Impact of distribution structure of regional medical and care resources on outpatient prescribing in Japan

Background : Under Japan's Medical Care Plan, secondary medical areas are geographic units designed to ensure sufficient hospital beds for general medical care, considering local conditions. Although prescription disparities should be avoided to promote equitable medical care provision and appropriate allocation of medical resources in terms of cost, considerable regional differences exist in prescription quantities, which are attributed to regional characteristics. Understanding the factors behind these differences may help improve equity in medical access through drug supply and facilitate appropriate evaluation of the role and positioning of secondary medical areas. This study aimed to clarify the impact of regional and medical care characteristics on outpatient prescription quantities. Methods : This cross-sectional study utilized data from 2020, the most recent year for which national census data are publicly available. First, an exploratory factor analysis (EFA) was conducted for each of the three groups of variables: regional characteristics, regional medical and care resources, and the drug prescription standardized claims–data ratio (SCR). Next, structural equation modeling (SEM) was applied to identify a valid structural model. This allowed for a consistent SEM approach to assess the impact of regional characteristics and regional medical and care resources on regional outpatient prescriptions. Results : The EFA yielded six factors from regional characteristics, six from regional medical and care resources, and 17 from regional outpatient prescription SCR. A structural equation model including five factors from the outpatient prescription SCR was validated. The model suggested that regional clinic function factors formed a baseline for outpatient prescription SCR factors, and these were influenced by other regional medical and care resources factors. Conclusions : The study demonstrated the validity of a model in which outpatient prescription volume is influenced by regional characteristics through regional medical and care resources. These findings may support efforts to establish more effective medical zones and develop more accurate models of prescription volume.