DX54
An Assessment of Adherence Among Multiple Sclerosis Patients Newly Initiating Treatment with a Self-Injectable Versus Oral Disease-Modifying Drug
Objectives: To evaluate adherence among MS patients newly initiating a self-injectable versus oral DMD.
Methods: MS patients (age 18–63; ≥1 medical claim with MS diagnosis: ICD-9-CM:340.xx) with ≥1 DMD claim (first claim=index date), with continuous eligibility 12 months pre- and post-index, and with no DMD use during the pre-index period, were identified from a random sample of 5 million lives in the IMS LifeLink Plus database from 7/1/2010–6/30/2013. Patients were stratified by index DMD type: self-injectable versus oral. Fisher and Wilcoxon tests were used in unadjusted statistical comparisons. Logistic regression was used to evaluate the likelihood of nonadherence (12-month post-index categorical medication possession ratio <0.8 vs ≥0.8) to index DMD group. Covariates included age, sex, and baseline comorbidities.
Results: The analysis included 5238 self-injectable and 444 oral DMD patients (mean age: 43.0 vs 44.0, respectively; p=0.0418). In unadjusted analyses, the percentage of patients who were nonadherent in the self-injectable (45.2%) and oral (41.8%) DMD groups did not differ statistically (p=0.1791). After controlling for covariates, index DMD type was not a significant predictor of nonadherence (p=0.1858). Male sex and older age groups (vs 18–34) were associated with significantly lower likelihood of nonadherence (odds ratio [OR]: 0.811 and ORs: 0.697–0.813, respectively; p<0.05). Depression was associated with higher likelihood of nonadherence (OR: 1.732, p<0.0001).
Conclusions: In this analysis, there was no difference in nonadherence attributable to self-injectable versus oral DMDs. Male sex and older age were associated with a lower risk of nonadherence and depression was associated with a higher risk of nonadherence.