Etanercept-Methotrexate Combination Therapy Initiators Have Greater Adherence and Persistence Than Triple Therapy Initiators With Rheumatoid Arthritis

Abstract

Objective: To estimate adherence and persistence with etanercept plus methotrexate (ETN-MTX) combination therapy and MTX, hydroxychloroquine, and sulfasalazine triple therapy at 1 year following treatment initiation in adults with rheumatoid arthritis (RA).

Methods: This retrospective analysis used data from the Truven Health MarketScan Commercial and Medicare Supplemental databases from January 2009 to July 2013. Adherence was defined as having percentage of days covered >80% for all drugs within each regimen. Persistence was defined as no treatment gap >45 days for any drug and no addition or switching to other disease-modifying antirheumatic drugs. Multiple logistic regression models were employed in the analyses to control for potential confounders.

Results: A total of 3,724 ETN-MTX patients and 818 triple therapy patients were eligible. At 1 year, 27.9% who were taking ETN-MTX and 18.2% using triple therapy were adherent to all agents in their regimen (P < 0.0001), and 29.4% who were taking ETN-MTX and 23.2% using triple therapy were persistent (P < 0.001). After adjusting for confounders, ETN-MTX patients had significantly greater odds of being adherent (odds ratio [OR] 1.79, 95% confidence interval [95% CI] 1.47-2.17) and persistent (OR 1.45, 95% CI 1.20-1.72) compared with patients using triple therapy.

Conclusion: Patients with RA initiating treatment with ETN-MTX combination therapy demonstrated greater adherence and persistence at 1 year than patients initiating triple therapy.

Figure 1

Index date definition for triple therapy regimen for patients with a treatment gap for either or both of the first 2 agents. If the days supply for all drugs in triple therapy regimen overlapped ≥28 days, the patient qualified as a triple therapy user, and the date that the last drug in the series was prescribed was the index date. If a patient did not have overlap of ≥28 days for all drugs, a patient could qualify as a triple therapy user if a subsequent prescription for either of the first two drugs occurred ≤30 days after the end of the days supply for the first claim for that drug.

Figure 2

Crude persistence on individual agents for patients who did not switch from their index treatment regimen. The percentages of patients who were persistent on individual agents of (A) ETN‐MTX combination therapy and (B) triple therapy through 1 year are shown. ETN = etanercept; MTX = methotrexate; HCQ = hydroxychloroquine; SSZ = sulfasalazine.