Cost effectiveness of screening strategies for early identification of HIV and HCV infection in injection drug users

Cost effectiveness of hepatitis C direct acting agents

INTRODUCTION

Introduction of direct acting antivirals (DAA) has transformed treatment of chronic hepatitis C (HCV) and made the elimination of HCV an achievable goal set forward by World Health Organization by 2030. Multiple barriers need to be overcome for successful eradication of HCV. Availability of pan-genotypic HCV regimens has decreased the need for genotype testing but maintained high efficacy associated with DAAs.

AREAS COVERED

In this review, we will assess the cost-effectiveness of DAA treatment in patients with chronic HCV disease, with emphasis on general, cirrhosis, and vulnerable populations.

EXPERT OPINION

Multiple barriers exist limiting eradication of HCV, including cost to treatment, access, simplified testing, and implementing policy to foster treatment for all groups of HCV patients. Clinically, DAAs have drastically changed the landscape of HCV, but focused targeting of vulnerable groups is needed. Public policy will continue to play a strong role in eliminating HCV. While we will focus on the cost-effectiveness of DAA, several other factors regarding HCV require on going attention, such as increasing public awareness and decreasing social stigma associated with HCV, offering universal screening followed by linkage to treatment and improving preventive interventions to decrease spread of HCV.

Financing Benefits and Barriers to Routine HIV Screening in Clinical Settings in the United States: A Scoping Review

The Centers for Disease Control and Prevention recommends everyone between 13-64 years be tested for HIV at least once as a routine procedure. Routine HIV screening is reimbursable by Medicare, Medicaid, expanded Medicaid, and most commercial insurance plans. Yet, scaling-up HIV routine screening remains a challenge. We conducted a scoping review for studies on financial benefits and barriers associated with HIV screening in clinical settings in the U.S. to inform an evidence-based strategy to scale-up routine HIV screening. We searched Ovid MEDLINE^®, Cochrane, and Scopus for studies published between 2006-2020 in English. The search identified 383 Citations; we screened 220 and excluded 163 (outside the time limit, irrelevant, or outside the U.S.). Of the 220 screened articles, we included 35 and disqualified 155 (did not meet the eligibility criteria). We organized eligible articles under two themes: financial benefits/barriers of routine HIV screening in healthcare settings (9 articles); and Cost-effectiveness of routine screening in healthcare settings (26 articles). The review concluded drawing recommendations in three areas: (1) Finance: Incentivize healthcare providers/systems for implementing HIV routine screening and/or separate its reimbursement from bundle payments; (2) Personnel: Encourage nurse-initiated HIV screening programs in primary care settings and educate providers on CDC recommendations; and (3) Approach: Use opt-out approach.

Testing strategies to detect acute and prevalent HIV infection in adult outpatients seeking healthcare for symptoms compatible with acute HIV infection in Kenya: a cost-effectiveness analysis

BACKGROUND

Detection of acute and prevalent HIV infection using point-of-care nucleic acid amplification testing (POC-NAAT) among outpatients with symptoms compatible with acute HIV is critical to HIV prevention, but it is not clear if it is cost-effective compared with existing HIV testing strategies.

METHODS

We developed and parametrised a decision tree to compare the cost-effectiveness of (1) provider-initiated testing and counselling (PITC) using rapid tests, the standard of care; (2) scaled-up provider-initiated testing and counselling (SU-PITC) in which all patients were tested with rapid tests unless they opted out; and (3) opt-out testing and counselling using POC-NAAT, which detects both acute and prevalent infection. The model-based analysis used data from the Tambua Mapema Plus randomised controlled trial of a POC-NAAT intervention in Kenya, supplemented with results from a stochastic, agent-based network model of HIV-1 transmission and data from published literature. The analysis was conducted from the perspective of the Kenyan government using a primary outcome of cost per disability-adjusted life-year (DALY) averted over a 10-year time horizon.

RESULTS

After analysing the decision-analytical model, the average per patient cost of POC-NAAT was $214.9 compared with $173.6 for SU-PITC and $47.3 for PITC. The mean DALYs accumulated per patient for POC-NAAT were 0.160 compared with 0.176 for SU-PITC and 0.214 for PITC. In the incremental analysis, SU-PITC was eliminated due to extended dominance, and the incremental cost-effectiveness ratio (ICER) comparing POC-NAAT to PITC was $3098 per DALY averted. The ICER was sensitive to disability weights for HIV/AIDS and the costs of antiretroviral therapy.

CONCLUSION

POC-NAAT offered to adult outpatients in Kenya who present for care with symptoms compatible with AHI is cost-effective and should be considered for inclusion as the standard of HIV testing in this population.

TRIAL REGISTRATION NUMBER

Tambua Mapema ("Discover Early") Plus study (NCT03508908) conducted in Kenya (2017-2020) i.e., Post-results.

Country versus pharmaceutical company interests for hepatitis C treatment

Hepatitis C virus (HCV) is one of the leading causes of liver disease and is responsible for massive health and economic burden worldwide. The disease is asymptomatic in its early stages, but it can progress over time to fatal end-stage liver disease. Thus, the majority of individuals infected with HCV are unaware of their chronic condition. Recent treatment options for HCV can completely cure the infection but are costly. We developed a game model between a pharmaceutical company (PC) and a country striving to maximize its citizens' utility. First, the PC determines the price of HCV treatment; then, the country responds with corresponding screening and treatment strategies. We employed an analytical framework to calculate the utility of the players for each selected strategy. Calibrated to detailed HCV data from Israel, we found that the PC will gain higher revenue by offering a quantity discount rather than using standard fixed pricing per treatment, by indirectly forcing the country to conduct more screening than it desired. By contrast, risk-sharing agreements, in which the country pays only for successful treatments are beneficial for the country. Our findings underscore that policy makers worldwide should prudently consider recent offers by PCs to increase screening either directly, via covering HCV screening, or indirectly, by providing discounts following a predetermined volume of sales. More broadly, our approach is applicable in other healthcare settings where screening is essential to determine treatment strategies.

Cost-effectiveness of implementing HIV and HIV/syphilis dual testing among key populations in Viet Nam: a modelling analysis

OBJECTIVES

Key populations, including sex workers, men who have sex with men, and people who inject drugs, have a high risk of HIV and sexually transmitted infections. We assessed the health and economic impacts of different HIV and syphilis testing strategies among three key populations in Viet Nam using a dual HIV/syphilis rapid diagnostic test (RDT).

SETTING

We used the spectrum AIDS impact model to simulate the HIV epidemic in Viet Nam and evaluated five testing scenarios among key populations. We used a 15-year time horizon and a provider perspective for costs.

PARTICIPANTS

We simulate the entire population of Viet Nam in the model.

INTERVENTIONS

We modelled five testing scenarios among key populations: (1) annual testing with an HIV RDT, (2) annual testing with a dual RDT, (3) biannual testing using dual RDT and HIV RDT, (4) biannual testing using HIV RDT and (5) biannual testing using dual RDT.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome is incremental cost-effectiveness ratios. Secondary outcomes include HIV and syphilis cases.

RESULTS

Annual testing using a dual HIV/syphilis RDT was cost-effective (US$10 per disability-adjusted life year (DALY)) and averted 3206 HIV cases and treated 27 727 syphilis cases compared with baseline over 15 years. Biannual testing using one dual test and one HIV RDT (US$1166 per DALY), or two dual tests (US$5672 per DALY) both averted an additional 875 HIV cases, although only the former scenario was cost-effective. Annual or biannual HIV testing using HIV RDTs and separate syphilis tests were more costly and less effective than using one or two dual RDTs.

CONCLUSIONS

Annual HIV and syphilis testing using dual RDT among key populations is cost-effective in Vietnam and similar settings to reach global reduction goals for HIV and syphilis.

