An observational study of socioeconomic and clinical gradients among diabetes patients hospitalized for avoidable causes: Evidence of underlying health disparities in China?

Introduction. Diabetes is an ambulatory care sensitive condition that can generally be managed in outpatient settings with little or no need for inpatient care. As a preliminary step to investigate whether health disparities can be detected in the inpatient setting in China, we study how diabetic patients hospitalized without prior primary care contact or with greater severity of illness differ from other diabetic inpatients along socioeconomic and clinical dimensions. Methods. We conduct an observational study using three years of clinical data for more than 1,800 adult patients with diabetes at two tertiary hospitals in East China. Univariate analysis and probit regression are used to characterize the differences in socioeconomic and clinical factors between patients hospitalized for diabetes with no prior primary care contact and those hospitalized with previous treatment experience. Secondarily, we use ordinary least squares regression to estimate the socioeconomic and clinical differences associated with poor serum glucose control at admission. Results: We find that compared with patients hospitalized after prior treatment experience, inpatients with no previous primary care contact for diabetes have worse clinical laboratory values, are more likely to be young and male, to have lower education attainment, and to have poorer blood sugar control. Insurance, urban residence, and previous use of diabetic medication are in turn negatively correlated with HbA1c levels upon admission. Conclusion: Among hospitalized diabetic patients, socioeconomic factors such as lower education attainment, rural residence and lack of full insurance are associated with avoidable hospitalizations or worse indicators of health. Although we cannot definitively rule out selection bias, these findings are consistent with health disparities observable even at the inpatient level. Future studies should study the underlying mechanism by which traditionally vulnerable groups are more likely to be hospitalized for avoidable causes and with greater severity of illness.