Factors associated with adherence to combination therapy of interferon and ribavirin for patients with chronic hepatitis C: Importance of patient's motivation and physician's treatment experience

Background/Aims: Adherence to combination therapy with interferon (IFN) or pegylated IFN plus ribavirin for chronic hepatitis C patients is important for a better virological response. However, the impact of the patient's treatment experience and treatment centre on adherence to combination therapy has not been fully analysed. In this prospective study, we analysed the factors that might have an effect on adherence to therapy in patients who had initial or retreatment IFN therapy. Patients and methods: We consecutively enrolled 363 patients with chronic hepatitis C; 221 were IFN naïve and 142 were undergoing retreatment. The mean ages of the naïve and retreatment groups were 54.8 and 55.7 years respectively. IFN α-2b was administered daily for 2 weeks, followed by three times per week for 22 weeks, while ribavirin was administered daily. We evaluated the tolerability and response to combination therapy and analysed its relevant factors. Results: Of the 363 patients, 189 (52%) achieved 80% adherence. The multivariate logistic regression analysis revealed that retreatment, centre with more patients treated, patient age (<55 years), male, genotype 2 and dosage of IFN per weight (<0.13 million units/kg) were associated with achievement of 80% adherence to combination therapy. Accordingly, the achievement of 80% adherence was more frequent in the retreatment (62%) than that in the naïve group (46%) (P < 0.01) and in centres with more patients treated (57%) than in those with less patients treated (46%) (P = 0.03). Conclusion: The present data suggest that the patient's motivation and the physician's treatment experience may be important for a better adherence to combination therapy for patients with chronic hepatitis C.