Objective: Many countries have recently established registration databases in the field of rehabilitation to clarify their current status. However, these databases are primarily created for inpatients, with only a few large-scale databases for outpatients. The present study aimed to clarify secular changes, age distribution, and regional disparities in the implementation of outpatient rehabilitation in Japan using the National Database of Health Insurance Claims.Materials and Methods: Using the National Database of Health Insurance Claims Open Data published by the Ministry of Health, Labor, and Welfare, the number of outpatient rehabilitation units from 2014 to 2018 were extracted and examined.Results: The total number of units for outpatient rehabilitation increased gradually from 2014 to 2018. Orthopedic rehabilitation accounted for more than 80% of the total number of units for outpatient rehabilitation in 2018. The total number of units for outpatient rehabilitation according to age was highest among those in their late 70s, while cerebrovascular and dysphagia rehabilitation had the highest number of units in children.Conclusion: The total number of units for outpatient rehabilitation gradually increased from 2014 to 2018; whereas the number of total units for outpatient rehabilitation according to age was the highest among those in their late 70s. However, cerebrovascular rehabilitation and dysphagia rehabilitation had the highest number of units in children. The implementation status of rehabilitation in each region varied greatly among prefectures, suggesting the need for policy planning to eliminate regional disparities.

Objectives: This study aimed to determine the relationship between the number of board-certified physiatrists and the amount of inpatient rehabilitation delivered.Materials and Methods: We analyzed open data from 2017 in the National Database of Health Insurance Claims and Specific Health Checkups of Japan and compared the volume of inpatient rehabilitation services between prefectures to examine regional disparities. We also examined the relationship between the volume of rehabilitation services provided and the number of board-certified physiatrists.Results: The population-adjusted number of inpatient rehabilitation units per prefecture ranged from a maximum of 659,951 to a minimum of 172,097, a disparity of 3.8-fold. The population-adjusted number of board-certified physiatrists was 4.8 in the highest region and 0.8 in the lowest region, a disparity of 5.8-fold. The population-adjusted number of board-certified physiatrists was significantly correlated with the population-adjusted total number of inpatient rehabilitation units (r=0.600, P<0.001). Correlations were between the number of board-certified physiatrists and the number of rehabilitation units in cerebrovascular and orthopedic services, but not in cardiovascular, respiratory, or oncology services.Conclusion: Large regional disparities manifested in the amount of inpatient rehabilitation provided in Japan. An association was found between the number of board-certified physiatrists and rehabilitation units delivered. It may be necessary to train more BCPs in regions with fewer units to eliminate these disparities.