Alternative antiretroviral monitoring strategies for HIV-infected patients in east Africa: opportunities to save more lives?

Potential health benefits of integrated screening strategies for alcohol, tobacco, other substance use, depression, anxiety, and chronic pain among people living with HIV in the USA: a mathematical modelling study

BACKGROUND

Alcohol use, tobacco use, and other substance use often co-occur with depression, anxiety, and chronic pain, forming a constellation of alcohol, substance, and mood-related (CASM) conditions that disproportionately affects people with HIV in the USA. We used a microsimulation model to evaluate how alternative screening strategies accounting for CASM interdependence could affect life expectancy in people with HIV in the USA.

METHODS

We augmented a microsimulation model previously validated to predict US adult life expectancy, including in people with HIV. Using data from the Veterans Aging Cohort Study, we incorporated CASM co-occurrence, inferred causal relationships between CASM conditions, and assessed the effects of CASM on HIV treatment and preventive care. We simulated an in-care HIV cohort exposed to alternative CASM screening and diagnostic assessment strategies, ranging from currently recommended screenings (alcohol, tobacco, and depression, with diagnostic assessments for conditions screening positive) to a series of integrated strategies (screening for alcohol, tobacco, or depression with additional diagnostic assessments if any screened positive) to a maximal saturation strategy (diagnostic assessments for all CASM conditions).

FINDINGS

The saturation strategy increased life expectancy by 0·95 years (95% CI 0·93-0·98) compared with no screening. Recommended screenings provided much less benefit: 0·06 years (0·03-0·09) gained from alcohol screening, 0·08 years (0·06-0·11) from tobacco screening, 0·10 years (0·08-0·11) from depression screening, and 0·25 years (0·22-0·27) from all three screenings together. One integrated strategy (screening alcohol, tobacco, and depression with diagnostic assessment for all CASM conditions if any screened positive) produced near-maximal benefit (0·82 years [0·80-0·84]) without adding substantial screening burden, albeit requiring additional diagnostic assessments.

INTERPRETATION

Primary care providers for people with HIV should consider comprehensive diagnostic assessment of CASM conditions if one or more conditions screen positive.

FUNDING

US National Institute on Alcohol Abuse and Alcoholism.

Real-Time Infectious Disease Modeling to Inform Emergency Public Health Decision Making

Infectious disease transmission is a nonlinear process with complex, sometimes unintuitive dynamics. Modeling can transform information about a disease process and its parameters into quantitative projections that help decision makers compare public health response options. However, modelers face methodologic challenges, data challenges, and communication challenges, which are exacerbated under the time constraints of a public health emergency. We review methods, applications, challenges and opportunities for real-time infectious disease modeling during public health emergencies, with examples drawn from the two deadliest pandemics in recent history: HIV/AIDS and coronavirus disease 2019 (COVID-19).

Expected final online publication date for the Annual Review of Public Health, Volume 43 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Evaluating Alternative Designs of a Multilevel HIV Intervention in Maharashtra, India: The Impact of Stakeholder Constraints

Background. Multilevel interventions combine individual component interventions, and their design can be informed by decision analysis. Our objective was to identify the optimal combination of interventions for alcohol-using HIV+ individuals on antiretroviral drug therapy in Maharashtra, India, explicitly considering stakeholder constraints. Methods. Using an HIV simulation, we evaluated the expected net monetary benefit (ENMB), the probability of lying on the efficiency frontier (PEF), and annual program costs of 5,836 unique combinations of 15 single-focused HIV risk-reduction interventions. We evaluated scenarios of 1) no constraints (i.e., maximize expected value), 2) short-term budget constraints (limits on annual programmatic costs of US$200,000 and $400,000), and 3) a constraint stemming from risk aversion (requiring that the strategy has >50% PEF). Results. With no constraints, the combination including long individual alcohol counseling, text-message adherence support, long group counseling for sex-risk, and long individual counseling for sex-risk (annual cost = $428,886; PEF ∼27%) maximized ENMB and would be the optimal design. With a cost constraint of $400,000, the combination including long individual alcohol counseling, text-message adherence support, brief group counseling for sex-risk, and long individual counseling for sex-risk (annual cost = $374,745; PEF ∼4%) maximized ENMB. With a cost constraint of $200,000, the combination including long individual alcohol counseling, text-message adherence support, and brief group counseling for sex-risk (annual cost = $187,335; PEF ∼54%) maximized ENMB. With the risk aversion constraint, the same configuration (long individual alcohol counseling, text-message support, and brief group counseling for sex-risk) maximized health benefit. Conclusion. Evaluating the costs, risks, and projected benefits of alternatives supports informed decision making prior to initiating study; however, stakeholder constraints should be explicitly included and discussed when using decision analyses to guide study design.

Cost-effectiveness of a combination strategy to enhance the HIV care continuum in Swaziland: Link4Health

INTRODUCTION

Link4Health, a cluster-RCT, demonstrated the effectiveness of a combination strategy targeting barriers at various HIV continuum steps on linkage to and retention in care; showing effectiveness in achieving linkage to HIV care within 1 month plus retention in care at 12 months after HIV testing for people living with HIV (RR 1.48, 95% CI 1.19-1.96, p = 0.002). In addition to standard of care, Link4Health included: 1) Point-of-care CD4+ count testing; 2) Accelerated ART initiation; 3) Mobile phone appointment reminders; 4) Care and prevention package including commodities and informational materials; and 5) Non-cash financial incentive. Our objective was to evaluate the cost-effectiveness of a scale-up of the Link4Health strategy in Swaziland.

METHODS AND FINDINGS

We incorporated the effects and costs of the Link4Health strategy into a computer simulation of the HIV epidemic in Swaziland, comparing a scenario where the strategy was scaled up to a scenario with no implementation. The simulation combined a deterministic compartmental model of HIV transmission with a stochastic microsimulation of HIV progression calibrated to Swaziland epidemiological data. It incorporated downstream health costs potentially saved and infections potentially prevented by improved linkage and treatment adherence. We assessed the incremental cost-effectiveness ratio of Link4Health compared to standard care from a health sector perspective reported in US$2015, a time horizon of 20 years, and a discount rate of 3% in accordance with WHO guidelines.[1] Our results suggest that scale-up of the Link4Health strategy would reduce new HIV infections over 20 years by 11,059 infections, a 7% reduction from the projected 169,019 cases and prevent 5,313 deaths, an 11% reduction from the projected 49,582 deaths. Link4Health resulted in an incremental cost per infection prevented of $13,310 and an incremental cost per QALY gained of $3,560/QALY from the health sector perspective.

