Cost-effectiveness of combination therapy with etravirine in treatment-experienced adults with HIV-1 infection

Estimating the Cost-Effectiveness of HIV Self-Testing in the United States Using Net Benefit Regression

BACKGROUND

Cost-effectiveness analysis of HIV self-testing using patient-level data from a randomized clinical trial can inform HIV prevention funding decisions. Cost-effectiveness analysis using net-benefit regression addresses the sampling uncertainty in the trial data and the variability of policymakers' willingness to pay (WTP).

METHODS

We used published data from a 12-month longitudinal randomized clinical trial that enrolled 2665 men who had sex with men randomly assigned to the self-testing arm (participants receiving self-test kits) and control arm (participants receiving standard-of-care), and the self-testing arm identified 48 additional new HIV cases. We used net-benefit regression to investigate the cost-effectiveness of an HIV self-testing intervention, which compared the incremental cost per new HIV diagnosis with policymakers' WTP thresholds. We addressed the uncertainties in estimating the incremental cost and the policymakers' WTP per new diagnosis through the incremental net-benefit (INB) regression and cost-effectiveness acceptability curve (CEAC) analyses.

RESULTS

From the health care provider's perspective, the INB analysis showed a positive net benefit of HIV self-testing compared with standard-of-care when policymakers' WTP per new HIV diagnosis was $9365 (95% confidence interval: $5700 to $25,500) or higher. The CEAC showed that the probability of HIV self-testing being cost-effective compared with standard-of-care was 58% and >99% at a WTP of $10 000 and $50 000 per new HIV diagnosis, respectively.

CONCLUSION

The INB and CEAC analyses suggest that HIV self-testing has the potential to be cost-effective for relatively low values of policymakers' WTP.

The Cost-Effectiveness and Budget Impact of Ibalizumab-uiyk for Adults with Multidrug-Resistant HIV-1 Infection in the United States

BACKGROUND

Ibalizumab-uiyk (ibalizumab) is a first-in-class, long-acting, postattachment HIV-1 inhibitor for adults with multidrug-resistant (MDR) HIV-1 infection. This analysis examines the cost-effectiveness and budget impact of ibalizumab treatment for this difficult-to-treat population in the United States.

METHODS

A Markov model followed cohorts of adults with MDR HIV-1 infection through two final lines of antiretroviral therapy: ibalizumab + optimized background therapy (OBT) or OBT alone followed by nonsuppressive therapy. Model inputs were based on ibalizumab clinical trial data, market uptake projections, and published literature, with costs in 2019 dollars. The cost-effectiveness analysis assessed costs and health outcomes from a health care sector perspective for individuals receiving ibalizumab + OBT versus OBT alone over a lifetime time horizon. The budget-impact analysis estimated the impact on payer budgets of the introduction of ibalizumab over 3 years for a hypothetical commercial health plan.

RESULTS

Compared with individuals receiving OBT alone, individuals receiving ibalizumab + OBT incurred higher costs but lived longer, healthier lives, with an incremental cost of $133,040 per QALY gained. For a hypothetical commercial health plan with 1 million members, the introduction of ibalizumab + OBT was estimated to increase budgets by $217,260, $385,245, and $560,310 ($0.018, $0.032, and $0.047 per member per month) in years 1, 2, and 3, respectively. These results were found to be robust in sensitivity and scenario analyses.

CONCLUSIONS

Ibalizumab may represent a cost-effective and affordable option to improve health outcomes for individuals with MDR HIV-1 infection.

Improving access to antiretrovirals in China: economic analyses of dolutegravir in HIV-1 patients

BACKGROUND

The World Health Organisation recommended dolutegravir (DTG)-based antiretroviral therapy (ART) regimens are available but not reimbursed through the public reimbursement system in China. The objective of this analysis was to evaluate the cost-effectiveness of DTG (DTG + TDF/3TC) compared to efavirenz (EFV + TDF/3TC) in treatment-naive and ritonavir-boosted lopinavir (LPV/r + TDF/3TC) in first-line ART failure HIV-1-infected patients in China.

