Modeling Adherence Interventions Among Youth with HIV in the United States: Clinical and Economic Projections

Projected Life Expectancy for Adolescents With HIV in the US

Importance

Life expectancy is a key measure of overall population health. Life expectancy estimates for youth with HIV in the US are needed in the current HIV care and treatment context to guide health policies and resource allocation.

Objective

To compare life expectancy between 18-year-old youth with perinatally acquired HIV (PHIV), youth with nonperinatally acquired HIV (NPHIV), and youth without HIV.

Design, Setting, and Participants

Using a US-focused adolescent-specific Monte Carlo state-transition HIV model, we simulated individuals from age 18 years until death. We estimated probabilities of HIV treatment and care engagement, HIV progression, clinical events, and mortality from observational cohorts and clinical trials for model input parameters. The simulated individuals were 18-year-old race and ethnicity-matched youth with PHIV, youth with NPHIV, and youth without HIV; 47%, 85%, and 50% were assigned male sex at birth, respectively. Individuals were categorized by US Centers for Disease Control and Prevention-defined HIV acquisition risk: men who have sex with men, people who ever injected drugs, heterosexually active individuals at increased risk for HIV infection, or average risk for HIV infection. Distributions were 3%, 2%, 12%, and 83% for youth with PHIV and youth without HIV, and 80%, 6%, 14%, and 0% for youth with NPHIV, respectively. Among the simulated youth in this analysis, individuals were 61% Black, 24% Hispanic, and 15% White, respectively.

Exposures

HIV status by timing of acquisition.

Main Outcomes

Life expectancy loss for youth with PHIV and youth with NPHIV: difference between mean projected life expectancy under current and ideal HIV care scenarios compared with youth without HIV. Uncertainty intervals reflect varying adolescent HIV-related mortality inputs (95% CIs).

Results

Compared with youth without HIV (life expectancy: male, 76.3 years; female, 81.7 years), male youth with PHIV and youth with NPHIV had projected life expectancy losses of 10.4 years (95% CI, 5.5-18.1) and 15.0 years (95% CI, 9.3-26.8); female youth with PHIV and youth with NPHIV had projected life expectancy losses of 11.8 years (95% CI, 6.4-20.2) and 19.5 years (95% CI, 13.8-31.6), respectively. When receiving ideal HIV care, life expectancy losses were projected to improve for youth with PHIV (male: 0.5 years [95% CI, 0.3-1.8]: female: 0.6 years [95% CI, 0.4-2.1]) but were projected to persist for youth with NPHIV (male: 6.0 years [95% CI, 5.0-9.1]; female: 10.4 years [95% CI, 9.4-13.6]).

Conclusions

This adolescent-focused microsimulation modeling analysis projected that youth with HIV would have shorter life expectancy than youth without HIV. Projected differences were larger for youth with NPHIV compared with youth with PHIV. Differences in mortality by sex at birth, sexual behavior, and injection drug use contributed to lower projected life expectancy among youth with NPHIV. Interventions focused on HIV care and social factors are needed to improve life expectancy for youth with HIV in the US.

Projecting the Clinical and Economic Impacts of Changes to HIV Care Among Adolescents and Young Adults in the United States: Lessons From the COVID-19 Pandemic

BACKGROUND

During the COVID-19 pandemic, many US youth with HIV (YHIV) used telehealth services; others experienced disruptions in clinic and antiretroviral therapy (ART) access.

METHODS

Using the Cost-effectiveness of Preventing AIDS Complications (CEPAC)-Adolescent HIV microsimulation model, we evaluated 3 scenarios: 1) Clinic: in-person care; 2) Telehealth: virtual visits, without CD4 or viral load monitoring for 12 months, followed by return to usual care; and 3) Interruption: complete care interruption with no ART access or laboratory monitoring for 6 months (maximum clinic closure time), followed by return to usual care for 80%. We assigned higher 1-year retention (87% vs 80%) and lower cost/visit ($49 vs $56) for Telehealth vs Clinic. We modeled 2 YHIV cohorts with non-perinatal (YNPHIV) and perinatal (YPHIV) HIV, which differed by mean age (22 vs 16 years), sex at birth (85% vs 47% male), starting CD4 count (527/μL vs 635/μL), ART, mortality, and HIV-related costs. We projected life months (LMs) and costs/100 YHIV over 10 years.

