Correction to: Mass testing and treatment for malaria followed by weekly fever screening, testing and treatment in Northern Senegal: feasibility, cost and impact.

An amendment to this paper has been published and can be accessed via the original article.

Malaria case investigation with reactive focal testing and treatment: operational feasibility and lessons learned from low and moderate transmission areas in Amhara Region, Ethiopia.

BACKGROUND: When malaria transmission is very low, investigation of passively detected malaria cases and reactive focal testing and treatment (FTAT) in the case and neighbouring households can identify and contain the source and spread of infections. METHODS: Case investigation with reactive FTAT for malaria was implemented in 10 villages in Amhara Region, Ethiopia during the 2014/2015 malaria transmission season. Intervention villages were purposively selected based on the incidence of passively detected Plasmodium falciparum and mixed infections (P. falciparum and Plasmodium vivax) during the 2013 transmission season. A passively detected P. falciparum or mixed index case triggered an investigation that targeted the index case household and the closest 10 neighbouring households in a 100-m radius. All consenting household members received a rapid diagnostic test (RDT) and RDT-positive individuals received artemether-lumefantrine (P. falciparum, mixed) or chloroquine (P. vivax). RESULTS: From October 2014 to February 2015, 407 P. falciparum or mixed index cases (approximately 6.5 per 1000 population) were passively detected. Of these, 220 (54.1%) were investigated, of which 87.3% were male, 61.8% were age 20-39 years [median age: 27 years (range 1-90)], and 58.6% spent ≥ 1 night away from home in the past month (ranging from 0.0 to 94.1% by village). Among the 4077 residents in the 914 households investigated, 3243 (79.5%) received an RDT and 127 (3.9%) were RDT-positive (2.2% P. falciparum, 0.5% P. vivax, 1.2% mixed). Three epidemiological patterns were found. In six villages, there were almost no cases, with less than 10 index and secondary cases. In three villages, most index cases had a history of travel (> 62%), but there were a small number of secondary cases (< 10). Lastly, in one village none of the index cases had a history of recent travel and there was a large number of secondary cases (n = 105). CONCLUSIONS: Three types of malaria transmission patterns were observed: (1) low importation and low local transmission; (2) high importation and low local transmission; and, (3) low importation and high local transmission. To achieve malaria elimination in Amhara Region, intervention strategies targeting these different patterns of transmission and population movement are required.

A framework for evaluating the costs of malaria elimination interventions: an application to reactive case detection in Southern Province of Zambia, 2014.

BACKGROUND: This paper summarizes a framework for evaluating the costs of malaria elimination interventions and applies this approach to one key component of the elimination strategy-reactive case detection (RCD)-implemented through 173 health facilities across 10 districts in Southern Province of Zambia during 2014. METHODS: The primary unit of analysis is the health facility catchment area (HFCA). A five-step approach was followed to estimate implementation costs: organize preliminary information; estimate basic unit costs; estimate activity unit costs; estimate and organize final unit cost database; and create the final costing database (one row of data per HFCA). By working through a specific application, the overall logic of the analysis and details of each step are presented. An electronic annex also provides all details of the analysis. Because population varies substantially across HFCAs, all results are reported per 1000 population in HFCAs. RESULTS: During 2014, 38.9 households per HFCA were visited for RCD services; 166.8 individuals were tested and 32.3 tested positive and were treated. The mean annual cost per HFCA was $1177 (median = $923, IQR $651-$1417). Variation in costs was driven by the number of CHWs and passive cases detected. CHW-related costs and data review meetings accounted for the largest share of costs. Rapid diagnostic tests and drugs accounted for less than 10 % of total costs. CONCLUSIONS: The framework presented here follows standard methods in applied costing of public health interventions (combining ingredients- and activity-based costing approaches into one final cost analysis). Through an application to a specific programme implemented in Zambia in 2014, the details of how to apply such methods to an actual programme are presented. Such details are not typically presented in existing costing analyses but are required for applied analysts working with national malaria control programmes and other organizations to complete such analyses as part of routine programme implementation. Obtaining data and information for implementing the approach remains complicated, in part because analysts from one organization may not have easy access to information from another organization. This basic approach is transparent and easily applied to other malaria elimination interventions being implemented in sub-Saharan Africa and elsewhere.

Mass testing and treatment for malaria in low transmission areas in Amhara Region, Ethiopia.

