Potential associated factors of functional disability in Chinese older inpatients: A multicenter cross-sectional study

Background: Older adults are vulnerable to a decline in physical functioning, including basic activities of daily living (ADL) and higher-level instrumental activities of daily living (IADL). The causes of functional disability in older adults are multifactorial. A comprehensive understanding of these factors will contribute toward future health service planning. However, studies of ADL and IADL in Chinese older adults are insufficient. The aim of this study is to describe the level of ADL and IADL in different age groups and explore the factors associated with functional disability in Chinese older inpatients. Methods: We conducted a cross-sectional study consisted of 9,996 Chinese older inpatients aged 65 years and older. Participants were recruited from six provinces or municipality city in southwest (Sichuan province), northeast (Heilongjiang), south central (Hubei province), northern (Beijing municipality city), northwest (Qinghai province), and eastern China (Zhejiang province) from October 2018 to February 2019. The levels of ADL and IADL were measured by scores of the Barthel index and Instrumental Activities of Daily Living Scale in consecutive intervals from 65 years of age. After controlling for the cluster effect of hospital wards, a mixed-effect generalized linear model was used to examine the association between functional disability and covariates. Results: The average ADL score was 27.68±4.59 and the mean IADL score 6.76±2.01 for all participants. A negative correlation between scores and age was observed, and there was a significant difference in ADL and IADL scores among different age groups. The top negatively influential factor in ADL and IADL was stair climbing and shopping, respectively. After controlling for the cluster effect of hospital wards, aging, emaciation, frailty, depression, falling accidents in past 12 months, hearing dysfunction, cognitive dysfunction, urinary dysfunction, and defecation dysfunction were associated with ADL and IADL. Patients transitioned from the emergency department and other hospitals were also affected by ADL disability. Former smoking was associated with lower IADL scores. Higher level of education, living in a building without elevators, and current alcohol consumption were correlated with better IADL performance. Conclusion: Decreased functional ability was associated with the increasing age. Sociodemographic characteristics (such as age), physical health variables (frailty, emaciation, hearing dysfunction, urinary dysfunction, defecation dysfunction, falling accidents in past 12 months), and mental health variables (cognitive dysfunction, depression) were associated with functional disability. These findings potentially have major importance for the planning of hospital services, discharge planning, and post-discharge care.