Disabilities in activities of daily living and in instrumental activities of daily living among older adults in China, 2011–15: a longitudinal cohort study

BackgroundWith global population ageing, the population of older adults (aged ≥60 years) is rapidly growing, and most such individuals are in need of health care and assistance. We aimed to assess changes in disability in basic activities of daily living (ADL), and in instrumental activities of daily living (IADL) among older Chinese individuals.MethodsWe used data from three surveys of the China Health and Retirement Longitudinal Study, conducted in 2011 (n=7380), 2013 (n=8328), and 2015 (n=9594). Data on six ADL measures (dressing, bathing, eating, walking, toileting, and urination and defecation) and six IADL measures (doing housework, shopping, cooking, managing money, taking medicine, and telephoning) were collected through interviews. We defined disability as need of assistance or inability to perform any of the ADLs or IADLs. Generalised estimating equation models were used to assess the time trend in the prevalence of disabilities in ADL and IADL.FindingsThe prevalence of disability in IADLs increased from 1496 (20·96%, weighted) of 7330 participants in 2011 to 2584 (26·51%, weighted) of 9348 in 2015, with a relative annual increase of 1·92% in the total sample (ptrend<0·0001). The trend was statistically significant (ptrend<0·001) in all subgroups by age, sex, and living region. The prevalence of disability in ADLs showed little change from 2011 (759 [11·40%, weighted] of 7354) to 2015 (983 [10·03%, weighted] of 9554), with a relative annual change of 0·12% in the total sample (ptrend=0·2429), and in all subgroups by age, sex, and living region (ptrend>0·10). After controlling for various confounding factors, functional capacities in ADLs and IADLs were substantially worse in women than in men.InterpretationThe prevalence of IADL disability increased among older Chinese adults during 2011–15, whereas the prevalence of ADL disability remained stable. Improvements in lifestyle, socioeconomics, and health care might reduce disabilities in ADL, but lifespan extension might expand IADL disability as more frail and older individuals survive with health problems.FundingNational Natural Science Foundation of China (grant number 81573262 ).