BackgroundHepatitis C virus (HCV) infection is common among people who inject drugs, yet well-described barriers mean that only a minority have accessed HCV treatment. Recent developments in HCV diagnosis and treatment facilitate innovative approaches to HCV care that improve access to, and uptake of, care by people who inject drugs.ObjectiveThis study aims to examine feasibility, acceptability, likely clinical effectiveness, and cost-effectiveness of an integrated model of HCV care for patients receiving opioid substitution treatment in general practice.MethodsA pre- and postintervention design with an embedded economic analysis was used to establish the feasibility, acceptability, and clinical and cost-effectiveness of a complex intervention to optimize HCV identification and linkage to HCV treatment among patients prescribed methadone in primary care. The “complex intervention” comprised general practitioner (GP)/practice staff education, nurse-led clinical support, and enhanced community-based HCV assessment of patients. General practices in North Dublin were recruited from the professional networks of the research team and from GPs who attended educational sessions.ResultsA total of 135 patients from 14 practices participated. Follow-up data were collected 6 months after intervention from 131 (97.0%) patients. With regard to likely clinical effectiveness, among patients with HCV antibody positivity, there was a significant increase in the proportions of patients who had a liver FibroScan (17/101, 16.8% vs 52/100, 52.0%; P<.001), had attended hepatology/infectious diseases services (51/101, 50.5% vs 61/100 61.0%; P=.002), and initiated treatment (20/101, 19.8% vs 30/100, 30.0%; P=.004). The mean incremental cost-effectiveness ratio of the intervention was €13,255 (US $13,965.14) per quality-adjusted life-year gained at current full drug list price (€39,729 [US $41,857.48] per course), which would be cost saving if these costs are reduced by 88%.ConclusionsThe complex intervention involving clinical support, access to assessment, and practitioner education has the potential to enhance patient care, improving access to assessment and treatment in a cost-effective manner.