Evaluation of four chemotherapy regimens for treatment of advanced AIDS-associated Kaposi sarcoma in Kenya: a cost-effectiveness analysis.

BACKGROUND: The most effective treatment for advanced AIDS-associated Kaposi sarcoma is paclitaxel or pegylated liposomal doxorubicin (PLD); neither is routinely used in sub-Saharan Africa due to limited availability and high cost. We examined the clinical impact, costs, and cost-effectiveness of paclitaxel or PLD in Kenya, compared with etoposide or bleomycin-vincristine. METHODS: In this study, we use the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-International Model to project clinical outcomes and costs among people living with HIV and advanced Kaposi sarcoma on antiretroviral therapy. We compared four different treatment strategies: etoposide, bleomycin-vincristine, paclitaxel, or PLD. We derived cohort characteristics and costs from the Kenyan Academic Model for Providing Access to Healthcare network, and adverse events, efficacy, and mortality from clinical trials. We projected model outcomes over a lifetime and included life expectancy, per-person lifetime costs, and incremental cost-effectiveness ratios (ICERs). We conducted budget impact analysis for 5-year total costs and did deterministic and probabilistic sensitivity analyses to evaluate the effect of uncertainty in input parameters. FINDINGS: We found that paclitaxel would be more effective than bleomycin-vincristine and would increase life expectancy by 4·2 years per person. PLD would further increase life expectancy by 0·6 years per person. Paclitaxel would be the most cost-effective strategy (ICER US$380 per year-of-life-saved compared with bleomycin-vincristine) and would remain cost-effective across a range of scenarios. PLD would be cost-effective compared with paclitaxel if its price were reduced to $100 per cycle (base case $180 per cycle). Implementing paclitaxel instead of bleomycin-vincristine would save approximately 6400 life-years and would increase the overall 5-year Kenyan health-care costs by $3·7 million; increased costs would be primarily related to ongoing HIV care given improved survival. INTERPRETATION: Paclitaxel would substantially increase life expectancy and be cost-effective compared with bleomycin-vincristine for advanced AIDS-associated Kaposi sarcoma in Kenya and should be the standard of care. PLD would further improve survival and be cost-effective with a 44% price reduction. FUNDING: US National Institutes of Health and Massachusetts General Hospital. TRANSLATION: For the Swahili translation of the abstract see Supplementary Materials section.

Cost-effectiveness of a Novel Lipoarabinomannan Test for Tuberculosis in Patients With Human Immunodeficiency Virus.

BACKGROUND: A novel urine lipoarabinomannan assay (FujiLAM) has higher sensitivity and higher cost than the first-generation AlereLAM assay. We evaluated the cost-effectiveness of FujiLAM for tuberculosis testing among hospitalized people with human immunodeficiency virus (HIV), irrespective of symptoms. METHODS: We used a microsimulation model to project clinical and economic outcomes of 3 testing strategies: (1) sputum Xpert MTB/RIF (Xpert), (2) sputum Xpert plus urine AlereLAM (Xpert+AlereLAM), (3) sputum Xpert plus urine FujiLAM (Xpert+FujiLAM). The modeled cohort matched that of a 2-country clinical trial. We applied diagnostic yields from a retrospective study (yields for Xpert/Xpert+AlereLAM/Xpert+FujiLAM among those with CD4 <200 cells/µL: 33%/62%/70%; among those with CD4 ≥200 cells/µL: 33%/35%/47%). Costs of Xpert/AlereLAM/FujiLAM were US$15/3/6 (South Africa) and $25/3/6 (Malawi). Xpert+FujiLAM was considered cost-effective if its incremental cost-effectiveness ratio (US$/year-of-life saved) was <$940 (South Africa) and <$750 (Malawi). We varied key parameters in sensitivity analysis and performed a budget impact analysis of implementing FujiLAM countrywide. RESULTS: Compared with Xpert+AlereLAM, Xpert+FujiLAM increased life expectancy by 0.2 years for those tested in South Africa and Malawi. Xpert+FujiLAM was cost-effective in both countries. Xpert+FujiLAM for all patients remained cost-effective compared with sequential testing and CD4-stratified testing strategies. FujiLAM use added 3.5% (South Africa) and 4.7% (Malawi) to 5-year healthcare costs of tested patients, primarily reflecting ongoing HIV treatment costs among survivors. CONCLUSIONS: FujiLAM with Xpert for tuberculosis testing in hospitalized people with HIV is likely to increase life expectancy and be cost-effective at the currently anticipated price in South Africa and Malawi. Additional studies should evaluate FujiLAM in clinical practice settings.

