Background: It remains unclear whether instrumental activities of daily living (IADL) decline during hospitalization is related to mortality rates. This study examined the relationship between IADL decline during hospitalization and the one-year mortality rate in elderly heart failure (HF) patients.

Methods: Five hundred seventy-six consecutive patients who were hospitalized for acute decompensated HF and underwent rehabilitation were divided into groups based on changes in IADL during hospitalization: IADL maintained and IADL decline. IADL was assessed by the National Center for Geriatrics and Gerontology-Activities of Daily Living Scale (NCGG-ADL). IADL decline was defined as Δ NCGG-ADL ≤ -1 point. The primary outcome was one-year all-cause mortality rate after discharge. Outcomes were examined using the Kaplan-Meier method with the log-rank test and Cox proportional hazards models using the existing prognostic risk factors for HF.

Results: Of 576 patients, 20% (n = 113) had IADL decline during hospitalization, and 9.2% (n = 35) and 6.0% (n = 18) died of all-cause and cardiovascular disease within one year after discharge, respectively. The IADL-decline group had significantly higher one-year all-cause mortality rates after adjusting for risk factors (hazard ratio: 1.923, 95% confidence interval 1.085-3.409; P = 0.023). Among the IADL subcategories, outdoor activity items such as "go out by oneself," "take a bus or train," and "shop for necessities" were more likely to change from independent to dependent during hospitalization.

Conclusion: IADL decline during hospitalization was associated with an increased all-cause mortality rate at one-year after discharge in elderly HF patients.