BACKGROUND: In areas with ongoing malaria transmission, strategies to clear parasites from populations can reduce infection and transmission. The objective of this paper was to describe a malaria mass testing and treatment (MTAT) intervention implemented in six kebeles (villages) in Amhara Region, Ethiopia, at the beginning of the 2014 transmission season. METHODS: Intervention kebeles were selected based on incidence of passively detected Plasmodium falciparum and mixed (P. falciparum and P. vivax) malaria cases during the 2013 malaria transmission season. All households in intervention kebeles were targeted; consenting residents received a rapid diagnostic test (RDT) and RDT-positive individuals received artemether-lumefantrine for P. falciparum/mixed infections or chloroquine for P. vivax. Data were collected on MTAT participation, sociodemographic characteristics, malaria risk factors, and RDT positivity. RESULTS: Of 9162 households targeted, 7974 (87.0 %) participated in the MTAT. Among the 35,389 residents of these households, 30,712 (86.8 %) received an RDT. RDT-positivity was 1.4 % (0.3 % P. vivax, 0.7 % P. falciparum, 0.3 % mixed), ranging from 0.3 to 5.1 % by kebele; 39.4 % of RDT-positive individuals were febrile, 28.5 % resided in the same household with another RDT-positive individual, 23.0 % were not protected by vector control interventions [mosquito net or indoor residual spray (IRS)], and 7.1 % had travel history. For individuals under 10 years of age, the odds of being RDT-positive was significantly higher for those with fever, recent use of anti-malarial drugs or residing in the same household with another RDT-positive individual; 59.0 % of RDT-positive individuals had at least one of these risk factors. For individuals 10 years of age and older, the odds of being RDT positive was significantly higher for those with reported travel, fever, recent use of anti-malarial drugs, no use of vector control, and those residing in the same household as another RDT-positive individual; 71.2 % of RDT-positive individuals had at least one of these risk factors. CONCLUSIONS: In the Ethiopia setting, an MTAT intervention is operationally feasible and can be conducted with high coverage. RDT-positivity is low and varies widely by kebele. While several risk factors are significantly associated with RDT-positivity, there are still many RDT-positive individuals who do not have any of these risk factors. Strategies that target populations for testing and treatment based on these risk factors alone are likely to leave many infections undetected.

The impact of the 2013 WHO antiretroviral therapy guidelines on the feasibility of HIV population prevention trials.

BACKGROUND: Several cluster-randomized HIV prevention trials aim to demonstrate the population-level preventive impact of antiretroviral therapy (ART). 2013 World Health Organization (WHO) guidelines raising the ART initiation threshold to CD4 <500/µL could attenuate these trials' effect size by increasing ART usage in control clusters. METHODS: We used a computational model to simulate strategies from a hypothetical cluster-randomized HIV prevention trial. The primary model outcome was the relative reduction in 24-month HIV incidence between control (ART offered with CD4 below threshold) and intervention (ART offered to all) strategies. We assessed this incidence reduction using the revised (CD4 <500/µL) and prior (CD4 <350/µL) control ART initiation thresholds. Additionally, we evaluated changes to trial characteristics that could bolster the incidence reduction. RESULTS: With a control ART initiation threshold of CD4 <350/µL, 24-month HIV incidence under control and intervention strategies was 2.46/100 person-years (PY) and 1.96/100 PY, a 21% reduction. Raising the threshold to CD4 <500/µL decreased the incidence reduction by more than one-third, to 12%. Using this higher threshold, moving to a 36-month horizon (vs 24-month), yearly control-strategy HIV screening (vs bian-nual), and intervention-strategy screening every 2 months (vs biannual), resulted in a 31% incidence reduction that was similar to effect size projections for ongoing trials. Alternate assumptions regarding cross-cluster contamination had the greatest influence on the incidence reduction. CONCLUSIONS: Implementing the 2013 WHO HIV treatment threshold could substantially diminish the incidence reduction in HIV population prevention trials. Alternative HIV testing frequencies and trial horizons can bolster this incidence reduction, but they could be logistically and ethically challenging. The feasibility of HIV population prevention trials should be reassessed as the implementation of treatment guidelines evolves.

Retention in care, resource utilization, and costs for adults receiving antiretroviral therapy in Zambia: a retrospective cohort study.