CONCLUSIONS

Using a threshold of <3 x per capita GDP, the Link4Health strategy is likely to be a cost-effective strategy for responding to the HIV epidemic in Swaziland.

Using value of information methods to determine the optimal sample size for effectiveness trials of alcohol interventions for HIV-infected patients in East Africa

Background

Unhealthy alcohol consumption exacerbates the HIV epidemic in East Africa. Potential benefits of new trials that test the effectiveness of alcohol interventions could not be evaluated by traditional sampling methods. Given the competition for health care resources in East Africa, this study aims to determine the optimal sample size given the opportunity cost of potentially re-allocating trial funds towards cost-effective alcohol treatments.

Methods

We used value of information methods to determine the optimal sample size by maximizing the expected net benefit of sampling for a hypothetical 2-arm intervention vs. control randomized trial, across ranges of policymaker’s willingness-to-pay for the health benefit of an intervention. Probability distributions describing the relative likelihood of alternative trial results were imputed based on prior studies. In the base case, policymaker’s willingness-to-pay was based on a simultaneously resource-constrained priority (routine HIV virological testing). Sensitivity analysis was performed for various willingness-to-pay thresholds and intervention durations.

Results

A new effectiveness trial accounting for the benefit of more precise decision-making on alcohol intervention implementation would benefit East Africa $67,000 with the optimal sample size of 100 persons per arm under the base case willingness-to-pay threshold and intervention duration of 20 years. At both a conservative willingness-to-pay of 1 x GDP/capita and a high willingness-to-pay of 3 x GDP/capita for an additional health gain added by an alcohol intervention, a new trial was not recommended due to limited decision uncertainty. When intervention duration was 10 or 5 years, there was no return on investment across suggested willingness-to-pay thresholds.

Conclusions

Value of information methods could be used as an alternative approach to assist the efficient design of alcohol trials. If reducing unhealthy alcohol use is a long-term goal for HIV programs in East Africa, additional new trials with optimal sample sizes ranging from 100 to 250 persons per arm could save the opportunity cost of implementing less cost-effective alcohol strategies in HIV prevention. Otherwise, conducting a new trial is not recommended.

Betting on the fastest horse: Using computer simulation to design a combination HIV intervention for future projects in Maharashtra, India

Objective

To inform the design of a combination intervention strategy targeting HIV-infected unhealthy alcohol users in Maharashtra, India, that could be tested in future randomized control trials.

Methods

Using probabilistic compartmental simulation modeling we compared intervention strategies targeting HIV-infected unhealthy alcohol users on antiretroviral therapy (ART) in Maharashtra, India. We tested interventions targeting four behaviors (unhealthy alcohol consumption, risky sexual behavior, depression and antiretroviral adherence), in three formats (individual, group based, community) and two durations (shorter versus longer). A total of 5,386 possible intervention combinations were tested across the population for a 20-year time horizon and intervention bundles were narrowed down based on incremental cost-effectiveness analysis using a two-step probabilistic uncertainty analysis approach.

Results

Taking into account uncertainty in transmission variables and intervention cost and effectiveness values, we were able to reduce the number of possible intervention combinations to be used in a randomized control trial from over 5,000 to less than 5. The most robust intervention bundle identified was a combination of three interventions: long individual alcohol counseling; weekly Short Message Service (SMS) adherence counseling; and brief sex risk group counseling.

Conclusions

In addition to guiding policy design, simulation modeling of HIV transmission can be used as a preparatory step to trial design, offering a method for intervention pre-selection at a reduced cost.

Is more research always needed? Estimating optimal sample sizes for trials of retention in care interventions for HIV-positive East Africans

INTRODUCTION

Given the serious health consequences of discontinuing antiretroviral therapy, randomised control trials of interventions to improve retention in care may be warranted. As funding for global HIV research is finite, it may be argued that choices about sample size should be tied to maximising health.

METHODS

For an East African setting, we calculated expected value of sample information and expected net benefit of sampling to identify the optimal sample size (greatest return on investment) and to quantify net health gains associated with research. Two hypothetical interventions were analysed: (1) one aimed at reducing disengagement from HIV care and (2) another aimed at finding/relinking disengaged patients.

RESULTS

When the willingness to pay (WTP) threshold was within a plausible range (1-3 × GDP; US$1377-4130/QALY), the optimal sample size was zero for both interventions, meaning that no further research was recommended because the pre-research probability of an intervention's effectiveness and value was sufficient to support a decision on whether to adopt the intervention and any new information gained from additional research would likely not change that decision. In threshold analyses, at a higher WTP of $5200 the optimal sample size for testing a risk reduction intervention was 2750 per arm. For the outreach intervention, the optimal sample size remained zero across a wide range of WTP thresholds and was insensitive to variation. Limitations, including not varying all inputs in the model, may have led to an underestimation of the value of investing in new research.

CONCLUSION

In summary, more research is not always needed, particularly when there is moderately robust prestudy belief about intervention effectiveness and little uncertainty about the value (cost-effectiveness) of the intervention. Users can test their own assumptions at http://torchresearch.org.

