Social Environment, Lifestyle, and Genetic Predisposition With Dementia Risk: A Long-Term Longitudinal Study Among Older Adults.

BACKGROUND: The role of social environment, that is, the aggregate effect of social determinants of health (SDOHs), in determining dementia is unclear. METHODS: We developed a novel polysocial risk score for dementia based on 19 SDOH among 5 199 participants in the Health and Retirement Study, United States, to measure the social environmental risk. We used a survival analysis approach to assess the association between social environment and dementia risk in 2006-2020. We further studied the interaction between social environment and lifestyles, and explored racial disparities. RESULTS: The study participants (mean age = 73.4 years, SD = 8.3; 58.0% female; 11.6% African American) were followed up for an average of 6.2 years, and 1 089 participants developed dementia. Every 1-point increase in the polysocial risk score (ranging from 0 to 10) was associated with a 21.6% higher risk (adjusted hazard ratio [aHR] = 1.21, 95% confidence intervals [95% CI] = 1.15-1.26) of developing dementia, other things being equal. Among participants with high social environmental risk, regular exercise and moderate drinking were associated with a 43%-60% lower risk of developing dementia (p < .001). In addition, African Americans were 1.3 times (aHR = 2.28, 95% CI = 1.96-2.66) more likely to develop dementia than European Americans, other things being equal. CONCLUSION: An adverse social environment is linked to higher dementia risk, but healthy lifestyles can partially offset the increased social environmental risk. The polysocial risk score can complement the existing risk tools to identify high-risk older populations, and guide the design of targeted social environmental interventions, particularly focusing on improving the companionship of the older people, to prevent dementia.

Association between multimorbidity and informal long-term care use in China: a nationwide cohort study.

BACKGROUND: The impact of multimorbidity on long-term care (LTC) use is understudied, despite its well-documented negative effects on functional disabilities. The current study aims to assess the association between multimorbidity and informal LTC use in China. We also explored the socioeconomic and regional disparities. METHODS: The study included 10,831 community-dwelling respondents aged 45 years and older from the China Health and Retirement Longitudinal Study in 2011, 2015, and 2018 for analysis. We used a two-part model with random effects to estimate the association between multimorbidity and informal LTC use. Heterogeneity of the association by socioeconomic position (education and income) and region was explored via a subgroup analysis. We further converted the change of informal LTC hours associated with multimorbidity into monetary value and calculated the 95% uncertainty interval (UI). RESULTS: The reported prevalence of multimorbidity was 60·0% (95% CI: 58·9%, 61·2%) in 2018. We found multimorbidity was associated with an increased likelihood of receiving informal LTC (OR = 2·13; 95% CI: 1·97, 2·30) and more hours of informal LTC received (IRR = 1·20; 95% CI: 1·06, 1·37), ceteris paribus. Participants in the highest income quintile received more hours of informal LTC care (IRR = 1·62; 95% CI: 1·31, 1·99). The estimated monetary value of increased informal LTC hours among participants with multimorbidity was equivalent to 3·7% (95% UI: 2·2%, 5·4%) of China's GDP in 2018. CONCLUSION: Our findings substantiate the threat of multimorbidity to LTC burden. It is imperative to strengthen LTC services provision, especially among older adults with multimorbidity and ensure equal access among those with lower income.

Life-course inequalities in intrinsic capacity and healthy ageing, China.

Objective: To investigate the contribution of early-life factors on intrinsic capacity of Chinese adults older than 45 years. Methods: We used data on 21 783 participants from waves 1 (2011) and 2 (2013) of the China Health and Retirement Longitudinal Study (CHARLS), who also participated in the 2014 CHARLS Life History Survey to calculate a previously validated measure of intrinsic capacity. We considered 11 early-life factors and investigated their direct association with participants' intrinsic capacity later in life, as well as their indirect association through four current socioeconomic factors. We used multivariable linear regression and the decomposition of the concentration index to investigate the contribution of each determinant to intrinsic capacity inequalities. Findings: Participants with a favourable environment in early life (that is, parental education, childhood health and neighbourhood environment) had a significantly higher intrinsic capacity score in later life. For example, participants with a literate father recorded a 0.040 (95% confidence interval, CI: 0.020 to 0.051) higher intrinsic capacity score than those with an illiterate father. This inequality was greater for cognitive, sensory and psychological capacities than locomotion and vitality. Overall, early-life factors directly explained 13.92% (95% CI: 12.07 to 15.77) of intrinsic capacity inequalities, and a further 28.57% (95% CI: 28.19 to 28.95) of these inequalities through their influence on current socioeconomic inequalities. Conclusion: Unfavourable early-life factors appear to decrease late-life health status in China, particularly cognitive, sensory and psychological capacities, and these effects are exacerbated by cumulative socioeconomic inequalities over a person's life course.

Quantifying the financial impact of overuse in primary care in China: A standardised patient study.

