Coste-efectividad del tratamiento antirretroviral de alta eficacia

Resumo

Introduction: To evaluate effectiveness, cost and cost-effectiveness ratio of the therapeutic treatments used on HIV-infected patients, comparing the patterns based on non-nucleoside reverse transcriptase inhibitors (NNRTI) versus boosted protease inhibitors (PI/r), lopinavir/ritonavir versus atazanavir/ritonavir and the different nucleoside analogue reverse transcriptase inhibitors backbones (NRTI). Methods: Ambispective, cohort study in a single institution. The patients were included in the study if they had been taking at least 3 antiretroviral drugs for at least 6 months. For the analysis of the effectiveness, HIV viral load and CD4+ counts and opportunistic infections were taken into consideration. The analyzed costs were direct as well as indirect. Cost, effectiveness and cost-effectiveness ratio were analyzed for each treatment pattern after 12 and 24 months from the beginning of the treatment. Results: 128 patients were included in the analysis of effectiveness and costeffectiveness ratio. The 128 patients received a total of 151 antiretroviral treatments grouped into 7 different patterns. Efavirenz, lopinavir/ritonavir and the combination of lamivudine (or emtricitabine) + tenofovir were the most used NNRTI, IP/r and NRTI, respectively. The analysis of the virological response does not show any differences of significant difference between the patterns based on EFV and those based on an IP/r, between LPV/r and ATV/r, nor between the different NRTI which form the structure of the antiretroviral pattern. Significant differences were only found in the long-term increase in CD4+ lymphocytes (after 24 months of treatment) between the different IP/r and the different drugs that form the nucleosidic structure: LPV/r was associated with a stronger long-term increase in CD4+ lymphocytes than ATV/r (p=0.039), and the combination 3TC+ddl showed a smaller increase than the rest of the nucleosidic combinations (p=0.002). No differences in adherence and developed toxicity were found among the analyzed treatment patterns (except for the pattern which included estavudine), although bigger percentages of virological response were associated to better values of adherence to the treatment. The most frequent adverse effects were lipodystrophy syndrome and lipid toxicity. The use of efavirenz in connection with an IP/r brings an annual saving between 1,712 € and 2,456 € per patient. The most inexpensive IP/r is LPV/r, while the most inexpensive NRTI couple is lamivudine + zidovudine. The use of efavirenz in connection with an IP/r helps us save more than 20,000 € per patient after the first year of treatment, and more than 30,000 € after the second year of treatment. Lopinavir/ritonavir turns out as more cost-effective during the first year of treatment than atazanavir/ritonavir, but less so after the second year. The most cost-effective NRTI couple is lamivudine+zidovudine. Conclusions: There are no differences in effectiveness between the different analyzed antiretroviral patterns, whereas there are differences in their associated costs, the direct cost which derives from the treatment pattern being the most impressive. The use of efavirenz turns out to be more cost-effective than the use of an IP/r. Lopinavir/ritonavir seems to be more cost-effective in the first 12 months of treatment, while atazanavir/ritonavir seems so after 24 months. The most costeffective pattern is efavirenz+lamivudine+zidovudine.