[Analysis of costs and cost-effectiveness of preferred GESIDA/National AIDS Plan regimens for initial antiretroviral therapy in human immunodeficiency virus infected adult patients in 2013]

Introduction: The GESIDA and National AIDS Plan panel of experts have proposed "preferred regimens" of antiretroviral treatment (ART) as initial therapy in HIV infected patients for 2013. The objective of this study is to evaluate the costs and effectiveness of initiating treatment with these "preferred regimens".

Methods: An economic assessment of costs and effectiveness (cost/effectiveness) was performed using decision tree analysis models. Effectiveness was defined as the probability of having viral load <50copies/mL at week48, in an intention-to-treat analysis. Cost of initiating treatment with an ART regime was defined as the costs of ART and its consequences (adverse effects, changes of ART regime and drug resistance analyses) during the first 48weeks. The perspective of the analysis is that of the National Health System was applied, only taking into account differential direct costs: ART (official prices), management of adverse effects, resistance studies, and determination of HLA B*5701. The setting is Spain and the costs are those of 2013. A sensitivity deterministic analysis was performed, constructing three scenarios for each regimen: baseline, most favourable, and most unfavourable cases.

Results: In the baseline case scenario, the cost of initiating treatment ranges from 6,747euros for TDF/FTC+NVP to 12,059euros for TDF/FTC+RAL. The effectiveness ranges between 0.66 for ABC/3TC+LPV/r and ABC/3TC+ATV/r, and 0.87 for TDF/FTC+RAL and ABC/3TC+RAL. Effectiveness, in terms of cost/effectiveness, varies between 8,396euros and 13,930euros per responder at 48weeks, for TDF/FTC/RPV and TDF/FTC+RAL, respectively.

Conclusions: Taking ART at official prices, the most effective regimen was TDF/FTC/RPV, followed by the rest of non-nucleoside containing regimens. The sensitivity analysis confirms the robustness of these findings.