Background Biologic DMARDs (bDMARDs) are used to treat patients (pts) with moderate to severe rheumatoid arthritis (RA). Pts may experience clinical benefits from treatment with bDMARDs alone or with a conventional synthetic DMARD (csDMARD).
Objectives To assess treatment patterns and healthcare resource use (HCRU) after prescription/administration of a bDMARD alone or with a csDMARD.
Methods In this retrospective cohort analysis, pts aged ≥18 years (yrs) with an RA diagnosis (ICD9: 714.xx) who were prescribed/administered a DMARD (2007–2011) were selected from de-identified US electronic health records (EHR; Humedica). Index date was date of first prescription/administration for a bDMARD (adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab, anakinra, tocilizumab). Pts did not receive bDMARDs for ≥6 months pre-index and were followed for ≥1 yr post-index. Pts were classified by index biologic monotherapy (Bmono) or combination therapy with bDMARD and csDMARD (B+CScombo; based on methotrexate, leflunomide, sulfasalazine, hydroxychloroquine at index). Regression analyses for switch (new bDMARD/csDMARD prescription/administration and no index drug for ≥120 days) and RA-related costs were assessed controlling for differences in pt demographics/characteristics. RA-related costs were derived from a pt subset with linked Optum claims data and applied to RA visits and pharmacy use in EHR.
Results Of 2119 pts initiating a bDMARD, 70.6% received Bmono and 29.1% received B+CScombo; 0.2% had ≥2 biologics. Pt characteristics and treatment patterns are presented in Table 1. Mean age and percentage of females were similar for Bmono and B+CScombo pts. Compared with B+CScombo pts, Bmono pts were more likely to be treated by a rheumatologist, had a higher Deyo-Charlson Co-morbidity Index score and were more likely to have cardiovascular disease, hyperlipidaemia, hypertension and renal disease. Most Bmono and B+CScombo pts were prescribed a TNF inhibitor (TNFi). During 1-yr follow-up (FU), B+CScombo pts were less likely to switch index regimen vs Bmono pts (OR 0.37; 95% CI 0.27, 0.51; p<0.0001). More than one-third of Bmono pts switched index regimen, with most switching to a csDMARD. A small proportion of B+CScombo pts switched index regimen with more than half switching the bDMARD of the B+CScombo regimen and the remainder switching the csDMARD of the B+CScombo regimen. Compared with Bmono pts, B+CScombo pts had lower mean RA-related office and outpatient visits but more prescriptions. Adjusted total RA-related costs were 30% lower for Bmono vs B+CScombo pts.
Conclusions In this analysis of EHR data characterising bDMARD prescriptions/administrations in pts with RA, 70.6% received Bmono, and had a greater prevalence of co-morbidities and were more likely to be treated by a rheumatologist vs B+CScombo pts. B+CScombo pts were less likely to switch index regimen in 1-yr of FU and had lower RA-related medical HCRU but greater total costs vs Bmono pts. High prevalence of Bmono use may be due to a stricter concomitant csDMARD definition or the data source, which included specialties other than rheumatology.
Acknowledgements This study was sponsored by Pfizer Inc. Editorial Support was provided by Karen Irving at Complete Medical Communications and funded by Pfizer Inc.
Disclosure of Interest J. Harnett Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., R. Gerber Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., D. Gruben Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., D. Wiederkehr Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., E. Mahgoub Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., G. Wallenstein Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., A. Koenig Shareholder of: Pfizer Inc., Employee of: Pfizer Inc.