Using the multiphase optimization strategy (MOST) to optimize an HIV care continuum intervention for vulnerable populations: a study protocol

BACKGROUND

More than half of persons living with HIV (PLWH) in the United States are insufficiently engaged in HIV primary care and not taking antiretroviral therapy (ART), mainly African Americans/Blacks and Hispanics. In the proposed project, a potent and innovative research methodology, the multiphase optimization strategy (MOST), will be employed to develop a highly efficacious, efficient, scalable, and cost-effective intervention to increase engagement along the HIV care continuum. Whereas randomized controlled trials are valuable for evaluating the efficacy of multi-component interventions as a package, they are not designed to evaluate which specific components contribute to efficacy. MOST, a pioneering, engineering-inspired framework, addresses this problem through highly efficient randomized experimentation to assess the performance of individual intervention components and their interactions. We propose to use MOST to engineer an intervention to increase engagement along the HIV care continuum for African American/Black and Hispanic PLWH not well engaged in care and not taking ART. Further, the intervention will be optimized for cost-effectiveness. A similar set of multi-level factors impede both HIV care and ART initiation for African American/Black and Hispanic PLWH, primary among them individual- (e.g., substance use, distrust, fear), social- (e.g., stigma), and structural-level barriers (e.g., difficulties accessing ancillary services). Guided by a multi-level social cognitive theory, and using the motivational interviewing approach, the study will evaluate five distinct culturally based intervention components (i.e., counseling sessions, pre-adherence preparation, support groups, peer mentorship, and patient navigation), each designed to address a specific barrier to HIV care and ART initiation. These components are well-grounded in the empirical literature and were found acceptable, feasible, and promising with respect to efficacy in a preliminary study.

METHODS/DESIGN

Study aims are: 1) using a highly efficient fractional factorial experimental design, identify which of five intervention components contribute meaningfully to improvement in HIV viral suppression, and secondary outcomes of ART adherence and engagement in HIV primary care; 2) identify mediators and moderators of intervention component efficacy; and 3) using a mathematical modeling approach, build the most cost-effective and efficient intervention package from the efficacious components. A heterogeneous sample of African American/Black and Hispanic PLWH (with respect to age, substance use, and sexual minority status) will be recruited with a proven hybrid sampling method using targeted sampling in community settings and peer recruitment (N = 512).

DISCUSSION

This is the first study to apply the MOST framework in the field of HIV prevention and treatment. This innovative study will produce a culturally based HIV care continuum intervention for the nation's most vulnerable PLWH, optimized for cost-effectiveness, and with exceptional levels of efficacy, efficiency, and scalability.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02801747 , Registered June 8, 2016.

Economic evaluation of mobile phone text message interventions to improve adherence to HIV therapy in Kenya

BACKGROUND

A surge in mobile phone availability has fueled low cost short messaging service (SMS) adherence interventions. Multiple systematic reviews have concluded that some SMS-based interventions are effective at improving antiretroviral therapy (ART) adherence, and they are hypothesized to improve retention in care. The objective of this study was to evaluate the cost-effectiveness of SMS-based adherence interventions and explore the added value of retention benefits.

METHODS

We evaluated the cost-effectiveness of weekly SMS interventions compared to standard care among HIV+ individuals initiating ART for the first time in Kenya. We used an individual level micro-simulation model populated with data from two SMS-intervention trials, an East-African HIV+ cohort and published literature. We estimated average quality adjusted life years (QALY) and lifetime HIV-related costs from a healthcare perspective. We explored a wide range of scenarios and assumptions in one-way and multivariate sensitivity analyses.

RESULTS

We found that SMS-based adherence interventions were cost-effective by WHO standards, with an incremental cost-effectiveness ratio (ICER) of $1,037/QALY. In the secondary analysis, potential retention benefits improved the cost-effectiveness of SMS intervention (ICER = $864/QALY). In multivariate sensitivity analyses, the interventions remained cost-effective in most analyses, but the ICER was highly sensitive to intervention costs, effectiveness and average cohort CD4 count at ART initiation. SMS interventions remained cost-effective in a test and treat scenario where individuals were assumed to initiate ART upon HIV detection.

CONCLUSIONS

Effective SMS interventions would likely increase the efficiency of ART programs by improving HIV treatment outcomes at relatively low costs, and they could facilitate achievement of the UNAIDS goal of 90% viral suppression among those on ART by 2020.

Changing Cycle Lengths in State-Transition Models: Challenges and Solutions

The choice of a cycle length in state-transition models should be determined by the frequency of clinical events and interventions. Sometimes there is need to decrease the cycle length of an existing state-transition model to reduce error in outcomes resulting from discretization of the underlying continuous-time phenomena or to increase the cycle length to gain computational efficiency. Cycle length conversion is also frequently required if a new state-transition model is built using observational data that have a different measurement interval than the model's cycle length. We show that a commonly used method of converting transition probabilities to different cycle lengths is incorrect and can provide imprecise estimates of model outcomes. We present an accurate approach that is based on finding the root of a transition probability matrix using eigendecomposition. We present underlying mathematical challenges of converting cycle length in state-transition models and provide numerical approximation methods when the eigendecomposition method fails. Several examples and analytical proofs show that our approach is more general and leads to more accurate estimates of model outcomes than the commonly used approach. MATLAB codes and a user-friendly online toolkit are made available for the implementation of the proposed methods.

Laboratory Monitoring of Antiretroviral Therapy for HIV Infection: Cost-Effectiveness and Budget Impact of Current and Novel Strategies

BACKGROUND

Optimal laboratory monitoring of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) remains controversial. We evaluated current and novel monitoring strategies in Côte d'Ivoire, West Africa.

METHODS

We used the Cost-Effectiveness of Preventing AIDS Complications -International model to compare clinical outcomes, cost-effectiveness, and budget impact of 11 ART monitoring strategies varying by type (CD4 and/or viral load [VL]) and frequency. We included "adaptive" strategies (biannual then annual monitoring for patients on ART/suppressed). Mean CD4 count at ART initiation was 154/μL. Laboratory test costs were CD4=$11 and VL=$33. The standard of care (SOC; biannual CD4) was the comparator. We assessed cost-effectiveness relative to Côte d'Ivoire's 2013 per capita GDP ($1500).

RESULTS

Discounted life expectancy was 16.69 years for SOC, 16.97 years with VL confirmation of immunologic failure, and 17.25 years for adaptive VL. Mean time on failed first-line ART was 3.7 years for SOC and <0.9 years for all routine/adaptive VL strategies. VL failure confirmation was cost-saving compared with SOC. Adaptive VL had an incremental cost-effectiveness ratio (ICER) of $4100/year of life saved compared with VL confirmation and increased the 5-year budget by $310/patient compared with SOC. Adaptive VL achieved an ICER <1× GDP if second-line ART and VL costs simultaneously decreased to $156 and $13, respectively.

CONCLUSIONS

VL confirmation of immunologic failure is more effective and less costly than CD4 monitoring in Côte d'Ivoire. Adaptive VL monitoring reduces time on failing ART, is cost-effective, and should become standard in Côte d'Ivoire and similar settings.

