Examining the evidence on the causal effect of HAART on transmission of HIV using the Bradford Hill criteria

Communicable Disease Screening and Human Immunodeficiency Virus Prevention in the Emergency Department

Emergency departments (ED) provide care to populations with high rates of communicable diseases, like HIV, hepatitis C virus, and syphilis. For many patients, the ED is their sole entry point into the healthcare system and they do not routinely access screening and prevention services elsewhere. As such, the ED can serve an important public health role through communicable disease identification, treatment, and prevention. In this article, we examine national recommendations, peer-reviewed literature, and expert consensus to provide cutting edge strategies for implementing communicable infectious disease screening and prevention programs into routine ED care.

Understanding clinical outcome measures reported in HIV pregnancy studies involving antiretroviral-naive and antiretroviral-experienced women

HIV infection is a clinically significant public health disease and contributes to increased risk of maternal and fetal morbidity and mortality. HIV pregnancy studies use outcome measures as metrics to show how people with HIV feel, function, or survive. These endpoints are crucial for tracking the evolution of HIV illness over time, assessing the effectiveness of antiretroviral therapy (ART), and comparing outcomes across studies. Although the need for ideal outcome measures is widely acknowledged, selecting acceptable outcome measures for these HIV pregnancy studies can be challenging. We discuss the many outcome measures that have been implemented over time to assess HIV in pregnancy studies, their benefits, and drawbacks. Finally, we offer suggestions for improving the reporting of outcome measures in HIV in pregnancy studies. Medical professionals can best care for pregnant women living with HIV receiving ART by having a thorough understanding of these outcome metrics.

Presenting a conceptual framework for an HIV prevention and care continuum and assessing the feasibility of empirical measurement in Estonia: A case study

Objective

We aim to show the feasibility of using an integrated prevention and care continuum (PCC) model as a complete and improved tool for HIV control measurement and programming. Alignment of prevention and care continua is essential to further improve health outcomes and minimize HIV transmission risk.

Design

Cross-sectional study.

Methods

Data from 977 persons who inject drugs (PWID) collected in 2011–2016 in Tallinn, Estonia, were used to construct an HIV PCC for PWID, stratified by risk for acquiring or transmitting HIV infection and by coverage of combined interventions. We also estimated the average protective effect of current levels of intervention provision.

Results

74.4%, 20.3% and 35.2% of PWID were currently using needle and syringe programmes (NSP), drug treatment and HIV testing, respectively. 51.1% of current PWID were HIV seropositive and of those 62.5% were currently on ART and 19.0% were virally suppressed. Across the PCC, individuals moved between categories of being aware and ever using drug treatment (resulting in -50% “leakage”); from ever having used to currently using drug treatment (-59%); between “ever testing” and “current (continuous) testing” (-62%); and from self-reported antiretroviral therapy (ART) adherence to viral suppression (-70%). Use of prevention services was higher among those at risk of transmission (HIV positive). The overall reduction in acquisition risk among HIV-negative PWID was 77.7% (95% CrI 67.8–84.5%), estimated by the modelled protective effects of current levels of NSP, drug treatment and ART compared to none of these services.

Conclusions

Our findings suggest that developing a cohesive model for HIV prevention and treatment is feasible and reflects the bi-directional relationships between prevention and care. The integrated continuum model indicates the major factors which may predict the epidemic course and control response.

Global, regional and country-level 90-90-90 estimates for 2018: assessing progress towards the 2020 target

Supplemental Digital Content is available in the text

Background:

In 2014, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and partners set the 90–90–90 target for the year 2020: diagnose 90% of all people living with HIV (PLHIV); treat 90% of people who know their status; and suppress the virus in 90% of people on treatment. In 2015, countries began reporting to UNAIDS on progress against 90–90–90 using standard definitions and methods.

Methods:

We used data submitted to UNAIDS from 170 countries to assess country-specific progress towards 90–90–90 through 2018. To assess global and regional progress, overall and by sex for adults aged 15 years and older, we combined country-reported data with estimates generated with a Bayesian hierarchical model.