BACKGROUND: Of the estimated 800,000 adults living with HIV in Zambia in 2011, roughly half were receiving antiretroviral therapy (ART). As treatment scale up continues, information on the care provided to patients after initiating ART can help guide decision-making. We estimated retention in care, the quantity of resources utilized, and costs for a retrospective cohort of adults initiating ART under routine clinical conditions in Zambia. METHODS: Data on resource utilization (antiretroviral [ARV] and non-ARV drugs, laboratory tests, outpatient clinic visits, and fixed resources) and retention in care were extracted from medical records for 846 patients who initiated ART at ≥15 years of age at six treatment sites between July 2007 and October 2008. Unit costs were estimated from the provider's perspective using site- and country-level data and are reported in 2011 USD. RESULTS: Patients initiated ART at a median CD4 cell count of 145 cells/µL. Fifty-nine percent of patients initiated on a tenofovir-containing regimen, ranging from 15% to 86% depending on site. One year after ART initiation, 75% of patients were retained in care. The average cost per patient retained in care one year after ART initiation was $243 (95% CI, $194-$293), ranging from $184 (95% CI, $172-$195) to $304 (95% CI, $290-$319) depending on site. Patients retained in care one year after ART initiation received, on average, 11.4 months' worth of ARV drugs, 1.5 CD4 tests, 1.3 blood chemistry tests, 1.4 full blood count tests, and 6.5 clinic visits with a doctor or clinical officer. At all sites, ARV drugs were the largest cost component, ranging from 38% to 84% of total costs, depending on site. CONCLUSIONS: Patients initiate ART late in the course of disease progression and a large proportion drop out of care after initiation. The quantity of resources utilized and costs vary widely by site, and patients utilize a different mix of resources under routine clinical conditions than if they were receiving fully guideline-concordant care. Improving retention in care and guideline concordance, including increasing the use of tenofovir in first-line ART regimens, may lead to increases in overall treatment costs.

Clinician- and Patient-Directed Communication Strategies for Patients With Cancer at High Mortality Risk: A Cluster Randomized Trial.

Importance: Serious illness conversations (SICs) that elicit patients' values, goals, and care preferences reduce anxiety and depression and improve quality of life, but occur infrequently for patients with cancer. Behavioral economic implementation strategies (nudges) directed at clinicians and/or patients may increase SIC completion. Objective: To test the independent and combined effects of clinician and patient nudges on SIC completion. Design, Setting, and Participants: A 2 × 2 factorial, cluster randomized trial was conducted from September 7, 2021, to March 11, 2022, at oncology clinics across 4 hospitals and 6 community sites within a large academic health system in Pennsylvania and New Jersey among 163 medical and gynecologic oncology clinicians and 4450 patients with cancer at high risk of mortality (≥10% risk of 180-day mortality). Interventions: Clinician clusters and patients were independently randomized to receive usual care vs nudges, resulting in 4 arms: (1) active control, operating for 2 years prior to trial start, consisting of clinician text message reminders to complete SICs for patients at high mortality risk; (2) clinician nudge only, consisting of active control plus weekly peer comparisons of clinician-level SIC completion rates; (3) patient nudge only, consisting of active control plus a preclinic electronic communication designed to prime patients for SICs; and (4) combined clinician and patient nudges. Main Outcomes and Measures: The primary outcome was a documented SIC in the electronic health record within 6 months of a participant's first clinic visit after randomization. Analysis was performed on an intent-to-treat basis at the patient level. Results: The study accrued 4450 patients (median age, 67 years [IQR, 59-75 years]; 2352 women [52.9%]) seen by 163 clinicians, randomized to active control (n = 1004), clinician nudge (n = 1179), patient nudge (n = 997), or combined nudges (n = 1270). Overall patient-level rates of 6-month SIC completion were 11.2% for the active control arm (112 of 1004), 11.5% for the clinician nudge arm (136 of 1179), 11.5% for the patient nudge arm (115 of 997), and 14.1% for the combined nudge arm (179 of 1270). Compared with active control, the combined nudges were associated with an increase in SIC rates (ratio of hazard ratios [rHR], 1.55 [95% CI, 1.00-2.40]; P = .049), whereas the clinician nudge (HR, 0.95 [95% CI, 0.64-1.41; P = .79) and patient nudge (HR, 0.99 [95% CI, 0.73-1.33]; P = .93) were not. Conclusions and Relevance: In this cluster randomized trial, nudges combining clinician peer comparisons with patient priming questionnaires were associated with a marginal increase in documented SICs compared with an active control. Combining clinician- and patient-directed nudges may help to promote SICs in routine cancer care. Trial Registration: ClinicalTrials.gov Identifier: NCT04867850.

The clinical and economic impact of genotype testing at first-line antiretroviral therapy failure for HIV-infected patients in South Africa.

