[Prevalence, patterns and long-term changes of multimorbidity in adults from 10 regions of China]

Objective: To describe the prevalence of multimorbidity and its secular trend, and to explore the common patterns of multimorbidity in Chinese adults. Methods: A total of 25 033 participants who attended the second resurvey of China Kadoorie Biobank (CKB) were included in the study. We used data collected both at baseline (2004-2008) and at resurvey (2013-2014). A total of 13 chronic conditions were included, defined by self-reported, physical examination, and blood sample testing. Multimorbidity was defined as co-existence of two or more chronic conditions. Patterns of multimorbidity were explored using hierarchical cluster analysis. Results: The mean age of participants was (51.5±10.1) years at baseline and (59.5±10.2) years at second resurvey. The prevalence of multimorbidity increased from 33.5% to 58.1% over (8.0±0.8) years of follow-up. The average number of chronic conditions per person increased from 1.15 to 1.82 and all participants increased 0.42 conditions per 5 years on average. Participants who were older, less educated or lived in urban areas had a higher prevalence of multimorbidity and a higher increase in the number of chronic conditions. The increase in the number of chronic conditions was also higher among smokers and heavy alcohol drinkers. The most common multimorbidity pattern in the present population consisted of obesity, hypertension, diabetes, stroke, and heart disease. Conclusions: The prevalence of multimorbidity in Chinese adults is increasing rapidly due to ageing population. Populations of different sociodemographic background and lifestyle habits may have different prevalence of multimorbidity and changes in rates over time.