Examining the Influence of Behavioral Factors on Compliance and Persistence with Glatiramer Acetate Injection for Relapsing-Remitting Multiple Sclerosis

Abstract

Objective: To evaluate the relationship between compliance and persistence with glatiramer acetate (GA) and the behavioral variables in the transtheoretical model of change. Methods: Patients diagnosed with relapsing-remitting multiple sclerosis and being treated with GA for the first time, whether treatment-naïve (TN) or treatment-experienced (TE), were eligible for this prospective, observational, 12-week study. Institutional Review Board approval was obtained for each of 32 US study sites, and written informed consent was obtained for all patients prior to study procedures. Four office visits were required. Study procedures included baseline self-injection training and patient-reported behavioral variable surveys. Injection competence and medication compliance and persistence were assessed at weeks 4 and 12. Results: A total of 257 patients were enrolled; 80.9% were female, 81.6% white, and 60.0% TN. The evaluable population included 146 TN patients and 88 TE patients having discontinued beta-interferons. TE patients were at a significantly higher readiness stage, were less concerned about the negative aspects of self-injection, but had lower levels of MS self-efficacy than TN patients. While compliance and persistence rates did not differ between TN and TE groups, there were differences in outcome predictors. For the TN patients both higher self-injection competence at baseline and improvement in self-injection competence over the first month of therapy were predictive of better compliance and persistence with GA. Separate from injection competence, higher levels of functional self-efficacy were directly associated with better persistence in TN patients. None of the behavioral variables appeared to predict compliance or persistence for the TE patients. Conclusion: Among the TN, injection competency at baseline and improvement over the first month of use were significant predictors of compliance and persistence to GA at 12 weeks.Improving self-injection competence should be a priority when planning interventions for TN patients. Behavioral factors predicting compliance and persistence among TE patients require further study. ClinicalTrials.gov (number NCT00238654)