Association between subjective well-being and all-cause mortality among older adults in China

Although several studies in high-income countries have suggested a positive association between subjective well-being (SWB) and mortality, studies conducted in low- and middle-income countries, such as China, are scarce. The purpose of this study is to examine the association between SWB and all-cause mortality among the older Chinese population.

Data were from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a population-based longitudinal cohort study in 22 of 31 provinces in mainland China. A total of 13,282 individuals aged 65 ≥ years who were recruited in 2002 and followed-up until 2018 were included. SWB was assessed with an eight-item tool covering life satisfaction, positive affect (including optimism, happiness, personal control and conscientiousness) and negative affect (including anxiety, loneliness and uselessness). Cox proportional hazards regression methods were carried out to estimate the association between SWB and total mortality, adjusting for a wide range of potential confounders. Subgroup analyses and interaction analyses were further conducted.

During the 16.5 years of follow-up, 8459 deaths were identified. Greater SWB was independently associated with a reduced risk of all-cause mortality (adjusted hazard ratio [HR] = 0.85, 95% confidence interval [CI] = 0.81-0.89) after adjustment for age, sex, marital status, education level, place of residence, smoking status, drinking, exercise, diet, BMI, hypertension, diabetes, heart disease, cerebrovascular diseases and cancer. Of the eight individual SWB symptoms, only 2 items, feelings of uselessness (adjusted HR = 0.94, 95% CI = 0.89-0.99) and happiness (adjusted HR = 0.91, 95% CI = 0.86-0.95), were significantly associated with total mortality. Associations remained significant across all subgroups regardless of different characteristics.

Higher SWB overall and 2 certain symptoms (feelings of uselessness and happiness) were independently associated with all-cause mortality risk among older Chinese adults. The association was consistent across different groups, suggesting that promoting a healthier SWB may be beneficial to all older individuals irrespective of their characteristics.