OP0015 INCIDENCE, RISK FACTORS AND VALIDATION OF THE RABBIT SCORE FOR SERIOUS INFECTIONS IN A REAL LIFE PROSPECTIVE STUDY OF PATIENTSWITH RHEUMATOID ARTHRITIS: DATA FROM 1.549 PATIENTS

Abstract

Background Identification of the risk factors for the development of serious infections in patients with rheumatoid arthritis (RA) is critical for designing preventive measures and early treatment. Objectives To identify risk factors for serious infections and to validate the RABBIT risk score in RA patients in daily clinical practice. Methods Multicenter, prospective study of RA patients in Greece. Demographics, disease characteristics, treatments and co-morbidities were prospectively collected via a web-based platform at baseline and one year later. The observed incidence of serious infections was compared to the one estimated by the RABBIT score. Results 1.549 RA patients were included (women: 78%, mean age: 63 years, mean disease duration: 10.4 years, RF and/or anti-CCP positive: 54%, mean DAS28: 3.4, mean HAQ: 0.5, bDMARD use: 46%, corticosteroid use: 36%). During follow-up, 38 serious infections were recorded (incidence: 2.3/100 patient-years). Patients who developed a serious infection had longer disease duration (14.2 vs. 10.3 years, p=0.02), higher HAQ at baseline (0.85 vs. 0.5, p=0.006), a history of previous serious infection (26% vs. 10%, p=0.002) and were more likely to have chronic lung disease (23% vs. 9%, p=0.008) or cardiovascular disease (23% vs. 11%, p=0.04). Disease duration (OR: 1.04, CI: 1.01-1.08, p=0.025), history of previous infection (OR: 3.3, CI: 1.3-8.1, p=0.01) and chronic lung disease (OR: 3.03, CI: 1.17-7.85, p=0.023) remained statistical significant in multivariate logistic regression analysis. bDMARD use was not associated with increased risk in uni-or multi-variate analysis. Data for RABBIT score calculation were available in 1.349 patients. Estimated incidence per 100 patient-years was divided in Q1-Q4 quartiles (25-50-75th percentiles: 0.94-1.35-2.15). Estimated and observed incidence rates were in Q1: 0.8 and 0.54, Q2: 1.14 and 0.79, Q3: 1.76 and 1.84 and Q4: 3.7 and 5.6, respectively (Hosmer Lemeshaw test, p=0.9). Conclusion In this large, real life, prospective study of RA patients, the incidence of serious infections was 2.3/100 patient-years. Longer disease duration, history of previous serious infections and chronic lung disease were independently associated with the development of serious infections. RABBIT score predicted rather accurately the risk for serious infections in our cohort.