A Systematic Review of Simulation Models to Track and Address the Opioid Crisis

The opioid overdose crisis is driven by an intersecting set of social, structural, and economic forces. Simulation models offer a tool to help us understand and address this complex, dynamic, and nonlinear social phenomenon. We conducted a systematic review of the literature on simulation models of opioid use and overdose up to September 2019. We extracted modeling types, target populations, interventions, and findings. Further, we created a database of model parameters used for model calibration, and evaluated study transparency and reproducibility. Of the 1,398 articles screened, we identified 88 eligible articles. The most frequent types of models were compartmental (36%), Markov (20%), system dynamics (16%), and Agent-Based models (16%). Over a third evaluated intervention cost-effectiveness (40%), and another third (39%) focused on treatment and harm reduction services for people with opioid use disorder (OUD). More than half (61%) discussed calibrating their models to empirical data, and 31% discussed validation approaches used in their modeling process. From the 63 studies that provided model parameters, we extracted the data sources on opioid use, OUD, OUD treatment, cessation/relapse, emergency medical services, and mortality parameters. This database offers a tool that future modelers can use to identify potential model inputs and evaluate comparability of their models to prior work. Future applications of simulation models to this field should actively tackle key methodological challenges, including the potential for bias in the choice of parameter inputs, investment in model calibration and validation, and transparency in the assumptions and mechanics of simulation models to facilitate reproducibility.

Predicting the Effectiveness of Endemic Infectious Disease Control Interventions: The Impact of Mass Action versus Network Model Structure

BACKGROUND

Analyses of the effectiveness of infectious disease control interventions often rely on dynamic transmission models to simulate intervention effects. We aim to understand how the choice of network or compartmental model can influence estimates of intervention effectiveness in the short and long term for an endemic disease with susceptible and infected states in which infection, once contracted, is lifelong.

METHODS

We consider 4 disease models with different permutations of socially connected network versus unstructured contact (mass-action mixing) model and heterogeneous versus homogeneous disease risk. The models have susceptible and infected populations calibrated to the same long-term equilibrium disease prevalence. We consider a simple intervention with varying levels of coverage and efficacy that reduces transmission probabilities. We measure the rate of prevalence decline over the first 365 d after the intervention, long-term equilibrium prevalence, and long-term effective reproduction ratio at equilibrium.

RESULTS

Prevalence declined up to 10% faster in homogeneous risk models than heterogeneous risk models. When the disease was not eradicated, the long-term equilibrium disease prevalence was higher in mass-action mixing models than in network models by 40% or more. This difference in long-term equilibrium prevalence between network versus mass-action mixing models was greater than that of heterogeneous versus homogeneous risk models (less than 30%); network models tended to have higher effective reproduction ratios than mass-action mixing models for given combinations of intervention coverage and efficacy.

CONCLUSIONS

For interventions with high efficacy and coverage, mass-action mixing models could provide a sufficient estimate of effectiveness, whereas for interventions with low efficacy and coverage, or interventions in which outcomes are measured over short time horizons, predictions from network and mass-action models diverge, highlighting the importance of sensitivity analyses on model structure.

HIGHLIGHTS

• We calibrate 4 models-socially connected network versus unstructured contact (mass-action mixing) model and heterogeneous versus homogeneous disease risk-to 10% preintervention disease prevalence.• We measure the short- and long-term intervention effectiveness of all models using the rate of prevalence decline, long-term equilibrium disease prevalence, and effective reproduction ratio.• Generally, in the short term, prevalence declined faster in the homogeneous risk models than in the heterogeneous risk models.• Generally, in the long term, equilibrium disease prevalence was higher in the mass-action mixing models than in the network models, and the effective reproduction ratio was higher in network models than in the mass-action mixing models.

Economic evaluation of HIV testing options for low-prevalence high-income countries: a systematic review

INTRODUCTION

This study reviewed the economic evidence of rapid HIV testing versus conventional HIV testing in low-prevalence high-income countries; evaluated the methodological quality of existing economic evaluations of HIV testing studies; and made recommendations on future economic evaluation directions of HIV testing approaches.

METHODS

A systematic search of selected databases for relevant English language studies published between Jan 1, 2001, and Jan 30, 2019, was conducted. The methodological design quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and the Drummond tool. We reported the systematic review according to the PRISMA guidelines.

RESULTS

Five economic evaluations met the eligibility criteria but varied in comparators, evaluation type, perspective, and design. The methodologic quality of the included studies ranged from medium to high. We found evidence to support the cost-effectiveness of rapid HIV testing approaches in low-prevalence high-income countries. Rapid HIV testing was associated with cost per adjusted life year (QALY), ranging from $42,768 to $90,498. Additionally, regardless of HIV prevalence, rapid HIV testing approaches were the most cost-effective option.

CONCLUSIONS

There is evidence for the cost-effectiveness of rapid HIV testing, including the use of saliva-based testing compared to usual care or hospital-based serum testing. Further studies are needed to draw evidence on the relative cost-effectiveness of the distinct options and contexts of rapid HIV testing.

<p>Evidence-Based Framework and Implementation of China’s Strategy in Combating COVID-19</p>

Introduction

In less than two months, the COVID-19 outbreak in China was controlled through the stringent strategies of screening and isolation. This article aims to use empirical data from all cases from a prefecture-level city of China to introduce and examine the feasibility and efficiency of the screening and isolation strategies and how these were essential in combatting the COVID-19 outbreak.

Methods

For this retrospective study, all confirmed COVID-19 patients were recruited from the Taizhou prefecture-level city of Zhejiang province, China.

Results

Of the city’s total population, 24% were screened for COVID-19 and isolated at home or designated locations for two weeks. From these, a total of 146 confirmed cases of COVID-19 were analysed. Of all cases, 51% were traced from Wuhan, and 21% of patients were in close contact with confirmed cases from outside of the city. Initially, 13% of all patients reported having no clear symptoms, while 42% of patients presented with fever and/or other symptoms. Compared with local patients, new arrivals to the city had fewer days between their exposure and the development of symptoms of COVID-19 (P<0.001), and fewer days from the time they developed symptoms to the confirmation of COVID-19 (P<0.001), respectively.

Conclusion

This study has fully confirmed that controlling the COVID-19 outbreak through screening and isolation is effective, efficient, and essential. The evidence-based framework and implementation of China’s strategy to combat COVID-19 can explain how China contained the COVID-19 outbreak in a short time period. This study offers important references and implications for containing the COVID-19 pandemic in the global community.

Health outcomes and cost-effectiveness of diversion programs for low-level drug offenders: A model-based analysis

BACKGROUND

Cycles of incarceration, drug abuse, and poverty undermine ongoing public health efforts to reduce overdose deaths and the spread of infectious disease in vulnerable populations. Jail diversion programs aim to divert low-level drug offenders toward community care resources, avoiding criminal justice costs and disruptions in treatment for HIV, hepatitis C virus (HCV), and drug abuse. We sought to assess the health benefits and cost-effectiveness of a jail diversion program for low-level drug offenders.

METHODS AND FINDINGS

We developed a microsimulation model, calibrated to King County, Washington, that captured the spread of HIV and HCV infections and incarceration and treatment systems as well as preexisting interventions such as needle and syringe programs and opiate agonist therapy. We considered an adult population of people who inject drugs (PWID), people who use drugs but do not inject (PWUD), men who have sex with men, and lower-risk heterosexuals. We projected discounted lifetime costs and quality-adjusted life years (QALYs) over a 10-year time horizon with and without a jail diversion program and calculated resulting incremental cost-effectiveness ratios (ICERs) from the health system and societal perspectives. We also tracked HIV and HCV infections, overdose deaths, and jail population size. Over 10 years, the program was estimated to reduce HIV and HCV incidence by 3.4% (95% CI 2.7%-4.0%) and 3.3% (95% CI 3.1%-3.4%), respectively, overdose deaths among PWID by 10.0% (95% CI 9.8%-10.8%), and jail population size by 6.3% (95% CI 5.9%-6.7%). When considering healthcare costs only, the program cost $25,500/QALY gained (95% CI $12,600-$48,600). Including savings from reduced incarceration (societal perspective) improved the ICER to $6,200/QALY gained (95% CI, cost-saving $24,300). Sensitivity analysis indicated that cost-effectiveness depends on diversion program participants accessing community programs such as needle and syringe programs, treatment for substance use disorder, and HIV and HCV treatment, as well as diversion program cost. A limitation of the analysis is data availability, as fewer data are available for diversion programs than for more established interventions aimed at people with substance use disorder. Additionally, like any model of a complex system, our model relies on simplifying assumptions: For example, we simplified pathways in the healthcare and criminal justice systems, modeled an average efficacy for substance use disorder treatment, and did not include costs associated with homelessness, unemployment, and breakdown in family structure.