Sustainable HIV treatment in Africa through viral-load-informed differentiated care

There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.

HIV Treatment in Resource-Limited Environments: Treatment Coverage and Insights

BACKGROUND

The effects of antiretroviral treatment on the HIV epidemic are complex. HIV-infected individuals survive longer with treatment, but are less likely to transmit the disease. The standard coverage measure improves with the deaths of untreated individuals and does not consider the fact that some individuals may acquire the disease and die before receiving treatment, making it susceptible to overestimating the long-run performance of antiretroviral treatment programs.

OBJECTIVE

The objective was to propose an alternative coverage definition to better measure the long-run performance of HIV treatment programs.

METHODS

We introduced cumulative incidence-based coverage as an alternative to measure an HIV treatment program's success. To numerically compare the definitions, we extended a simulation model of HIV disease and treatment to represent a dynamic population that includes uninfected and HIV-infected individuals. Also, we estimated the additional resources required to implement various treatment policies in a resource-limited setting.

RESULTS

In a synthetic population of 600,000 people of which 44,000 (7.6%) are infected, and eligible for treatment with a CD4 count of less than 500 cells/mm(3), assuming a World Health Organization (WHO)-defined coverage rate of 50% of eligible people, and treating these individuals with a single treatment regimen, the gap between the current WHO coverage definition and our proposed one is as much as 16% over a 10-year planning horizon.

CONCLUSIONS

Cumulative incidence-based definition of coverage yields a more accurate representation of the long-run treatment success and along with the WHO and other definitions of coverage provides a better understanding of the HIV treatment progress.

Impact and Cost-Effectiveness of Hypothetical Strategies to Enhance Retention in Care within HIV Treatment Programs in East Africa

OBJECTIVES

Attrition from care among HIV infected patients can lead to poor clinical outcomes. Our objective was to evaluate hypothetical interventions seeking to improve retention-in-care (RIC) for HIV-infected patients in East Africa, asking whether they could offer favorable value compared to earlier ART initiation.

METHODS

We used a micro-simulation model to analyze two RIC focused strategies within an East African HIV treatment program--"risk reduction," defined as intervention(s) that decrease the risk of attrition from care; and "outreach," defined as interventions that find patients and relink them with care. We compared this to earlier ART treatment as a measure of the potential health benefits forgone (e.g., opportunity cost).

RESULTS

Reducing attrition by 40% at an average cost of $10 per person remains a less efficient use of resources compared to ensuring full access to ART (cost- effectiveness ratio $1300 vs $3700) for ART eligible patients. An outreach intervention had limited clinical benefit in our simulation. If intervention costs are <$10 per person, however, an intervention able to achieve a 40% (or greater) reduction in attrition may be a cost-effective next implementation option following implementation of earlier ART treatment.

CONCLUSIONS

Our results suggest that programs should consider retention focused programs once they have already achieved high degrees of ART coverage among eligible patients. It is important that decision makers understand the epidemiology and associated outcomes of those patients who are classified as lost to follow up in their systems prior to implementation in order to achieve the highest value.

Targeting an alcohol intervention cost-effectively to persons living with HIV/AIDS in East Africa

BACKGROUND

In the current report, we ask if targeting a cognitive behavioral therapy (CBT)-based intervention aimed at reducing hazardous alcohol consumption to HIV-infected persons in East Africa would have a favorable value at costs that are feasible for scale-up.

METHODS

Using a computer simulation to inform HIV prevention decisions in East Africa, we compared 4 different strategies for targeting a CBT intervention-(i) all HIV-infected persons attending clinic; (ii) only those patients in the pre-antiretroviral therapy (ART) stages of care; (iii) only those patients receiving ART; and (iv) only those patients with detectable viral loads (VLs) regardless of disease stage. We define targeting as screening for hazardous alcohol consumption (e.g., using the Alcohol Use Disorders Identification Test and offering the CBT intervention to those who screen positive). We compared these targeting strategies to a null strategy (no intervention) or a hypothetical scenario where an alcohol intervention was delivered to all adults regardless of HIV status.

RESULTS

An intervention targeted to HIV-infected patients could prevent 18,000 new infections, add 46,000 quality-adjusted life years (QALYs), and yield an incremental cost-effectiveness ratio of $600/QALY compared to the null scenario. Narrowing the prioritized population to only HIV-infected patients in pre-ART phases of care results in 15,000 infections averted, the addition of 21,000 QALYs and would be cost-saving, while prioritizing based on an unsuppressed HIV-1 VL test results in 8,300 new infections averted, adds 6,000 additional QALYs, and would be cost-saving as well.

CONCLUSIONS

Our results suggest that targeting a cognitive-based treatment aimed at reducing hazardous alcohol consumption to subgroups of HIV-infected patients provides favorable value in comparison with other beneficial strategies for HIV prevention and control in this region. It may even be cost-saving under certain circumstances.

Implementing tobacco use treatment guidelines in community health centers in Vietnam

Background

Vietnam has a smoking prevalence that is the second highest among Southeast Asian countries (SEACs). According to the World Health Organization (WHO), most reductions in mortality from tobacco use in the near future will be achieved through helping current users quit. Yet, largely due to a lack of research on strategies for implementing WHO-endorsed treatment guidelines in primary care settings, services to treat tobacco dependence are not readily available to smokers in low middle-income countries (LMICs) like Vietnam. The objective of this study is to conduct a cluster randomized controlled trial that compares the effectiveness of two system-level strategies for implementing evidence-based guidelines for the treatment of tobacco use in 26 public community health centers (CHCs) in Vietnam.

Methods/Design

The current study will use a cluster-randomized design and multiple data sources (patient exit interviews, provider and village health worker (VHW) surveys, and semi-structured provider/VHW interviews) to study the process of adapting and implementing clinical practice guidelines in Vietnam and theory-driven mechanisms hypothesized to explain the comparative effectiveness of the two strategies for implementation. CHCs will be randomly assigned to either of the following: (1) training plus clinical reminder system (TC) or (2) TC + referral to a VHW (TCR) for three in person counseling sessions. The primary outcome is provider adherence to tobacco use treatment guidelines. The secondary outcome is 6-month biochemically verified smoking abstinence.

