Association of functional status and hospital-acquired functional decline with 30-day outcomes in medical inpatients: A prospective cohort study

Background: There is growing evidence that patients with functional decline are at increased risk of readmission, mortality and institutionalization. Instruments to measure the status of self-care could provide important information for efficient care planning. The widely used Self Care Index serves as an indicator for the severity of nursing dependency. To date, no evidence is available on the association of the instrument with rehospitalization, mortality and institutionalization.

Objectives: To examine the association of functional status measures (Self Care Index on admission, at discharge and functional decline) with 30-day mortality, readmission and institutionalization in hospitalized non-surgical patients.

Design: Prospective cohort study.

Participants: We included 4540 emergency medical patients at a single hospital in Switzerland.

Methods: Primary outcome was 30-day mortality rate; secondary outcomes were 30-day readmission and institutionalization. We analyzed the association of the functional status with the binary endpoints using logistic regression models and C-statistics for discrimination.

Results: All of the examined measures were significant predictors of overall 30-day mortality; Self Care Index on admission: adj. OR: 0.90 (95% CI: 0.87-0.92); Self Care Index at discharge: adj. OR: 0.86 (95% CI: 0.83-0.88); functional decline: adj. OR: 1.22 (95% CI: 1.14-1.31) and all Self Care Index single items. A combined model (functional status on admission and functional decline during hospitalization) showed a good accuracy with regard to the AUC: adj. AUC: 0.80 (95% CI: 0.74-0.86).

Conclusions: Several functional measures were associated with 30-day mortality. Self Care Index total score, five single items and a combined model showed the best performance.