Low-Cost, High-Volume Health Services Contribute the Most to Unnecessary Health Spending due to Low-Value Care in Japan.

Importance: As healthcare costs continue to rise, high-income countries-including Japan-face the urgent task of reducing healthcare spending incurred by low-value care. However, evidence is limited as to which low-value care services contribute most to unnecessary healthcare spending outside of the United States. Objective: To identify which low-value care services contribute the most to unnecessary healthcare spending in Japan. Design Setting and Participants: The cross-sectional study of all beneficiaries using a population-based claims database from April 1, 2022, to March 31, 2023, encompassing all age groups, reflecting approximately 2% of the total Japanese population. Main Outcomes and Measures: We identified 52 low-value care services based on clinical evidence, and examined their contributions to healthcare spending using two versions of claims-based measures with different sensitivities and specificities (broader and narrower definitions). Each service was categorized into four groups based on its average per-service price: very low (<1,000 Japanese yen [JPY] = 8 US dollars [USD] in 2022), low (1,000-9,999 JPY), medium (10,000-99,999 JPY), or high (≥100,000 JPY). Results: Among 1,923,484 beneficiaries (mean [SD] age 58.6 [23.5] years; 52.7% female), we identified 3.1 million (narrower definition) to 3.7 million (broader definition) episodes of low-value care services (1.6-1.9 per capita), with 36-40% of patients receiving at least one low-value care service. These services accounted for 0.7-1.0% of total healthcare spending, amounting to 207-331 billion JPY (1.7-2.6 billion USD) when extrapolated nationwide with adjustments for age, sex, and region. When applying narrower definitions, over 99% of low-value care episodes involved very-low-cost or low-cost services, which accounted for 67% of unnecessary healthcare spending-far exceeding the 33% attributed to medium-cost or high-cost services. Conclusion and Relevance: Over one in three Japanese individuals received low-value care during 2022-2023, contributing to 0.7-1.0% of total healthcare spending. Among these services, low-cost services contributed to virtually all low-value care utilization and over two-thirds of unnecessary healthcare spending. Compared to focusing solely on high-cost services, targeting the reduction of frequently performed, lower-cost services may be a more effective strategy for reducing wasteful spending.