Results:

A total of 60 countries reported on all three 90s in 2018, up from 23 in 2015. Among all PLHIV worldwide, 79% (67–92%) knew their HIV status. Of these, 78% (69–82%) were accessing treatment and 86% (72–92%) of people accessing treatment had suppressed viral loads. Of the 37.9 million (32.7–44.0 million) PLHIV worldwide, 53% (43–63%) had suppressed viral loads. The gap to fully achieving 73% of PLHIV with suppressed viral load was 7.7 million; 15 countries had already achieved this target by 2018.

Conclusion:

Increased data availability has led to improved measures of country and global progress towards the 90–90–90 target. Although gains in access to testing and treatment continue, many countries and regions are unlikely to reach the 90–90–90 target by 2020.

Health provider training is associated with improved engagement in HIV care among adolescents and young adults in Kenya

OBJECTIVES

Adolescents and young adults (AYA) have poorer retention, viral suppression, and survival than other age groups. We evaluated correlates of initial AYA engagement in HIV care at facilities participating in a randomized trial in Kenya.

DESIGN

Retrospective cohort study.

METHODS

Electronic medical records from AYA ages 10-24 attending 24 HIV care facilities in Kenya were abstracted. Facility surveys assessed provider trainings and services. HIV provider surveys assessed AYA training and work experience. Engagement in care was defined as return for first follow-up visit within 3 months among newly enrolled or recently re-engaged (returning after >3 months out of care) AYA. Multilevel regression estimated risk ratios and 95% confidence intervals (CIs), accounting for clustering by facility. Final models adjusted for AYA individual age and median AYA age and number enrolled per facility.

RESULTS

Among 3662 AYA records at first eligible visit, most were female (75.1%), older (20-24 years: 54.5%), and on antiretroviral therapy (79.5%). Overall, 2639 AYA returned for care (72.1%) after enrollment or re-engagement visit. Engagement in care among AYA was significantly higher at facilities offering provider training in adolescent-friendly care (85.5 vs. 67.7%; adjusted risk ratio (aRR) 1.11, 95% CI: 1.01-1.22) and that used the Kenyan government's AYA care checklist (88.9 vs. 69.2%; aRR 1.14, 95% CI: 1.06-1.23). Engagement was also significantly higher at facilities where providers reported being trained in AYA HIV care (aRR 1.56, 95% CI: 1.13-2.16).

CONCLUSION

Adolescent-specific health provider training and tools may improve quality of care and subsequent AYA engagement. Health provider interventions are needed to achieve the '95-95-95' targets for AYA.

Cost-Effectiveness of the 'One4All' HIV Linkage Intervention in Guangxi Zhuang Autonomous Region, China

BACKGROUND

In Guangxi Zhuang Autonomous Region, China, an estimated 80% of newly-identified antiretroviral therapy (ART)-eligible patients are not engaged in ART. Delayed ART uptake ultimately translates into high rates of HIV morbidity, mortality, and transmission. To enhance HIV testing receipt and subsequent treatment uptake in Guangxi, the Chinese Center for Disease Control and Prevention (CDC) executed a cluster-randomized trial to assess the effectiveness and cost-effectiveness of a streamlined HIV testing algorithm (the One4All intervention) in 12 county-level hospitals.

OBJECTIVE

To determine the incremental cost-effectiveness of the One4All intervention delivered at county hospitals in Guangxi, China, compared to the current standard of care (SOC).

PERSPECTIVE

Health System.

TIME HORIZON

1-, 5-and 25-years.

METHODS

We adapted a dynamic, compartmental HIV transmission model to simulate HIV transmission and progression in Guangxi, China and identify the economic impact and health benefits of implementing the One4All intervention in all Guangxi hospitals. The One4All intervention algorithm entails rapid point-of-care HIV screening, CD4 and viral load testing of individuals presenting for HIV screening, with same-day results and linkage to counselling. We populated the model with data from the One4All trial (CTN-0056), China CDC HIV registry and published reports. Model outcomes were HIV incidence, mortality, costs, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER) of the One4All intervention compared to SOC.