Implementing Generalized Additive Models to Estimate the Expected Value of Sample Information in a Microsimulation Model: Results of Three Case Studies.

BACKGROUND: The expected value of sample information (EVSI) can help prioritize research but its application is hampered by computational infeasibility, especially for complex models. We investigated an approach by Strong and colleagues to estimate EVSI by applying generalized additive models (GAM) to results generated from a probabilistic sensitivity analysis (PSA). METHODS: For 3 potential HIV prevention and treatment strategies, we estimated life expectancy and lifetime costs using the Cost-effectiveness of Preventing AIDS Complications (CEPAC) model, a complex patient-level microsimulation model of HIV progression. We fitted a GAM-a flexible regression model that estimates the functional form as part of the model fitting process-to the incremental net monetary benefits obtained from the CEPAC PSA. For each case study, we calculated the expected value of partial perfect information (EVPPI) using both the conventional nested Monte Carlo approach and the GAM approach. EVSI was calculated using the GAM approach. RESULTS: For all 3 case studies, the GAM approach consistently gave similar estimates of EVPPI compared with the conventional approach. The EVSI behaved as expected: it increased and converged to EVPPI for larger sample sizes. For each case study, generating the PSA results for the GAM approach required 3 to 4 days on a shared cluster, after which EVPPI and EVSI across a range of sample sizes were evaluated in minutes. The conventional approach required approximately 5 weeks for the EVPPI calculation alone. CONCLUSION: Estimating EVSI using the GAM approach with results from a PSA dramatically reduced the time required to conduct a computationally intense project, which would otherwise have been impractical. Using the GAM approach, we can efficiently provide policy makers with EVSI estimates, even for complex patient-level microsimulation models.

The value of point-of-care CD4+ and laboratory viral load in tailoring antiretroviral therapy monitoring strategies to resource limitations.

OBJECTIVE: To examine the clinical and economic value of point-of-care CD4 (POC-CD4) or viral load monitoring compared with current practices in Mozambique, a country representative of the diverse resource limitations encountered by HIV treatment programs in sub-Saharan Africa. DESIGN/METHODS: We use the Cost-Effectiveness of Preventing AIDS Complications-International model to examine the clinical impact, cost (2014 US$), and incremental cost-effectiveness ratio [$/year of life saved (YLS)] of ART monitoring strategies in Mozambique. We compare: monitoring for clinical disease progression [clinical ART monitoring strategy (CLIN)] vs. annual POC-CD4 in rural settings without laboratory services and biannual laboratory CD4 (LAB-CD4), biannual POC-CD4, and annual viral load in urban settings with laboratory services. We examine the impact of a range of values in sensitivity analyses, using Mozambique's 2014 per capita gross domestic product ($620) as a benchmark cost-effectiveness threshold. RESULTS: In rural settings, annual POC-CD4 compared to CLIN improves life expectancy by 2.8 years, reduces time on failed ART by 0.6 years, and yields an incremental cost-effectiveness ratio of $480/YLS. In urban settings, biannual POC-CD4 is more expensive and less effective than viral load. Compared to biannual LAB-CD4, viral load improves life expectancy by 0.6 years, reduces time on failed ART by 1.0 year, and is cost-effective ($440/YLS). CONCLUSION: In rural settings, annual POC-CD4 improves clinical outcomes and is cost-effective compared to CLIN. In urban settings, viral load has the greatest clinical benefit and is cost-effective compared to biannual POC-CD4 or LAB-CD4. Tailoring ART monitoring strategies to specific settings with different available resources can improve clinical outcomes while remaining economically efficient.

