Abstract
BACKGROUND: The study aimed to examine the direct medical cost and impact of tocilizumab (TOZ) versus adalimumab (ADM) and etanercept (ETC) on reducing the levels of two inflammatory markers (e.g., C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)) among patients with rheumatoid arthritis (RA) using real-world data from Saudi Arabia. METHOD: This was a single-center retrospective cohort study in which data for biologic-naïve RA patients aged ≥ 18 years and treated with TOZ, ADM, ETC were retrieved from the electronic medical records (EMRs) of a university-affiliated tertiary care center in Riyadh, Saudi Arabia. Patients were followed up at least one year after the treatment initiation. Bottom-up microcosting was utilized to estimate the direct medical costs. Additionally, inverse probability treatment weighting and bootstrapping with 10,000 replications were conducted to generate 95% confidence levels for costs and the mean reductions in CRP and ESR levels. RESULTS: The number of patients who met the inclusion criteria and were included in the analysis was 150 patients (TOZ (n = 56), ADM (n = 41), ETC (n = 53)). Patients on TOZ had 3.96 mg/L (95% CI: -0.229-4.95) and 11.21 mm/hr (95% CI: 10.28-18.11) higher mean reductions in the CRP and ESR levels compared to their counterparts on ADM, ETC, respectively. However, this was associated with mean annual incremental costs of USD 10,087.88 (95% CI: 9494.50-11,441.63) in all cost-effectiveness bootstrap distributions. CONCLUSION: Tocilizumab has shown better effectiveness in reducing the levels of CRP and ESR but with higher costs. Future studies should examine whether the reduction of these two inflammatory markers is associated with quality-adjusted life years (QALYs) gains.