CONCLUSIONS

We found that diversion programs for low-level drug offenders are likely to be cost-effective, generating savings in the criminal justice system while only moderately increasing healthcare costs. Such programs can reduce incarceration and its associated costs, and also avert overdose deaths and improve quality of life for PWID, PWUD, and the broader population (through reduced HIV and HCV transmission).

Cost-effectiveness of frequent HIV screening among high-risk young men who have sex with men in the United States

BACKGROUND

Of new HIV infections in the US, 20% occur among young men who have sex with men (YMSM, ages 13-24), but >50% of YMSM with HIV are unaware of their status. Using Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) data, we projected the clinical benefit and cost-effectiveness of frequent HIV screening among high-risk YMSM from age 15.

METHODS

Using a mathematical simulation, we examined 3 screening strategies: Yearly, 6-monthly, and 3-monthly, each in addition to the Status quo (SQ, 0.7-10.3% screened/year, stratified by age). We used published data (YMSM-specific when available) including: HIV incidences (0.91-6.41/100PY); screen acceptance (80%), linkage-to-care/antiretroviral therapy (ART) initiation (76%), HIV transmission (0.3-86.1/100PY, by HIV RNA), monthly ART costs ($2,290-$3,780), and HIV per-screen costs ($38). Projected outcomes included CD4 count at diagnosis, primary HIV transmissions from ages 15-30, quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios (ICERs, $/quality-adjusted life-year saved [QALY]; threshold ≤$100,000/QALY).

RESULTS

Compared to SQ, all strategies increased projected CD4 at diagnosis (296 to 477-515 cells/µL) and quality-adjusted life expectancy from age 15 (44.4 to 48.3-48.7 years) among YMSM acquiring HIV. Compared to SQ, all strategies increased discounted lifetime cost for the entire population ($170,800 to $178,100-$185,000/person). Screening 3-monthly was cost-effective (ICER: $4,500/QALY) compared to SQ and reduced primary transmissions through age 30 by 40%. Results were most sensitive to transmission rates; excluding the impact of transmissions, screening Yearly was ≤$100,000/QALY (ICER: $70,900/QALY).

CONCLUSIONS

For high-risk YMSM in the US, HIV screening 3-monthly compared to less frequent screening will improve clinical outcomes and be cost-effective.

Elimination of hepatitis C virus in Germany: modelling the cost-effectiveness of HCV screening strategies

BACKGROUND

Chronic hepatitis C is a major public health burden. With new interferon-free direct-acting agents (showing sustained viral response rates of more than 98%), elimination of HCV seems feasible for the first time. However, as HCV infection often remains undiagnosed, screening is crucial for improving health outcomes of HCV-patients. Our aim was to assess the long-term cost-effectiveness of a nationwide screening strategy in Germany.

METHODS

We used a Markov cohort model to simulate disease progression and examine long-term population outcomes, HCV associated costs and cost-effectiveness of HCV screening. The model divides the total population into three subpopulations: general population (GEP), people who inject drugs (PWID) and HIV-infected men who have sex with men (MSM), with total infection numbers being highest in GEP, but new infections occurring only in PWIDs and MSM. The model compares four alternative screening strategies (no/basic/advanced/total screening) differing in participation and treatment rates.

RESULTS

Total number of HCV-infected patients declined from 275,000 in 2015 to between 125,000 (no screening) and 14,000 (total screening) in 2040. Similarly, lost quality adjusted life years (QALYs) were 320,000 QALYs lower, while costs were 2.4 billion EUR higher in total screening compared to no screening. While incremental cost-effectiveness ratio (ICER) increased sharply in GEP and MSM with more comprehensive strategies (30,000 EUR per QALY for total vs. advanced screening), ICER decreased in PWIDs (30 EUR per QALY for total vs. advanced screening).

CONCLUSIONS

Screening is key to have an efficient decline of the HCV-infected population in Germany. Recommendation for an overall population screening is to screen the total PWID subpopulation, and to apply less comprehensive advanced screening for MSM and GEP.

Cost-effectiveness of scaling-up HCV prevention and treatment in the United States for people who inject drugs

AIMS

To examine the cost-effectiveness of hepatitis C virus (HCV) treatment of people who inject drugs (PWID), combined with medication-assisted treatment (MAT) and syringe-service programs (SSP), to tackle the increasing HCV epidemic in the United States.

DESIGN

HCV transmission and disease progression models with cost-effectiveness analysis using a health-care perspective.

SETTING

Rural Perry County, KY (PC) and urban San Francisco, CA (SF), USA. Compared with PC, SF has a greater proportion of PWID with access to MAT or SSP. HCV treatment of PWID is negligible in both settings.

PARTICIPANTS

PWID data were collected between 1998 and 2015 from Social Networks Among Appalachian People, U Find Out, Urban Health Study and National HIV Behavioral Surveillance System studies.

INTERVENTIONS AND COMPARATOR

Three intervention scenarios modeled: baseline-existing SSP and MAT coverage with HCV screening and treatment with direct-acting antiviral for ex-injectors only as per standard of care; intervention 1-scale-up of SSP and MAT without changes to treatment; and intervention 2-scale-up as intervention 1 combined with HCV screening and treatment for current PWID.

MEASUREMENTS

Incremental cost-effectiveness ratios (ICERs) and uncertainty using cost-effectiveness acceptability curves. Benefits were measured in quality-adjusted life-years (QALYs).

FINDINGS

For both settings, intervention 2 is preferred to intervention 1 and the appropriate comparator for intervention 2 is the baseline scenario. Relative to baseline, for PC intervention 2 averts 1852 more HCV infections, increases QALYS by 3095, costs $21.6 million more and has an ICER of $6975/QALY. For SF, intervention 2 averts 36 473 more HCV infections, increases QALYs by 7893, costs $872 million more and has an ICER of $11 044/QALY. The cost-effectiveness of intervention 2 was robust to several sensitivity analysis.

CONCLUSIONS

Hepatitis C screening and treatment for people who inject drugs, combined with medication-assisted treatment and syringe-service programs, is a cost-effective strategy for reducing hepatitis C burden in the United States.

Evidence for optimal HIV screening and testing intervals in HIV-negative individuals from various risk groups: A systematic review

Background

Human immunodeficiency virus (HIV) testing plays a crucial role in Canada's HIV prevention and treatment efforts and is the first step to achieving the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets; however, how often Canadians, including populations at increased risk of HIV exposure, should be tested is unclear. We conducted a systematic literature review to determine the optimal HIV screening and testing intervals.

Objective

To examine the current evidence on HIV testing intervals in HIV-negative individuals from various risk groups and to assess the potential harms and patients' values and preferences associated with different testing frequencies.

Methods

We searched MEDLINE/PubMed, Scopus, Embase, the Cochrane Library, PsychINFO and EconLit for studies on different frequencies of HIV testing published between January 2000 and September 2016. An additional search was conducted for grey literature published between January 2000 and October 2016. Data extraction included study characteristics, participants, exposure, outcomes and economic variables. The quality of the studies was assessed and results summarized.

Results

Of the 2,702 articles identified from the searches, 27 met the inclusion criteria for review. This included assessments of HIV testing intervals among the general population, men who have sex with men, people who use injection drugs and sex workers. Optimal testing intervals across risk groups ranged from one-time testing to every three months. Data from modelling studies may not be representative of the Canadian context. Few studies identified potential harms of increased screening, specifically an increase in both false positive and false negative results. There were only two studies that addressed patient values and preferences concerning HIV screening, which suggested that the majority of participants were amenable to routine screening through their primary care provider.

Conclusion

There was insufficient evidence to support optimal HIV screening and testing intervals for different populations. Context-specific factors, such as budget allocation, human resources, local epidemiology, socioeconomic factors and risk behaviours, along with clinical judgement, inform whom and how often to screen, suggesting the need for research specific to Canada. Research on patient preferences as well as the benefits and harms of more frequent screening are also indicated.