BACKGROUND: In resource-limited settings, genotype testing at virologic failure on first-line antiretroviral therapy (ART) may identify patients with wild-type (WT) virus. After adherence counseling, these patients may safely and effectively continue first-line ART, thereby delaying more expensive second-line ART. METHODS: We used the Cost-Effectiveness of Preventing AIDS Complications International model of human immunodeficiency virus (HIV) disease to simulate a South African cohort of HIV-infected adults at first-line ART failure. Two strategies were examined: no genotype vs genotype, assuming availability of protease inhibitor-based second-line ART. Model inputs at first-line ART failure were mean age 38 years, mean CD4 173/µL, and WT virus prevalence 20%; genotype cost was $300 per test and delay to results, 3 months. Outcomes included life expectancy, per-person costs (2010 US dollars), and incremental cost-effectiveness ratios (dollars per years of life saved [YLS]). RESULTS: No genotype had a projected life expectancy of 106.1 months, which with genotype increased to 108.3 months. Per-person discounted lifetime costs were $16 360 and $16 540, respectively. Compared to no genotype, genotype was very cost-effective, by international guidance, at $900/YLS. The cost-effectiveness of genotype was sensitive to prevalence of WT virus (very cost-effective when prevalence ≥ 12%), CD4 at first-line ART failure, and ART efficacy. Genotype-associated delays in care ≥ 5 months decreased survival and made no genotype the preferred strategy. When the test cost was <$100, genotype became cost-saving. CONCLUSIONS: Genotype resistance testing at first-line ART failure is very cost-effective in South Africa. The cost-effectiveness of this strategy will depend on prevalence of WT virus and timely response to genotype results.

Cluster Randomized Pragmatic Clinical Trial Testing Behavioral Economic Implementation Strategies to Improve Tobacco Treatment for Patients With Cancer Who Smoke.

PURPOSE: Few cancer centers systematically engage patients with evidence-based tobacco treatment despite its positive effect on quality of life and survival. Implementation strategies directed at patients, clinicians, or both may increase tobacco use treatment (TUT) within oncology. METHODS: We conducted a four-arm cluster-randomized pragmatic trial across 11 clinical sites comparing the effect of strategies informed by behavioral economics on TUT engagement during oncology encounters with cancer patients. We delivered electronic health record (EHR)-based nudges promoting TUT across four nudge conditions: patient only, clinician only, patient and clinician, or usual care. Nudges were designed to counteract cognitive biases that reduce TUT engagement. The primary outcome was TUT penetration, defined as the proportion of patients with documented TUT referral or a medication prescription in the EHR. Generalized estimating equations were used to estimate the parameters of a linear model. RESULTS: From June 2021 to July 2022, we randomly assigned 246 clinicians in 95 clusters, and collected TUT penetration data from their encounters with 2,146 eligible patients who smoke receiving oncologic care. Intent-to-treat (ITT) analysis showed that the clinician nudge led to a significant increase in TUT penetration versus usual care (35.6% v 13.5%; OR = 3.64; 95% CI, 2.52 to 5.24; P < .0001). Completer-only analysis (N = 1,795) showed similar impact (37.7% clinician nudge v 13.5% usual care; OR = 3.77; 95% CI, 2.73 to 5.19; P < .0001). Clinician type affected TUT penetration, with physicians less likely to provide TUT than advanced practice providers (ITT OR = 0.67; 95% CI, 0.51 to 0.88; P = .004). CONCLUSION: EHR nudges, informed by behavioral economics and aimed at oncology clinicians, appear to substantially increase TUT penetration. Adding patient nudges to the implementation strategy did not affect TUT penetration rates.

The cost-effectiveness of pre-exposure prophylaxis for HIV infection in South African women.

BACKGROUND: Recent trials report the short-term efficacy of tenofovir-based pre-exposure prophylaxis (PrEP) for prevention of human immunodeficiency virus (HIV) infection. PrEP's long-term impact on patient outcomes, population-level transmission, and cost-effectiveness remains unknown. METHODS: We linked data from recent trials to a computer model of HIV acquisition, screening, and care to project lifetime HIV risk, life expectancy (LE), costs, and cost-effectiveness, using 2 PrEP-related strategies among heterosexual South African women: (1) women receiving no PrEP and (2) women not receiving PrEP (a tenofovir-based vaginal microbicide). We used a South African clinical cohort and published data to estimate population demographic characteristics, age-adjusted incidence of HIV infection, and HIV natural history and treatment parameters. Baseline PrEP efficacy (percentage reduction in HIV transmission) was 39% at a monthly cost of $5 per woman. Alternative parameter values were examined in sensitivity analyses. RESULTS: Among South African women, PrEP reduced mean lifetime HIV risk from 40% to 27% and increased population discounted (undiscounted) LE from 22.51 (41.66) to 23.48 (44.48) years. Lifetime costs of care increased from $7280 to $9890 per woman, resulting in an incremental cost-effectiveness ratio of $2700/year of life saved, and may, under optimistic assumptions, achieve cost savings. Under baseline HIV infection incidence assumptions, PrEP was not cost saving, even assuming an efficacy >60% and a cost <$1. At an HIV infection incidence of 9.1%/year, PrEP achieved cost savings at efficacies ≥50%. CONCLUSIONS: PrEP in South African women is very cost-effective by South African standards, conferring excellent value under virtually all plausible data scenarios. Although optimistic assumptions would be required to achieve cost savings, these represent important benchmarks for future PrEP study design.