METHODS

A dynamic Markov model comprising of 5 response states and 6 CD4+ count-based health states was used. Efficacy, estimated as probability of virologic suppression (HIV RNA < 50 copies/mL) at 48 weeks, was obtained from a published network meta-analysis for ART-naive patients and from the DAWNING study for patients failing first-line ART. Baseline cohort characteristics were informed using DTG phase 3 studies and the DAWNING study data, respectively. Health state utilities were derived from DTG phase 3 studies. A 5-year cost-effectiveness analyses was conducted using the societal perspective. Outcomes were quality-adjusted-life-years (QALYs), life-years (LYs), incremental cost per QALYs (ICER).

RESULTS

The viral suppression rates for DTG + TDF/3TC were higher than EFV + TDF/3TC (75.3% vs 64.0%) in treatment-naive and LPV/r + TDF/3TC (74.8% vs 58.4%) in first-line ART failure patients. This resulted in higher QALYs for DTG + TDF/3TC in treatment-naive (4.232 vs 4.227) and first-line failure settings (4.224 vs 4.221). Total discounted cost for DTG + TDF/3TC patients (RMB 219.259 in treatment-naive and RMB 238,746 in first-line failures) were lower than comparators (EFV + TDF/3TC:RMB 221,605; LPV/r + TDF/3TC:RMB 244,364), thereby DTG dominated in both settings. Probabilistic sensitivity analyses indicated the probability of DTG + TDF/3TC being cost effective was 98.2% in treatment-naive setting and 100% in first-line failure setting at a willingness to pay threshold of RMB 100,000/QALY.

CONCLUSIONS

With lower costs, higher response rates and higher QALYs, DTG + TDF/3TC can be considered as a cost-effective alternative for treatment naive and first-line failure patients in China.

Cost-Effectiveness of Dolutegravir as a First-Line Treatment Option in the HIV-1-Infected Treatment-Naive Patients in Russia

OBJECTIVES

To evaluate the cost effectiveness of dolutegravir + abacavir/lamivudine (DTG + ABC/3TC) compared with raltegravir + abacavir/lamivudine (RAL + ABC/3TC) and ritonavir-boosted darunavir + abacavir/lamivudine (DRV/r + ABC/3TC) in HIV-1-infected treatment-naive patients in Russia.

METHODS

A dynamic Markov model was developed with five response states and six CD4⁺-based health states. Efficacy estimated as probability of viral suppression (HIV RNA <50 copies/ml) at 48 weeks was obtained from a published network meta-analysis. Baseline cohort characteristics and health state utilities were informed using DTG phase 3 clinical trials. Health care resource use was obtained from literature and costed using published unit costs. Costs (presented in Russian rubles) included antiretroviral drug costs; HIV management costs such as routine care; costs of treating cardiovascular conditions, opportunistic infections, and drug-related adverse effects; and mortality costs. A patient lifetime analysis was conducted using the societal perspective. Outcomes were quality-adjusted life-years (QALYs), life-years, incremental cost per QALY ratio, and incremental cost per responder.

RESULTS

The viral suppression rate among patients receiving DTG + ABC/3TC was 71.7% compared with 65.2% for RAL + ABC/3TC and 59.6% for DRV/r + ABC/3TC. The mean duration of response per patient was 116.6 months for DTG + ABC/3TC, 108.6 months for RAL + ABC/3TC, and 98.9 months for DRV/r + ABC/3TC. Total discounted costs for treatment over patient lifetime were RUB 2.89, 5.32, and 4.38 million for DTG + ABC/3TC, RAL + ABC/3TC, and DRV/r + ABC/3TC, respectively. Lifetime discounted QALYs were 12.73 for patients on DTG + ABC/3TC and 12.72 each for patients on RAL + ABC/3TC and DRV/r + ABC/3TC. DTG + ABC/3TC thus dominated the other two alternatives.

CONCLUSIONS

With lower costs, higher response rates, and comparable QALYs, DTG + ABC/3TC can be considered as a cost-effective alternative.

