Prevalence and correlates of successful ageing: a comparative study between China and South Korea.

Successful ageing is often defined as a later life with less disease and disease-related disability, high level of cognitive and physical functions, and an active life style. Few studies have compared successful ageing across different societies in a non-Western social context. This study aims to compare prevalence and correlates of successful ageing between China and South Korea. The data come from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and the Korean Longitudinal Study of Ageing (KLoSA). A total of 19,346 community-dwelling elders over 65 years were included, 15,191 from China and 4,155 from Korea. A multidimensional construct of successful ageing was used, with the criteria of no major comorbidity, being free of disability, good mental health, engaging in social or productive activity, and satisfaction on life. Correlates of successful ageing included demographics (gender, age, and rural/urban residence), socioeconomic features (financial status, education, and spouse accompany), and health behaviours (smoking, alcohol-drinking, and exercising). The results showed that 18.6 % of the older adults in China was successful agers, which was less than 25.2 % in Korea. When gender and age were adjusted, older adults were 51 % less likely to be successful agers in China than Korea (p < 0.001). The association patterns between successful ageing and its correlates are similar between China and Korea. However, before the socioeconomic variables are under control, rural residence was negatively related to successful ageing in China, whereas this is not the case in Korea. And the gender gap of successful ageing was mostly explained by socioeconomic features and health behaviours in Korea, but not in China. In both countries, good financial condition was highly associated with successful ageing. The study suggests that advancement of public health system could better control progression of non-communicable diseases among old people and thus promote successful ageing.