RESULTS

Over 10 years, LMs in Clinic and Telehealth would be similar (YNPHIV: 11 350 vs 11 360 LMs; YPHIV: 11 680 LMs for both strategies); costs would be $0.3M (YNPHIV) and $0.4M (YPHIV) more for Telehealth than Clinic. Interruption would be less effective (YNPHIV: 11 230 LMs; YPHIV: 11 620 LMs) and less costly (YNPHIV: $1.3M less; YPHIV: $0.2M less) than Clinic. Higher retention in Telehealth led to increased ART use and thus higher costs.

CONCLUSIONS

Telehealth could be as effective as in-person care for some YHIV, at slightly increased cost. Short interruptions to ART and laboratory monitoring may have negative long-term clinical implications.

Cost-Effectiveness of Anti-retroviral Adherence Interventions for People Living with HIV: A Systematic Review of Decision Analytical Models

BACKGROUND

Although safe and effective anti-retrovirals (ARVs) are readily available, non-adherence to ARVs is highly prevalent among people living with human immunodeficiency virus/acquired immunodeficiency syndrome (PLWHA). Different adherence-improving interventions have been developed and examined through decision analytic model-based health technology assessments. This systematic review aimed to review and appraise the decision analytical economic models developed to assess ARV adherence-improvement interventions.

METHODS

The review protocol was registered on PROSPERO (CRD42022270039), and reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Relevant studies were identified through searches in six generic and specialized bibliographic databases, i.e. PubMed, Embase, NHS Economic Evaluation Database, PsycINFO, Health Economic Evaluations Database, tufts CEA registry and EconLit, from their inception to 23 October 2022. The cost-effectiveness of adherence interventions is represented by the incremental cost-effectiveness ratio (ICER). The quality of studies was assessed using the quality of the health economics studies (QHES) instrument. Data were narratively synthesized in the form of tables and texts. Due to the heterogeneity of the data, a permutation matrix was used for quantitative data synthesis rather than a meta-analysis.

RESULTS

Fifteen studies, mostly conducted in North America (8/15 studies), were included in the review. The time horizon ranged from a year to a lifetime. Ten out of 15 studies used a micro-simulation, 4/15 studies employed Markov and 1/15 employed a dynamic model. The most commonly used interventions reported include technology based (5/15), nurse involved (2/15), directly observed therapy (2/15), case manager involved (1/15) and others that involved multi-component interventions (5/15). In 1/15 studies, interventions gained higher quality-adjusted life years (QALYs) with cost savings. The interventions in 14/15 studies were more effective but at a higher cost, and the overall ICER was well below the acceptable threshold mentioned in each study, indicating the interventions could potentially be implemented after careful interpretation. The studies were graded as high quality (13/15) or fair quality (2/15), with some methodological inconsistencies reported.

CONCLUSION

Counselling and smartphone-based interventions are cost-effective, and they have the potential to reduce the chronic adherence problem significantly. The quality of decision models can be improved by addressing inconsistencies in model selection, data inputs incorporated into models and uncertainty assessment methods.

Long-Acting Antiretroviral Drug Therapy in Adolescents: Current Status and Future Prospects

Approximately 50% of human immunodeficiency virus (HIV)-infected adolescents fail to achieve complete viral suppression, largely due to nonadherence to their antiretroviral drug regimens. Numerous personal, financial, and societal barriers contribute to nonadherence, which may lead to the development of HIV drug resistance. Long-acting antiretroviral drugs hold the promise of improved adherence because they remove the need for swallowing one or more pills daily. Cabotegravir (an integrase strand transfer inhibitor) and rilpivirine (a non-nucleoside reverse transcriptase inhibitor) can now be intramuscularly co-administered to HIV-infected adolescents every 4-8 weeks if they are virologically suppressed and without resistance mutations to cabotegravir or rilpivirine. Adverse effects are few and non-severe. Widespread use of this complete antiretroviral therapy may be limited by drug costs, need for sites and skilled personnel who can administer the injections, and ethical challenges. Other long-acting medications and new antiretroviral therapy delivery systems are under active investigation and show great promise.

Cost-Effectiveness of Long-Acting Injectable HIV Preexposure Prophylaxis in the United States : A Cost-Effectiveness Analysis

BACKGROUND

The HIV Prevention Trials Network (HPTN) 083 trial demonstrated the superiority of long-acting injectable cabotegravir (CAB-LA) compared with oral emtricitabine-tenofovir disoproxil fumarate (F/TDF) for HIV preexposure prophylaxis (PrEP).