A Systematic Comparison of African American and Non-African American Patients on Psychosocial Aspects of Hepatitis C Infection

The purpose of this study was to compare African American and non-African American hepatitis C virus (HCV) patients on self-reported symptoms of HCV liver disease and psychosocial characteristics commonly affected by it in a sample of 309 patients enrolled in a randomized controlled trial. African Americans (n = 196) rated a higher reliance on religion/spirituality for coping with HCV compared to non-African Americans. This study's findings are a basis for encouragement of public health efforts and programs to seek partnerships with African American faith and religious communities to identify and treat undiagnosed cases of HCV and promote HCV awareness.

Cost-effectiveness of HIV screening in high-income countries: A systematic review

INTRODUCTION

Over 2 million people in high-income countries live with HIV. Early diagnosis and treatment present benefits for infected subjects and reduce secondary transmissions. Cost-effectiveness analyses are important to effectively inform policy makers and consequently implement the most cost-effective programmes. Therefore, we conducted a systematic review regarding the cost-effectiveness of HIV screening in high-income countries.

METHODS

We followed PRISMA statements and included all papers evaluating the cost-effectiveness of HIV screening in the general population or in specific subgroups.

RESULTS

Thirteen studies considered routine HIV testing in the general population. The most cost-effective option appeared to be associating one-time testing of the general population with annual screening of high-risk groups, such as injecting-drug users. Thirteen studies assessed the cost-effectiveness of HIV screening in specific settings, outlining the attractiveness of similar programmes in emergency departments, primary care, sexually transmitted disease clinics and substance abuse treatment programmes.

DISCUSSION

Evidence regarding the health benefits and cost-effectiveness of HIV screening is growing, even in low-prevalence countries. One-time screenings offered to the adult population appear to be a valuable choice, associated with repeated testing in high-risk populations. The evidence regarding the benefits of using a rapid test, even in terms of cost-effectiveness, is growing. Finally, HIV screening seems useful in specific settings, such as emergency departments and STD clinics.

Intervention Packages to Reduce the Impact of HIV and HCV Infections Among People Who Inject Drugs in Eastern Europe and Central Asia: A Modeling and Cost-effectiveness Study

Background

We evaluated the effectiveness and cost-effectiveness of interventions targeting hepatitis C virus (HCV) and HIV infections among people who inject drugs (PWID) in Eastern Europe/Central Asia. We specifically considered the needle-syringe program (NSP), opioid substitution therapy (OST), HCV and HIV diagnosis, antiretroviral therapy (ART), and/or new HCV treatment (direct acting antiviral [DAA]) in Belarus, Georgia, Kazakhstan, Republic of Moldova, and Tajikistan.

Methods

We developed a deterministic dynamic compartmental model and evaluated the number of infections averted, costs, and incremental cost-effectiveness ratios (ICERs) of interventions. OST decreased frequencies of injecting by 85% and NSP needle sharing rates by 57%; ART was introduced at CD4 <350 and DAA at fibrosis stage ≥F2 at a $2370 to $23 280 cost.

Results

Increasing NSP+OST had a high impact on transmissions (infections averted in PWID: 42% in Tajikistan to 55% in Republic of Moldova for HCV; 30% in Belarus to 61% in Kazakhstan for HIV over 20 years). Increasing NSP+OST+ART was very cost-effective in Georgia (ICER = $910/year of life saved [YLS]), and was cost-saving in Kazakhstan and Republic of Moldova. NSP+OST+ART and HIV diagnosis was very cost-effective in Tajikistan (ICER = $210/YLS). Increasing the coverage of all interventions was always the most effective strategy and was cost-effective in Belarus and Kazakhstan (ICER = $12 960 and $21 850/YLS); it became cost-effective/cost-saving in all countries when we decreased DAA costs.

Conclusion

Increasing NSP+OST coverage, in addition to ART and HIV diagnosis, had a high impact on both epidemics and was very cost-effective and even cost-saving. When HCV diagnosis was improved, increased DAA averted a high number of new infections if associated with NSP+OST.

Structural Sensitivity in HIV Modeling: A Case Study of Vaccination

Structural assumptions in infectious disease models, such as the choice of network or compartmental model type or the inclusion of different types of heterogeneity across individuals, might affect model predictions as much as or more than the choice of input parameters. We explore the potential implications of structural assumptions on HIV model predictions and policy conclusions. We illustrate the value of inference robustness assessment through a case study of the effects of a hypothetical HIV vaccine in multiple population subgroups over eight related transmission models, which we sequentially modify to vary over two dimensions: parameter complexity (e.g., the inclusion of age and HCV comorbidity) and contact/simulation complexity (e.g., aggregated compartmental vs. individual/disaggregated compartmental vs. network models). We find that estimates of HIV incidence reductions from network models and individual compartmental models vary, but those differences are overwhelmed by the differences in HIV incidence between such models and the aggregated compartmental models (which aggregate groups of individuals into compartments). Complexities such as age structure appear to buffer the effects of aggregation and increase the threshold of net vaccine effectiveness at which aggregated models begin to overestimate reductions. The differences introduced by parameter complexity in estimated incidence reduction also translate into substantial differences in cost-effectiveness estimates. Parameter complexity does not appear to play a consistent role in differentiating the projections of network models.

Economic evaluation of HCV testing approaches in low and middle income countries

Background

Hepatitis C virus (HCV) infection represents a major public health burden with diverse epidemics worldwide, but at present, only a minority of infected persons have been tested and are aware of their diagnosis. The advent of highly effective direct acting antiviral (DAA) therapy, which is becoming available at increasingly lower costs in low and middle income countries (LMICs), represents a major opportunity to expand access to testing and treatment. However, there is uncertainty as to the optimal testing approaches and who to prioritize for testing. We undertook a narrative review of the cost-effectiveness literature on different testing approaches for chronic hepatitis C infection to inform decision-making and formulation of recommendations in the 2017 World Health Organization (WHO) viral hepatitis testing guidelines.

Methods

We undertook a focused search and narrative review of the literature for cost effectiveness studies of testing approaches in three main groups:- 1) focused testing of specific high-risk groups (defined as those who are part of a population with higher seroprevalence or who have a history of exposure or high-risk behaviours); 2) “birth cohort” testing among easily identified age groups (i.e. specific birth cohorts) known to have a high prevalence of HCV infection; and 3) routine testing in the general population. Articles included were those published in PubMed, written in English and published after 2000.

Results

We identified 26 eligible studies. Twenty-four of them were from Europe (n = 14) or the United States (n = 10). There was only one study from a LMIC (Egypt) and this evaluated general population testing. Thirteen studies evaluated focused testing among specific groups at high risk for HCV infection, including nine in persons who inject drugs (PWID); five among people in prison, and one among HIV-infected men who have sex with men (MSM). Eight studies evaluated birth cohort testing, and five evaluated testing in the general population. Most studies were based on a one-time testing intervention, but in one study testing was undertaken every 5 years and in another among HIV-infected MSM there was more frequent testing. Comparators were generally either: 1) no testing, 2) the status quo, or 3) multiple different strategies. Overall, we found broad agreement that focused testing of high risk groups such as persons who inject drugs and men who have sex with men was cost-effective, as was birth cohort testing. Key drivers of cost-effectiveness were the prevalence of HCV infection in these groups, efficacy and cost of treatment, stage of disease and linkage to care. The evidence for routine population testing was mixed, and the cost-effectiveness depends largely on the prevalence of HCV.

Conclusions

The evidence base for different HCV testing approaches in LMICs is limited, minimizing the contribution of cost-effectiveness data alone to decision-making and recommendations on testing approaches in the 2017 WHO viral hepatitis testing guidelines. Overall, the guidelines recommended focused testing in high risk-groups, particularly PWID, prisoners, and men who have sex with men; with consideration of two other approaches:- birth cohort testing in those countries with epidemiological evidence of a significant birth cohort effect; and routine access to testing across the general population in those countries with a high HCV seroprevalence above 2% - 5% in the general population. Further implementation research on different testing approaches is needed in order to help guide national policy planning.

Risk stratification in compartmental epidemic models: Where to draw the line?

