Publications
290 results found
Ralph L, McCoy S, Hallett T, et al., 2014, Research on hormonal contraception and HIV Reply, LANCET, Vol: 383, Pages: 305-306, ISSN: 0140-6736
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- Citations: 3
Birger RB, Hallett TB, Sinha A, et al., 2014, Modeling the Impact of Interventions Along the HIV Continuum of Care in Newark, New Jersey, CLINICAL INFECTIOUS DISEASES, Vol: 58, Pages: 274-284, ISSN: 1058-4838
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- Citations: 20
Keebler D, Revill P, Braithwaite S, et al., 2014, Cost-effectiveness of different strategies to monitor adults on antiretroviral treatment: a combined analysis of three mathematical models, LANCET GLOBAL HEALTH, Vol: 2, Pages: E35-E43, ISSN: 2214-109X
Eaton JW, Menzies NA, Stover J, et al., 2014, Health benefits, costs, and cost-effectiveness of earlier eligibility for adult antiretroviral therapy and expanded treatment coverage: a combined analysis of 12 mathematical models, The Lancet Global Health, Vol: 2, Pages: E23-E34, ISSN: 2214-109X
BackgroundNew WHO guidelines recommend initiation of antiretroviral therapy for HIV-positive adults with CD4 counts of 500 cells per μL or less, a higher threshold than was previously recommended. Country decision makers have to decide whether to further expand eligibility for antiretroviral therapy accordingly. We aimed to assess the potential health benefits, costs, and cost-effectiveness of various eligibility criteria for adult antiretroviral therapy and expanded treatment coverage.MethodsWe used several independent mathematical models in four settings—South Africa (generalised epidemic, moderate antiretroviral therapy coverage), Zambia (generalised epidemic, high antiretroviral therapy coverage), India (concentrated epidemic, moderate antiretroviral therapy coverage), and Vietnam (concentrated epidemic, low antiretroviral therapy coverage)—to assess the potential health benefits, costs, and cost-effectiveness of various eligibility criteria for adult antiretroviral therapy under scenarios of existing and expanded treatment coverage, with results projected over 20 years. Analyses assessed the extension of eligibility to include individuals with CD4 counts of 500 cells per μL or less, or all HIV-positive adults, compared with the previous (2010) recommendation of initiation with CD4 counts of 350 cells per μL or less. We assessed costs from a health-system perspective, and calculated the incremental cost (in US$) per disability-adjusted life-year (DALY) averted to compare competing strategies. Strategies were regarded very cost effective if the cost per DALY averted was less than the country's 2012 per-head gross domestic product (GDP; South Africa: $8040; Zambia: $1425; India: $1489; Vietnam: $1407) and cost effective if the cost per DALY averted was less than three times the per-head GDP.FindingsIn South Africa, the cost per DALY averted of extending eligibility for antiretroviral therapy to adult patients with CD4 counts of 500 cells per &
Anderson SJ, Harper M, Kilonzo N, et al., 2014, Erratum: Maximising the effect of combination HIV prevention in Kenya-Authors' reply (Lancet (2014) 384 (1426-27)), The Lancet, Vol: 384, ISSN: 0140-6736
Hallett TB, Menzies NA, Revill P, et al., 2014, Using modeling to inform international guidelines for antiretroviral treatment, AIDS, Vol: 28, Pages: S1-S4, ISSN: 0269-9370
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- Citations: 10
Martin NK, Devine A, Eaton JW, et al., 2014, Modeling the impact of early antiretroviral therapy for adults coinfected with HIV and hepatitis B or C in South Africa, AIDS, Vol: 28, Pages: S35-S46, ISSN: 0269-9370
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- Citations: 21
Pretorius C, Menzies NA, Chindelevitch L, et al., 2014, The potential effects of changing HIV treatment policy on tuberculosis outcomes in South Africa: results from three tuberculosis-HIV transmission models, AIDS, Vol: 28, Pages: S25-S34, ISSN: 0269-9370
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- Citations: 33
Braithwaite RS, Nucifora KA, Toohey C, et al., 2014, How do different eligibility guidelines for antiretroviral therapy affect the cost-effectiveness of routine viral load testing in sub-Saharan Africa?, AIDS, Vol: 28, Pages: S73-S83, ISSN: 0269-9370
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- Citations: 18
Vassall A, Remme M, Watts C, et al., 2013, Financing Essential HIV Services: A New Economic Agenda, PLOS MEDICINE, Vol: 10, ISSN: 1549-1277
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- Citations: 34
Hallett TB, 2013, Early HIV Infection in the United States: A Virus's Eye View, PLOS MEDICINE, Vol: 10, ISSN: 1549-1277
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- Citations: 1
van de Vijver DAMC, Nichols BE, Abbas UL, et al., 2013, Preexposure prophylaxis will have a limited impact on HIV-1 drug resistance in sub-Saharan Africa: a comparison of mathematical models, AIDS, Vol: 27, Pages: 2943-2951, ISSN: 0269-9370
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- Citations: 54
van de Vijver DA, Nichols BE, Abbas UL, et al., 2013, Pre-exposure prophylaxis (PrEP) will have a limited impact on the prevalence of HIV-1 drug resistance in sub-Saharan Africa: comparison of mathematical models, AIDS, Vol: 27, Pages: 2943-2951, ISSN: 0269-9370