Cost-effectiveness of adding an agent that improves immune responses to initial antiretroviral therapy (ART) in HIV-infected patients: guidance for drug development.

PURPOSE: Adding an immune-enhancing agent to initial antiretroviral therapy (ART) for HIV is a potential strategy to ensure that patients achieve optimal immune response. METHOD: Using a mathematical model of HIV disease and treatment, we evaluated the treatment benefits and cost-effectiveness of adding a hypothetical immune-enhancing agent to the initial 6 months of ART. We assumed that the additional agent would result in a higher CD4 increase that would provide clinical benefit. The additional cost ($1,900/month) was based on the cost of a drug currently under investigation for immune enhancement. Outcomes included projected life expectancy and cost-effectiveness in 2009 US dollars/quality-adjusted life year (QALY) with costs and QALYs discounted at 3% annually. RESULTS: Compared to standard ART, immune-enhanced ART resulting in an additional 40 CD4 cell/µL increase at 6 months yields a 2.4 month projected undiscounted life expectancy increase with a cost-effectiveness ratio of $107,600/QALY. Achieving a cost-effectiveness ratio <$100,000/QALY requires a >43 CD4 cell/µL improvement, or >19 cells/µL if immune-enhancing agent costs are halved. CONCLUSIONS: In addition to showing clinical efficacy, investigational immune enhancement agents need to increase CD4 counts more than has been previously observed or have a lower cost to be considered cost-effective in the United States.

Rationale and protocol for a cluster randomized pragmatic clinical trial testing behavioral economic implementation strategies to improve tobacco treatment rates for cancer patients who smoke.

BACKGROUND: Routine evidence-based tobacco use treatment minimizes cancer-specific and all-cause mortality, reduces treatment-related toxicity, and improves quality of life among patients receiving cancer care. Few cancer centers employ mechanisms to systematically refer patients to evidence-based tobacco cessation services. Implementation strategies informed by behavioral economics can increase tobacco use treatment engagement within oncology care. METHODS: A four-arm cluster-randomized pragmatic trial will be conducted across nine clinical sites within the Implementation Science Center in Cancer Control Implementation Lab to compare the effect of behavioral economic implementation strategies delivered through embedded messages (or "nudges") promoting patient engagement with the Tobacco Use Treatment Service (TUTS). Nudges are electronic medical record (EMR)-based messages delivered to patients, clinicians, or both, designed to counteract known patient and clinician biases that reduce treatment engagement. We used rapid cycle approaches (RCA) informed by relevant stakeholder experiences to refine and optimize our implementation strategies and methods prior to trial initiation. Data will be obtained via the EMR, clinician survey, and semi-structured interviews with a subset of clinicians and patients. The primary measure of implementation is penetration, defined as the TUTS referral rate. Secondary outcome measures of implementation include patient treatment engagement (defined as the number of patients who receive FDA-approved medication or behavioral counseling), quit attempts, and abstinence rates. The semi-structured interviews, guided by the Consolidated Framework for Implementation Research, will assess contextual factors and patient and clinician experiences with the nudges. DISCUSSION: This study will be the first in the oncology setting to compare the effectiveness of nudges to clinicians and patients, both head-to-head and in combination, as implementation strategies to improve TUTS referral and engagement. We expect the study to (1) yield insights into the effectiveness of nudges as an implementation strategy to improve uptake of evidence-based tobacco use treatment within cancer care, and (2) advance our understanding of the multilevel contextual factors that drive response to these strategies. These results will lay the foundation for how patients with cancer who smoke are best engaged in tobacco use treatment and may lead to future research focused on scaling this approach across diverse centers. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04737031 . Registered 3 February 2021.

Behavioral economic implementation strategies to improve serious illness communication between clinicians and high-risk patients with cancer: protocol for a cluster randomized pragmatic trial.