Discussion

The proposed implementation strategies draw on evidence-based approaches and a growing literature that supports the effectiveness of integrating community health workers as members of the health care team to improve access to preventive services. We hypothesize that the value of these implementation strategies is additive and that incorporating a referral resource that allows providers to delegate the task of offering counseling (TCR) will be superior to TC alone in improving delivery of cessation assistance to smokers. The findings of this research have potential to guide large-scale adoption of promising strategies for implementing and disseminating tobacco use treatment guidelines throughout the public health system in Vietnam and will serve as a model for similar action in other LMICs.

Trial registration

NCT01967654

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-015-0328-8) contains supplementary material, which is available to authorized users.

The cost-effectiveness of monitoring strategies for antiretroviral therapy of HIV infected patients in resource-limited settings: software tool

Background

The cost-effectiveness of routine viral load (VL) monitoring of HIV-infected patients on antiretroviral therapy (ART) depends on various factors that differ between settings and across time. Low-cost point-of-care (POC) tests for VL are in development and may make routine VL monitoring affordable in resource-limited settings. We developed a software tool to study the cost-effectiveness of switching to second-line ART with different monitoring strategies, and focused on POC-VL monitoring.

Methods

We used a mathematical model to simulate cohorts of patients from start of ART until death. We modeled 13 strategies (no 2^nd-line, clinical, CD4 (with or without targeted VL), POC-VL, and laboratory-based VL monitoring, with different frequencies). We included a scenario with identical failure rates across strategies, and one in which routine VL monitoring reduces the risk of failure. We compared lifetime costs and averted disability-adjusted life-years (DALYs). We calculated incremental cost-effectiveness ratios (ICER). We developed an Excel tool to update the results of the model for varying unit costs and cohort characteristics, and conducted several sensitivity analyses varying the input costs.

Results

Introducing 2^nd-line ART had an ICER of US$1651-1766/DALY averted. Compared with clinical monitoring, the ICER of CD4 monitoring was US$1896-US$5488/DALY averted and VL monitoring US$951-US$5813/DALY averted. We found no difference between POC- and laboratory-based VL monitoring, except for the highest measurement frequency (every 6 months), where laboratory-based testing was more effective. Targeted VL monitoring was on the cost-effectiveness frontier only if the difference between 1^st- and 2^nd-line costs remained large, and if we assumed that routine VL monitoring does not prevent failure.

Conclusion

Compared with the less expensive strategies, the cost-effectiveness of routine VL monitoring essentially depends on the cost of 2^nd-line ART. Our Excel tool is useful for determining optimal monitoring strategies for specific settings, with specific sex-and age-distributions and unit costs.

Opportunities for improving the efficiency of paediatric HIV treatment programmes

Objectives:

To conduct two economic analyses addressing whether to: routinely monitor HIV-infected children on antiretroviral therapy (ART) clinically or with laboratory tests; continue or stop cotrimoxazole prophylaxis when children become stabilized on ART.

Design and methods:

The ARROW randomized trial investigated alternative strategies to deliver paediatric ART and cotrimoxazole prophylaxis in 1206 Ugandan/Zimbabwean children. Incremental cost-effectiveness and value of implementation analyses were undertaken. Scenario analyses investigated whether laboratory monitoring (CD4⁺ tests for efficacy monitoring; haematology/biochemistry for toxicity) could be tailored and targeted to be delivered cost-effectively. Cotrimoxazole use was examined in malaria-endemic and non-endemic settings.

Results:

Using all trial data, clinical monitoring delivered similar health outcomes to routine laboratory monitoring, but at a reduced cost, so was cost-effective. Continuing cotrimoxazole improved health outcomes at reduced costs. Restricting routine CD4⁺ monitoring to after 52 weeks following ART initiation and removing toxicity testing was associated with an incremental cost-effectiveness ratio of $6084 per quality-adjusted life-year (QALY) across all age groups, but was much lower for older children (12+ years at initiation; incremental cost-effectiveness ratio = $769/QALY). Committing resources to improve cotrimoxazole implementation appears cost-effective. A healthcare system that could pay $600/QALY should be willing to spend up to $12.0 per patient-year to ensure continued provision of cotrimoxazole.

Conclusion:

Clinically driven monitoring of ART is cost-effective in most circumstances. Routine laboratory monitoring is generally not cost-effective at current prices, except possibly CD4⁺ testing amongst adolescents initiating ART. Committing resources to ensure continued provision of cotrimoxazole in health facilities is more likely to represent an efficient use of resources.

Cost-effectiveness of HIV drug resistance testing to inform switching to second line antiretroviral therapy in low income settings

Background

To guide future need for cheap resistance tests for use in low income settings, we assessed cost-effectiveness of drug resistance testing as part of monitoring of people on first line ART - with switching from first to second line ART being conditional on NNRTI drug resistance mutations being identified.

Methods

An individual level simulation model of HIV transmission, progression and the effect of ART which accounts for adherence and resistance development was used to compare outcomes of various potential monitoring strategies in a typical low income setting in sub-Saharan Africa. Underlying monitoring strategies considered were based on clinical disease, CD4 count or viral load. Within each we considered a strategy in which no further measures are performed, one with a viral load measure to confirm failure, and one with both a viral load measure and a resistance test. Predicted outcomes were assessed over 2015–2025 in terms of viral suppression, first line failure, switching to second line regimen, death, HIV incidence, disability-adjusted-life-years averted and costs. Potential future low costs of resistance tests ($30) were used.

Results

The most effective strategy, in terms of DALYs averted, was one using viral load monitoring without confirmation. The incremental cost-effectiveness ratio for this strategy was $2113 (the same as that for viral load monitoring with confirmation). ART monitoring strategies which involved resistance testing did not emerge as being more effective or cost effective than strategies not using it. The slightly reduced ART costs resulting from use of resistance testing, due to less use of second line regimens, was of similar magnitude to the costs of resistance tests.

Conclusion

Use of resistance testing at the time of first line failure as part of the decision whether to switch to second line therapy was not cost-effective, even though the test was assumed to be very inexpensive.

