Eva Martinez, Jose Manuel Garcia, Delicias Muñoz, Marta Comellas, Irmina Gozalbo, Luis Lizan, Carlos Polanco

To assess disease-modifying therapy (DMT) preferences in a population of patients with multiple sclerosis (MS) and to estimate the association between sociodemographic and clinical factors and these preferences. Preferences for DMTs attributes were measured using a discrete choice experiment. Analysis of preferences was assessed using mixed-logit hierarchical Bayes regression. A multilinear regression was used to evaluate the association between the preferences for each attribute and patients' demographic and clinical characteristics. A Student's t-test or Welch's t-test was used for subgroup comparisons. A total of 125 patients were included in the final analysis (62.9% female, mean age 44.5 years, 71.5% with relapsing-remitting MS diagnosis). The most important factor for patients was the possibility of suffering from the side effects of the treatment (relative importance [RI] =50%), followed by a delay in disease progression (RI =19.4%), and route and frequency of administration (RI =14.3%). According to maximum acceptable risk, patients were willing to accept an increase of 3.8% in severity of side effects, for a delay of 1 year in disease progression. Treatment duration was the most prevalent factor affecting preferences, followed by the age of patients, type of MS, level of education, and the type of current treatment. Patients treated orally were significantly more concerned about the route and frequency of administration (P=0.026) than patients on injectable therapy. Naïve patients stated significantly less importance to prevention of relapses (P=0.021) and deterioration of the capacity for performing usual daily life activities (P=0.015). Finally, patients with >5 years since diagnosis were significantly less concerned about preventing disease progression (P=0.021), and more concerned about treatment side effects (P=0.052) than compared with patients with <5 years of MS history. The most important attribute for MS patients was side effects of DMTs, followed by delay in disability progression. Experience with DMTs and time since MS diagnosis changed patients' preferences. These results give information to adjust new DMT treatment in order to satisfy patients' preferences and therefore, improve adherence to treatment.