Association between early in-hospital physiological and functional changes and fall risk in older adults: a...

To examine whether early in-hospital changes in functional status and selected physiological parameters were associated with subsequent falls among hospitalized older adults.

This retrospective multicenter cohort study used electronic health record and administrative data from two tertiary hospitals in Japan between 2018 and 2024. Patients aged 65 years or older underwent landmark assessments on hospital days 3 (LM3) and 7 (LM7). Functional trajectories were defined from changes in transfer ability between admission and each landmark; physiological changes included serum albumin, hemoglobin, and sodium. The outcome was the first documented in-hospital fall within 30 days after each landmark. Associations were estimated using multivariable logistic regression with multiple imputation.

Of 112,103 eligible patients, 83,297 were included in LM3 and 61,071 in LM7. Patients ranged in age from 65 to 106 years in both cohorts; 40.6% of the LM3 cohort and 40.9% of the LM7 cohort were female. Persistent or worsening transfer impairment was associated with higher fall risk at both landmarks. Acute functional decline was associated with higher fall risk at LM7 but not LM3. Declines in hemoglobin and serum sodium were independently associated with higher fall risk in both analyses, whereas changes in serum albumin were not. Findings were consistent across sensitivity analyses.

Functional and physiological changes during early hospitalization were associated with subsequent fall risk in older adults. Reassessment on hospital days 3 and 7 may complement admission-based assessment by identifying evolving vulnerability and supporting time-sensitive fall-prevention strategies.