OBJECTIVE

To identify the maximum price premium (that is, greatest possible price differential) that society should be willing to accept for the additional benefits of CAB-LA over tenofovir-based PrEP among men who have sex with men and transgender women (MSM/TGW) in the United States.

DESIGN

Simulation, cost-effectiveness analysis.

DATA SOURCES

Trial and published data, including estimated HIV incidence (5.32, 1.33, and 0.26 per 100 person-years for off PrEP, generic F/TDF and branded emtricitabine-tenofovir alafenamide (F/TAF), and CAB-LA, respectively); 28% 6-year PrEP retention. Annual base-case drug costs: $360 and $16 800 for generic F/TDF and branded F/TAF. Fewer side effects with branded F/TAF versus generic F/TDF were assumed.

TARGET POPULATION

476 700 MSM/TGW at very high risk for HIV (VHR).

TIME HORIZON

10 years.

PERSPECTIVE

Health care system.

INTERVENTION

CAB-LA versus generic F/TDF or branded F/TAF for HIV PrEP.

OUTCOME MEASURES

Primary transmissions, quality-adjusted life-years (QALYs), costs (2020 U.S. dollars), incremental cost-effectiveness ratios (ICERs; U.S. dollars per QALY), maximum price premium for CAB-LA versus tenofovir-based PrEP.

RESULTS OF BASE-CASE ANALYSIS

Compared with generic F/TDF (or branded F/TAF), CAB-LA increased life expectancy by 28 000 QALYs (26 000 QALYs) among those at VHR. Branded F/TAF cost more per QALY gained than generic F/TDF compared with no PrEP. At 10 years, CAB-LA could achieve an ICER of at most $100 000 per QALY compared with generic F/TDF at a maximum price premium of $3700 per year over generic F/TDF (CAB-LA price <$4100 per year).

RESULTS OF SENSITIVITY ANALYSIS

In a PrEP-eligible population at high risk for HIV, rather than at VHR (n = 1 906 800; off PrEP incidence: 1.54 per 100 person-years), CAB-LA could achieve an ICER of at most $100 000 per QALY versus generic F/TDF at a maximum price premium of $1100 per year over generic F/TDF (CAB-LA price <$1500 per year).

LIMITATION

Uncertain clinical and economic benefits of averting future transmissions.

CONCLUSION

Effective oral PrEP limits the additional price society should be willing to pay for CAB-LA.

PRIMARY FUNDING SOURCE

FHI 360; Eunice Kennedy Shriver National Institute of Child Health and Human Development; National Institute of Allergy and Infectious Diseases; National Heart, Lung, and Blood Institute; National Institute on Drug Abuse; the Reich HIV Scholar Award; and the Steve and Deborah Gorlin MGH Research Scholars Award.

Exploration of a Mobile Technology Vulnerability Scale's association with antiretroviral adherence among young adults living with HIV in the United States

BACKGROUND

Young adults living with HIV (YLWH) have suboptimal adherence to antiretroviral therapy (ART) and HIV care outcomes. Mobile health technologies are increasingly used to deliver interventions to address HIV health outcomes. However, not all YLWH have equal and consistent access to mobile technologies.

METHODS

Using our novel Mobile Technology Vulnerability Scale (MTVS) to evaluate how vulnerable an individual feels with regard to their personal access to mobile technology in the past 6 months, we conducted a cross-sectional online survey with 271 YLWH (18-29 years) in the US to evaluate the relationships between MTVS and self-reported ART adherence.

RESULTS

Participants reported changes in phone numbers (25%), stolen (14%) or lost (22%) phones, and disconnections of phone service due to non-payment (39%) in the past 6 months. On a scale of 0 to 1 (0 having no mobile technology vulnerability and 1 having complete mobile technology vulnerability), participants had a mean MTVS of 0.33 (SD =0.26). Black and financially constrained participants had the highest MTVS, which was significantly higher that other racial/ethnic and financially non-constrained groups, respectively. Higher MTVS was significantly associated with ART non-adherence and non-persistence.

CONCLUSIONS

Findings suggest the need to measure MTVS to recognize pitfalls when using mobile health interventions and identify populations whose inconsistent mobile technology access may be related to worse health outcomes.