Socioeconomic differences in hospital care use for stroke and ischaemic heart disease in the China Kadoorie Biobank study

The rapid economic, demographic, and epidemiologic transitions that occurred in China in recent decades have increased the burden of non-communicable diseases, including cardiovascular diseases (CVD), as well as health expenditures and health inequalities. In 2009, China launched major healthcare reforms to provide equal and affordable basic healthcare for all by 2020. This thesis aims to study healthcare use for CVD across socioeconomic groups in China by examining: (i) trends in hospital care utilisation and outcomes for stroke and ischaemic heart disease (IHD) by socioeconomic groups over an 8-year period; (ii) gender differences in the management of acute IHD; and (iii) impact of health insurance (HI) cost sharing and socioeconomic characteristics on choice of hospital tiers for stroke and IHD. The analyses involved half a million adults in the China Kadoorie Biobank, recruited in 2004-2008 and followed-up until 2017 through linked HI records, and disease and death registries. After adjustment for demographic, socioeconomic, lifestyle and morbidity factors, hospitalisation rates for stroke and IHD each increased by 4-5% per year in 2009-2016. Higher socioeconomic groups had higher hospitalisation rates, but the annual proportional increases were greater among those with lower levels of education or income, urban or rural resident HI schemes, and in rural areas. Lower socioeconomic groups had higher stroke and IHD case fatality rates, but achieved greater proportional reductions in these during 2009-2016 than higher socioeconomic groups. The average length of hospital stay decreased by 2% annually and to a greater extent in higher than lower socioeconomic groups. There were marked gender differences in the use of invasive coronary tests and procedures for acute IHD in 2004-2016. While the use of cardiac enzymes did not differ between women and men with acute myocardial infarction, women had 20% lower rates of coronary angiography and 15% lower rates of revascularisation. Compared to men, women with angina or other IHD had 3%, 13-34% and 39-44% lower rates of having cardiac enzyme tests, coronary angiography and revascularisation, respectively. However, socioeconomic and health system factors did not explain the gender differences in the use of invasive tests and procedures for IHD. In China, hospitals are classified into three tiers, with higher tier hospitals being larger, better equipped, and typically located in urban areas. While over 60% of urban residents with first stroke or IHD admissions in 2009-2017 chose tier 3 hospitals, only around 30% of rural residents chose tier 3 hospitals. In urban areas, higher reimbursement rates were associated with higher odds of choosing all hospital tiers, and higher tier 3 deductibles with lower odds of choosing tier 3 hospitals. In rural areas, higher tier 3 reimbursement rates were associated with higher odds of choosing tier 3 hospitals, and higher tier 1 deductibles with lower odds of choosing tier 1 hospitals. However, higher tier 2 and 3 deductibles in rural areas were associated with higher odds of choosing these hospitals. Individuals with higher socioeconomic status and, separately, more severe disease were more likely to choose tier 3 than tier 1 or 2 hospitals. These findings should inform further strategies to reduce socioeconomic and gender disparities and facilitate choice of appropriate hospital tiers in the use of hospital care for different types of CVD across China.