Association between patient complexity and healthcare costs in primary care on a Japanese island: a cross-sectional study

Objectives This study aimed to elucidate the relationship between patient complexity and healthcare costs in a primary care setting on a Japanese island. Design Cross-sectional study. Setting Tarama Clinic, Okinawa Miyako Hospital, on Tarama Island, Okinawa Prefecture, Japan. Participants Patients who visited Tarama Clinic from 1 April 2018 to 30 June 2018, were aged 20 years or above, were resident in Tarama Village and had decision-making capacity. Outcome measures Patient complexity scored using Patient Centred Assessment Method (PCAM), healthcare costs per person per year/visit and participant characteristics. Results We included 355 study participants. The means (SD) of the total PCAM scores and healthcare costs per person per year/visit were 21.4 (5.7) and 1056.4 (952.7)/125.7 (86.7) in US dollars, respectively. Spearman's rank correlation coefficients between the total PCAM scores and healthcare costs per person per year/visit were 0.33 and 0.28 (p values <0.0001and <0.0001), respectively. The healthcare costs per person tended to be relatively low in the patient groups with the highest complexity. In the groups, the proportion of those with psychological conditions tended to be higher and those with cardiovascular diseases tended to be lower than in the other groups. Multiple regression analysis showed that total PCAM scores were associated with healthcare costs per person per year/visit, which were log-transformed: the regression coefficients were 3.87x10(-2)and 2.34x10(-2), respectively; the p values were <0.001and <0.001, respectively. Conclusions This study clarified the association between patient complexity and healthcare costs in a primary care setting on a Japanese island. We found that such costs tended to be relatively low in patient groups with the highest complexity. In primary care, healthcare costs probably do not accurately reflect the value of services provided by medical institutions; it may be essential to introduce a system that provides incentives for problem-solving approaches to social issues.