Prediction for TNF Inhibitor Users in RA Patients According to Reimbursement Criteria Based on DAS28

Abstract

Objective: The purpose of this study is to examine the dif-ference between the numbers of patients in rheumatoid ar-thritis (RA) who are eligible to TNF inhibitors by the past Korean National Health Insurance reimbursement guide-line and by the disease activity score with 28-joint assess-ment (DAS28) based criteria.

Methods: Data were obtained from a multi-center registry for biologics users in Korean RA patients, BIOlogics Phar-macoepidemiologic StudY (BIOPSY). DAS28 was calcu-lated 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 eli-gible 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 moe reasonable as a tool for deciding early responsive-ness 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 appro-priate 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.