Abstract and Introduction
Abstract
Objective: To determine the cost of each therapeutic protocol (TP) used for HIV-positive patients and to identify the most frequently adopted one by relating it to the cost and by identifying the drug (drugs) that is more competitive in relation to expense.
Setting: Infectious Disease Department and Hospital Pharmacy, Ospedale Maggiore, Bologna, Italy. The department treats approximately 600 outpatients with HIV infection each year.
Patients and methods: 464 patients with HIV infection were examined every 3 months and clinicians judged whether the treatment (usually consisting of three drugs) was to be continued or changed according to its effectiveness, availability and possible new treatment options. The study also ascertained the cost of antiretroviral drugs within the period 1 January 2001-30 April 2002, and identified the most commonly used therapeutic protocols, the relevant daily cost and the frequency of use in all patients. The cost of the various protocols (most TPs were grouped in the most frequently used 15 regimens) was considered only at the end of the study, in order to define the percentage differences in cost. Importantly, from the beginning, this aspect was not a primary factor in drug choice.
Results: The antiretroviral drug cost was 4,448,186 lire (L) in 2001 and L1,536,984 in the first 4 months of 2002, with an increase of 3.5% compared with the same period in 2001. In the 16 months under consideration, 55.21% of the cost was associated with nucleoside reverse transcriptase inhibitors (NRTI), 25.97% with protease inhibitors (PI) and 18.83% with non-nucleoside reverse transcriptase inhibitors (NNRTI). Among the 464 TPs considered, 331 (71.33%) were distributed among 15 prevalent TPs. The least expensive TP (L9.95/day; time of costing 1 January 2001-30 April 2002) comprised two drugs (stavudine and lamivudine) and showed a cost differential of +L16.74 (+62.70%) compared with the most expensive one (zidovudine, lamivudine, lopinavir and ritonavir). The most used TP (zidovudine, lamivudine and nevirapine) covered 61 cases (13.1%) with a daily cost of L19.61 (time of costing 1 January 2001-30 April 2002).
Conclusions: This study demonstrated that, starting with decisions that take into account the efficacy of the therapy and the compliance of the patients, and choosing ethical protocols agreed upon with the patients, it is possible to reduce the costs of the TPs. Of the 464 TPs examined, NNRTIs were used in 46.7% of the cases and a PI in 39.6% (16.1% of the latter drug group was boosted with ritonavir). Only 7% of TPs used two drugs (NRTIs). The two less expensive TPs comprised two drugs only (NRTIs). Among the three-drug TPs with a lower cost, the drug pattern was two NRTIs and one NNRTI. The remaining TPs included a PI as a third drug and demonstrated a cost increase greater than 50% with respect to the less expensive treatment
Introduction
The cost of antiretroviral therapies in HIV-positive patients is difficult to manage,[1-6] but following the satisfactory results recorded in recent years in various cohorts, the use of this type of therapy in developed countries is increasing.[7-9]
Antiretroviral therapy is long-term therapy that requires administration of a large number of pills. Although this number is lower in some cases, every drug is associated with adverse effects that may vary from patient to patient.
In a previous economic analysis of antiretroviral therapy in the 3-year period 1998-2000, we found that for the ambulatory care of about 600 patients the yearly cost rose from $US2,220,705 to $US3,776,683.[7] This increase can be reasonably attributed to two factors: the increasing number of patients treated with three or four drugs instead of the two previously used, and the ever-higher percentage of patients matching the treatment parameters and willing to undergo therapy.[10]
Therapeutic plans (TPs) must show proven "efficacy" before their efficiency can be discussed. Efficacy means a good therapeutic result: i.e. the level of HIV copies in blood (viral load) has to be lower than the cut-off level and the CD4+ lymphocyte count must increase. It would therefore be interesting to retrospectively determine, in the case mix under consideration, the actual cost for each TP and the related percentage of use compared with the total of the treatments. To better clarify the intent of the study, the cost factor was not taken into consideration in the choice of TPs; the most important factors were the single drug efficacy for each patient, the number of pills administered, good tolerability as reported by patients at follow-up, the absence of adverse effects, and patient compliance. In the case of virological/clinical inefficacy, the most important factor was the stength of the drug cocktail (e.g. through boosting).