Economic evaluations of infectious disease control interventions frequently use dynamic compartmental epidemic models. Such models capture heterogeneity in risk of infection by stratifying the population into discrete risk groups, thus approximating what is typically continuous variation in risk. An important open question is whether and how different risk stratification choices influence model predictions of intervention effects. We develop equivalent Susceptible-Infected-Susceptible (SIS) dynamic transmission models: an unstratified model, a model stratified into a high-risk and low-risk group, and a model with an arbitrary number of risk groups. Absent intervention, the models produce the same overall prevalence of infected individuals in steady state. We consider an intervention that either reduces the contact rate or increases the disease clearance rate. We develop analytical and numerical results characterizing the models and the effects of the intervention. We find that there exist multiple feasible choices of risk stratification, contact distribution, and within- and between-group contact rates for models that stratify risk. We show analytically and empirically that these choices can generate different estimates of intervention effectiveness, and that these differences can be significant enough to alter conclusions from cost-effectiveness analyses and change policy recommendations. We conclude that the choice of how to discretize risk in compartmental epidemic models can influence predicted effectiveness of interventions. Therefore, analysts should examine multiple alternatives and report the range of results.

Estimation of the cost-effectiveness of HIV prevention portfolios for people who inject drugs in the United States: A model-based analysis

BACKGROUND

The risks of HIV transmission associated with the opioid epidemic make cost-effective programs for people who inject drugs (PWID) a public health priority. Some of these programs have benefits beyond prevention of HIV-a critical consideration given that injection drug use is increasing across most United States demographic groups. To identify high-value HIV prevention program portfolios for US PWID, we consider combinations of four interventions with demonstrated efficacy: opioid agonist therapy (OAT), needle and syringe programs (NSPs), HIV testing and treatment (Test & Treat), and oral HIV pre-exposure prophylaxis (PrEP).

METHODS AND FINDINGS

We adapted an empirically calibrated dynamic compartmental model and used it to assess the discounted costs (in 2015 US dollars), health outcomes (HIV infections averted, change in HIV prevalence, and discounted quality-adjusted life years [QALYs]), and incremental cost-effectiveness ratios (ICERs) of the four prevention programs, considered singly and in combination over a 20-y time horizon. We obtained epidemiologic, economic, and health utility parameter estimates from the literature, previously published models, and expert opinion. We estimate that expansions of OAT, NSPs, and Test & Treat implemented singly up to 50% coverage levels can be cost-effective relative to the next highest coverage level (low, medium, and high at 40%, 45%, and 50%, respectively) and that OAT, which we assume to have immediate and direct health benefits for the individual, has the potential to be the highest value investment, even under scenarios where it prevents fewer infections than other programs. Although a model-based analysis can provide only estimates of health outcomes, we project that, over 20 y, 50% coverage with OAT could avert up to 22,000 (95% CI: 5,200, 46,000) infections and cost US$18,000 (95% CI: US$14,000, US$24,000) per QALY gained, 50% NSP coverage could avert up to 35,000 (95% CI: 8,900, 43,000) infections and cost US$25,000 (95% CI: US$7,000, US$76,000) per QALY gained, 50% Test & Treat coverage could avert up to 6,700 (95% CI: 1,200, 16,000) infections and cost US$27,000 (95% CI: US$15,000, US$48,000) per QALY gained, and 50% PrEP coverage could avert up to 37,000 (22,000, 58,000) infections and cost US$300,000 (95% CI: US$162,000, US$667,000) per QALY gained. When coverage expansions are allowed to include combined investment with other programs and are compared to the next best intervention, the model projects that scaling OAT coverage up to 50%, then scaling NSP coverage to 50%, then scaling Test & Treat coverage to 50% can be cost-effective, with each coverage expansion having the potential to cost less than US$50,000 per QALY gained relative to the next best portfolio. In probabilistic sensitivity analyses, 59% of portfolios prioritized the addition of OAT and 41% prioritized the addition of NSPs, while PrEP was not likely to be a priority nor a cost-effective addition. Our findings are intended to be illustrative, as data on achievable coverage are limited and, in practice, the expansion scenarios considered may exceed feasible levels. We assumed independence of interventions and constant returns to scale. Extensive sensitivity analyses allowed us to assess parameter sensitivity, but the use of a dynamic compartmental model limited the exploration of structural sensitivities.

CONCLUSIONS

We estimate that OAT, NSPs, and Test & Treat, implemented singly or in combination, have the potential to effectively and cost-effectively prevent HIV in US PWID. PrEP is not likely to be cost-effective in this population, based on the scenarios we evaluated. While local budgets or policy may constrain feasible coverage levels for the various interventions, our findings suggest that investments in combined prevention programs can substantially reduce HIV transmission and improve health outcomes among PWID.

Allocative and implementation efficiency in HIV prevention and treatment for people who inject drugs

BACKGROUND

Estimated global new HIV infections among people who inject drugs (PWID) remained stable over the 2010-2015 period and the target of a 50% reduction over this period was missed. To achieve the 2020 UNAIDS target of reducing adult HIV infections by 75% compared to 2010, accelerated action in scaling up HIV programs for PWID is required. In a context of diminishing external support to HIV programs in countries where most HIV-affected PWID live, it is essential that available resources are allocated and used as efficiently as possible.

METHODS

Allocative and implementation efficiency analysis methods were applied. Optima, a dynamic, population-based HIV model with an integrated program and economic analysis framework was applied in eight countries in Eastern Europe and Central Asia (EECA). Mathematical analyses established optimized allocations of resources. An implementation efficiency analysis focused on examining technical efficiency, unit costs, and heterogeneity of service delivery models and practices.

RESULTS

Findings from the latest reported data revealed that countries allocated between 4% (Bulgaria) and 40% (Georgia) of total HIV resources to programs targeting PWID - with a median of 13% for the eight countries. When distributing the same amount of HIV funding optimally, between 9% and 25% of available HIV resources would be allocated to PWID programs with a median allocation of 16% and, in addition, antiretroviral therapy would be scaled up including for PWID. As a result of optimized allocations, new HIV infections are projected to decline by 3-28% and AIDS-related deaths by 7-53% in the eight countries. Implementation efficiencies identified involve potential reductions in drug procurement costs, service delivery models, and practices and scale of service delivery influencing cost and outcome. A high level of implementation efficiency was associated with high volumes of PWID clients accessing a drug harm reduction facility.

CONCLUSION

A combination of optimized allocation of resources, improved implementation efficiency and increased investment of non-HIV resources is required to enhance coverage and improve outcomes of programs for PWID. Increasing efficiency of HIV programs for PWID is a key step towards avoiding implicit rationing and ensuring transparent allocation of resources where and how they would have the largest impact on the health of PWID, and thereby ensuring that funding spent on PWID becomes a global best buy in public health.

Acute HIV infection transmission among people who inject drugs in a mature epidemic setting

OBJECTIVE

Estimates for the contribution of transmission arising from acute HIV infections (AHIs) to overall HIV incidence vary significantly. Furthermore, little is known about AHI-attributable transmission among people who inject drugs (PWID), including the extent to which interventions targeting chronic infections (e.g. HAART as prevention) are limited by AHI transmission. Thus, we estimated the proportion of transmission events attributable to AHI within the mature HIV epidemic among PWID in New York City (NYC).

DESIGN

Modeling study.

METHODS

We constructed an interactive sexual and injecting transmission network using an agent-based model simulating the HIV epidemic in NYC between 1996 and 2012. Using stochastic microsimulations, we cataloged transmission from PWID based on the disease stage of index agents to determine the proportion of infections transmitted during AHI (in primary analyses, assumed to last 3 months).

RESULTS

Our calibrated model approximated the epidemiological features of the mature HIV epidemic in NYC between 1996 and 2012. Annual HIV incidence among PWID dropped from approximately 1.8% in 1996 to 0.7% in 2012. Over the 16-year period, AHI accounted for 4.9% (10th/90th percentile: 0.1-12.3%) of incident HIV cases among PWID. The annualized contribution of AHI increased over this period from 3.6% in 1996 to 5.9% in 2012.

CONCLUSION

Our results suggest that, in mature epidemics such as NYC, between 3% and 6% of transmission events are attributable to AHI among PWID. Current HIV treatment as prevention strategies are unlikely to be substantially affected by AHI-attributable transmission among PWID populations in mature epidemic settings.