RESULTS

The One4All testing intervention was more costly than SOC (CNY 2,182 vs. CNY 846), but facilitated earlier ART access, resulting in delayed disease progression and mortality. Over a 25-year time horizon, we estimated that introducing One4All in Guangxi would result in 802 averted HIV cases and 1629 averted deaths at an ICER of CNY 11,678 per QALY gained. Sensitivity analysis revealed that One4All remained cost-effective at even minimal levels of effectiveness. Results were robust to changes to a range of parameters characterizing the HIV epidemic over time.

CONCLUSIONS

The One4All HIV testing strategy was highly cost-effective by WHO standards, and should be prioritized for widespread implementation in Guangxi, China. Integrating the intervention within a broader combination prevention strategy would enhance the public health response to HIV/AIDS in Guangxi.

HIV prevention and treatment strategies can help address the overdose crisis

Since the 1990s, effective HIV prevention and treatment strategies have been coordinated and implemented in the United States, resulting in substantial reductions in HIV-related death and HIV transmission among people who use injection drugs. During the same period, despite substantial long-term funding of War on Drugs policies, opioid addiction, driven by increased prescription opioid use and heroin accessibility, has made overdose the leading cause of accidental injury death in the United States. This commentary describes how the prevention and treatment successes among people who use drugs in the HIV/AIDS epidemic can be applied to address the opioid overdose crisis.

The 'Expanded HIV care in opioid substitution treatment' (EHOST) cluster-randomized, stepped-wedge trial: A study protocol

The public health response to HIV/AIDS has turned its focus onto optimizing health care system delivery to maximize case identification, access and sustained engagement in antiretroviral treatment (ART). Opioid Agonist Treatment (OAT) provides a critical opportunity for HIV testing and linkage to ART. The EHOST study is a cluster-randomized, stepped-wedge trial to evaluate a prescriber-focused intervention to increase HIV testing rates, and optimize ART engagement and retention outcomes among individuals engaged in OAT. The study will encompass all drug treatment clinics currently admitting patients for the treatment of opioid use disorder across the province of British Columbia, encompassing an estimated 90% of the OAT caseload. The trial will be executed over a 24-month period, with groups of clinics receiving the intervention in 6-month intervals. Evaluation of the proposed intervention's effectiveness will focus on three primary outcomes: (i) the HIV testing rate among those not known to be HIV positive; (ii) the rate of ART initiation among those not on ART; and (iii) the rate of ART continuation among those on ART. A difference-in-differences analytical framework will be applied to estimate the intervention's effect. This approach will assess site-specific changes in primary outcomes across clusters while adjusting for potential residual heterogeneity in patient case mix, volume, and quality of care across clinics. Statistical analysis of outcomes will be conducted entirely with linked population-level administrative health datasets. Facilitated by established collaborations between key stakeholders across the province, the EHOST intervention promises to optimize HIV testing and care within a marginalized and hard-to-reach population.

Cost-effectiveness analysis along the continuum of HIV care: how can we optimize the effect of HIV treatment as prevention programs?

The cascade of HIV care has been proposed as a useful tool to monitor health system performance across the key stages of HIV care delivery to reduce morbidity, mortality, and HIV transmission, the focal points of HIV Treatment as Prevention campaigns. Interventions to improve the cascade at its various stages may vary substantially in their ability to deliver health value per amount expended. In order to meet global antiretroviral treatment access targets, there is an urgent need to maximize the value of health spending by prioritizing cost-effective interventions. We executed a literature review on economic evaluations of interventions to improve specific stages of the cascade of HIV care. In total, 33 articles met the criteria for inclusion in the review, 22 (67 %) of which were published within the last 5 years. Nonetheless, substantial gaps in our knowledge remain, particularly for interventions to improve linkage and retention in HIV care in developed and developing-world settings and generalized and concentrated epidemics. We make the case here that the attention of scientists and policymakers needs to turn to the development, implementation, and rigorous evaluation of interventions to improve the various stages of the cascade of HIV care.

Treatment as prevention--where next?

