Background Patients with chronic hepatitis B (CHB) require long treatment in order to be able to achieve and maintain viral suppression. Therapy health outcomes are affected by how long and how the patients take their medications. Thus persistence should be defined and measured separately from adherence. For that reason we thought it would be interesting to analyse persistence on account of the limited number of studies that at present exist.

Purpose To determine persistence among patients receiving nucleos (t)ide analogues (NUC) for CHB and to analyse the evolution of treatment persistence.

Material and methods We conducted a retrospective study that included patients with CHB who initiated antiviral therapy and were attending the pharmaceutical care office between January 2002 and December 2011. Patients included in a clinical trial or who did not personally collect their medication were excluded. The variables were: age, gender, antiretroviral therapy (ART), reason for switch to another NUC and persistence. Patients were stratified according to the genetic barrier (GB) of the therapy (high GB therapies: tenofovir and entecavir and low GB therapies: lamivudina, adefovir and lamivudina plus adefovir). We used the Kaplan-Meier method to analyse non-persistence over the time of the study and to calculate the number of patients at risk of non-persistence each year.

Results 102 patients were included. Most were men (72.5%). Average age was 45 ± 13 years. Lamivudine was prescribed in 32.4% of patients, entecavir in 24.5%, adefovir in 17.6%, tenofovir in 15.6% and lamivudine plus adefovir in 9.8%. The reasons for switching to another NUC were: breakthrough (72.7%), other (15.2%) and non-responder (12.1%). There was a statistically significant difference between low GB drugs (31.95; 95% CI 26.04 to 37.86) and high GB drugs (41.35; 95% CI 34.47 to 48.32 months). Log rank test: p = 0.008.

Conclusion This study showed that high GB drugs had a better profile of persistence in the initial therapy of patients with CHB. The main reason for switching to another ART was breakthrough. These data will help in designing educational programmes, supporting pharmacist intervention to improve persistence to NUC for hepatitis B.

References and/or Acknowledgements

1. Cramer JA, Roy A, Burrell A, et al. Medication compliance and persistence: terminology and definitions. Value Health 2008;11:44-7

References and/or AcknowledgementsNo conflict of interest.