Delayed switch of antiretroviral therapy after virologic failure associated with elevated mortality among HIV-infected adults in Africa

OBJECTIVE

Routine monitoring of plasma HIV RNA among HIV-infected patients on antiretroviral therapy (ART) is unavailable in many resource-limited settings. Alternative monitoring approaches correlate poorly with virologic failure and can substantially delay switch to second-line therapy. We evaluated the impact of delayed switch on mortality among patients with virologic failure in Africa.

DESIGN

A cohort.

METHODS

We examined patients with confirmed virologic failure on first-line nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens from four cohorts with serial HIV RNA monitoring in Uganda and South Africa. Marginal structural models aimed to estimate the effect of delayed switch on mortality in a hypothetical trial in which switch time was randomly assigned. Inverse probability weights adjusted for measured confounders including time-updated CD4+ T-cell count and HIV RNA. Results: Among 823 patients with confirmed virologic failure, the cumulative incidence of switch 180 days after failure was 30% [95% confidence interval (CI) 27-33]. The majority of patients (74%) had not failed immunologically as defined by WHO criteria by the time of virologic failure. Adjusted mortality was higher for individuals who remained on first-line therapy than for those who had switched [odds ratio (OR) 2.1, 95% CI 1.1-4.2]. Among those without immunologic failure, the relative harm of failure to switch was similar (OR 2.4; 95% CI 0.99-5.8) to that of the entire cohort, although of borderline statistical significance.

CONCLUSION

Among HIV-infected patients with confirmed virologic failure on first-line ART, remaining on first-line therapy led to an increase in mortality relative to switching. Our results suggest that detection and response to confirmed virologic failure could decrease mortality.

Impact of interventions targeting unhealthy alcohol use in Kenya on HIV transmission and AIDS-related deaths

BACKGROUND

HIV remains a major cause of preventable morbidity and mortality in Kenya. The effects of behaviors that accompany unhealthy alcohol consumption are a pervasive risk factor for HIV transmission and progression. Our objective was to estimate the portion of HIV infections attributable to unhealthy alcohol use and to evaluate the impact of hypothetical interventions directed at unhealthy alcohol use on HIV infections and deaths.

METHODS

We estimated outcomes over a time horizon of 20 years using a computer simulation of the Kenyan population. This computer simulation integrates a compartmental model of HIV transmission with a mechanistic model of HIV progression that was previously validated in sub-Saharan Africa. Integration of the transmission and progression models allows simultaneous consideration of alcohol's effects on HIV transmission and progression (e.g., lowering antiretroviral adherence may increase transmission risk by elevating viral load, and may simultaneously increase progression by increasing the likelihood of AIDS). The simulation considers important aspects of heterogeneous sexual mixing patterns, including assortativeness of partners by age and activity level, age-discordant relationships, and high activity subgroups. Outcomes included number of new HIV infections, number of AIDS deaths, and infectivity (number of new infections per infected person per year).

RESULTS

Our model estimated that the effects of behaviors accompanying unhealthy alcohol consumption are responsible for 13.0% of new HIV infections in Kenya. An alcohol intervention with effectiveness similar to that observed in a published randomized controlled trial of a cognitive-behavioral therapy-based intervention in Kenya (45% reduction in unhealthy alcohol consumption) could prevent nearly half of these infections, reducing their number by 69,858 and reducing AIDS deaths by 17,824 over 20 years. Estimates were sensitive to assumptions with respect to the magnitude of alcohol's underlying effects on condom use, antiretroviral therapy adherence, and sexually transmitted infection prevalence.

CONCLUSIONS

A substantial number of new HIV infections in Kenya are attributable to unhealthy alcohol use. An alcohol intervention with the effectiveness observed in a published randomized controlled trial has the potential to reduce infections over 20 years by nearly 5% and avert nearly 18,000 deaths related to HIV.

How do different eligibility guidelines for antiretroviral therapy affect the cost-effectiveness of routine viral load testing in sub-Saharan Africa?

BACKGROUND

Increased eligibility guidelines of antiretroviral therapy (ART) may lead to greater routine viral load monitoring. However, in resource-constrained settings, the additional resources required by greater routine viral load monitoring may impair ability to comply with expanded eligibility guidelines for ART.

OBJECTIVE

We use a published validated computer simulation of the HIV epidemic in East African countries (expanded to include transmission as well as disease progression) to evaluate the cost-effectiveness of routine viral load monitoring.

METHODS

We explored alternative scenarios regarding cost, frequency, and switching threshold of routine viral load monitoring (including every 6 or every 12 months; and switching thresholds of 1000, or 10 000 copies/ml), as well as alternative scenarios regarding ART initiation (200, 350, 500  cells/μl, and no CD4 cell threshold). For each ART initiation strategy, we sought to identify the viral load monitoring strategy at which the incremental cost-effectiveness ratio (ICER) of more frequent routine viral load testing became more favorable than the ICER of more expansive ART eligibility. Cost inputs were based on data provided by the Academic Model Providing Access to Healthcare (AMPATH), and disease progression inputs were based on prior published work. We used a discount rate of 3%, a time horizon of 20 years, and a payer perspective.

RESULTS

Across a wide range of scenarios, and even when considering the beneficial effect of virological monitoring at reducing HIV transmission, earlier ART initiation conferred far greater health benefits for resources spent than routine virological testing, with ICERs of approximately $1000 to $2000 for earlier ART initiation, versus ICERs of approximately $5000 to $25 000 for routine virological monitoring. ICERs of viral load testing were insensitive to the cost of the viral load test, because most of the costs originated from the downstream higher costs of later regimens. ICERs of viral load testing were very sensitive to the relative cost of second-line compared with first-line regimens, assuming favorable value when the costs of these regimens were equal.

CONCLUSION

If all HIV patients are not yet treated with ART starting at 500  cells/μl and costs of second regimens remain substantially more expensive than first-line regimens, resources would buy more population health if they are spent on earlier ART rather than being spent on routine virological testing.

Cost-effectiveness of different strategies to monitor adults on antiretroviral treatment: a combined analysis of three mathematical models

BACKGROUND

WHO's 2013 revisions to its Consolidated Guidelines on antiretroviral drugs recommend routine viral load monitoring, rather than clinical or immunological monitoring, as the preferred monitoring approach on the basis of clinical evidence. However, HIV programmes in resource-limited settings require guidance on the most cost-effective use of resources in view of other competing priorities such as expansion of antiretroviral therapy coverage. We assessed the cost-effectiveness of alternative patient monitoring strategies.