BACKGROUND: Serious illness conversations (SICs) are an evidence-based approach to eliciting patients' values, goals, and care preferences that improve patient outcomes. However, most patients with cancer die without a documented SIC. Clinician-directed implementation strategies informed by behavioral economics ("nudges") that identify high-risk patients have shown promise in increasing SIC documentation among clinicians. It is unknown whether patient-directed nudges that normalize and prime patients towards SIC completion-either alone or in combination with clinician nudges that additionally compare performance relative to peers-may improve on this approach. Our objective is to test the effect of clinician- and patient-directed nudges as implementation strategies for increasing SIC completion among patients with cancer. METHODS: We will conduct a 2 × 2 factorial, cluster randomized pragmatic trial to test the effect of nudges to clinicians, patients, or both, compared to usual care, on SIC completion. Participants will include 166 medical and gynecologic oncology clinicians practicing at ten sites within a large academic health system and their approximately 5500 patients at high risk of predicted 6-month mortality based on a validated machine-learning prognostic algorithm. Data will be obtained via the electronic medical record, clinician survey, and semi-structured interviews with clinicians and patients. The primary outcome will be time to SIC documentation among high-risk patients. Secondary outcomes will include time to SIC documentation among all patients (assessing spillover effects), palliative care referral among high-risk patients, and aggressive end-of-life care utilization (composite of chemotherapy within 14 days before death, hospitalization within 30 days before death, or admission to hospice within 3 days before death) among high-risk decedents. We will assess moderators of the effect of implementation strategies and conduct semi-structured interviews with a subset of clinicians and patients to assess contextual factors that shape the effectiveness of nudges with an eye towards health equity. DISCUSSION: This will be the first pragmatic trial to evaluate clinician- and patient-directed nudges to promote SIC completion for patients with cancer. We expect the study to yield insights into the effectiveness of clinician and patient nudges as implementation strategies to improve SIC rates, and to uncover multilevel contextual factors that drive response to these strategies. TRIAL REGISTRATION: ClinicalTrials.gov , NCT04867850 . Registered on April 30, 2021. FUNDING: National Cancer Institute P50CA244690.

Test and treat DC: forecasting the impact of a comprehensive HIV strategy in Washington DC.

BACKGROUND: The United States and international agencies have signaled their commitment to containing the human immunodeficiency virus (HIV) epidemic via early case identification and linkage to antiretroviral therapy (ART) immediately at diagnosis. We forecast outcomes of this approach if implemented in Washington DC. METHODS: Using a mathematical model of HIV case detection and treatment, we evaluated combinations of HIV screening and ART initiation strategies. We define current practice as no regular screening program and ART at CD4 counts < or = 350 cells/microL, and we define test and treat as annual screening and administration of ART at diagnosis. Outcomes include life expectancy of HIV-infected persons and changes in the population time with transmissible HIV RNA levels. Data, largely from Washington DC, include undiagnosed HIV prevalence of 0.6%, annual incidence of 0.13%, 31% rate of test offer, 60% rate of acceptance, and 50% linkage to care. Input parameters, including optimized ART efficacy, are varied in sensitivity analyses. RESULTS: Projected life expectancies, from an initial mean age of 41 years, are 23.9, 25.0, and 25.6 years for current practice, test and treat, and test and treat with optimized ART, respectively. Compared with current practice, test and treat leads to a 14.7% reduction in time spent with transmissible HIV RNA level in the next 5 years; test and treat with optimized ART results in a 27.3% reduction. CONCLUSIONS: An expanded HIV test and treat program in Washington DC will increase life expectancy of HIV-infected patients but will have a modest impact on HIV transmission over the next 5 years and is unlikely to halt the HIV epidemic.

Cost-effectiveness of tenofovir as first-line antiretroviral therapy in India.

BACKGROUND: World Health Organization guidelines for antiretroviral treatment (ART) in resource-limited settings recommend either stavudine or tenofovir as part of initial therapy. We evaluated the clinical outcomes and cost-effectiveness of first-line ART using tenofovir in India, compared with current practice using stavudine or zidovudine. METHODS: We used a state-transition model of human immunodeficiency virus (HIV) disease to examine strategies using different nucleoside reverse-transcriptase inhibitors, combined with lamivudine and nevirapine, compared with no ART: (1) stavudine, (2) stavudine with substitution by zidovudine after 6 months, (3) zidovudine, and (4) tenofovir. Data were from the Y. R. Gaitonde Centre for AIDS Research and Education in Chennai, India, and published studies. Results. Discounted mean per person survival was 36.9 months (40.2 months undiscounted) with no ART, 115.5 months (145.3) with stavudine-containing ART, 115.7 months (145.6) with stavudine and 6-month zidovudine substitution, 115.8 months (145.6) with zidovudine-containing ART, and 125.8 months (162.0) with initial tenofovir. Discounted lifetime medical costs were $610 with no ART and ranged from $5580 with stavudine-containing ART to $5720 with zidovudine-containing ART. Initial tenofovir had an incremental cost-effectiveness ratio of $670 per year of life saved, compared with no ART, and was more economically efficient than the other regimens. RESULTS: were most sensitive to variations in the costs of first-line tenofovir, access to additional ART after treatment failure, and quality of life adjustment. CONCLUSIONS: Using tenofovir as part of first-line ART in India will improve survival, is cost-effective by international standards, and should be considered for initial therapy for HIV-infected patients in India.

Meeting human resources for health staffing goals by 2018: a quantitative analysis of policy options in Zambia.