Effective but costly: How to tackle difficult trade-offs in evaluating health improving technologies in liver diseases

In the current context of rising health care costs and decreasing sustainability, it is becoming increasingly common to resort to decision analytical modeling and health economics evaluations. Decision analytic models are analytical tools that help decision makers to select the best choice between alternative health care interventions, taking into consideration the complexity of the disease, the socioeconomic context, and the relevant differences in outcomes. We present a brief overview of the use of decision analytical models in health economic evaluations and their applications in the area of liver diseases. The aim is to provide the reader with the basic elements to evaluate health economic analysis reports and to discuss some limitations of the current approaches, as highlighted by the case of the therapy of chronic hepatitis C. To serve its purpose, health economics evaluations must be able to do justice to medical innovation and the market while protecting patients and society and promoting fair access to treatment and its economic sustainability.

CONCLUSION

New approaches and methods able to include variables such as prevalence of the disease, budget impact, and sustainability into the cost-effectiveness analysis are needed to reach this goal. (Hepatology 2016;64:1331-1342).

Who to test and how to test for chronic hepatitis C infection - 2016 WHO testing guidance for low- and middle-income countries

Testing and diagnosis of hepatitis C virus (HCV) infection is the gateway for access to both treatment and prevention services, and crucial for an effective hepatitis epidemic response. In contrast to HIV, a systematic approach to hepatitis C testing has been fragmented and limited to a few countries, and there remains a large burden of undiagnosed cases globally. Key challenges in the current hepatitis testing response, include lack of simple, reliable, and low cost diagnostic tests, laboratory capacity, and testing facilities; inadequate data to guide country-specific hepatitis testing approaches and who to test; stigmatization and social marginalization of some groups with or at risk of viral hepatitis; and lack of international or national guidelines on hepatitis testing for resource-limited settings. New tools to support the hepatitis global response include the 2016 Global Hepatitis Health Sector Strategy which include targets for testing and diagnosis, and World Health Organization (WHO) 2016 hepatitis testing guidelines for adults, adolescents, and children in low- and middle-income countries. The testing guidance complements recent published WHO guidance on the prevention, care and treatment of chronic hepatitis C and hepatitis B infection. These testing guidelines outline the public health approach to strengthening and expanding current testing practices for HCV and HBV and address what serological and virological assays to use, and who to test, as well as interventions to promote linkage to prevention and care after testing. They are intended for use across all age groups and populations. See boxes for key recommendations. Future directions and innovations in viral hepatitis testing include use of point-of-care assays for nucleic acid testing (NAT) and core antigen; validation of dried blood spots specimens with different commercial serological and NAT assays; multiplex and polyvalent platforms for integrated testing of HIV, HBV and HCV; and potential for self-testing.

Impact of HIV Status Notification on Risk Behaviors among Men Who Inject Drugs in Kermanshah, West of Iran

BACKGROUND

It is unclear whether knowing of current HIV status is associated with change in injecting behaviors among people who inject drugs (PWID) in Iran. The objective of the present study was to determine whether awareness of HIV positive status is associated with a reduction in injecting risk behaviors, after matching for socio-demographic characteristics.

METHODS

Five hundred male PWID were recruited in 2014 from two drop-in centers (DICs) in Kermanshah west of Iran. Trained interviewers collected data on socio-demographic characteristics, HIV testing and drug-related risk behaviors over the last month prior to interview using a structured questionnaire. Our primary exposure of interest was awareness of HIV status, used to group participants into three categories: positive, negative, unaware. We used coarsened exact matching to make the three groups statistically equivalent based on age, place of residence, education and income, and then compared them regarding the proportion of borrowing, lending and reuse of syringes.

RESULTS

Matched sample (n=320) had a mean age ± standard deviation (SD) of 33.5 ±7.6 yr. Overall, 25% (95% CI: 14%, 32%) of participants reported "borrowing a syringe" in the past month and 15% (95% CI: 7%, 22%) of them reported "lending a used syringe" to others in the past month. In comparison to PWID who were unaware of their HIV status, those knew they were HIV positive (OR 1.68, CI95%1.32-2.81) or negative (OR 1.54; 95% CI: 1.28, 2.71) were both more likely to report borrowing syringes in past month.

CONCLUSIONS

PWID WHO know they are positive for HIV are more likely to borrow another person's syringe, to report reuse of their own used syringes and less likely to report lending their syringes to others. Strategies to scale up HIV testing and counseling for PWID, which also increase awareness of HIV status, may decrease injecting related the risk behaviors.

Cost-Effectiveness of HIV Preexposure Prophylaxis for People Who Inject Drugs in the United States

BACKGROUND

The total population health benefits and costs of HIV preexposure prophylaxis (PrEP) for people who inject drugs (PWID) in the United States are unclear.

OBJECTIVE

To evaluate the cost-effectiveness and optimal delivery conditions of PrEP for PWID.

DESIGN

Empirically calibrated dynamic compartmental model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Adult U.S. PWID.

TIME HORIZON

20 years and lifetime.

INTERVENTION

PrEP alone, PrEP with frequent screening (PrEP+screen), and PrEP+screen with enhanced provision of antiretroviral therapy (ART) for individuals who become infected (PrEP+screen+ART). All scenarios are considered at 25% coverage.

OUTCOME MEASURES

Infections averted, deaths averted, change in HIV prevalence, discounted costs (in 2015 U.S. dollars), discounted quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

PrEP+screen+ART dominates other strategies, averting 26 700 infections and reducing HIV prevalence among PWID by 14% compared with the status quo. Achieving these benefits costs $253 000 per QALY gained. At current drug prices, total expenditures for PrEP+screen+ART could be as high as $44 billion over 20 years.

RESULTS OF SENSITIVITY ANALYSIS

Cost-effectiveness of the intervention is linear in the annual cost of PrEP and is dependent on PrEP drug adherence, individual transmission risks, and community HIV prevalence.

LIMITATION

Data on risk stratification and achievable PrEP efficacy levels for U.S. PWID are limited.

CONCLUSION

PrEP with frequent screening and prompt treatment for those who become infected can reduce HIV burden among PWID and provide health benefits for the entire U.S. population, but, at current drug prices, it remains an expensive intervention both in absolute terms and in cost per QALY gained.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse.

Cost-Effectiveness of Frequent HIV Testing of High-Risk Populations in the United States

PURPOSE

Data showing a high incidence of HIV infection among men who have sex with men (MSM) who had annual testing suggest that more frequent HIV testing may be warranted. Testing technology is also a consideration given the availability of sensitive testing modalities and the increased use of less-sensitive rapid, point-of-care antibody tests. We assessed the cost-effectiveness of HIV testing of MSM and injection drug users (IDUs) at 3- and 6-month intervals using fourth-generation and rapid tests.

METHODS

We used a published mathematical model of HIV transmission to evaluate testing intervals for each population using cohorts of 10,000 MSM and IDU. We incorporated HIV transmissions averted due to serostatus awareness and viral suppression. We included costs for HIV testing and treatment initiation, and also treatment costs saved from averted transmissions.

RESULTS

For MSM, HIV testing was cost saving or cost effective over a 1-year period for both 6-month compared with annual testing and quarterly compared with 6-month testing using either test. Testing IDU every 6 months compared with annually was moderately cost effective over a 1-year period with a fourth-generation test, while testing with rapid, point-of-care tests or quarterly was not cost effective. MSM results remained robust in sensitivity analysis, whereas IDU results were sensitive to changes in HIV incidence and continuum-of-care parameters. Threshold analyses on costs suggested that additional implementation costs could be incurred for more frequent testing for MSM while remaining cost effective.

CONCLUSIONS

HIV testing of MSM as frequently as quarterly is cost effective compared with annual testing, but testing IDU more frequently than annually is generally not cost effective.

HIV Infection Care and Viral Suppression Among People Who Inject Drugs, 28 U.S. Jurisdictions, 2012-2013

Objectives:

Assess outcomes along the care continuum for HIV-infected people who inject drugs (PWID), by type of facility and stage of infection at diagnosis.