METHODS

We evaluated a range of monitoring strategies, including clinical, CD4 cell count, and viral load monitoring, alone and together, at different frequencies and with different criteria for switching to second-line therapies. We used three independently constructed and validated models simultaneously. We estimated costs on the basis of resource use projected in the models and associated unit costs; we quantified impact as disability-adjusted life years (DALYs) averted. We compared alternatives using incremental cost-effectiveness analysis.

FINDINGS

All models show that clinical monitoring delivers significant benefit compared with a hypothetical baseline scenario with no monitoring or switching. Regular CD4 cell count monitoring confers a benefit over clinical monitoring alone, at an incremental cost that makes it affordable in more settings than viral load monitoring, which is currently more expensive. Viral load monitoring without CD4 cell count every 6-12 months provides the greatest reductions in morbidity and mortality, but incurs a high cost per DALY averted, resulting in lost opportunities to generate health gains if implemented instead of increasing antiretroviral therapy coverage or expanding antiretroviral therapy eligibility.

INTERPRETATION

The priority for HIV programmes should be to expand antiretroviral therapy coverage, firstly at CD4 cell count lower than 350 cells per μL, and then at a CD4 cell count lower than 500 cells per μL, using lower-cost clinical or CD4 monitoring. At current costs, viral load monitoring should be considered only after high antiretroviral therapy coverage has been achieved. Point-of-care technologies and other factors reducing costs might make viral load monitoring more affordable in future.

FUNDING

Bill & Melinda Gates Foundation, WHO.

Developments in CD4 and viral load monitoring in resource-limited settings

CD4 counts and human immunodeficiency virus (HIV) load testing are essential components of HIV care, and making these tests available in resource-limited settings is critical to the roll-out of HIV treatment globally. Until recently, the evidence supporting the importance of laboratory monitoring in resource-limited settings was lacking, but there is now a consensus emerging that testing should become routine to ensure the longevity of treatment programs. Low-cost, point-of-care testing offers the potential to fill this role as it potentially improves all aspects of HIV care, ranging from the diagnosis and staging of HIV infection in both infants and adults to monitoring for treatment failure once antiretroviral therapy has been initiated. It is imperative for low-cost solutions to become a reality, but it is equally imperative that close scrutiny be given to each new device that hits the market to ensure they perform optimally in all settings.

Modeling the cost-effectiveness of HIV treatment: how to buy the most 'health' when resources are limited

PURPOSE OF REVIEW

To summarize recent cost-effectiveness analyses (CEAs) that evaluate optimal treatment strategies for persons living with HIV/AIDS (PLWHA).

RECENT FINDINGS

Efforts to attain universal coverage of current treatment guidelines (e.g., initiation at CD4 cell count <350 cells/μl) are generally very costeffective. Expansion of access beyond current guidelines will additionally improve clinical outcomes and aversion of new HIV infections; however, cost-effectiveness is more uncertain. Increasing access to antiretroviral therapy (ART) offers greater health benefit than investing the same funds in intensive laboratory monitoring for those on ART, particularly in those settings in which universal coverage has not yet been attained. Recommended ART regimens (e.g., tenofovir) have favorable cost-effectiveness when compared with substitution of newer, more expensive agents (e.g., rilpivirine, darunavir) or substitution of older, cheaper alternatives that are more toxic (e.g., stavudine).

SUMMARY

There is increasing use of CEA to evaluate decisions regarding HIV treatment in order to buy the most 'health' with limited resources. Expansion of ART access provides substantial clinical and preventive benefit and offers favorable cost-effectiveness. Intensive laboratory monitoring may not be the highest priority in settings in which resources are constrained. Further work on the economic impact, clinical effectiveness, and feasibility of ART treatment for all (e.g., no CD4 cell initiation criteria) is needed.

Averting HIV infections in New York City: a modeling approach estimating the future impact of additional behavioral and biomedical HIV prevention strategies

Background

New York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically.

Methods

A new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC.

Results

Ten unique interventions were able to provide a prevention benefit at an annual program cost of less than $360,000, the threshold for consideration as a cost-saving intervention (because of offsets by future HIV treatment costs averted). An optimized portfolio of these specific interventions could result in up to a 34% reduction in new HIV infections over the next 20 years. The cost-per-infection averted of the portfolio was estimated to be $106,378; the total cost was in excess of $2 billion (over the 20 year period, or approximately $100 million per year, on average). The cost-savings of prevented infections was estimated at more than $5 billion (or approximately $250 million per year, on average).

Conclusions

Optimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs.

What is needed to eliminate new pediatric HIV infections: the contribution of model-based analyses

PURPOSE OF REVIEW

Computer simulation models can identify key clinical, operational, and economic interventions that will be needed to achieve the elimination of new pediatric HIV infections. In this review, we summarize recent findings from model-based analyses of strategies for prevention of mother-to-child HIV transmission (MTCT).

RECENT FINDINGS

In order to achieve elimination of MTCT (eMTCT), model-based studies suggest that scale-up of services will be needed in several domains: uptake of services and retention in care (the PMTCT 'cascade'), interventions to prevent HIV infections in women and reduce unintended pregnancies (the 'four-pronged approach'), efforts to support medication adherence through long periods of pregnancy and breastfeeding, and strategies to make breastfeeding safer and/or shorter. Models also project the economic resources that will be needed to achieve these goals in the most efficient ways to allocate limited resources for eMTCT. Results suggest that currently recommended PMTCT regimens (WHO Option A, Option B, and Option B+) will be cost-effective in most settings.

SUMMARY

Model-based results can guide future implementation science, by highlighting areas in which additional data are needed to make informed decisions and by outlining critical interventions that will be necessary in order to eliminate new pediatric HIV infections.

Switching HIV treatment in adults based on CD4 count versus viral load monitoring: a randomized, non-inferiority trial in Thailand

BACKGROUND

Viral load (VL) is recommended for monitoring the response to highly active antiretroviral therapy (HAART) but is not routinely available in most low- and middle-income countries. The purpose of the study was to determine whether a CD4-based monitoring and switching strategy would provide a similar clinical outcome compared to the standard VL-based strategy in Thailand.

