Trends in disparities in healthcare utilisation between and within health insurances in China between 2008 and 2018: a repeated cross-sectional study

BACKGROUND: Fragmentation in China’s social health insurance schemes and income gap have been recognised as important factors for the inequitable use of healthcare. This study assessed trends in disparities in healthcare utilisation between and within health insurances in China between 2008 and 2018. METHODS: We used data from the 2008, 2013, and 2018 China National Health Services Survey. Outpatient visit, inpatient admission and foregone inpatient care were chosen to measure healthcare utilisation and underutilisation by health insurances. Absolute differences and rate ratios were generated to examine disparities between and within health insurances, and changes in disparities were analysed descriptively. Pearson χ2 tests were used to test for statistical significance of differences. RESULTS: The outpatient visit rate for respondents covered by the urban resident-based basic medical insurance scheme (URBMI) more than doubled between 2008 and 2018, increasing from 10.5% (9.7-11.2) to 23.5% (23.1-23.8). Inpatient admission rates for respondents covered by URBMI and the new rural cooperative medical scheme (NRCMS) more than doubled between 2008 and 2018, increasing by 7.2 (p < 0.0001) and 7.4 (p < 0.0001) percentage points, respectively. Gaps in outpatient visits and inpatient admissions narrowed across the urban employee-based basic medical insurance scheme (UEBMI), URBMI, and NRCMS through 2008 to 2018, and by 2018 the gaps were small. The rate ratios of foregone inpatient care between NRCMS and UEBMI fell from 0.9 (p > 0.1) in 2008 to 0.8 (p < 0.0001) in 2018. Faster increases in outpatient and inpatient utilisation and greater reductions in foregone inpatient care were observed in poor groups than in wealthy groups within URBMI and NRCMS. However, the poor groups within UEBMI, URBMI, and NRCMS were always more likely to forego inpatient care in comparison with their wealthy counterparts. CONCLUSIONS: Remarkable increases in healthcare utilisation of URBMI and NRCMS, especially among the poorest groups, were accompanied by improvements in inequality in healthcare utilisation across UEBMI, URBMI, and NRCMS, and in income-based inequality in healthcare utilisation within URBMI and NRCMS. However, the poor groups were always more likely to forego admission to hospital, as recommended by doctors. We suggest further focus on the foregoing admission care of the poor groups. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12939-022-01633-4.