Methods:

Data reported by 28 jurisdictions to the National HIV Surveillance System by December 2014 were used to identify PWID aged ≥13 years, diagnosed with HIV infection before December 31, 2013. Analyses used the CDC definition of linkage to care (LTC), retention in care (RIC), and viral suppression (VS), and are stratified by age, sex, race/ethnicity, and type of facility and stage of HIV infection at diagnosis.

Results:

Of 1,409 PWID diagnosed with HIV in 2013, 1,116 (79.2%) were LTC with the lowest percentages among males (78.4%); blacks (77.5%) ages 13-24 years (69.0%); those diagnosed in early stage infection (71.6%); and at screening, diagnostic, or referral agencies (60.0%). Of 80,958 PWID living with HIV in 2012, 40,234 (49.7%) were RIC and 34,665 (42.8%) achieved VS. The lowest percentages for RIC and VS were among males (47.1% and 41.3% respectively); those diagnosed with late stage disease (47.1% and 42.4%); and young people. Whites had the lowest RIC (47.0%) while blacks had the lowest VS (41.1%).

Conclusion:

Enhanced LTC activities are needed for PWID diagnosed at screening, diagnostic or referral agencies versus those diagnosed at inpatient or outpatient settings, especially among young people and blacks diagnosed in early stage infection. Less than half of PWID are retained in care or reach viral suppression indicating the need for continued engagement and return to care activities over the long term.

Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections

Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.

Cost-Effectiveness of HBV and HCV Screening Strategies--A Systematic Review of Existing Modelling Techniques

Introduction

Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches.

Methods

A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions.

Results

The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology.

Conclusion

When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers.

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.

Costs per Diagnosis of Acute HIV Infection in Community-based Screening Strategies: A Comparative Analysis of Four Screening Algorithms

BACKGROUND

In nonhealthcare settings, widespread screening for acute human immunodeficiency virus (HIV) infection (AHI) is limited by cost and decision algorithms to better prioritize use of resources. Comparative cost analyses for available strategies are lacking.

METHODS

To determine cost-effectiveness of community-based testing strategies, we evaluated annual costs of 3 algorithms that detect AHI based on HIV nucleic acid amplification testing (EarlyTest algorithm) or on HIV p24 antigen (Ag) detection via Architect (Architect algorithm) or Determine (Determine algorithm) as well as 1 algorithm that relies on HIV antibody testing alone (Antibody algorithm). The cost model used data on men who have sex with men (MSM) undergoing community-based AHI screening in San Diego, California. Incremental cost-effectiveness ratios (ICERs) per diagnosis of AHI were calculated for programs with HIV prevalence rates between 0.1% and 2.9%.

RESULTS

Among MSM in San Diego, EarlyTest was cost-savings (ie, ICERs per AHI diagnosis less than $13.000) when compared with the 3 other algorithms. Cost analyses relative to regional HIV prevalence showed that EarlyTest was cost-effective (ie, ICERs less than $69.547) for similar populations of MSM with an HIV prevalence rate >0.4%; Architect was the second best alternative for HIV prevalence rates >0.6%.

CONCLUSIONS

Identification of AHI by the dual EarlyTest screening algorithm is likely to be cost-effective not only among at-risk MSM in San Diego but also among similar populations of MSM with HIV prevalence rates >0.4%.

Economic evaluation of screening programs for hepatitis C virus infection: evidence from literature

BACKGROUND

Hepatitis C is a liver infection caused by hepatitis C virus. Its main complications are cirrhosis and liver cancer. According to the World Health Organization (WHO), more than 185 million people worldwide are infected with hepatitis C virus and, of these, 350,000 die every year. Due to the high disease prevalence and the existence of effective (and expensive) medical treatments able to dramatically change the prognosis, early detection programs can potentially prevent the development of serious chronic conditions, improve health, and save resources.

OBJECTIVE

To summarize the available evidence on the cost-effectiveness of screening programs for hepatitis C.

METHODS

A literature search was performed on PubMed and Scopus search engines. Trip database was queried to identify reports produced by the major Health Technology Assessment (HTA) agencies. Three reviewers dealt with study selection and data extraction blindly.

RESULTS

Ten papers eventually met the inclusion criteria. In studies focusing on asymptomatic cohorts of individuals at general risk the cost/quality adjusted life year of screening programs ranged between US $4,200 and $50,000/quality adjusted life year gained, while in those focusing on specific risk factors the incremental cost-effectiveness ratio ranged between $848 and $128,424/quality adjusted life year gained. Age of the target population and disease prevalence were the main cost-effectiveness drivers.

CONCLUSION

Our results suggest that, especially in the long run, screening programs represent a cost-effective strategy for the management of hepatitis C.

A systematic review on cost effectiveness of HIV prevention interventions in the United States

BACKGROUND

The Centers for Disease Control and Prevention (CDC) focus on funding HIV prevention interventions likely to have high impact on the HIV epidemic. In its most recent funding announcement to state and local health department grantees, CDC required that health departments allocate the majority of funds to four HIV prevention interventions: HIV testing, prevention with HIV-positives and their partners, condom distribution and policy initiatives.

OBJECTIVE

We conducted a systematic review of the published literature to determine the extent of the cost-effectiveness evidence for each of those interventions.

METHODOLOGY

We searched for US-based studies published through October 2012. The studies that qualified for inclusion contained original analyses that reported costs per quality-adjusted life-year saved, life-year saved, HIV infection averted, or new HIV diagnosis. For each study, paired reviewers performed a detailed review and data extraction. We reported the number of studies related to each intervention and summarized key cost-effectiveness findings according to intervention type. Costs were converted to 2011 US dollars.

RESULTS

Of the 50 articles that met the inclusion criteria, 33 related to HIV testing, 15 assessed prevention with HIV-positives and partners, three reported on condom distribution, and one reported on policy initiatives. Methodologies and cost-effectiveness metrics varied across studies and interventions, making them difficult to compare.

CONCLUSION

Our review provides an updated summary of the published evidence of cost effectiveness of four key HIV prevention interventions recommended by CDC. With the exception of testing-related interventions, including partner services, where economic evaluations suggest that testing often can be cost effective, more cost-effectiveness research is needed to help guide the most efficient use of HIV prevention funds.

Hepatitis C and HIV Coinfection for Social Workers in Public Health, Medical and Substance Use Treatment Settings

Hepatitis C virus (HCV) infection is a leading cause of liver disease and liver-related deaths among those living with human immunodeficiency virus (HIV) infection. Due to recent pharmacologic advancements with direct acting antivirals, if detected and treated, HCV antiviral therapy can prevent liver disease progression and permanently cure coinfected patients of HCV. The objectives of this article are to inform public health social workers and social workers in medical and substance use treatment settings of the public health burden of HCV/HIV coinfection and to highlight state-of-the art pharmacologic advancements in HCV antiviral therapy.

Dynamic modelling of hepatitis C virus transmission among people who inject drugs: a methodological review

Equipment sharing among people who inject drugs (PWID) is a key risk factor in infection by hepatitis C virus (HCV). Both the effectiveness and cost-effectiveness of interventions aimed at reducing HCV transmission in this population (such as opioid substitution therapy, needle exchange programmes or improved treatment) are difficult to evaluate using field surveys. Ethical issues and complicated access to the PWID population make it difficult to gather epidemiological data. In this context, mathematical modelling of HCV transmission is a useful alternative for comparing the cost and effectiveness of various interventions. Several models have been developed in the past few years. They are often based on strong hypotheses concerning the population structure. This review presents compartmental and individual-based models to underline their strengths and limits in the context of HCV infection among PWID. The final section discusses the main results of the papers.

Knowledge and awareness of acute human immunodeficiency virus infection among mobile app-using men who have sex with men: a missed public health opportunity

In a national online survey, we assessed awareness and knowledge of acute human immunodeficiency virus (HIV) infection manifestation among 1748 men who have sex with men (MSM). Only 39% of respondents were aware that acute HIV infection may be accompanied by symptoms. Education and increased access to acute HIV testing may facilitate MSM to appropriately seek acute HIV testing.