Uptake of antiretroviral regimens with associated durable virologic suppression has been shown to reduce the risk of HIV transmission. Expanding antiretroviral therapy (ART) programs at a population level may serve as a vital strategy in the elimination of the AIDS epidemic. The global expansion of ART programs has greatly improved access to life-saving therapies and is likely to achieve the target of 15 million individuals on therapy set by UNAIDS. In addition to the incontrovertible gains in terms of life expectancy, growing evidence demonstrates that durable virologic suppression is associated with significant reductions in HIV transmission amongst heterosexual couples and men who have sex with men. Expansion of successful ART programs, best monitored by a program-level continuum of care cascade to assess progress in diagnosis, retention in care, and virologic suppression, is associated with reductions in HIV incidence at a population level. Expanding and sustaining successful ART delivery at a global level is a key component in a comprehensive approach to combating the HIV epidemic over the next two decades.

Knowledge, Beliefs and Practices Regarding Antiretroviral Medications for HIV Prevention: Results from a Survey of Healthcare Providers in New England

Background

Antiretroviral treatment for HIV-infection before immunologic decline (early ART) and pre-exposure chemoprophylaxis (PrEP) can prevent HIV transmission, but routine adoption of these practices by clinicians has been limited.

Methods

Between September and December 2013, healthcare practitioners affiliated with a regional AIDS Education and Training Center in New England were invited to complete online surveys assessing knowledge, beliefs and practices regarding early ART and PrEP. Multivariable models were utilized to determine characteristics associated with prescribing intentions and practices.

Results

Surveys were completed by 184 practitioners. Respondent median age was 44 years, 58% were female, and 82% were white. Among ART-prescribing clinicians (61% of the entire sample), 64% were aware that HIV treatment guidelines from the Department of Health and Human Services recommended early ART, and 69% indicated they would prescribe ART to all HIV-infected patients irrespective of immunologic status. However, 77% of ART-prescribing clinicians would defer ART for patients not ready to initiate treatment. Three-fourths of all respondents were aware of guidance from the U.S. Centers for Disease Control and Prevention recommending PrEP provision, 19% had prescribed PrEP, and 58% of clinicians who had not prescribed PrEP anticipated future prescribing. Practitioners expressed theoretical concerns and perceived practical barriers to prescribing early ART and PrEP. Clinicians with higher percentages of HIV-infected patients (aOR 1.16 per 10% increase in proportion of patients with HIV-infection, 95% CI 1.01–1.34) and infectious diseases specialists (versus primary care physicians; aOR 3.32, 95% CI 0.98–11.2) were more likely to report intentions to prescribe early ART. Higher percentage of HIV-infected patients was also associated with having prescribed PrEP (aOR 1.19, 95% CI 1.06–1.34), whereas female gender (aOR 0.26, 95% CI 0.10–0.71) was associated with having not prescribed PrEP.

Conclusions

These findings suggest many clinicians have shifted towards routinely recommending early ART, but not PrEP, so interventions to facilitate PrEP provision are needed.

The causal effect of opioid substitution treatment on HAART medication refill adherence

BACKGROUND

People who inject drugs (PWID) account for roughly 13% of the prevalent HIV/AIDS population outside of sub-Saharan Africa, and access to opioid substitution treatment (OST) is limited in many settings globally. OST likely facilitates access to HAART, yet sparse evidence is available to support this hypothesis. Our objective was to determine the causal impact of OST exposure on HAART adherence among HIV-positive PWID in a Canadian setting.

METHODS

We executed a retrospective cohort study using linked population-level data for British Columbia, Canada (January 1996-March 2010). We considered HIV-positive PWID after meeting HAART initiation criteria. A marginal structural model was estimated on a monthly timescale using inverse probability of treatment weights. The primary outcome was 95% HAART adherence, according to pharmacy refill compliance. Exposure to OST was defined as 95% of OST receipt, and we controlled for a range of fixed and time-varying covariates.

RESULTS

Our study included 1852 (63.3%) HIV-positive PWID with a median follow-up of 5.5 years; 34% were female and 39% had previously accessed OST. The baseline covariate-adjusted odds of HAART adherence following OST exposure was 1.96 (95% confidence interval: 1.72-2.24), although the adjusted odds estimated within the marginal structural model was 1.68 (1.48-1.92). Findings were robust to sensitivity analyses on model specification.

CONCLUSION

In a setting characterized by universal healthcare and widespread access to both office-based OST and HAART, OST substantially increased the odds of HAART adherence. This underlines the need to address barriers to OST globally to reduce the disease burden of both opioid dependence and HIV/AIDS.

