Inequality, inequity and the rise of non-communicable disease inChina

Abstract

Background: Rapid economic growth in mainland China has been accompanied in recent years by rising levels of inequality and a growing burden of non-communicable disease (NCD), though little is known at present about the relations between these forces. This thesis makes use of data from a large sample of older men and women in Guangzhou, one of China’s most developed cities, to examine the relations between inequality, inequity and non-communicable disease. Objectives: This thesis addresses two research questions: what is the relationship between inequality/inequity and non-communicable disease in China; and what are the implications of this relationship for health policy in China. These two questions lead to two working hypotheses: first, that inequalities may be both a cause and consequence of NCDs in China, potentially creating a vicious cycle which reinforces inequality and inequity; and second, that reducing dependence on out of pocket payments as a source of healthcare finance may help to prevent the continuation of the inequality-NCD cycle. Methods: I used data from the Guangzhou Biobank Cohort Study (GBCS), including 30,499 men and women aged 50 or over from Guangzhou and multi-variable regression methods to examine associations of socioeconomic position at four life stages (childhood, early adulthood, late adulthood and current) with several health outcomes: self-rated health, chronic obstructive pulmonary disease, metabolic syndrome and markers of immunological inflammation (white blood cells, granulocytes and lymphocytes). These analyses related to the hypothesis that inequalities may be a cause of non-communicable disease in China. I also examined whether inequity may be a consequence of non-communicable disease by measuring whether horizontal inequity (deviation from the principle of equal access to healthcare for equal need) was greater for treatment of NCDs than for general healthcare. I tested this using both concentration index methods and multi-variable regression models. For comparative purposes, I conducted these analyses in data from three settings: Guangzhou, Hong Kong and Scotland (UK). Results: I found that socioeconomic deprivation across the life course was associated with poorer self-rated health, higher risk of COPD, higher white cell and granulocyte cell counts and (in women only) higher risk metabolic syndrome and higher lymphocyte cell counts. I also found evidence of pro-rich inequity in utilisation of treatment for three major non-communicable conditions (hypertension, hyperglycaemia and dyslipidaemia) in Guangzhou, whilst there was no evidence of inequity in general healthcare utilisation (doctor consultations and hospital admissions) or treatment of gastric ulcer. Conclusion: My findings gave qualified support for the idea that socioeconomic inequalities may contribute to some, though not all, non-communicable diseases in China. Moreover, the mechanisms which link socioeconomic inequality to NCDs in China remain unclear. My results also supported the suggestion that a rising burden of non-communicable disease may contribute to greater pro-rich inequity in healthcare utilisation, especially for conditions which are chronic and asymptomatic. As rates of NCDs continue to rise in China and other developing countries, policies to prevent and treat common NCDs may be improved by a clearer understanding of how inequality is related to non-communicable disease.