Inpatient Walking Activity to Predict Readmission in Older Adults

Abstract

Objective: To compare the 30-day readmission predictive power of in-hospital walking activity and in-hospital activities of daily living (ADLs) in older acutely ill patients. In addition, we sought to identify preliminary walking thresholds that could support the targeting of interventions aimed at minimizing rehospitalizations.

Design: Prospective, observational clinical cohort study. Step counts during hospitalization were assessed via accelerometry. ADL function was assessed within 48 hours of admission.

Setting: Acute care hospital.

Participants: One hundred sixty-four ambulatory persons aged 65 years and older admitted to the hospital from the community with an acute medical illness.

Interventions: Not applicable.

Main outcome measures: Readmission back to the index hospital (yes vs no) within 30 days of discharge.

Results: Twenty-six patients (15.8%) were readmitted within 30 days of discharge. Walking activity during hospitalization was more strongly and significantly associated with 30-day readmission (odds ratio=0.90; 95% confidence interval, 0.82-0.98) than ADL function (odds ratio=0.45; 95% confidence interval, 0.14-1.45) after adjusting for relevant readmission risk factors. The predictive accuracy (area under the curve) was highest for models that included walking activity and changed little with the addition of ADLs. A walking threshold of 275 steps or more per day identified patients at reduced 30-day readmission risk.

Conclusions: Walking activity was a stronger predictor of readmission than ADLs. Monitoring patient activity during hospitalization may provide clinicians with valuable information on early readmission risk not captured by measures of ADLs. Further study is needed to replicate these findings and monitor walking activity posthospitalization to further advance our understanding of readmission risk.

Keywords: Accelerometry; Activities of daily living; Geriatrics; Patient readmission; Rehabilitation.

Figure 1

Receiver operating characteristic (ROC) curve of mean daily steps on readmission status. AUC = area under the curve. The value of 475 mean daily steps represent the walking threshold identified via the Youden Index criteria.