Costs of health resource utilization among HIV-positive individuals in British Columbia, Canada: results from a population-level study

BACKGROUND

Through delayed HIV disease progression, highly active antiretroviral therapy (HAART) may reduce direct medical costs, thus at least partially offsetting therapy costs. Recent findings regarding the secondary preventive benefits of HAART necessitate careful consideration of funding allocations for HIV/AIDS care. Our objective is to estimate non-HAART direct medical costs at different levels of disease progression and over time in British Columbia, Canada.

METHODS

We considered the population of individuals with HIV/AIDS within a set of linked disease registries and health administrative databases (N = 11,836) from 1996 to 2010. Costs of hospitalization, physician billing, diagnostic testing and non-HAART medications were calculated in 2010 Canadian dollars. Effects of covariates on quarterly costs were assessed with a two-part model with logit for probability of non-zero costs and a generalized linear model (GLM). Net effects of CD4 strata on direct non-HAART medical costs were evaluated over time during the study period.

RESULTS

Compared with person-quarters in which CD4 >500/mm(3), costs were Can$185 (95 % confidence interval [CI] 132-239) greater for CD4 350-500/mm(3), Can$441 (95 % CI 366-516) greater for CD4 200-350/mm(3) and Can$1,173 (95 % CI 1,051-1,294) greater when CD4 <200/mm(3). Prior to HIV care initiation, individuals incurred costs Can$385 (95 % CI 283-487) greater than in periods with CD4 >500/mm(3). Hospitalization comprised the majority of the increment in costs amongst those with no measured CD4. Evaluated at CD4 state conditional means, those with CD4 <200/mm(3) incurred quarterly costs of Can$5,781 (95 % CI 4,716-6,846) versus Can$1,307 (95 % CI 1,154-1,460; p < 0.001) for CD4 ≥500/mm(3) in 2010.

CONCLUSION

Non-HAART direct medical costs were substantially lower for individuals during periods of sustained virologic suppression and high CD4 count. HIV treatment and prevention evaluations require detailed health resource use data to inform funding allocation decisions.

The HIV epidemic in Southern Africa - Is an AIDS-free generation possible?

Southern Africa, home to about 20 % of the global burden of infection continues to experience high rates of new HIV infection despite substantial programmatic scale-up of treatment and prevention interventions. While several countries in the region have had substantial reductions in HIV infection, almost half a million new infections occurred in this region in 2012. Sexual transmission remains the dominant mode of transmission. A recent national household survey in Swaziland revealed an HIV prevalence of 14.3 % among 18-19 year old girls, compared to 0.8 % among their male peers. Expanded ART programmes in Southern Africa have resulted in dramatically decreased HIV incidence and HIV mortality rates. In South Africa alone, it is estimated that more than 2.1 million of the 6.1 million HIV-positive people were receiving ART by the end of 2012, and that this resulted in more than 2.7 million life-years saved, and hundreds of thousands of HIV infections averted. Biological, behavioural and structural factors all contribute to the ongoing high rates of new HIV infection; however, as the epidemic matures and mortality is reduced from increased ART coverage, epidemiological trends become hard to quantify. What is clear is that a key driver of the Southern African epidemic is the high incidence rate of infection in young women, a vulnerable population with limited prevention options. Moreover, whilst ongoing trials of combination prevention, microbicides and behavioural economics hold promise for further epidemic control, an AIDS-free generation will not be realised unless incident infections in key populations are reduced.

HIV testing behaviors and attitudes among community recruited methamphetamine users in a South African township

Methamphetamine users in South Africa are at high risk for HIV infection and transmission, but little is known about HIV testing in this population. We examined HIV testing behaviors and attitudes in 362 methamphetamine users recruited using chain referral sampling from one peri-urban community. Many (44 %) had not been HIV tested in the past year. HIV testing was associated with positive testing attitudes, less AIDS stigma, and greater methamphetamine stigma. Among participants who reported HIV infection (8 %), less than half were linked to care. Findings highlight the need to identify barriers to HIV service uptake for methamphetamine users.