How has the cost of antiretroviral therapy changed over the years? A database analysis in Italy

Background

The number of human immunodeficiency virus (HIV)-related hospitalizations has decreased worldwide in recent years, due to the availability of combined antiretroviral therapies (cART). The present analysis aimed to analyse the economic, and clinical burden of HIV management, after the introduction of systematic use of cART.

Methods

Data from HIV-infected patients, treated at Policlinico San Martino Hospital in Genova (Italy) were retrospectively collected. A comparison between years 2009 and 2015 was performed. HIV-related admissions were identified by using the Diagnosis-Related Group (DRG) codes. The resource consumption of outpatient services was derived by using a modelling approach. Expenditure for drugs was also analysed, as aggregate data.

Results

The number of HIV-infected patients was 898 in 2009 and 1006 in 2015. Overall, the virological success rate improved from 2009 to 2015, as the percentage of patients with HIV-RNA < 50 copies/mL increased from 79 to 89% (P < 0.05). The average incidence of hospitalizations per-patient decreased from 0.30 in 2009, to 0.13 in 2015. Average expenditure per-patient decreased from €10,107 in 2009 to €9063 in 2015.

Conclusions

The present analysis confirmed the role of cART in controlling HIV viral load and, consequently, in reducing hospitalizations, admissions to day-hospital and the use of outpatient services.

Clinical improvements and economic savings more than compensated the investments required to treat HIV-infected patients with cART. Health Authorities should invest in modern cART supply and universal treatment, to use at best the available resources and obtain a cost-effective improvement of health in people living with HIV. Additional research, with the involvement of different centers and the use of patient-specific data, are recommended to consolidate the findings of this analysis.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3507-x) contains supplementary material, which is available to authorized users.

Cost-effectiveness of dolutegravir/abacavir/lamivudine in HIV-1 treatment-Naive (TN) patients in France

BACKGROUND

To evaluate the cost-effectiveness of an integrase inhibitor (INI), dolutegravir (DTG), in combination with abacavir (ABC)/lamivudine (3TC) in France, in treatment-naive (TN) HIV adult patients.

METHODS

The ARAMIS microsimulation Markov model, evaluates costs and effects of DTG vs. first-line ARVs options including INIs (raltegravir, elvitegravir/c), protease inhibitors (PIs) (darunavir/r, atazanavir/r, lopinavir/r), non-nucleoside reverse transcriptase inhibitors (efavirenz and rilpivirine). Efficacy and safety data were derived from phase III studies and network meta-analysis. Treatment algorithms were based on French guidelines and experts opinion. Costs included routine HIV and opportunistic infection care, and death.

RESULTS

The model showed the fixed-dose combination DTG/ABC/3TC was more effective than all other recommended regimens: patients stayed longer on first-line, and lived longer and healthier. With the exception of EFV, DTG/ABC/3TC was more efficacious and less costly compared to all strategies. The cost per QALY gained (ICER) for DTG compared to EFV was €6,939. DTG/ABC/3TC was more efficacious and less costly compared to INIs and PIs in all deterministic sensitivity analyses.

CONCLUSION

DTG/ABC/3TC was cost-effective in the management of HIV TN patients in France. These results are mainly explained by its lower price compared to other INIs and PIs, DTG's superior efficacy and high barrier to resistance.

Cost-effectiveness analysis of dolutegravir plus backbone compared with raltegravir plus backbone, darunavir+ritonavir plus backbone and efavirenz/tenofovir/emtricitabine in treatment naïve and experienced HIV-positive patients

Background

In January 2014, the European Medicines Agency issued a marketing authorization for dolutegravir (DTG), a second-generation integrase strand transfer inhibitor for HIV treatment. The study aimed at determining the incremental cost-effectiveness ratio (ICER) of the use of DTG+backbone compared with raltegravir (RAL)+backbone, darunavir (DRV)+ritonavir(r)+backbone and efavirenz/tenofovir/emtricitabine (EFV/TDF/FTC) in HIV-positive treatment-naïve patients and compared with RAL+backbone in treatment-experienced patients, from the Italian National Health Service’s point of view.

