Do Oral Disease Modifying Agents (DMTs) Improve Adherence to MS Treatment? a Comparison of Oral and Injectable Drugs
Objectives: To determine if adherence and tolerability of oral DMTs is better than with injectables in our MS Center population.
Methods: We developed the MS Treatment Adherence Questionnaire (MS-TAQ) and collected data from October-November 2014. The MS-TAQ is composed of 6 questions: patient’s current DMT, number of missed doses in 4 weeks, reason dose was missed, perceived side effects, ease of administration, and medication satisfaction. Medication types were divided into 3 groups: subcutaneous or intramuscular (SC/IM), monthly IV injections, and oral DMTs. We analyzed the responses using Fisher’s Exact Test (α=0.05) to determine if responses varied by medication type.
Results: We had 209 patients, 75.1% female and 24.9% male, mean age of 50.4 years. Eighty-nine patients (42.5%) were on oral medication, 90 (43%) on a SC/IM drug, and the remaining 30 (14.5%) on an IV infusion. Fifty-five percent of patients on oral DMTs reported no missed doses as compared with 70.8% of patients taking SC/IM and 93.3% on patients receiving IV infusions (p=0.005). Reason for missed dose differed with respect to medication type (p=0.017) with forgetfulness being reported in 37.6% and 26.5% of patients receiving oral and IM/SC DMTs respectively. In addition, side effects were significantly different for each medication type (p<0.0001). The overwhelming majority of those on IV did not experience side effects (74.3%), whereas only a minority of those taking orals (18.6%) and SC/IM (20.2%) responded as such. Ease of taking medication was reported by 77%, 60% and 33% of patients on oral, IV and SC/IM injections, respectively (p<0.0001). Patient satisfaction did not significantly vary by medication type (p=0.235).
Conclusions: In our population, lack of adherence was significantly higher in patients receiving oral as compared to injectable DMTs, despite their reported ease of administration. Side effect profile may have been a contributing factor to this outcome. Health care providers should implement strategies to improve DMT adherence, regardless of medication route.