Decomposition of Socioeconomic Inequality in Cognitive Performance among adults aged 50+ in China: Results from WHO SAGE Wave 1

Abstract

Background: Poor cognitive performance is a significant threat to older adults that affects daily activities, reduces life quality and results in societal problems. Over the past few decades, China witnessed a remarkable demographic and economic transition that ensued wealth distribution disparities that adversely affected health between and within the rural and urban areas of China. Addressing these inequalities in cognitive performance is essential from both social and public health perspectives.

Aim: The study estimated the wealth-related inequality in cognitive performance and analysed social determinants' contribution to the observed inequality among adults aged 50+ in rural and urban areas of China.

Methodology: We used the World Health Organization’s Study on global AGEing and adult health (SAGE) Wave 1 (2007-2010) data in China. The study included a nationally representative sample of 12,201 older adults aged 50 years and above. We analysed wealth-related inequality in cognitive performance using the concentration index, followed by the Wagstaff decomposition analysis to analyse the inequality's determinants.

Results: The overall estimated concentration index for the rural residence was (0.039) whereas, for the urban residence was (0.044), indicating substantial pro-rich wealth-related inequalities in cognitive performance disfavouring the less affluent population. A higher degree of pro-rich inequality in cognitive performance existed in urban areas. It was also observed that the health inequality decreased with age for the rural residence while it increased for the urban residence. Lastly, these inequalities were explained mainly by socio-economic and material conditions for both areas of residence irrespective of the age groups and to a lesser extent by socio-demographic characteristics, general health and psychosocial conditions.

 Conclusions: This study demonstrates significant wealth-related, pro-rich inequality in cognitive performance among older people in China. Socio-economic and material conditions were among the main contributors to the rural and urban disparity in cognition among older adults. The findings highlight the importance of addressing the socio-economic root causes of inequality in cognitive health and cognitive care among older populations in China.