Prioritizing HIV comparative effectiveness trials based on value of information: generic versus brand-name ART in the US.

BACKGROUND: Value of Information (VOI) analysis examines whether to acquire information before making a decision. We introduced VOI to the HIV audience, using the example of generic antiretroviral therapy (ART) in the US. METHODS AND FINDINGS: We used a mathematical model and probabilistic sensitivity analysis (PSA) to generate probability distributions of survival (in quality-adjusted life years, QALYs) and cost for three potential first-line ART regimens: three-pill generic, two-pill generic, and single-pill branded. These served as input for a comparison of two hypothetical two-arm trials: three-pill generic versus single-pill branded; and two-pill generic versus single-pill branded. We modeled pre-trial uncertainty by defining probability distributions around key inputs, including 24-week HIV-RNA suppression and subsequent ART failure. We assumed that, without a trial, patients received the single-pill branded strategy. Post-trial, we assumed that patients received the most cost-effective strategy. For both trials, we quantified the probability of changing to a generic-based regimen upon trial completion and the expected VOI in terms of improved health outcomes and costs. Assuming a willingness to pay (WTP) threshold of $100 000/QALY, the three-pill trial led to more treatment changes (84%) than the two-pill trial (78%). Estimated VOI was $48 000 (three-pill trial) and $35 700 (two-pill trial) per future patient initiating ART. CONCLUSIONS: A three-pill trial of generic ART is more likely to lead to post-trial treatment changes and to provide more value than a two-pill trial if policy decisions are based on cost-effectiveness. Value of Information analysis can identify trials likely to confer the greatest impact and value for HIV care.

The clinical and economic impact of point-of-care CD4 testing in mozambique and other resource-limited settings: a cost-effectiveness analysis.

BACKGROUND: Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. METHODS AND FINDINGS: We use a validated model of HIV testing, linkage, and treatment (CEPAC-International) to examine two strategies of immunological staging in Mozambique: (1) laboratory-based CD4 testing (LAB-CD4) and (2) point-of-care CD4 testing (POC-CD4). Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs). Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%), probability of correctly detecting antiretroviral therapy (ART) eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90%) or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%), and test cost (LAB-CD4, US$10; POC-CD4, US$24). In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570) to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%-61.0%), increasing to 65.0% (95% CI, 64.9%-65.1%) with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6-9.6 y) and US$2,440 (95% CI, US$2,440-US$2,450) and increase with POC-CD4 to 10.3 y (95% CI, 10.3-10.3 y) and US$2,800 (95% CI, US$2,790-US$2,800); the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS) (95% CI, US$480-US$520/YLS). POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity/specificity and higher cost than published values. In other resource-limited settings with fewer opportunities to access care, POC-CD4 has a greater impact on clinical outcomes and remains cost-effective compared to LAB-CD4. Limitations of the analysis include the uncertainty around input parameters, which is examined in sensitivity analyses. The potential added benefits due to decreased transmission are excluded; their inclusion would likely further increase the value of POC-CD4 compared to LAB-CD4. CONCLUSIONS: POC-CD4 at the time of HIV diagnosis could improve survival and be cost-effective compared to LAB-CD4 in Mozambique, if it improves linkage to care. POC-CD4 could have the greatest impact on mortality in settings where resources for HIV testing and linkage are most limited. Please see later in the article for the Editors' Summary.

Lopinavir/ritonavir versus darunavir plus ritonavir for HIV infection: a cost-effectiveness analysis for the United States.