Overuse of health care is a potential factor in explaining the rapid increase in health care expenditure in many countries; however, it is difficult to measure overuse. This study employed the novel method of using unannounced standardised patients (SPs) to identify overuse, document its patterns and quantify its financial impact on patients in primary care in China. We trained 18 SPs to present consistent cases of two common chronic diseases and recorded 492 physician-patient interactions in 63 public and private primary hospitals in a capital city in western China in 2017 and 2018. Overuse, defined as the provision of unnecessary medical tests and drugs, was identified by a panel of medical experts based on national clinical guidelines. We estimated linear regression models to investigate how hospital, physician and patient characteristics were associated with overuse and to quantify the financial impact of overuse after controlling for a series of fixed effects. We found overuse in 72.15% of the SP visits. The high prevalence of overuse was similar among public and private hospitals, low-competence and high-competence physicians, male and female physicians, junior and senior physicians and male and female patients, but it varied between patients presenting different diseases. Compared to the non-overuse group, overuse significantly increased the total cost by 117.8%, the test cost by 58.8% and the drug cost by 100.3%. The financial impact of overuse was consistent across the aforementioned hospital, physician and patient characteristics. We suggest that the overuse observed in this study is unlikely to be attributable to physician incompetence but rather to the financing framework for primary care in China. These findings illuminate the cost escalation of primary care in China, which is a form of medical inefficiency that should be urgently addressed.

Disease burden of ageing, sex and regional disparities and health resources allocation: a longitudinal analysis of 31 provinces in Mainland China.

OBJECTIVES: To measure the disease burden of ageing based on age-related diseases (ARDs), the sex and regional disparities and the impact of health resources allocation on the burden in China. DESIGN: A national comparative study based on Global Burden of Diseases Study estimates and China's routine official statistics. SETTING AND PARTICIPANTS: Thirty-one provinces of Mainland China were included for analysis in the study. No individuals were involved. METHODS: We first identified the ARDs and calculated the disability-adjusted life years (DALYs) of ARDs in 2016. We assessed the ARD burden disparities by province and sex and calculated the provincial ARD burden-adjusted age. We assessed historical changes between 1990 and 2016. Fixed effects regression models were adopted to evaluate the impact of health expenditures and health workforce indicators on the ARD burden in 2010-2016. RESULTS: In 2016, China's total burden of ARDs was 15 703.7 DALYs (95% uncertainty intervals: 12 628.5, 18 406.2) per 100 000 population. Non-communicable diseases accounted for 91.9% of the burden. There were significant regional disparities. The leading five youngest provinces were Beijing, Guangdong, Shanghai, Zhejiang and Fujian, located on the east coast of China with an ARD burden-adjusted age below 40 years. After standardising the age structure, western provinces, including Tibet, Qinghai, Guizhou and Xinjiang, had the highest burden of ARDs. Males were disproportionately affected by ARDs. China's overall age-standardised ARD burden has decreased since 1990, and females and eastern provinces experienced the largest decline. Regression results showed that the urban-rural gap in health workforce density was positively associated with the ARD burdens. CONCLUSION: Chronological age alone does not provide a strong enough basis for appropriate ageing resource planning or policymaking. In China, concerted efforts should be made to reduce the ARDs burden and its disparities. Health resources should be deliberately allocated to western provinces facing the greatest health challenges due to future ageing.

Intrinsic Capacity: Validation of a New WHO Concept for Healthy Aging in a Longitudinal Chinese Study.

BACKGROUND: The World Health Organization has proposed a model of healthy aging built around the concept of functional ability, comprising an individual's intrinsic capacity, the physical and social environment they occupy, and interactions between the two. However, these constructs have been poorly defined. We examined the structure of intrinsic capacity in a representative sample of the Chinese population aged 60 years and older and assessed its value in predicting declining performance in instrumental activities of daily living (IADLs) and activities of daily living (ADLs) using similar methods to a construct validation previously undertaken in an English cohort. METHODS: Deidentified data were accessed on 7 643 participants of the China Health and Retirement Longitudinal Study 2011 and 2013 waves. Incrementally related structural equation modeling was applied, including exploratory and confirmatory factor analysis, and path analysis. Multiple linear regression tested construct validity, and simple and serial mediation models assessed predictive validity. RESULTS: Factor loadings for the models showed a clear structure for intrinsic capacity: 1 general factor with 5 subfactors-locomotor, cognitive, psychological and sensory capacities, and vitality (reflecting underlying physiologic changes). Intrinsic capacity predicted declining performance in both IADLs (standardized coefficient (SE) -0.324 (0.02), p < .001) and ADLs (-0.227 (0.03), p < .001), after accounting for age, sex, education, wealth, and number of chronic diseases. Each characteristic was associated with intrinsic capacity, providing strong construct validity. CONCLUSIONS: Assessment of intrinsic capacity provides valuable information on an individual's subsequent functioning beyond that afforded by age, other personal factors, and multimorbidity.