How can we get close to zero? The potential contribution of biomedical prevention and the investment framework towards an effective response to HIV

Background

In 2011 an Investment Framework was proposed that described how the scale-up of key HIV interventions could dramatically reduce new HIV infections and deaths in low and middle income countries by 2015. This framework included ambitious coverage goals for prevention and treatment services resulting in a reduction of new HIV infections by more than half. However, it also estimated a leveling in the number of new infections at about 1 million annually after 2015.

Methods

We modeled how the response to AIDS can be further expanded by scaling up antiretroviral treatment (ART) within the framework provided by the 2013 WHO treatment guidelines. We further explored the potential contributions of new prevention technologies: ‘Test and Treat’, pre-exposure prophylaxis and an HIV vaccine.

Findings

Immediate aggressive scale up of existing approaches including the 2013 WHO guidelines could reduce new infections by 80%. A ‘Test and Treat’ approach could further reduce new infections. This could be further enhanced by a future highly effective pre-exposure prophylaxis and an HIV vaccine, so that a combination of all four approaches could reduce new infections to as low as 80,000 per year by 2050 and annual AIDS deaths to 260,000.

Interpretation

In a set of ambitious scenarios, we find that immediate implementation of the 2013 WHO antiretroviral therapy guidelines could reduce new HIV infections by 80%. Further reductions may be achieved by moving to a ‘Test and Treat’ approach, and eventually by adding a highly effective pre-exposure prophylaxis and an HIV vaccine, if they become available.

Gonadal function and reproductive health in women with human immunodeficiency virus infection

Most human immunodeficiency virus (HIV) infections among women occur early in reproductive life, which highlights the importance of understanding the impact of HIV on reproductive functions, and also the potential implications of reproductive function and aging on the course of HIV disease. Ovarian function is a crucial component of reproductive biology in women, but standard assessment methods are of limited applicability to women with chronic diseases such as HIV. Pregnancy can now be achieved without transmission of HIV to sexual partner or newborn, but complications of pregnancy may be more common in women infected with HIV than uninfected women.

Treatment as prevention: are Argentinean HIV care providers willing to adopt earlier antiretroviral therapy?

HIV guidelines increasingly recommend antiretroviral therapy (ART) initiation at a higher CD4 levels. The extent to which these evolving standards are translated into routine clinical care has not been evaluated in Argentina. During October 2012, we conducted an online survey among Argentinean HIV clinicians to assess their attitudes and practices toward ART initiation and its potential use for HIV prevention. Of the 280 physicians included, 61% would prescribe ART at CD4 ≤ 500 cells/µL for asymptomatic patients. Although, only 11% would recommend ART irrespective of CD4 cell count, 72% would do it for serodiscordant couples, and 75% for sex workers. Most participants agreed that they would consider earlier initiation of ART if transmission risk exists, and that expansion of ART could help decrease HIV incidence. These results suggest that a large proportion of Argentinean HIV care providers are willing to adopt the recently updated Argentinean guidelines recommending earlier ART, especially when high HIV transmission risk exists.

Recently diagnosed gay men talk about HIV treatment decisions

Background In recent years, there has been increasing evidence that early initiation of antiretroviral therapy (ART) may provide health benefits for those infected with HIV. There has also been significant discussion about the role of HIV treatment in preventing onward transmission of the virus. Early provision and uptake of ART to people recently diagnosed with HIV could achieve both individual and public health outcomes. The success of such an initiative relies, in part, on the preparedness of those recently diagnosed with HIV to engage with the therapy. Methods: The HIV Seroconversion Study collects both quantitative and qualitative data from people in Australia who have recently been diagnosed with HIV. During 2011–2012, 53 gay or bisexual men recruited across Australia took part in semistructured interviews as part of the study. The men were asked about their knowledge and experience of, and their decisions about whether or not to commence, HIV treatment. Results: The interviews identified differing levels of knowledge about HIV treatments and divergent views about the health and prevention benefits of ART. For some, treatments provided a sense of control over the virus; others were apprehensive and distrustful, and preferred to resist commencing treatments for as long as possible. Conclusions: If early initiation of treatment is to be encouraged, appropriate measures must be in place to ensure recently diagnosed individuals have access to the appropriate information and the support they need to enable them to make informed choices and, if necessary, to address their fears.