Materials and methods

A published Monte Carlo Individual Simulation Model (ARAMIS-DTG model) was used to perform the analysis. Patients pass through mutually exclusive health states (defined in terms of diagnosis of HIV with or without opportunistic infections [OIs] and cardiovascular disease [CVD]) and successive lines of therapy. The model considers costs (2014) and quality of life per monthly cycle in a lifetime horizon. Costs and quality-adjusted life years (QALYs) are dependent on OI, CVD, AIDS events, adverse events and antiretroviral therapies.

Results

In treatment-naïve patients, DTG dominates RAL; compared with DRV/r, the ICER obtained is of 38,586 €/QALY (6,170 €/QALY in patients with high viral load) and over EFV/TDF/FTC, DTG generates an ICER of 33,664 €/QALY. In treatment-experienced patients, DTG compared to RAL leads to an ICER of 12,074 €/QALY.

Conclusion

The use of DTG+backbone may be cost effective in treatment-naïve and treatment-experienced patients compared with RAL+backbone and in treatment-naïve patients compared with DRV/r+backbone and EFV/TDF/FTC considering a threshold of 40,000 €/QALY.

Cost-Effectiveness of a Care Program for HIV/AIDS Patients Affiliated with a Health Insurer in Colombia, Comparing Three Health Care Providers Nationwide

BACKGROUND

In Colombia, HIV and AIDS constitute one of the major diseases of high cost to the health system, making necessary health risk management of patients with this disease through comprehensive health care programs with their respective evaluation of results.

OBJECTIVE

To evaluate the relative cost-effectiveness of a care program for patients with HIV/AIDS affiliated to a health insurer in Colombia, comparing their results in three Health care provider (HCP).

METHODS

The study population corresponded to a cohort of patients older than 18 years with HIV/AIDS and affiliated to a health insurer in Colombia during 2011 and 2012. A cost-effectiveness and cost-utility analysis of a health care program for this population was performed on the basis of a Markov model, in which quality-adjusted life-years (QALYs) and life-years gained were assessed. This analysis was conducted from the insurer perspective. The time horizon was life expectancy. A discount rate of 3% was applied.

RESULTS

Drugs accounted for 80.54% of care costs. The average annual cost of patients in health state 5 was 3 times higher than that of patients in state 1. HCP A compared with HCP B generated an additional 1.53 QALYs, with a rate of incremental cost-effectiveness of $2400 per QALY gained. HCP C showed a dominated behavior. The variables that most influence the uncertainty were the cost of HCP A in health state 5 (55.52%) and the cost of HCP B in state 3 (27.51%).

CONCLUSIONS

HCP A is a very cost-effective option considering a threshold of 1 time the per-capita gross domestic product.

Cost-Effectiveness of Dolutegravir in HIV-1 Treatment-Experienced (TE) Patients in France

Objectives

To evaluate the cost-effectiveness of a new generation integrase inhibitor (INI), dolutegravir (DTG), in France, in treatment-experienced (TE) and INI-naïve HIV-infected adults with at least two classes resistance compared to raltegravir (RAL), by adapting previously published Anti-Retroviral Analysis by Monte Carlo Individual Simulation (ARAMIS) model.

Methods

ARAMIS is a microsimulation Markov model with a lifetime time horizon and a monthly cycle length. Health states are defined as with or without opportunistic infection and death. In the initial cohort, efficacy and safety data were derived from a phase III study comparing DTG to RAL. Antiretroviral treatment algorithms, accounting for patient history, were based on French guidelines and experts opinion. Costs are mainly including treatment costs, routine HIV and opportunistic infection care, and death. Utilities depend on CD4+ cell count and the occurrence of opportunistic infections.

Results

The ARAMIS model indicates in the TE population that DTG compared to RAL over a life time is associated with 0.35 additional quality-adjusted life years (QALY; 10.75 versus 10.41) and additional costs of €7,266 (€390,001 versus €382,735). DTG increased costs are mainly related to a 9.1-month increase in life expectancy for DTG compared with RAL, and consequently a longer time spent on ART. The incremental cost-effectiveness ratio (ICER) for DTG compared with RAL is €21,048 per QALY gained. About 83% and 14% of total lifetime costs are associated with antiretroviral therapy and routine HIV care respectively. Univariate deterministic sensitivity analyses demonstrate the robustness of the model.

