

Falls are the leading cause of disability, premature institutionalization, and mortality in the aging population. Older adults with cognitive impairment are more susceptible to falls and have a significantly higher risk of falls compared to those with normal cognition. Physical activity (PA) is a key fall prevention strategy; however, evidence on the dose-response relationship between PA and falls among older adults with impaired cognition is limited. We investigated associations of physical activity and health symptoms with falls in cognitively diverse older adults to identify differential effects.

METHODS

We conducted a cross-sectional secondary analysis of 6,781 adults aged ≥ 65 who participated in both 2020 and 2022 Health and Retirement Study (HRS) interview years. Weighted survey logistic regression models estimated associations between PA levels and self-reported falls, defined as reporting at least one fall in the previous two years. Cognitive status was assessed using the 27-point HRS cognition scale. Models sequentially adjusted for demographics and health symptoms, including pain, dyspnea, obesity, and depressive symptoms.

RESULTS

In fully adjusted models, high-intensity PA was significantly associated with lower odds of falling (OR = 0.76, 95% CI: 0.60-0.98). Associations observed for moderate PA in partially adjusted models were attenuated and no longer statistically significant after full adjustment (OR = 0.83, 95% CI: 0.66-1.05). Mild PA was not significantly associated with falls across models. Stratified analyses showed a consistent pattern of lower odds of falls with increasing PA intensity in both cognition groups; however, significant associations for moderate and high PA were lost after adjusting for health symptoms in the normal cognition group. Among those with impaired cognition, only high-level PA demonstrated a similar attenuated trend, while mild and moderate PA remained non-significant across models. Chronic pain, dyspnea, and depressive symptoms were significantly associated with increased fall risk in both subgroups, while obesity was only significantly associated with falls in the normal cognition group.

CONCLUSIONS

Moderate and high-intensity PA were associated with lower odds of falls, with important effect modification by cognitive status and health symptoms. These findings suggest that fall prevention strategies should account for cognitive function and symptom burden when promoting physical activity in older adults.