BACKGROUND: The ARTEMIS trial compared first-line antiretroviral therapy (ART) with lopinavir/ritonavir (LPV/r) to darunavir plus ritonavir (DRV + RTV) for HIV-1-infected subjects. In order to fully assess the implications of this study, economic modelling extrapolating over a longer term is required. OBJECTIVE: The aim of this study was to simulate the course of HIV and its management, including the multiple factors known to be of importance in ART. METHODS: A comprehensive discrete event simulation was created to represent, as realistically as possible, ART management and HIV outcomes. The model was focused on patients for whom clinicians believed that LPV/r or DRV + RTV were good options as a first regimen. Prognosis was determined by the impact of initial treatment on baseline CD4+ T-cell count and viral load, adherence, virological suppression/failure/rebound, acquired resistance mutations, and ensuing treatment changes. Inputs were taken from trial data (ARTEMIS), literature and, where necessary, stated assumptions. Clinical measures included AIDS events, side effects, time on sequential therapies, cardiovascular events, and expected life-years lost as a result of HIV infection. The model underwent face, technical and partial predictive validation. Treatment-naive individuals similar to those in the ARTEMIS trial were modelled over a lifetime, and outcomes with first-line DRV + RTV were compared with those with LPV/r, both paired with tenofovir and emtricitabine. Up to three regimen changes were permitted. Drug prices were based on wholesale acquisition cost. Outcomes were lifetime healthcare costs (in 2011 US dollars) from the US healthcare system perspective and quality-adjusted life-years (QALYs) (discounted at 3 % per annum). RESULTS: Choice of LPV/r over DRV + RTV as initial ART resulted in nearly identical clinical outcomes, but distinctly different economic consequences. Starting with an LPV/r regimen potentially results in approximately US$25,000 discounted lifetime savings. Accumulated QALYs for LPV/r and DRV + RTV were 12.130 and 12.083, respectively (a 19-day difference). In sensitivity analyses, net monetary benefit ranged from US$12,000 to US$31,000, favouring LPV/r (base case US$27,762). CONCLUSIONS: A comprehensive simulation of lifetime course of HIV in the USA indicated that using LPV/r as first-line therapy compared with DRV + RTV may result in cost savings, with similar clinical outcomes.

Economic savings versus health losses: the cost-effectiveness of generic antiretroviral therapy in the United States.

BACKGROUND: U.S. HIV treatment guidelines recommend branded once-daily, 1-pill efavirenz-emtricitabine-tenofovir as first-line antiretroviral therapy (ART). With the anticipated approval of generic efavirenz in the United States, a once-daily, 3-pill alternative (generic efavirenz, generic lamivudine, and tenofovir) will decrease cost but may reduce adherence and virologic suppression. OBJECTIVE: To assess the clinical effect, costs, and cost-effectiveness of a 3-pill, generic-based regimen compared with a branded, coformulated regimen and to project the potential national savings in the first year of a switch to generic-based ART. DESIGN: Mathematical simulation of HIV disease. SETTING: United States. PATIENTS: HIV-infected persons. INTERVENTION: No ART (for comparison); 3-pill, generic-based ART; and branded ART. MEASUREMENTS: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios (ICERs) in dollars per quality-adjusted life-year (QALY). RESULTS: Compared with no ART, generic-based ART has an ICER of $21,100/QALY. Compared with generic-based ART, branded ART increases lifetime costs by $42,500 and per-person survival gains by 0.37 QALYs for an ICER of $114,800/QALY. Estimated first-year savings, if all eligible U.S. patients start or switch to generic-based ART, are $920 million. Most plausible assumptions about generic-based ART efficacy and costs lead to branded ART ICERs greater than $100,000/QALY. LIMITATION: The efficacy and price reduction associated with generic drugs are unknown, and estimates are intended to be conservative. CONCLUSION: Compared with a slightly less effective generic-based regimen, the cost-effectiveness of first-line branded ART exceeds $100,000/QALY. Generic-based ART in the United States could yield substantial budgetary savings to HIV programs. PRIMARY FUNDING SOURCE: National Institute of Allergy and Infectious Diseases.