Conclusion

DTG is cost-effective in the management of TE INI naive patients in France, from a collective perspective. These results could be explained by the superior efficacy of DTG in this population and its higher genetic barrier to resistance compared to RAL. These data need to be confirmed with longer-term real life data.

Cost-effectiveness analysis of tenofovir/emtricitabine and abacavir/lamivudine in combination with efavirenz or atazanavir/ritonavir for treatment-naïve adults with HIV-1 infection in the UK, based on the AIDS Clinical Trials Group 5202 clinical trial

OBJECTIVES

The aim of the study was to assess the cost-effectiveness of the four regimens studied in the AIDS Clinical Trials Group (ACTG) 5202 clinical trial, tenofovir/emtricitabine (TDF/FTC) or abacavir/lamivudine (ABC/3TC) in combination with efavirenz (EFV) or atazanavir/ritonavir (ATV/r), for treatment-naïve adults with HIV-1 infection in the UK.

METHODS

A Markov model with six health states based on CD4 cell count ranges was developed to predict long-term costs and health outcomes for individuals on first-line therapy. Head-to-head efficacy data comparing TDF/FTC + EFV, TDF/FTC + ATV/r, ABC/3TC + EFV, and ABC/3TC + ATV/r were obtained from ACTG 5202 for up to 192 weeks. Antiretroviral drug costs were based on current list prices. Other medical costs (2013 UK pounds sterling), utility values, and mortality rates were obtained from published sources. Base-case, sensitivity, and subgroup analyses (by baseline viral load) were conducted.

RESULTS

Individuals using TDF/FTC-based regimens were predicted to remain on first-line therapy longer and accrue more quality-adjusted life-years (QALYs) than individuals using ABC/3TC-based regimens. At a willingness-to-pay threshold of £30 000 per QALY gained, TDF/FTC-based regimens were predicted to be cost-effective compared with ABC/3TC-based regimens, with incremental cost-effectiveness ratios of £23 355 for TDF/FTC + EFV vs. ABC/3TC + EFV and £23 785 for TDF/FTC + ATV/r vs. ABC/3TC + ATV/r. Results were generally robust in subgroup, sensitivity, and scenario analyses.

CONCLUSIONS

In an analysis of the regimens studied in ACTG 5202 for treatment-naïve adults with HIV-1 infection in the UK, TDF/FTC-based regimens yielded more favourable health outcomes and were generally predicted to be cost-effective compared with ABC/3TC-based regimens. These results confirm that TDF/FTC-based regimens are not only clinically effective but also cost-effective.

Cost-Effectiveness of Dolutegravir in HIV-1 Treatment-Naive and Treatment-Experienced Patients in Canada

Introduction

The Antiretroviral Analysis by Monte Carlo Individual Simulation (ARAMIS) model was adapted to evaluate the cost-effectiveness of dolutegravir (DTG) in Canada in treatment-naive (TN) and treatment-experienced (TE) human immunodeficiency virus (HIV)-1 patients.

Methods

The ARAMIS-DTG model is a microsimulation model with a lifetime analytic time horizon and a monthly cycle length. Markov health states were defined by HIV health state (with or without opportunistic infection). DTG was compared to efavirenz (EFV), raltegravir (RAL), darunavir/ritonavir, rilpivirine (RPV), elvitegravir/cobicistat, atazanavir/ritonavir and lopinavir/ritonavir in TN patients and to RAL in TE patients. The initial cohort, the main efficacy data and safety data were derived from phase III clinical trials. Treatment algorithms were based on expert opinion. Costs normalized to the year 2013 included antiretroviral treatment cost, testing, adverse event, HIV and cardiovascular disease care and were derived from the literature.

Results

Dolutegravir was estimated to be the dominant strategy compared with all comparators in both TN and TE patients. Treatment with DTG was associated with additional quality-adjusted life-years that ranged from 0.17 (vs. RAL) to 0.47 (vs. EFV) in TN patients and was 0.60 in TE patients over a lifetime. Cost savings ranged from Can$1393 (vs. RPV) to Can$28,572 (vs. RAL) in TN patients and amounted to Can$3745 in TE patients. Sensitivity analyses demonstrated the robustness of the model.

