Introduction: Perceptions and experiences of medication efficacy, side-effects, dosing frequency and complexity, influence patient adherence to injectable disease-modifying treatments in patients with multiple sclerosis (MS), which ultimately impacts outcomes. Methods: Respondents with a self-reported diagnosis of MS completed an online discrete-choice-experiment survey (adapted United States survey), which included a series of treatment-choice questions. Each hypothetical treatment had six attributes: number of years until disability progression, number of relapses in the next four years, injection time, frequency of injections, flu-like symptoms, and injection-site reactions. Each attribute had a number of associated levels. Mixed-logit regression parameters were used to calculate preference weights of attribute levels and relative importance of treatment attributes. Results: In both France and the UK, 100 respondents completed the survey and provided sufficient data for analysis. In France, improving the time until disability progression from 2 to 4 years and reducing injection frequency from 'daily' to 'every two weeks' had a relative importance (vertical distance between preference weights for attribute levels) of 3.0 and 3.5, respectively. In the UK, these changes had a relative importance of 2.9 and 2.6 (Figure 2). In both countries, these changes were more important than changes in the other attributes assessed. Conclusion: Reducing the frequency of injectable MS treatments can be as important to patients as improvements in treatment efficacy.
