Prevalence, correlates and outcomes of multimorbidity among the middle-aged and elderly: Findings from the China Health and Retirement Longitudinal Study

Background: The multimorbidity associated with ageing has been prevalent worldwide and poses major challenges to the health care system. However, the research about multimorbidity in China is far from sufficient. Additionally, international studies on the influencing factors of multimorbidity and the impact on disability/mortality are still inconsistent. The aim of this study was to examine the prevalence, correlates and outcomes of multimorbidity among the middle-aged and elderly Chinese population. Methods: We used data from the China Health and Retirement Longitudinal Study (CHARLS). Logistic regression was performed to analyze the influencing factors of multimorbidity. The Cox proportional hazard model was used to evaluate the impact of multimorbidity on functional disability and all-cause mortality. Results: The prevalence of multimorbidity was 55.12 % in the whole study population and 65.60 % among people aged >= 65 years. Multimorbidity was significantly associated with old age (OR: 2.76, 95 % CI: 2.31-3.30), females (OR: 1.21, 95 % CI: 1.01-1.44), ex-smoker (OR: 2.07, 95 % CI: 1.58-2.72), ex-drinker (OR: 2.18, 95 % CI: 1.66-2.87), obesity (OR: 2.87, 95 % CI: 2.30-3.57), lower education (OR:1.32, 95 % CI: 1.08-1.61), living alone (OR: 1.26, 95 % CI: 1.02-1.55) and unemployment (OR: 1.66, 95 % CI: 1.11-2.48). Moreover, multimorbidity was correlated with disability (HR: 2.27, 95 % CI: 1.93-2.66) and all-cause mortality (HR: 1.95, 95 % CI: 1.36-2.80) after multivariable adjustment. Conclusions: Multimorbidity is highly prevalent in China and possesses significantly negative effects on health outcomes. Identification of the key population and tailored interventions on their modifiable risk factors should be paid much importance.