Association of hospital bed and primary care supply with avoidable hospitalizations in China: a longitudinal panel study, 2016–2023

The continuous expansion of hospital capacity presents a fundamental dilemma. While adequate inpatient resources are essential for meeting population health needs, excess bed availability may be associated with potentially avoidable healthcare utilization. This study aimed to evaluate the association between hospital bed expansion and avoidable hospitalizations in China and to quantify the primary care physician and assistant physician density required to mitigate demand induced by supply. We conducted a longitudinal panel study using aggregated administrative data from 121 jurisdictions at the county level in Guangdong Province, China, encompassing over 126 million residents from 2016 to 2023. The primary outcomes were hospitalization rates for five ambulatory care sensitive conditions: diabetes mellitus, hypertension, chronic heart failure, chronic obstructive pulmonary disease, and asthma. We utilized generalized estimating equations to calculate incidence rate ratios and to model the interaction between bed supply and primary care physician and assistant physician density. We also calculated the offset threshold, defined as the density of primary care physicians and assistant physicians at which the association between bed supply and hospitalization rates would be reduced to null. Over the study period, the mean hospital bed density increased by 13.98%, while primary care physician and assistant physician density increased by only 6.00%, reaching 0.53 per 1000 population in 2023. Higher bed density was consistently associated with increased hospitalization rates across all five conditions, with incidence rate ratios ranging from 1.04 to 1.13. Although primary care supply significantly moderated this association for diabetes and heart failure, the calculated protective offset thresholds (2.88 and 1.56 per 1000 population, respectively) were approximately three to five times higher than the current density of primary care physicians and assistant physicians. In China’s rapidly expanding health system, greater hospital bed capacity was consistently associated with higher rates of avoidable hospitalizations. Although a sufficient supply of primary care physicians and assistant physicians may attenuate this association, the current density remains structurally insufficient to support effective gatekeeping. Health reforms should prioritize parallel investments in primary care staffing to bridge the gap between existing resources and the thresholds required for sustainable population health management.