MerriKay Oleen-Burkey, Gabriel Pardo, Howard Zwibel and Douglas Denney
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)