Baseline Functional Status and One-year Mortality After Hospital Admission in Elderly Patients: a prospective cohort study.

Introduction: Hospitalization represents a major factor that may precipitate the loss of functional status and the cascade into dependence. The main objective of our study was to determine the effect of functional status measured before hospital admission on survival at one year after hospitalization in elderly patients.

Methods: Prospective cohort study of adult patients (over 65 years of age) admitted to either the general ward or intensive Care units (ICU) of a tertiary teaching hospital in Buenos Aires, Argentina. Main exposure was the pre-admission functional status determined by means of the modified "VIDA" questionnaire, which evaluates the instrumental activities of daily living. We used a multivariate Cox proportional hazards model to estimate the effect of prior functional status on time to all-cause death while controlling for measured confounding. Secondarily, we analyzed the effect of post-discharge functional decline on long-term outcomes.

Results: 297 patients were included in the present study. 12.8% died during hospitalization and 86 patients (33.2%) died within one year after hospital discharge. Functional status prior to hospital admission, measured by the VIDA questionnaire (e.g., one point increase), was associated with a lower hazard of all-cause mortality during follow-up (Hazard Ratio [HR]: 0.96; 95% Confidence Interval [CI]: 0.94-0.98). Finally, functional decline measured at 15 days after hospital discharge, was associated with higher risk of all-cause death during follow-up (HR: 2.19, 95% CI: 1.09-4.37) Conclusion: Pre-morbid functional status impacts long term outcomes after unplanned hospitalizations in elderly adults. Future studies should confirm these findings and evaluate the potential impact on clinical decision-making.