Conclusions

Dolutegravir is a dominant strategy in the management of TN and TE patients when compared to recommended comparators. This is mainly related to the high efficacy and high barrier to resistance.

Funding

ViiV Healthcare.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-015-0071-0) contains supplementary material, which is available to authorized users.

US-Based Drug Cost Parameter Estimation for Economic Evaluations

INTRODUCTION

In the United States, more than 10% of national health expenditures are for prescription drugs. Assessing drug costs in US economic evaluation studies is not consistent, as the true acquisition cost of a drug is not known by decision modelers. Current US practice focuses on identifying one reasonable drug cost and imposing some distributional assumption to assess uncertainty.

METHODS

We propose a set of Rules based on current pharmacy practice that account for the heterogeneity of drug product costs. The set of products derived from our Rules, and their associated costs, form an empirical distribution that can be used for more realistic sensitivity analyses and create transparency in drug cost parameter computation. The Rules specify an algorithmic process to select clinically equivalent drug products that reduce pill burden, use an appropriate package size, and assume uniform weighting of substitutable products. Three diverse examples show derived empirical distributions and are compared with previously reported cost estimates.

RESULTS

The shapes of the empirical distributions among the 3 drugs differ dramatically, including multiple modes and different variation. Previously published estimates differed from the means of the empirical distributions. Published ranges for sensitivity analyses did not cover the ranges of the empirical distributions. In one example using lisinopril, the empirical mean cost of substitutable products was $444 (range = $23-$953) as compared with a published estimate of $305 (range = $51-$523).

CONCLUSIONS

Our Rules create a simple and transparent approach to creating cost estimates of drug products and assessing their variability. The approach is easily modified to include a subset of, or different weighting for, substitutable products. The derived empirical distribution is easily incorporated into 1-way or probabilistic sensitivity analyses.

Cost effectiveness of darunavir/ritonavir combination antiretroviral therapy for treatment-naive adults with HIV-1 infection in Canada

OBJECTIVE

The AntiRetroviral Therapy with TMC114 ExaMined In naive Subjects (ARTEMIS) clinical trial examined the efficacy and safety of two ritonavir-boosted protease inhibitors (PI/r), darunavir/r 800/100 mg once daily (QD) and lopinavir/r 800/200 mg daily, both used in combination with tenofovir disoproxil fumarate/emtricitabine. This study aimed to assess the cost effectiveness of the darunavir/r regimen compared with the lopinavir/r regimen in treatment-naive adults with HIV-1 infection in Canada.

METHODS

A Markov model with a 3-month cycle time and six CD4 cell-count-based health states (>500, 351-500, 201-500, 101-200, 51-100, and 0-50 cells/mm(3)) followed a cohort of treatment-naive adults with HIV-1 infection through initial darunavir/r or lopinavir/r combination therapy and a common set of subsequent regimens over the course of their remaining lifetimes. Population characteristics and transition probabilities were estimated from the ARTEMIS clinical trial and other trials. Costs (in 2014 Canadian dollars), utilities, and mortality were estimated from Canadian sources and published literature. Costs and health outcomes were discounted at 5% per year. One-way and probabilistic sensitivity analyses were performed, including a simple indirect comparison of the darunavir/r initial regimen with an atazanavir/r-based regimen.

RESULTS

In the base-case lifetime analysis, individuals receiving initial therapy with the darunavir/r regimen experienced 0.25 more quality-adjusted life-years (QALYs) with lower antiretroviral drug costs (-$14,246) and total costs (-$18,402) than individuals receiving the lopinavir/r regimen, indicating that darunavir/r dominated lopinavir/r. In an indirect comparison with an atazanavir/r-based regimen, the darunavir/r regimen remained the dominant choice, but with lower cost savings (-$2,303) and QALY gains (0.02). Results were robust to a wide range of other changes in input parameter values, population characteristics, and modeling assumptions. The probabilistic sensitivity analysis demonstrated that the darunavir/r regimen was cost effective compared with the lopinavir/r regimen in over 86% of simulations for willingness-to-pay thresholds between $0 and $100,000 per QALY gained.

