Perceptions of Medication Can Predict MS Treatment Adherence, Persistence

Perceptions of a medication can predict treatment adherence and persistence — sticking with the same therapy — in people with multiple sclerosis (MS), a prospective observational study found.

The findings were the result of a clinical study (NCT02488343) evaluating the profile of adherence to therapy in patients ages 18 to 70 with relapsing-remitting MS (RRMS).

The study, “Beliefs about medication as predictors of medication adherence in a prospective cohort study among persons with multiple sclerosis,” was published in the journal BMC Neurology.

Adherence — following a treatment regimen and taking medications as scheduled — to disease-modifying therapies, called DMTs, varies among MS patients and is often below 80%. But besides demographic and clinical characteristics, there is not much information on the factors predicting treatment adherence in these patients.

To fill this knowledge gap, researchers in Israel assessed both adherence and persistence to DMTs and examined their association with diverse disease predictors. Persistence was defined as staying with the same DMT for the duration of the study, while adherence was categorized as the degree to which patients took their DMT doses as prescribed.

A total of 186 RRMS patients with a mean age of 40.6 were involved in the study. All were treated with DMTs at Carmel Medical Center, in Israel, between February 2016 and February 2019.

The patients had MS for a mean duration of 7.5 years and were on DMTs for a mean duration of 27.6 months, or just over two years. They were mostly married (60.2%), and women (72%), with high education and economic status. Health conditions other than MS were reported by 20.4% of patients and their average physical disability was relatively low to moderate (mean 2.62 in the Kurtzke Expanded Disability Status Scale).

In-person assessments were conducted at three time points: at the study’s start, and after six months and 12 months (one year).

At these visits, patients were asked to complete a number of questionnaires about their medication beliefs, perception of their illness, perceived health, medication habits, and emotional state. Physical disability also was assessed by a neurologist.

The researchers used multiple measures, including patient-reported outcomes — specifically the Multiple Sclerosis Treatment Adherence Questionnaire and Probabilistic Medication Adherence Scale — and medication claims, to assess treatment adherence and persistence.

The results of the survey showed that 69.9% of patients were adherent to DMTs after six months, and 71% after one year. Adherence ranged between 66.3 and 73.8%.

Persistence was lower, at 64.5%, meaning that more than one-third of patients switched medications during the 12 months of follow-up. Reasons cited for discontinuation included disease worsening (15 patients), pregnancy planning (14 patients), abnormal laboratory results (seven patients), and non-tolerability (30 patients).

A comparison between adherent and non-adherent patients found that adherence at six months was more common in people with a higher socioeconomic status. However, this association was not observed at 12 months.

Notably, one association that was observed for both six and 12 months was the patients’ beliefs about the usefulness and safety of DMTs. Individuals who were non-adherent more often believed that the prescribed therapy was an overtreatment and could be harmful than did adherent patients.

This association of beliefs about medication with adherence also was found when accounting for differences in age, gender, and socioeconomic status.

Other perceptions, including self-rated health, illness perception, habits, and emotional states (depression and anxiety) did not differ significantly between adherence groups, the findings showed.

Treatment persistence, just like adherence, also was predicted by patients’ perceptions. In particular, a statistical analysis adjusted for age and gender showed that concerns about medication, anxiety, younger age, and male gender each were significantly predictive of treatment persistence.

“The present work succeeded in characterizing this group, and suggests that people’s beliefs about medication at onset could predict their adherence and persistence,” the researchers wrote.

The study had several limitations, the researchers noted, including its small sample size, being conducted in a single center, not accounting for patients’ medication history, and reporting only on a one-year follow-up.

Nonetheless, these findings demonstrated that “adherence and persistence are predicted by medication beliefs of MS patients,” they concluded.

“As medication beliefs are modifiable, they should be assessed periodically and targeted as a focus of tailored interventions aimed to improve adherence and consequently health outcomes in MS patients,” they added.