BACKGROUND: The Ministry of Health (MOH) in Zambia is currently operating with fewer than half of the health workers required to deliver basic health services. The MOH has developed a human resources for health (HRH) strategic plan to address the crisis through improved training, hiring, and retention. However, the projected success of each strategy or combination of strategies is unclear. METHODS: We developed a model to forecast the size of the public sector health workforce in Zambia over the next ten years to identify a combination of interventions that would expand the workforce to meet staffing targets. The key forecasting variables are training enrolment, graduation rates, public sector entry rates for graduates, and attrition of workforce staff. We model, using Excel (Office, Microsoft; 2007), the effects of changes in these variables on the projected number of doctors, clinical officers, nurses and midwives in the public sector workforce in 2018. RESULTS: With no changes to current training, hiring, and attrition conditions, the total number of doctors, clinical officers, nurses, and midwives will increase from 44% to 59% of the minimum necessary staff by 2018. No combination of changes in staff retention, graduation rates, and public sector entry rates of graduates by 2010, without including training expansion, is sufficient to meet staffing targets by 2018 for any cadre except midwives. Training enrolment needs to increase by a factor of between three and thirteen for doctors, three and four for clinical officers, two and three for nurses, and one and two for midwives by 2010 to reach staffing targets by 2018. Necessary enrolment increases can be held to a minimum if the rates of retention, graduation, and public sector entry increase to 100% by 2010, but will need to increase if these rates remain at 2008 levels. CONCLUSIONS: Meeting the minimum need for health workers in Zambia this decade will require an increase in health training school enrolment. Supplemental interventions targeting attrition, graduation and public sector entry rates can help close the gap. HRH modelling can help MOH policy makers determine the relative priority and level of investment needed to expand Zambia's workforce to target staffing levels.

Cost-Effectiveness of Focal Mass Drug Administration and Mass Drug Administration with Dihydroartemisinin-Piperaquine for Malaria Prevention in Southern Province, Zambia: Results of a Community-Randomized Controlled Trial.

Community-wide administration of antimalarial drugs in therapeutic doses is a potential tool to prevent malaria infection and reduce the malaria parasite reservoir. To measure the effectiveness and cost of using the antimalarial drug combination dihydroartemisinin-piperaquine (DHAp) through different community-wide distribution strategies, Zambia's National Malaria Control Centre conducted a three-armed community-randomized controlled trial. The trial arms were as follows: 1) standard of care (SoC) malaria interventions, 2) SoC plus focal mass drug administration (fMDA), and 3) SoC plus MDA. Mass drug administration consisted of offering all eligible individuals DHAP, irrespective of a rapid diagnostic test (RDT) result. Focal mass drug administration consisted of offering DHAP to all eligible individuals who resided in a household where anyone tested positive by RDT. Results indicate that the costs of fMDA and MDA per person targeted and reached are similar (US$9.01 versus US$8.49 per person, respectively, P = 0.87), but that MDA was superior in all cost-effectiveness measures, including cost per infection averted, cost per case averted, cost per death averted, and cost per disability-adjusted life year averted. Subsequent costing of the MDA intervention in a non-trial, operational setting yielded significantly lower costs per person reached (US$2.90). Mass drug administration with DHAp also met the WHO thresholds for "cost-effective interventions" in the Zambian setting in 90% of simulations conducted using a probabilistic sensitivity analysis based on trial costs, whereas fMDA met these criteria in approximately 50% of simulations. A sensitivity analysis using costs from operational deployment and trial effectiveness yielded improved cost-effectiveness estimates. Mass drug administration may be a cost-effective intervention in the Zambian context and can help reduce the parasite reservoir substantially. Mass drug administration was more cost-effective in relatively higher transmission settings. In all scenarios examined, the cost-effectiveness of MDA was superior to that of fMDA.

HIV preexposure prophylaxis in the United States: impact on lifetime infection risk, clinical outcomes, and cost-effectiveness.

BACKGROUND: The combination of tenofovir and emtricitabine shows promise as HIV preexposure prophylaxis (PrEP). We sought to forecast clinical, epidemiologic, and economic outcomes of PrEP, taking into account uncertainties regarding efficacy, the risks of developing drug resistance and toxicity, behavioral disinhibition, and drug costs. METHODS: We adapted a computer simulation of HIV acquisition, detection, and care to model PrEP among men who have sex with men and are at high risk of HIV infection (i.e., 1.6% mean annual incidence of HIV infection) in the United States. Base-case assumptions included 50% PrEP efficacy and monthly tenofovir-emtricitabine costs of $753. We used sensitivity analyses to examine the stability of results and to identify critical input parameters. RESULTS: In a cohort with a mean age of 34 years, PrEP reduced lifetime HIV infection risk from 44% to 25% and increased mean life expectancy from 39.9 to 40.7 years (21.7 to 22.2 discounted quality-adjusted life-years). Discounted mean lifetime treatment costs increased from $81,100 to $232,700 per person, indicating an incremental cost-effectiveness ratio of $298,000 per quality-adjusted life-year gained. Markedly larger reductions in lifetime infection risk (from 44% to 6%) were observed with the assumption of greater (90%) PrEP efficacy. More-favorable incremental cost-effectiveness ratios were obtained by targeting younger populations with a higher incidence of infection and by improvements in the efficacy and cost of PrEP. CONCLUSIONS: PrEP could substantially reduce the incidence of HIV transmission in populations at high risk of HIV infection in the United States. Although it is unlikely to confer sufficient benefits to justify the current costs of tenofovir-emtricitabine, price reductions and/or increases in efficacy could make PrEP a cost-effective option in younger populations or populations at higher risk of infection. Given recent disappointments in HIV infection prevention and vaccine development, additional study of PrEP-based HIV prevention is warranted.