CONCLUSIONS

Darunavir/r 800/100 mg QD may be a cost-effective PI/r component of initial antiretroviral therapy for treatment-naive adults with HIV-1 infection in Canada.

Cost-effectiveness of newer antiretroviral drugs in treatment-experienced patients with multidrug-resistant HIV disease

OBJECTIVE

Newer antiretroviral drugs provide substantial benefits but are expensive. The cost-effectiveness of using antiretroviral drugs in combination for patients with multidrug-resistant HIV disease was determined.

DESIGN

A cohort state-transition model was built representing treatment-experienced patients with low CD4 counts, high viral load levels, and multidrug-resistant virus. The effectiveness of newer drugs (those approved in 2005 or later) was estimated from published randomized trials. Other parameters were estimated from a randomized trial and from the literature. The model had a lifetime time horizon and used the perspective of an ideal insurer in the United States. The interventions were combination antiretroviral therapy, consisting of 2 newer drugs and 1 conventional drug, compared with 3 conventional drugs. Outcome measures were life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness.

RESULTS

Substituting newer antiretroviral drugs increased expected survival by 3.9 years in advanced HIV disease. The incremental cost-effectiveness ratio of newer, compared with conventional, antiretroviral drugs was $75,556/QALY gained. Sensitivity analyses showed that substituting only one newer antiretroviral drug cost $54,559 to $68,732/QALY, depending on assumptions about efficacy. Substituting 3 newer drugs cost $105,956 to $117,477/QALY. Cost-effectiveness ratios were higher if conventional drugs were not discontinued.

CONCLUSIONS

In treatment-experienced patients with advanced HIV disease, use of newer antiretroviral agents can be cost-effective, given a cost-effectiveness threshold in the range of $50,000 to $75,000 per QALY gained. Newer antiretroviral agents should be used in carefully selected patients for whom less expensive options are clearly inferior.

A methodological review of models used to estimate the cost effectiveness of antiretroviral regimens for the treatment of HIV infection

The aim of this article was to perform a detailed methodological review of models used to estimate the cost effectiveness of drug treatment regimens for HIV infection in Europe and North America and assess the relationship between the different modeling approaches or key structural assumptions and the results. Electronic searches in three databases (MEDLINE, EMBASE, and the Cochrane Library) identified the cost-effectiveness models. Modeling approaches and structural assumptions were abstracted for all models. For three case studies of multiple analyses that compared the cost effectiveness of two drug regimens using the same clinical data inputs, differences in results were compared with differences in modeling approaches and structural assumptions. Forty-one model publications were reviewed. Recent models included Monte Carlo simulations, Markov models, or discrete-event simulation models, all including multiple lines of therapy and capturing the long-expected duration of efficacy of highly active antiretroviral therapy. In the three case studies, assumptions about the duration of efficacy after the trial time period, whether differences between the two regimens persist after the trial time period, the sequence of regimens after initial regimen failure, and the cost and utility assigned to adverse events, but not the modeling approach, were the most important factors in explaining differences in the results. As the models and treatment pathways get more complex, models should be validated using clinical trial data and local observational databases. The results of sensitivity analyses testing the impact of the structural assumptions that might change the results as identified in this review should also be presented in modeling papers.

The nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors in the treatment of HIV infections (AIDS)

The majority of the drugs currently used for the treatment of HIV infections (AIDS) belong to either of the following three classes: nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs). At present, there are 7 NRTIs, 5 NNRTIs, and 10 PIs approved for clinical use. They are discussed from the following viewpoints: (i) chemical formulae; (ii) mechanism of action; (iii) drug combinations; (iv) clinical aspects; (v) preexposure prophylaxis; (vi) prevention of mother-to-child transmission; (vii) their use in children; (viii) toxicity; (ix) adherence (compliance); (x) resistance; (xi) new NRTIs, NNRTIs, or PIs in (pre)clinical development; and (xii) the prospects for a "cure" of the disease.