Exploring Novel Reasons for Nonadherence to Disease-Modifying Therapies

Background

Although there is currently no cure for multiple sclerosis (MS), disease-modifying therapies (DMTs) can decrease rates of relapse and disease progression; however, patients may choose not to initiate DMT use or to discontinue use. The results of a large, multinational, multicenter study showed that that approximately 40% of patients stopped taking DMTs within 2.7 years of starting treatment. The most commonly reported reasons for no longer using DMTs were perceived lack of efficacy and side effects.¹

Trial data suggest that some patients do not take DMTs for reasons that are not logical or rational. The authors of this study hypothesized that these patients cite irrational reasons for avoiding DMTs as an avoidance coping strategy to downplay perceived disease severity and/or avoid being constantly reminded of their disease. Avoidance coping is common in patients who have chronic diseases such as MS. To the authors’ knowledge, at the time this study was conducted, avoidance coping and medication adherence in patients with MS had not been previously evaluated.¹

Methods

In this exploratory study, investigators analyzed data from a previously reported, parallel-group, randomized pilot trial that included patients at least 18 years of age with relapsing-remitting MS, who were not using DMTs at the time of screening or had no intention of initiating DMTs in the future. Patients received Motivational Interviewing-Cognitive Behavior Therapy (MI-CBT) sessions aimed at promoting treatment initiation or re-initiation.

Reasons for not using DMTs were identified by investigators by listening to audio recordings of each patient’s first MI-CBT session. Two post—MI-CBT outcomes were evaluated: 1) motivation and confidence to adhere to treatment (evaluated by self-reporting measures), and 2) treatment initiation or re-initiation (self-reported by the patient and confirmed with the patient’s physician). These data were analyzed to determine if the reasons for not using DMTs were correlated with worse outcomes after MI-CBT.¹

The goals of this study were to 1) establish criteria for coding the main reason why patients were not using DMTs (based on audio recordings of the MI-CBT sessions), 2) compare the clinical and psychological characteristics of the avoidance coping group with the other groups and evaluate whether the avoidance coping group could be identified using self‐reporting measures, and, 3) evaluate outcomes among patients in the avoidance coping group compared with outcomes in the other groups.¹

Results

Based on the recordings, investigators determined that there were 4 primary causes of nonadherence to DMTs: 1) patient perception of a mild MS disease course (6.4%); 2) costs of DMTs (14.1%); 3) side effects associated with DMTs (37.2%); and 4) avoidance coping (42.3%). Because of the small number of patients who cited mild MS disease course as their reason for nonadherence, this group was omitted from further analyses.¹

Demographic and clinical characteristics: Of the 78 patients who met the inclusion criteria for this exploratory analysis, the majority of patients were female (88.5%), Caucasian (82.1%), well educated (92.3% reported attending some college), and had used DMTs previously (89.7%). Mean age was 45.64 years, mean disease duration was 11.42 years, and mean Expanded Disability Status Scale (EDSS) score was 2.91.¹

There were no significant between-group differences in age, gender, ethnicity, education, disease duration, or number of exacerbations in the previous 2 years. There were between-group differences in EDSS scores (P = .028), prior DMT use (P = .031), and use of interferon (IFN) beta-1a (P = .004). A post hoc analysis showed that the avoidance coping group had the lowest mean EDSS scores; however, this difference was not significant. Post hoc analyses also revealed that the side effect group was more likely to have used DMTs previously, compared with the cost group (P = .017). Also, compared with patients in the avoidance coping group, those in the side effect group were more likely to have used IFN-beta-1a (P = .004). No significant differences in use of other types of DMTs were observed between groups.¹

Psychological characteristics: Between-group differences were observed for 2 items from the Multiple Sclerosis Treatment Adherence Questionnaire: “dissatisfaction with medication” (P = .021) and “side effects of medication” (P = .013). Between-group differences were also noted in whether the patient was currently and regularly seeing an MS provider (P = .001), whether the patient planned to visit a MS provider in the next 6 months (P = .008), and communication with the patient’s MS provider (P = .038). Post hoc analyses revealed that the side effect group reported greater dissatisfaction with taking medication and was more likely to report intolerable side effects and injection pain compared with the other groups. Compared with other groups, the cost group was more likely to agree with the statement “I can’t afford medications.” Compared with the avoidance coping group, the side effect group reported having better communication with MS providers (P = .038) and was more likely to have plans to see an MS physician in the next 6 months (P = .004). Also, patients in the side effect group were more likely to be currently seeing an MS physician compared with patients in the other groups (P = .004).¹

Outcomes: Significant differences were observed between groups in motivation, confidence, and the decision to initiate treatment with DMTs. Post hoc analyses showed that the side effect group and cost group had higher motivation compared with the avoidance coping group (P = .023 vs side effect group; P = .003 vs cost group). Follow‐up analyses using dummy coding showed greater motivation among patients in the cost group compared with those in the avoidance coping group (P = .008). Post hoc analyses also suggested that the avoidance coping group was less likely than the cost group to report confidence to take DMT in the next 2 weeks (P = .021) and that the avoidance coping group was less likely to have decided to initiate or re-initiate DMT compared with the side effect group (P = .019).¹

Conclusion

A sizable number of patients with MS provide implausible rationalizations for not taking DMTs, which the authors of this study attribute to avoidance coping. In this analysis, no patient characteristics were identified that would distinguish the avoidance coping group from others (ie, cost or side effects). Furthermore, this analysis revealed reasons why patients may decide not to take DMTs that have not been previously identified in published literature. Further research is needed to develop means of identifying patients who are not taking DMTs for avoidance coping reasons as well as strategies to promote initiation or re-initiation of DMTs in this patient population.¹

Reference

1.Schoor R, Bruce A, Bruce J, et al. Reasons for nonadherence and response to treatment in an adherence intervention trial for relapsing-remitting multiple sclerosis patients [published online November 28, 2018]. J Clin Psychol. 2018. doi: 10.1002/jclp.22725.