Relationship between IADL, physical function, physical activity, and fall-related efficacy among older people using daycare centers

The purpose of this study was to provide intervention measures for maintaining and improving the instrumental activities of daily living (IADL) of older people using daycare centers by identifying factors related to IADL. A timed up and go test time ≥11.6 sec, light physical activity (LPA) ≤193 min/day, or fall-related efficacy ≤125.5 points flags daycare users at high risk of IADL decline. Daycare staff could screen daycare users using these indices and then provide them with exercises to improve balance function, LPA, and fall-related function, potentially helping to maintain or improve their IADL. This study aimed to investigate associated factors and cutoff values for instrumental activities of daily living (IADL) in older people using daycare centers and to clarify the characteristics of the low IADL group. This multicenter cross-sectional study included 196 consecutive individuals receiving rehabilitation at two daycare centers between January and March 2024. Participants were ≥ 65 years old, able to walk, and provided consent. Excluded were those who did not wear an accelerometer or who missed more than two weeks of rehabilitation. Unpaired t-test, Mann–Whitney U test, and chi-square test were used to examine the characteristics of the low IADL group. Multiple regression analysis was used to determine the associated factors of IADL, with IADL as the objective variable and age, sex, nutritional status, timed up and go test (TUG), light physical activity (LPA), and fall-related efficacy as explanatory variables. Cutoff values for low IADL were calculated using receiver operating characteristic curves. The low IADL group (n = 64) had significantly higher TUG, and lower gait speed, LPA, and fall-related efficacy than the high IADL group (n = 23) (p < 0.05). Multiple regression analysis identified TUG, LPA, and fall-related efficacy as factors associated with IADL (p < 0.01). Cutoff values calculated for low IADL were TUG ≥ 11.6 s, LPA < 193.4 min, and fall-related efficacy < 125.5 points (p < 0.05). Associated factors and cutoff values for IADL in older daycare center users and characteristics of the low IADL group were identified that may aid in devising interventions to maintain and improve IADL in this population.