Health literacy and biosimilar acceptance in people with multiple sclerosis: a cross-sectional study

Biosimilar therapies represent a key strategy to improve sustainability and access to high-cost biologic treatments in multiple sclerosis (MS). Despite robust evidence supporting their efficacy and safety, patient resistance to biosimilar use and switching persists, often driven by informational gaps, patients’ health literacy processes, and nocebo-related mechanisms. While healthcare professionals play a central role in patient education, the specific contribution of nursing professionals, particularly MS nurses, remains underexplored. This study aimed to evaluate knowledge, attitudes, trust, and informational experiences related to biosimilars among individuals with MS, with particular attention to the perceived informational role of nurses. An observational, multicenter, cross-sectional study was conducted across Italy. Adult individuals with MS were recruited through the Italian Network of Multiple Sclerosis Nurses. A theory-informed questionnaire was developed to operationalize the four health literacy domains (access, understand, appraise, apply) in the context of biosimilar therapies. Descriptive analyses were performed to evaluate response patterns across domains. Ninety-nine participants were included. Awareness of biosimilars was low, with over 60% reporting no prior knowledge, indicating limitations in the access domain. Comprehension-related items showed relatively low agreement regarding feeling adequately informed, suggesting gaps in the understand domain. Trust in healthcare professionals was high, perceived informational completeness was lower, and many participants reported seeking additional information independently, reflecting tension within the appraise domain. Willingness to switch to or initiate biosimilars was moderately positive and strongly influenced by professional recommendations, particularly from physicians and nurses. Biosimilar acceptance in MS appears to be shaped more by difference in health literacy processes than by negative attitudes. MS nurses play a pivotal role in addressing these gaps, supporting informed understanding, reducing uncertainty, and guiding therapeutic decision-making. Strengthening nurse-led communication strategies may enhance patient confidence and promote informed, shared decision-making regarding biosimilar therapies.