Long-term etanercept retention patterns and factors associated with treatment discontinuation: a retrospective cohort study using Canadian claims-level data

Abstract

To examine 12-month retention rates over 6 years of etanercept patients in Canada, and to identify factors associated with treatment discontinuation. A retrospective cohort study was conducted using longitudinal prescription drug claims data from IQVIA Private Drug Plan database (PDP), Ontario Public Drug Plan database (OPDP), and Régie de l'assurance maladie du Québec database (RAMQ). Between 07/2008 and 06/2010, bio-naïve patients who initiated etanercept were identified and followed for 72 months. Twelve-month retention rates were estimated in one-year increments and factors associated with time to discontinuation over the 72-month period were identified using a Cox proportional hazards regression model. The study identified 4528 etanercept patients (61% female, 85% rheumatic diseases, and 15% psoriasis). Twelve-month etanercept retention rates increased significantly for patients following their first year on therapy (p < 0.0001), with 66% of patients retained at year 1 vs. 79, 82, 84, 83, and 79% at years 2, 3, 4, 5, and 6, respectively. 17.1% (n = 771) of patients were retained for the entire 72-month study. Patients with psoriasis were at increased risk (HR 1.199; p < 0.0001); while public drug coverage plan patients (OPDP HR 0.721; p < 0.0001 and RAMQ HR 0.537; p < 0.0001) were at decreased risk of treatment discontinuation. Twelve-month etanercept retention rates increased significantly for patients following their first year on therapy. Indication and drug coverage plan were associated with patients' time to etanercept discontinuation. With a better understanding of factors associated with retention, programs can be designed to address the specific needs of at-risk groups while supporting patients stable on therapy.

Reduction in the utilization of prednisone or methotrexate in Canadian claims data following initiation of etanercept in pediatric patients with juvenile idiopathic arthritis

“…Previous research in the Canadian setting has shown that annual retention of ETN treatment among pediatric patients with a medical history consistent with JIA (94%) or ankylosing spondylitis (5%) ranges from 78% in year 1 to 80 to 90% over years 2–6, [7] suggesting therapeutic efficacy and tolerability. These levels of ETN treatment retention are higher than those reported by adult patients in the same setting over the same time periods [7, 8].…”

“…Per privacy legislation in Quebec, a random sample drawn from the total RAMQ database was used in this study. These databases have been utilized previously in many studies evaluating the use of biologics and other medications in adult and pediatric patient populations [7, 8, 25–29].…”

“…The disease indications reported in Table 1 were inferred from a patient’s drug prescription history using an algorithm developed by IQVIA, which utilizes information on medication claims and prescriber types in a patient's history. [8, 30]. The algorithm was developed using a review of Canadian treatment guidelines, comparison to diagnosis-containing datasets, and input from treating experts to identify prescription and prescriber patterns that align with JIA and aims to exclude other diseases that ETN is indicated for, including psoriasis, rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis.…”

“…The algorithm does not identify different JIA categories. This algorithm and approach have been validated [30] and used in other published studies [8].…”

“…* Indications were inferred using an algorithm developed by IQVIA, which uses a patient’s drug history [7, 8, 30] † Groups with less than 6 patients/claims were adjusted to 3 to maintain privacyPDP, IQVIA Private Drug Plan; OPDP, Ontario Public Drug Plans; RAMQ, Quebec Public Drug Plan, Régie de l’assurance maladie du Québec…”