Background and importance Multiple sclerosis (MS) is a chronic progressive disease, one of the main causes of invalidity among young adults. Adherence may be difficult because treatment benefits are not immediately apparent, and most disease modifying therapies (DMTs) have tolerability and safety issues.

Aim and objectives In our hospital, where almost 800 MS patients are treated monthly, no study has assessed adherence, so the purpose of this study was to evaluate adherence and identify patient reported barriers regarding adherence.

Material and methods An observational retrospective study was conducted (January 2017 to January 2019). We evaluated adherence using missed dose ratio (MDR), and identified and quantified barriers to adherence using the MS treatment adherence questionnaire (MSTAQ). This tool has 30 items in three subscales: DMT barriers to adherence, DMT side effects (SE) and DMT coping strategies. We also collected demographic (age, sex) and treatment information (current DMT, DMT history, reason for switch therapy and exposure to treatment).

Results 60 patients (44 women), average age 40.47 years had a mean treatment exposure of 6.38 years. Adherence was high because only 11 had missed one or more doses in the last month (MDR >0). When asked about missed dose in general, 22 patients reported barriers to taking medication. DMT scores are described in table 1.

Conclusion and relevance Overall, adherence was high even though there were some barriers to adherence. SE and long duration of treatment could affect adherence, which is why it is important to detect and overcome barriers using such questionaries, to identify in time non-adherent patients and counsel them appropriately on how to use more coping strategies.

Conflict of interest No conflict of interest