류마티스관절염에서 DAS28에 근거한 보험급여기준 적용시 항 TNF제제 대상 환자 예측

Abstract

Objective The purpose of this study is to examine the difference between the numbers of patients in rheumatoid arthritis (RA) who are eligible to TNF inhibitors by the past Korean National Health Insurance reimbursement guideline and by the disease activity score with 28-joint assessment (DAS28) based criteria.

Methods Data were obtained from a multi-center registry for biologics users in Korean RA patients, BIOlogics Pharmacoepidemiologic StudY (BIOPSY). DAS28 was calculated based on either ESR or CRP, and DAS28 of more than 5.1 or between 3.2 and 5.1 with radiographic changes was defined as a cut-off point for the initiation of TNF inhibitors. For the maintenance criteria, we used both of improving in DAS28 score (>1.2) and low disease activity (DAS 28<3.2). Differences between the numbers in each step by two criteria were described with Chi-square test and Kappa agreement.

Results Of the 489 patients in BIOPSY, 299 were included in this study. Among them, 278 patients (93.0%) were eligible of TNF inhibitors when we applied the new initiation criteria with DAS28-ESR, and 244 patients (81.6%) were indicated for TNF inhibitors with DAS28-CRP. For the maintenance criteria, a low disease activity (DAS28<3.2) in 3 months after starting TNF inhibitors is too strict for achieving (33.6% with DAS28-ESR and 50.0% with DAS28-CRP). Instead, decreasing DAS28 by more than 1.2 is more reasonable as a tool for deciding early responsiveness of TNF inhibitors in RA patients (81.2% both with DAS28-ESR and DAS28-CRP).

Conclusion Our results show that the candidates for TNF inhibitors will be enormously changed according to a change in the reimbursement criteria. To define appropriate patients to receive TNF inhibitors, a further study with regard to the impact of changes in the reimbursement criteria on the outcomes of RA patients will be required.