# Modeling the Public Health Impact of Improved Antiretroviral Therapy Restart Patterns Among People with HIV Who Have Discontinued Treatment

## TL;DR

This study shows that restarting HIV treatment sooner after a treatment break can prevent new infections and save healthcare costs.

## Contribution

The novel contribution is a cost-consequence analysis modeling the impact of faster ART restarts on public health and economic outcomes.

## Key findings

- Restarting ART 12 weeks after discontinuation instead of 32 weeks could avert 88 HIV transmissions.
- The number needed to treat to avoid one new HIV transmission is 11.
- Improved ART restart patterns result in $101 million in lifetime cost savings.

## Abstract

Antiretroviral therapy (ART) has become a cornerstone of human immunodeficiency virus (HIV) management. However, a challenge in HIV care and policy is ensuring individuals remain engaged in care and on treatment over time. Discontinuation of ART is common for various reasons, and prolonged treatment interruptions can lead to worse health outcomes at the individual level and increased HIV transmissions at the public health level.

A cost-consequence analysis was conducted to evaluate the economic and public health impact of reducing the interval to ART restart among people with HIV (PWH) who have disengaged from care.

A state transition disease model was developed to calculate the economic benefits from improving treatment restart patterns from a United States healthcare payer perspective. Two hypothetical cohorts of 1000 PWH who discontinued ART were compared: a standard-of-care cohort where restart occurs 32 weeks after discontinuation, and a comparator cohort exploring the impact of reducing the time between ART discontinuation and restart to 12 weeks. Individuals were assigned to CD4-related health states, and rates of viral suppression were considered. Four outcomes, ART costs, CD4 health state costs, CD4-related mortality, and new HIV transmissions were calculated over a three-year time horizon. Cost savings from averted HIV cases were valued based on the lifetime excess healthcare costs for a PWH.

Increasing the proportion of individuals restarting ART and reducing time to restart was estimated to avert 88 HIV transmissions. This corresponds to a number needed to treat, defined as the number of PWH who would need to experience the earlier restart pattern of the comparator cohort, of 11 to avoid one new transmission, and $101 083 857 lifetime cost savings. Cost savings attributable to improved CD4 counts in the cohort were also found.

Enhancing ART restart patterns improves health and provides considerable cost savings by improving individuals’ CD4 counts and reducing new HIV transmissions from people who are viremic. Effective policies to promote care engagement and treatment adherence are predicted to improve the health of PWH and reduce new HIV cases.