METHODS AND FINDINGS

The Programs for HIV Prevention and Treatment (PHPT-3) non-inferiority randomized clinical trial compared a treatment switching strategy based on CD4-only (CD4) monitoring versus viral-load (VL). Consenting participants were antiretroviral-naïve HIV-infected adults (CD4 count 50-250/mm(3)) initiating non-nucleotide reverse transcriptase inhibitor (NNRTI)-based therapy. Randomization, stratified by site (21 public hospitals), was performed centrally after enrollment. Clinicians were unaware of the VL values of patients randomized to the CD4 arm. Participants switched to second-line combination with confirmed CD4 decline >30% from peak (within 200 cells from baseline) in the CD4 arm, or confirmed VL >400 copies/ml in the VL arm. Primary endpoint was clinical failure at 3 years, defined as death, new AIDS-defining event, or CD4 <50 cells/mm(3). The 3-year Kaplan-Meier cumulative risks of clinical failure were compared for non-inferiority with a margin of 7.4%. In the intent to treat analysis, data were censored at the date of death or at last visit. The secondary endpoints were difference in future-drug-option (FDO) score, a measure of resistance profiles, virologic and immunologic responses, and the safety and tolerance of HAART. 716 participants were randomized, 356 to VL monitoring and 360 to CD4 monitoring. At 3 years, 319 participants (90%) in VL and 326 (91%) in CD4 were alive and on follow-up. The cumulative risk of clinical failure was 8.0% (95% CI 5.6-11.4) in VL versus 7.4% (5.1-10.7) in CD4, and the upper-limit of the one-sided 95% CI of the difference was 3.4%, meeting the pre-determined non-inferiority criterion. Probability of switch for study criteria was 5.2% (3.2-8.4) in VL versus 7.5% (5.0-11.1) in CD4 (p=0.097). Median time from treatment initiation to switch was 11.7 months (7.7-19.4) in VL and 24.7 months (15.9-35.0) in CD4 (p=0.001). The median duration of viremia >400 copies/ml at switch was 7.2 months (5.8-8.0) in VL versus 15.8 months (8.5-20.4) in CD4 (p=0.002). FDO scores were not significantly different at time of switch. No adverse events related to the monitoring strategy were reported.

CONCLUSIONS

The 3-year rates of clinical failure and loss of treatment options did not differ between strategies although the longer-term consequences of CD4 monitoring would need to be investigated. These results provide reassurance to treatment programs currently based on CD4 monitoring as VL measurement becomes more affordable and feasible in resource-limited settings.

TRIAL REGISTRATION

ClinicalTrials.govNCT00162682 Please see later in the article for the Editors' Summary.

Cost-effectiveness of point-of-care viral load monitoring of antiretroviral therapy in resource-limited settings: mathematical modelling study

BACKGROUND

Monitoring of HIV viral load in patients on combination antiretroviral therapy (ART) is not generally available in resource-limited settings. We examined the cost-effectiveness of qualitative point-of-care viral load tests (POC-VL) in sub-Saharan Africa.

DESIGN

Mathematical model based on longitudinal data from the Gugulethu and Khayelitsha township ART programmes in Cape Town, South Africa.

METHODS

Cohorts of patients on ART monitored by POC-VL, CD4 cell count or clinically were simulated. Scenario A considered the more accurate detection of treatment failure with POC-VL only, and scenario B also considered the effect on HIV transmission. Scenario C further assumed that the risk of virologic failure is halved with POC-VL due to improved adherence. We estimated the change in costs per quality-adjusted life-year gained (incremental cost-effectiveness ratios, ICERs) of POC-VL compared with CD4 and clinical monitoring.

RESULTS

POC-VL tests with detection limits less than 1000 copies/ml increased costs due to unnecessary switches to second-line ART, without improving survival. Assuming POC-VL unit costs between US$5 and US$20 and detection limits between 1000 and 10,000 copies/ml, the ICER of POC-VL was US$4010-US$9230 compared with clinical and US$5960-US$25540 compared with CD4 cell count monitoring. In Scenario B, the corresponding ICERs were US$2450-US$5830 and US$2230-US$10380. In Scenario C, the ICER ranged between US$960 and US$2500 compared with clinical monitoring and between cost-saving and US$2460 compared with CD4 monitoring.

CONCLUSION

The cost-effectiveness of POC-VL for monitoring ART is improved by a higher detection limit, by taking the reduction in new HIV infections into account and assuming that failure of first-line ART is reduced due to targeted adherence counselling.

Virologic versus immunologic monitoring and the rate of accumulated genotypic resistance to first-line antiretroviral drugs in Uganda

Background

Viral load monitoring (VLM) to identify individuals failing antiretroviral therapy (ART) is not widely available in resource-limited settings. We compared the genotypic resistance patterns between clients with VLM versus immunological monitoring (IM).

Methods

Between 2004–2008, 559 ART naïve clients were enrolled in a prospective cohort, initiated on ART, and monitored with viral load (VL) and CD4+ cell counts every 6 months (VLM group). From February 2008 through June 2009, 998 clients on ART for 36–40 months (corresponding to the follow-up time of the VLM group) at the same clinic and monitored with CD4+ cell counts every 6 months were recruited into a cross sectional study (IM group). Samples from VLM clients at 12, 24 and 36 months and IM clients at 36–40 months with VL > 2000 copies/ml underwent genotypic drug resistance testing.

Results

Baseline characteristics were similar. Virologic failure (VL > 400 copies/ml) at 12, 24 and 36 months in the VLM group were 12%, 6% and 8% respectively, and in the IM group 10% at 36–40 months. Samples from 39 VLM and 70 IM clients were genotyped. 23/39 (59%) clients in the VLM group (at 12, 24 or 36 months) compared to 63/70 (90%) in the IM group, (P < 0.0001) had at least 1 non-nucleoside reverse transcriptase mutation. 19/39 (49%) of VLM clients had an M184V mutation compared to 61/70 (87%) in the IM group (P < 0.0001). Only 2/39 (5%) of VLM clients developed thymidine analogue mutations compared to 34/70 (49%) of IM clients (P < 0.0001).

Conclusions

Routine VL monitoring reduced the rate of accumulated genotypic resistance to commonly used ART in Uganda.