Mobility After Hospital Discharge as a Marker for 30-Day Readmission

BACKGROUND: Little is known about older patient's mobility soon after discharge home from an acute hospitalization. We examined daily postdischarge mobility levels as marker of overall health and response to in-hospital treatment in older medicine patients. METHODS: One hundred and eleven ambulatory men and women aged 65 years and older hospitalized with an acute medical illness and discharged to home were studied. Patients received an ankle-worn accelerometer during hospitalization and wore it continually for up to 1 week after discharge. Total number of steps taken per day was assessed. The primary outcome was all-cause 30-day readmission. RESULTS: Thirteen (11.7%) participants were readmitted within 30 days of discharge. There was a significant association between mean daily steps taken postdischarge and 30-day readmission (odds ratio = 0.85, 95% confidence interval = 0.72-0.99, and p = .04; odds ratio and confidence intervals were calculated for 500-step intervals). Though not statistically significant in the fully adjusted model (odds ratio = 0.83, 95% confidence interval = 0.71-1.02, and p = .08), mean daily steps was the strongest predictor among known readmission risk factors. The least active participants postdischarge were significantly more likely to be older (p = .02), be not married (p = .02), use a cane or walker prior to admission (p < .01), have longer lengths of hospital stay (p = .02), and be readmitted (p = .05). CONCLUSIONS: Mobility level soon after discharge home shows promise as a simple physical biomarker of overall health and risk of 30-day readmission in older patients.