Socioeconomic determinants for diagnosed non-communicable diseases among older people in China: Individual- and regional- level effects.

Non-communicable diseases (NCDs) have become the major contributors to premature death and disability in China. This study used the repeated cross-sectional datasets of the 2008, 2011, 2014, and 2018 Chinese Longitudinal Healthy Longevity Survey, with a total number of 44,886 observations, to investigate the association between doctor-diagnosed chronic diseases (DCDs) and socioeconomic status at both individual and province level by multilevel logistic models. Results showed that higher socioeconomic status at both individual and regional level (measured as urbanisation) were associated with higher odds of diagnosed chronic diseases among older people in China. This study also found a "convergent" effect on DCDs between individual income and urbanisation. Meanwhile, older people who can receive adequate medical support and who cannot receive adequate medical support have a "divergent" effect on DCDs by urbanisation. Additionally, older people with different types of public health insurance have a "paralleled" effect on DCDs by urbanisation. The implications of this study may be that chronic disease among older people in lower socioeconomic status was substantially underdiagnosed. Investment in primary health care could be a cost-effective way to reduce the inequalities of diagnosed chronic diseases.