BACKGROUND: Preexposure prophylaxis (PrEP) with tenofovir and emtricitabine can prevent new HIV-1 infections, but there is a concern that use of PrEP could increase HIV drug resistance resulting in loss of treatment options. We compared standardized outcomes from three independent mathematical models simulating the impact of PrEP on HIV transmission and drug resistance in sub-Saharan African countries.METHODS: All models assume that people using PrEP receive an HIV test every 3-6 months. The models vary in structure and parameter choices for PrEP coverage, effectiveness of PrEP (at different adherence levels) and the rate with which HIV drug resistance emerges and is transmitted.RESULTS: The models predict that the use of PrEP in conjunction with antiretroviral therapy will result in a lower prevalence of HIV than when only antiretroviral therapy is used. With or without PrEP, all models suggest that HIV drug resistance will increase over the next 20 years due to antiretroviral therapy. PrEP will increase the absolute prevalence of drug resistance in the total population by less than 0.5% and amongst infected individuals by at most 7%. Twenty years after the introduction of PrEP, the majority of drug-resistant infections is due to antiretroviral therapy (50-63% across models), whereas 40-50% will be due to transmission of drug resistance, and less than 4% to the use of PrEP.CONCLUSION: HIV drug resistance resulting from antiretroviral therapy is predicted to far exceed that resulting from PrEP. Concern over drug resistance should not be a reason to limit the use of PrEP.
Dimitrov D, Boily M-C, Brown ER, et al., 2013, Analytic Review of Modeling Studies of ARV Based PrEP Interventions Reveals Strong Influence of Drug-Resistance Assumptions on the Population-Level Effectiveness, PLOS One, Vol: 8, ISSN: 1932-6203
BackgroundFour clinical trials have shown that oral and topical pre-exposure prophylaxis (PrEP) based on tenofovir may be effective in preventing HIV transmission. The expected reduction in HIV transmission and the projected prevalence of drug resistance due to PrEP use vary significantly across modeling studies as a result of the broad spectrum of assumptions employed. Our goal is to quantify the influence of drug resistance assumptions on the predicted population-level impact of PrEP.MethodsAll modeling studies which evaluate the impact of oral or topical PrEP are reviewed and key assumptions regarding mechanisms of generation and spread of drug-resistant HIV are identified. A dynamic model of the HIV epidemic is developed to assess and compare the impact of oral PrEP using resistance assumptions extracted from published studies. The benefits and risks associated with ten years of PrEP use are evaluated under identical epidemic, behavioral and intervention conditions in terms of cumulative fractions of new HIV infections prevented, resistance prevalence among those infected with HIV, and fractions of infections in which resistance is transmitted.ResultsPublished models demonstrate enormous variability in resistance-generating assumptions and uncertainty in parameter values. Depending on which resistance parameterization is used, a resistance prevalence between 2% and 44% may be expected if 50% efficacious oral PrEP is used consistently by 50% of the population over ten years. We estimated that resistance may be responsible for up to a 10% reduction or up to a 30% contribution to the fraction of prevented infections predicted in different studies.ConclusionsResistance assumptions used in published studies have a strong influence on the projected impact of PrEP. Modelers and virologists should collaborate toward clarifying the set of resistance assumptions biologically relevant to the PrEP products which are already in use or soon to be added to the arsenal against
Ralph LJ, McCoy SI, Hallett T, et al., 2013, Next steps for research on hormonal contraception and HIV, LANCET, Vol: 382, Pages: 1467-1469, ISSN: 0140-6736
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- Citations: 19
Cohen MS, Smith MK, Muessig KE, et al., 2013, Antiretroviral treatment of HIV-1 prevents transmission of HIV-1: where do we go from here?, LANCET, Vol: 382, Pages: 1515-1524, ISSN: 0140-6736
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- Citations: 169
Hontelez JAC, Lurie MN, Baernighausen T, et al., 2013, Elimination of HIV in South Africa through Expanded Access to Antiretroviral Therapy: A Model Comparison Study, PLOS MEDICINE, Vol: 10, ISSN: 1549-1277
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- Citations: 91
Smit M, Smit C, Geerlings S, et al., 2013, Changes in First-Line cART Regimens and Short-Term Clinical Outcome between 1996 and 2010 in The Netherlands, PLOS One, Vol: 8, ISSN: 1932-6203
Objectives: Document progress in HIV-treatment in the Netherlands since 1996 by reviewing changing patterns of cART useand relating those to trends in patients’ short-term clinical outcomes between 1996 and 2010.Design and Methods: 1996–2010 data from 10,278 patients in the Dutch ATHENA national observational cohort wereanalysed. The annual number of patients starting a type of regimen was quantified. Trends in the following outcomes weredescribed: i) recovery of 150 CD4 cells/mm3 within 12 months of starting cART; ii) achieving viral load (VL) suppression#1,000 copies/ml within 12 months of starting cART; iii) switching from first-line to second-line regimen within three yearsof starting treatment; and iv) all-cause mortality rate per 100 person-years within three years of starting treatment.Results: Between 1996 and 2010, first-line regimens changed from lamivudine/zidovudine-based or lamivudine/stavudinebasedregimens with unboosted-PIs to tenofovir with either emtricitabine or lamivudine with NNRTIs. Mortality rates did notchange significantly over time. VL suppression and CD4 recovery improved over time, and the incidence of switching due tovirological failure and toxicity more than halved between 1996 and 2010. These effects appear to be related to the use ofnew regimens rather than improvements in clinical care.Conclusion: The use of first-line cART in the Netherlands closely follows changes in guidelines, to the benefit of patients.While there was no significant improvement in mortality, newer drugs with better tolerability and simpler dosing resulted inimproved immunological and virological recovery and reduced incidences of switching due to toxicity and virologicalfailure.
