Adherence and persistence in patients with rheumatoid arthritis at an integrated health system specialty pharmacy

Disease-modifying anti-rheumatic drugs (DMARDs) improve symptoms and delay progression of rheumatoid arthritis (RA), but adherence is often sub-optimal and many patients change medication (either "switching" to a medication with a different mechanism of action or "cycling" to a medication with the same mechanism of action) during the first year of therapy. Some integrated health-system specialty pharmacies embed pharmacists in clinics to help patients access and adhere to specialty medication. This study assessed DMARD switching, cycling, adherence, and persistence at an outpatient rheumatology clinic with an integrated health-system specialty pharmacy. We conducted a retrospective cohort study of adults with RA, naïve to biologic or targeted synthetic DMARDs, who filled ≥ 2 biologic or targeted synthetic DMARD prescriptions within 12 months. Adherence was measured using proportion of days covered (PDC); persistence was computed at 12 months. Univariate analyses compared adherence and persistence between patients with and without a medication change. Ordinal logistic regression examined whether PDC was associated with patient age, gender, race, insurance type, and medication change. We included 772 patients: 79% female/21% male, 89% White/11% non-White, median age 56 years (interquartile range = 48-63). Most patients (84%) did not change medication during the study period, 5% cycled medication one or more times (but did not switch), 9% switched medication one or more times (but did not cycle), and 2% of patients both switched and cycled during the study period. Median PDC of the sample was 0.94 and 73% of patients were persistent. Patients with a medication change had lower PDC than those without (0.89 vs 0.95, = 0.004), but rate of persistence did not significantly differ between groups (77 vs 72%, = 0.300). Odds of higher PDC was more likely for men (Odds ratio [OR] = 1.82, 95% confidence interval [CI]: 1.34-2.48, < 0.001) and less likely for patients who changed medication (OR = 0.65, CI: 0.47-0.91, = 0.011); age, race, and insurance type were not significant. Patients with RA demonstrated high medication adherence and persistence, and low rates of switching and cycling. Findings support evidence that integrated health-system specialty pharmacies with clinical pharmacists embedded in outpatient clinics help patients overcome barriers to medication adherence to persist on therapy. This study was funded by Sanofi, Inc. James and J. Choi were employed by S