Cost-effectiveness of rapid hepatitis C virus (HCV) testing and simultaneous rapid HCV and HIV testing in substance abuse treatment programs

AIMS

To evaluate the cost-effectiveness of rapid hepatitis C virus (HCV) and simultaneous HCV/HIV antibody testing in substance abuse treatment programs.

DESIGN

We used a decision analytic model to compare the cost-effectiveness of no HCV testing referral or offer, off-site HCV testing referral, on-site rapid HCV testing offer and on-site rapid HCV and HIV testing offer. Base case inputs included 11% undetected chronic HCV, 0.4% undetected HIV, 35% HCV co-infection among HIV-infected, 53% linked to HCV care after testing antibody-positive and 67% linked to HIV care. Disease outcomes were estimated from established computer simulation models of HCV [Hepatitis C Cost-Effectiveness (HEP-CE)] and HIV [Cost-Effectiveness of Preventing AIDS Complications (CEPAC)].

SETTING AND PARTICIPANTS

Data on test acceptance and costs were from a national randomized trial of HIV testing strategies conducted at 12 substance abuse treatment programs in the United States.

MEASUREMENTS

Lifetime costs (2011 US$) and quality-adjusted life years (QALYs) discounted at 3% annually; incremental cost-effectiveness ratios (ICERs).

FINDINGS

On-site rapid HCV testing had an ICER of $18,300/QALY compared with no testing, and was more efficient than (dominated) off-site HCV testing referral. On-site rapid HCV and HIV testing had an ICER of $64,500/QALY compared with on-site rapid HCV testing alone. In one- and two-way sensitivity analyses, the ICER of on-site rapid HCV and HIV testing remained <$100,000/QALY, except when undetected HIV prevalence was <0.1% or when we assumed frequent HIV testing elsewhere. The ICER remained <$100,000/QALY in 91% of probabilistic sensitivity analyses.

CONCLUSIONS

On-site rapid hepatitis C virus and HIV testing in substance abuse treatment programs is cost-effective at a <$100,000/quality-adjusted life year threshold.

A cost-benefit/cost-effectiveness analysis of an unsanctioned supervised smoking facility in the Downtown Eastside of Vancouver, Canada

BACKGROUND

Smoking crack involves the risk of transmitting diseases such as HIV and hepatitis C (HCV). The current study determines whether the formerly unsanctioned supervised smoking facility (SSF)-operated by the grassroot organization, Vancouver Area Network of Drug Users (VANDU) for the last few years-costs less than the costs incurred for health-care services as a direct consequence of not having such a program in Vancouver, Canada.

METHODS

The data pertaining to the attendance at the SSF was gathered in 2012-2013 by VANDU. By relying on this data, a mathematical model was employed to estimate the number of HCV infections prevented by the former facility in Vancouver's Downtown Eastside (DTES).

RESULTS

The DTES SSF's benefit-cost ratio was conservatively estimated at 12.1:1 due to its low operating cost. The study used 70% and 90% initial pipe-sharing rates for sensitivity analysis. At 80% sharing rate, the marginal HCV cases prevented were determined to be 55 cases. Moreover, at 80% sharing rate, the marginal cost-effectiveness ratio ranges from $1,705 to $97,203. The results from both the baseline and sensitivity analysis demonstrated that the establishment of the SSF by VANDU on average had annually saved CAD$1.8 million dollars in taxpayer's money.

CONCLUSIONS

Funding SSFs in Vancouver is an efficient and effective use of financial resources in the public health domain; therefore, Vancouver Coastal Health should actively participate in their establishment in order to reduce HCV and other blood-borne infections such as HIV within the non-injecting drug users.

Sofosbuvir-based treatment regimens for chronic, genotype 1 hepatitis C virus infection in U.S. incarcerated populations: a cost-effectiveness analysis

BACKGROUND

Prevalence of chronic hepatitis C virus (HCV) infection is high among incarcerated persons in the United States. New, short-duration, high-efficacy therapies may expand treatment eligibility in this population.

OBJECTIVE

To assess the cost-effectiveness of sofosbuvir for HCV treatment in incarcerated populations.

DESIGN

Markov model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Treatment-naive men with chronic, genotype 1 HCV monoinfection.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

No treatment, 2-drug therapy (pegylated interferon and ribavirin), or 3-drug therapy with either boceprevir or sofosbuvir. For inmates with short remaining sentences (<1.5 years), only no treatment or sofosbuvir 3-drug therapy was feasible; for those with long sentences (≥1.5 years; mean, 10 years), all strategies were considered. After release, eligible persons could receive sofosbuvir 3-drug therapy.

OUTCOME MEASURES

Discounted costs (in 2013 U.S. dollars), discounted quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

The strategies yielded 13.12, 13.57, 14.43, and 15.18 QALYs, respectively, for persons with long sentences. Sofosbuvir produced the largest absolute reductions in decompensated cirrhosis (16%) and hepatocellular carcinoma (9%), resulting in 2.1 additional QALYs at an added cost exceeding $54,000 compared with no treatment. For persons with short sentences, sofosbuvir cost $25,700 per QALY gained compared with no treatment; for those with long sentences, it dominated other treatments, costing $28,800 per QALY gained compared with no treatment.

RESULTS OF SENSITIVITY ANALYSIS

High reinfection rates in prison attenuated cost-effectiveness for persons with long sentences.

LIMITATIONS

Data on sofosbuvir's long-term effectiveness and price are limited. The analysis did not consider women, Hispanic persons, or patients co-infected with HIV or hepatitis B virus.

CONCLUSION

Sofosbuvir-based treatment is cost-effective for incarcerated persons, but affordability is an important consideration.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Identifying best-fitting inputs in health-economic model calibration: a Pareto frontier approach

BACKGROUND

To identify best-fitting input sets using model calibration, individual calibration target fits are often combined into a single goodness-of-fit (GOF) measure using a set of weights. Decisions in the calibration process, such as which weights to use, influence which sets of model inputs are identified as best-fitting, potentially leading to different health economic conclusions. We present an alternative approach to identifying best-fitting input sets based on the concept of Pareto-optimality. A set of model inputs is on the Pareto frontier if no other input set simultaneously fits all calibration targets as well or better.

METHODS

We demonstrate the Pareto frontier approach in the calibration of 2 models: a simple, illustrative Markov model and a previously published cost-effectiveness model of transcatheter aortic valve replacement (TAVR). For each model, we compare the input sets on the Pareto frontier to an equal number of best-fitting input sets according to 2 possible weighted-sum GOF scoring systems, and we compare the health economic conclusions arising from these different definitions of best-fitting.

RESULTS

For the simple model, outcomes evaluated over the best-fitting input sets according to the 2 weighted-sum GOF schemes were virtually nonoverlapping on the cost-effectiveness plane and resulted in very different incremental cost-effectiveness ratios ($79,300 [95% CI 72,500-87,600] v. $139,700 [95% CI 79,900-182,800] per quality-adjusted life-year [QALY] gained). Input sets on the Pareto frontier spanned both regions ($79,000 [95% CI 64,900-156,200] per QALY gained). The TAVR model yielded similar results.

CONCLUSIONS

Choices in generating a summary GOF score may result in different health economic conclusions. The Pareto frontier approach eliminates the need to make these choices by using an intuitive and transparent notion of optimality as the basis for identifying best-fitting input sets.

Sustained drug use changes after hepatitis C screening and counseling among recently infected persons who inject drugs: a longitudinal study

BACKGROUND

Notification of hepatitis C virus (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). It remains to be established whether postscreening behavioral changes extend over time for PWID and whether screening test notification has behavioral impacts among HCV-negative PWID. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWID.

METHODS

Initially HCV-seronegative PWID (n = 208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semiannual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable generalized estimating equation analyses were conducted to assess substance use and behavior changes over time and compare changes between HCV seroconverters and HCV-seronegative participants while adjusting for baseline characteristics.

RESULTS

Of the 208 participants (83% male; mean age, 34.7 years, mean follow-up time, 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV and status notification, whereas a 10% decrease for each additional 3 months of follow-up was observed for injection cocaine and heroin use among HCV seroconverters but not among HCV-seronegative PWID (P < .05). No significant changes were observed in alcohol use.

CONCLUSIONS

Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Among PWID deemed seronegative after screening, there is no sustained trend for change in risk behavior.