This study systematically evaluated the level of ADL and IADL among different age groups as well as the potential factors associated with functional disability based on a hospital-based large-scale cross-sectional national survey in China. Application of a mixed-effect generalized linear model with the hospital as a random effect not only controlled the cluster effect of hospital wards but also examined the effect of potential associated factors, including indicators for sociodemographic characteristics, physical health variables, and mental health variables, on both the prevalence and extent of functional disability.
The average ADL score was 89.51 ± 19.29 and the mean IADL score 6.76 ± 2.01 for all participants in this study, which indicates older adults are low dependency upon functional status [5, 17]. Besides, the findings of our study reported that functional ability tends to deteriorate with the aging process [6, 25], differing from certain studies conducted in welfare institutions and among ethnic minorities [8, 9]. The average age of the elderly living in Japanese welfare institutions was (80.0 ± 7.4) years old , as a country with a serious aging process , the functional status of the 80 years age-group may differ from those of the same age in other countries. Also, most of the Yi ethnic minority resides in the southwestern parts of China. The differences in ADL and IADL that appear to exist between the geography, ethnicity, and target aging population, which require further study.
This study reveals another phenomenon worthy of attention. The average ADL score in our study is lower than the Yi ethnic minority, whereas IADL score is higher than them . Perhaps because the inpatients enrolled in our study were all from tertiary hospitals and were more seriously ill when hospitalization, thus poor ADL ability was observed. However, low education level, outdated economy, healthcare, and culture contributed to the IADL problems in Yi ethnic minority older population . Even though our government has made great efforts, and healthcare and economic conditions in ethnic minority areas have been improved, providing adequate geriatric care source, financial support, and social help among the elderly of ethnic minorities are warranted.
Our results suggested that with increasing age, changes in the ADL ability were mainly in walking up and down stairs, mobility, transfers (from bed to chair and back), toilet use, and bathing. The activities most impactful on IADL in the present study as graded from high to low were shopping, food preparation, mode of transportation, laundry, and ability to handle finances. This finding is consistent with those of previous studies reporting that functional status rapidly declines with increasing age in terms of speed and executive function with regard to [17, 26], for example, walking, household tasks, and shopping . Although the biological aging process cannot be halted, it is urgent for our government to establish a home care-dominated, supported by community care, and supplemented with institutional care (such as welfare institution or nursing home) aimed at helping the elderly to self-manage their daily activities, reducing the risk of a decline in different aspects of functional independence, and meeting the escalating burden of the aging society [3, 27].
Apart from age, physical health variables such as emaciation, frailty bring about a series of negative effects on functional ability. Therefore, improving the nutritional status, healthy diet, and enough physical exercise is critical to inhibit the development and progression of poor functional status . To temporizes or halt the disabled process, our government should develop a dietary nutrition plan in different age groups among the elderly and encourage and carry out physical exercise programs for older adults at the social level. Moreover, communities in the wide rural areas should regularly organize the elderly into morning exercise groups and dance groups, which can be easily spotted in China’s urban parks or street corners . Also, vigorous evaluation studies in China on the health benefits of the dietary nutrition plan and regular physical activity programs among the elderly are required in the future.
Other physical health variables such as falling accidents in the previous 12 months, hearing dysfunction, urinary dysfunction, and defecation dysfunction were significantly associated with functional disability, which further supports previous research findings [8, 10, 11, 30]. Regarding these factors, early assessment, identification, and prevention are important. More advanced risk factor assessment scales and standardized nursing care measures may be useful in managing functional disability among older adults in the future .
With regard to mental health variables, our results suggested that functional disability was associated with depressive moods and cognitive dysfunction. This reminds us that ameliorate the depressive moods and delayed the deterioration of age-related cognition may help to further improve the functional ability . Previous research suggested that depression in the elderly was associated with a lack of family support [33, 34]. Therefore, older adults may need more daily companionship from their family members, relatives, and friends, and geriatric care services, such as home care are urgently needed [33, 35]. For another thing, priority should be given to raising public awareness of cognitive dysfunction and increasing medical support resources for early prevention, evaluation, intervention, and medical treatment of mental illness and poor health status in the elderly [36, 37].
Older patients from the emergency department or other hospitals present a greater risk of ADL disability. Perhaps because the geriatric population in emergency departments are accompanied by immobility, failure to eat and drink, incontinence, and functional decline [38,39,40]. Older patients who are transferred from district hospitals or community hospitals probably only received basic inpatient services before , which may potentially increase the risk of poor ADL. Screening for ADL ability in emergency department patients and transferred patients are needed, which can inform prognosis and hospital services planning, target discharge planning, and post-discharge care.
Interestingly, former alcohol drinkers had an increased risk of ADL disability compared with nondrinkers, whereas current alcohol drinkers had a low risk of IADL disability. Perhaps because compared to small to moderate alcohol consumption, long-term and heavy alcohol consumption are at an increased risk of functional disability . Also, a previous study indicated that older adults who consumed small to moderate amounts of alcohol were more likely to maintain functional status than nondrinkers, which might be related to the fact that small alcohol consumption has been associated with a decreased risk of cardiovascular events . However, the detailed evaluation of alcohol consumption based on information about the quantity and frequency of drinking alcoholic beverages requires further research.
Our study indicated that former smokers had a higher risk of IADL disability, which further supported previous research findings [10, 42]. This indicates maintaining a vigorous lifestyle, such as tobacco-free, might be essential for improving functional status after decades. The government should continue to promote no-smoking policies in public areas and smokers should quit smoking as soon as possible .
Higher-level education and residing in a building without elevators were likely to maintain a better IADL performance, perhaps because well-educated participants could better comprehend the development of disease and maintain their physical function with a positive attitude . In addition, residence in apartment block-type buildings in China is associated with better economic conditions. There exists the possibility that the geriatric population living in such buildings has a better quality of life and health monitoring that helps maintain IADL function.
There are limitations to this study that require discussion. First, because of convenience sampling, the patients enrolled in our study were selected from tertiary hospitals, and only one hospital in each province or municipality/city, which limited the generalizability of this study. Second, owing to the nature of the cross-sectional study design, we could only explore the relationship between functional disability and potential associated factors. Third, the target population in this study covered many wards or departments, and we did not analyze the medical treatment and nursing care use on functional disability in this study. Fourth, chronic diseases (such as cancer, diabetes, and cardiovascular diseases) could be associated with functional disabilities among older adults, the participants in this study covered many departments, and we did not analyze the impact of diseases in this paper. Prospective studies with more sophisticated evaluations are required in the future.