Gregson S, Hallett TB, Stover J, et al., 2013, Putting the burden of HIV in context, AIDS, Vol: 27, Pages: 2161-+, ISSN: 0269-9370
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- Citations: 1
Celum C, Hallett TB, Baeten JM, 2013, HIV-1 Prevention With ART and PrEP: Mathematical Modeling Insights Into Resistance, Effectiveness, and Public Health Impact, JOURNAL OF INFECTIOUS DISEASES, Vol: 208, Pages: 189-191, ISSN: 0022-1899
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- Citations: 18
Hallett TB, Eaton JW, 2013, A Side Door Into Care Cascade for HIV-Infected Patients?, JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES, Vol: 63, Pages: S228-S232, ISSN: 1525-4135
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- Citations: 84
Alsallaq R, Buttolph J, Cleland C, et al., 2013, ESTIMATING THE IMPACT OF COMBINED PREVENTION INTERVENTIONS TARGETING 15-24 YEARS-OLD MEN AND WOMEN IN NYANZA, KENYA, SEXUALLY TRANSMITTED INFECTIONS, Vol: 89, Pages: A269-A269, ISSN: 1368-4973
Vesga JF, Boily MC, Hallett TB, 2013, ESTIMATING THE IMPACT OF ANTIRETROVIRAL THERAPY AND CONDOMS IN THE HIV EPIDEMIC OF BOGOTA, COLOMBIA, SEXUALLY TRANSMITTED INFECTIONS, Vol: 89, Pages: A281-A281, ISSN: 1368-4973
Elmes J, Nhongo K, Hallett T, et al., 2013, THE SOCIAL ORGANISATION OF SEX WORK IN RURAL EASTERN ZIMBABWE AND ITS IMPLICATIONS FOR HIV INFECTION, SEXUALLY TRANSMITTED INFECTIONS, Vol: 89, Pages: A179-A180, ISSN: 1368-4973
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- Citations: 1
Elmes J, Nhongo K, Hallett T, et al., 2013, THE PRICE OF SEX: INSIGHTS INTO THE DETERMINANTS OF THE PRICE OF COMMERCIAL SEX AMONG FEMALE SEX WORKERS IN RURAL ZIMBABWE, SEXUALLY TRANSMITTED INFECTIONS, Vol: 89, Pages: A39-A39, ISSN: 1368-4973
Estill J, Egger M, Blaser N, et al., 2013, Cost-effectiveness of point-of-care viral load monitoring of antiretroviral therapy in resource-limited settings: mathematical modelling study, AIDS, Vol: 27, Pages: 1483-1492, ISSN: 0269-9370
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- Citations: 40
Estill J, Egger M, Johnson LF, et al., 2013, Monitoring of Antiretroviral Therapy and Mortality in HIV Programmes in Malawi, South Africa and Zambia: Mathematical Modelling Study, PLOS ONE, Vol: 8, ISSN: 1932-6203
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- Citations: 25
Cremin I, Alsallaq R, Dybul M, et al., 2013, The new role of antiretrovirals in combination HIV prevention: a mathematical modelling analysis, AIDS, Vol: 27, Pages: 447-458, ISSN: 0269-9370
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- Citations: 109
Alsallaq RA, Baeten JM, Celum CL, et al., 2013, Understanding the Potential Impact of a Combination HIV Prevention Intervention in a Hyper-Endemic Community, PLOS ONE, Vol: 8, ISSN: 1932-6203
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- Citations: 34
Chemaitelly H, Shelton JD, Hallett TB, et al., 2013, Only a fraction of new HIV infections occur within identifiable stable discordant couples in sub-Saharan Africa, AIDS, Vol: 27, Pages: 251-260, ISSN: 0269-9370
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- Citations: 36
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