Clinical impact and cost-effectiveness of antiretroviral therapy in India: starting criteria and second-line therapy.

BACKGROUND: India has more than 5.7 million people infected with human immunodeficiency virus (HIV). In 2004, the Indian government began providing antiretroviral therapy (ART), and there are now an estimated 56 500 people receiving ART. OBJECTIVE: To project the life expectancy, cost, and cost-effectiveness associated with different strategies for using ART in India, to inform treatment programs. METHODS: We utilized an HIV disease simulation model, incorporating data on natural history, treatment efficacy, and costs of care from India. Input parameters for the simulated cohort included mean age 32.6 years and mean CD4 count 318 cells/microl (SD 291 cells/microl). We examined different criteria for starting and stopping ART with a first-line regimen of stavudine/lamivudine/nevirapine, and the impact of a second-line protease-inhibitor-based regimen. Cost-effectiveness in US dollars per year of life saved (US$/YLS) was compared incrementally among alternative starting, sequencing, and stopping criteria. RESULTS: Discounted (undiscounted) mean survival ranged from 34.5 (37.5) months with no ART to 64.7 (73.6) months with one line of therapy initiated at CD4 <350 cells/microl, to 88.9 (106.5) months with two lines of therapy initiated at CD4 <350 cells/microl. Lifetime medical costs ranged from US$530 (no ART) to US$5430 (two ART regimens) per person. With one line of therapy, the incremental cost-effectiveness ratios ranged from US$430/YLS to US$550/YLS as the CD4 starting criterion was increased from CD4 <250 cells/microl to <350 cells/microl. Use of two lines of therapy had an incremental cost-effectiveness ratio of US$1880/YLS compared with the use of first-line therapy alone. Results were sensitive to the costs of second-line therapy and criteria for stopping therapy. CONCLUSIONS: In India, antiretroviral therapy will lead to major survival benefits and is cost-effective by World Health Organization criteria. The availability of second-line regimens will further increase survival, but their cost-effectiveness depends on their relative cost compared with first-line regimens.

Potential risks and benefits of HIV treatment simplification: a simulation model of a proposed clinical trial.

BACKGROUND: In recent studies, subjects who had achieved suppression of the human immunodeficiency virus (HIV) RNA level while receiving an initial 3-drug antiretroviral regimen successfully maintained suppression while receiving treatment with a "boosted" protease inhibitor (PI) alone. We projected the long-term outcomes of this treatment simplification strategy to inform the design of a proposed multicenter, randomized clinical trial. METHODS: We used published studies to estimate the efficacy, adverse effects, and cost of a sequence of HIV drug regimens for the simplification strategy, compared with those outcomes for the current standard-of-care (SOC) strategy. Using a published simulation model of HIV disease, we projected life expectancy, discounted quality-adjusted life expectancy (QALE), and discounted lifetime medical costs for each strategy. RESULTS: Subjects who have not developed PI-resistant HIV infection at the time of failure of the simplification regimen have a greater life expectancy (27.9 vs. 27.1 years) and QALE (14.9 vs. 14.7 years), compared with SOC subjects, because they receive an additional line of therapy without negative consequences for future treatment options. The QALE for the simplification strategy remains higher than that for the SOC, unless a large proportion of patients experiencing virologic failure while receiving the simplification regimen develop PI resistance. Depending on the probability of simplification regimen failure, the advantage is maintained even if HIV develops PI resistance in 42%-70% of subjects. Projected lifetime costs are $26,500-$72,400 per person lower for the simplification strategy than for the SOC strategy. CONCLUSIONS: An HIV treatment simplification strategy involving use of a boosted PI alone may lead to longer survival overall at lower cost, compared with the SOC combination therapy, because the simplification strategy potentially adds an additional line of therapy. The risk of emergence of PI resistance during treatment with a simplified regimen is a critical determinant of the viability of this strategy.