Journal of Rheumatic Diseases

Table. 3.

Proportions of seropositive and seronegative RA patients using claims database based on their definitions

Year Seropositive RA Seronegative RA


Diagnostic code* Diagnostic code with RIDR program Operational definition Diagnostic code* Diagnostic code with RIDR program Operational definition
2012 112,983 (224.4) 70,276 (139.6) 79,337 (157.6) 646,459 (1,284.1) NA 69,709 (138.5)
2016 150,058 (293.6) 96,330 (188.5) 103,083 (201.7) 688,053 (1,346.3) NA 74,038 (144.9)

Values are presented as number (prevalence). Prevalence presented as n/100,000 persons. RA: rheumatoid arthritis, NA: not applicable, RIDR: Rare Intractable Disease registration, ICD: International Classification of Diseases, DMARD: disease-modifying antirheumatic drug. *Estimated prevalence by ICD-10 diagnostic codes. Estimated prevalence by diagnostic codes which was applicable to RIDR program. Operational definition of RA was confined to prescription of any DMARDs under specific diagnostic codes (M05.X) at least once for each calendar year.

J Rheum Dis 2021;28:60~67 https://doi.org/10.4078/jrd.2021.28.2.60
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