Aim: To estimate the cost-effectiveness over a 4-year duration of lamivudine and adefovir dipivoxil for patients with hepatitis B 'e' antigen-negative chronic hepatitis B.
Methods: A decision analysis model has been used to perform a cost-effectiveness analysis of lamivudine and adefovir dipivoxil from the perspective of the Spanish Public Health System. Data were obtained from clinical trials.
Results: For the base-case, the total estimated cost per patient treated with lamivudine or adefovir dipivoxil for 4 years was 11,457 and 21,939 respectively. Virological response at year 4 for the lamivudine arm was 40.4% and 78.0% for the adefovir dipivoxil arm. The average cost-effectiveness ratio (cost per responding patient at year 4) was 28,375 for the lamivudine arm and 28,132 for the adefovir dipivoxil arm. The incremental cost-effectiveness ratio of adefovir dipivoxil vs. lamivudine (cost per additional responding patient with adefovir dipivoxil) was 27,872, demonstrating that this cost was slightly lower than the average cost-effectiveness ratios of adefovir dipivoxil or lamivudine. The sensitivity analysis demonstrated that the factors that most influence the cost-effectiveness were the response to adefovir dipivoxil and lamivudine at year 4.
Conclusion: Long-term treatment with adefovir dipivoxil is a cost-effective strategy in patients with chronic hepatitis B 'e' antigen-negative hepatitis.