Delayed global standardization and prefectural disparities in systematic lupus erythematosus treatment in Japan: a nationwide study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

Abstract

To evaluate the status of the global standardization of, and prefectural differences in, systematic lupus erythematosus (SLE) treatments in Japan. The Japanese National Database of Health Insurance Claims and Specific Health Checkups (NDB Japan) was used. A patient with SLE was defined as having a disease with ICD10 code M321 or M329 between April 2019 and March 2020, for which oral corticosteroids (OCS), immunosuppressive agents or biologic agents were prescribed at least once during a given month. SLE treatments were evaluated by treatment center type and prefecture. In total, 74,277 patients met the definition of SLE. The SLE prevalence was 60 per 100,000 (range: 47 - 102 per 100,000 by prefecture). Nationwide, 79.4% of the patients (range: 52.1% - 93.3% by prefecture) visited a specialized treatment center (STC); 37.4% (range: 26.4% - 51.3% by prefecture) received only OCS, with fewer of these patients visiting a STC than a non-STC (34.8% and 49.7%, p<0.001); and 21.4% (range: 10.7% - 35.0%) received HCQ, with more of these patients visiting a STC than a non-STC (23.0% and 13.5%; p<0.001). NDB Japan demonstrated delayed global standardization of, and prefectural disparity in, SLE treatments in Japan.