Applying the COM-B Model to Identify Barriers to Bulevirtide Adherence in Chronic Hepatitis D: A Multicenter Italian Study.

Adherence to treatment is a key determinant of clinical outcomes in chronic infectious diseases, including hepatitis D virus (HDV) infection. Even if bulevirtide (BLV) has shown a promising adherence profile in clinical trials, adherence is often compromised by various barriers in the context of HDV-especially among migrant populations. The aim of this study was to investigate the factors influencing adherence to BLV treatment in real-life settings in Italy. From May to September 2024, two anonymous surveys-one for HDV patients undergoing bulevirtide (BLV) treatment and one for their hepatologists-were conducted across five tertiary centers in Italy. The study employed the COM-B model (Capability, Opportunity, Motivation-Behaviour) to systematically explore the behavioural drivers influencing treatment adherence in this population and unmet needs. Of the 86 consecutive adult patients receiving bulevirtide (BLV) who were invited to participate, 83 (97%) completed the multilingual survey (35% > 60 years old, 48% Italians; 80% under BLV > 6 months) and were included in the analysis, together with 13 hepatologists. The findings revealed key challenges related to patient education, logistical access to medication, and psychological factors affecting motivation. Specifically, 10% had considered discontinuing treatment and 10% admitted to having missed doses. A deeper understanding of these multifactorial determinants may aid in the development of targeted interventions to enhance adherence and achieve personalized therapeutic outcomes for individuals living with HDV.