Prescription patterns and costs of antiretroviral therapy in HIV‐infected naïve patients: theoretical impact of a regional therapeutic protocol

In the Lazio region, about 10.000 HIV+subjects receive combination antiretroviral therapy (cART) with a medication expense of 78.177.632,28. In 2011, in order to standardize prescriptions, to monitor appropriateness, and to decrease drug costs, the Protocol for Regional Therapeutics (PTR) for cART was developed. Aim was to describe prescription patterns and costs of first‐line cART in 2010 and to estimate the theoretical impact of PTR application on medication costs. A cross‐sectional evaluation of first‐line cART prescribed during 2010 at the National Institute for Infectious Diseases was carried out. Data collected: age, date of HIV diagnosis, CD4, HIV‐RNA, antiretroviral drugs. cART were classified based on the PTR ranks as follows: a) recommended regimen (rank A1/A1); b) alternative regimens (ranks A1/B1; B1/A1; B1/B1); c) not recommended regimens. A descriptive analysis of prescription patterns together with their economic impact was carried out. A multivariate analysis was performed to identify predictive factors of higher regimen costs. The hypothetical transition of not recommended regimens to recommended or alternative regimens was assessed. 370 naïve patients were evaluated: mean age 42 y (range, 1–84), mean duration of HIV 41 months (range, 1–84); median CD4 269/mmc (135–349), log 10 HIV RNA 4.91 (4.4–5.4). A1/A1 regimens were prescribed in 62.2% (€163.789,28); A1/B1‐B1/A1‐B1/B1 in 22.8% (€73.831,75); not recommended cART in 15% (€54.929,95). Among A1/A1 regimes the most frequent were: TDF/FTC+EFV/(TDF+ FTC+EFV) in 39.4% and TDF+FTC+atazanavir/ritonavir in 22.7%. Up to 30 different cART (79% of all prescribed regimens) were used, each with a prescription prevalence lower than 1%. Mean patient‐month cART expense was €790,68. At multivariate analysis, higher plasma HIV RNA was associated with significantly higher first‐line regimen costs (coeff. B 48.64; 95% CI 22.78–74.50; P<0.0001). When applying the simulation model with the transition of all patients treated with not recommended regimens to recommended or alternative regimens, a total of €18.036,41 and €10.078,35 may have been achieved, respectively. A high prescription variability of cART has emerged. This finding is unlikely to be determined by clinical needs, especially because of the high frequency of not recommended regimens. Our findings highlight the need of standardized prescription strategies and that the introduction of PTR may allow a saving of up 10.4% of total cART expenses.