Pediatric HIV Transition Model: User’s Guide

The model projects the number of children, adolescents, and young adults on antiretroviral therapy (ART) who are eligible for transitions in care and switching to tenofovir/lamivudine/dolutegravir (TLD) or another newly-introduced regimen. Transitions in care can include transitioning from pediatric to adolescent or from adolescent to adult care and treatment. The model relies on existing HIV epidemiological estimates from the AIDS Impact Model (AIM) in Spectrum and programmatic data, such as the number of infants identified as living with HIV through early infant diagnosis (EID). The model can be used to run up to three different coverage scenarios: ART targets as a percentage of people living with HIV (PLHIV) covered, ART numerical targets, and increases in ART coverage based on recent trends in identification, linkage to care, and retention in care. To apply the Pediatric HIV Transition Model, users must enter all assumptions, including country selection, subnational unit definition, and baseline year for the projection. The model requires inputting data from AIM, which includes the number of people living with HIV by single-year age band and subnational unit. Users must also enter data on uncertainty PLHIV, ART targets, and transition trends. The model outputs include estimates of the number of people living with HIV by year, single-year age band, subnational unit, and gender, as well as the number of people eligible to transition, actually transitioning, and eligible to switch or be on TLD. The Pediatric HIV Transition Model can be applied in any PEPFAR-supported country, and this user's guide provides step-by-step instruction for applying the model. The model's configuration tab allows users to select the country, define the subnational units for analysis, and select a baseline year for the projection. The PLHIV single year by SNU tab requires inputting data from AIM, which includes the number of people living with HIV by single-year age band and subnational unit. The uncertainty PLHIV tab requires inputting data on the range in numbers of people living with HIV after running the uncertainty analysis feature. The model's ART targets tabs allow users to enter the percentage of people living with HIV targeted to be on ART each year or the number of people targeted to be on ART each year. The transition trends tab requires inputting data on the number of people by age and SNU actually transitioning care on average. The eligibility for TLD tab requires inputting data on the percentage of people by age and SNU actually eligible for TLD initiation. The model's results include estimates of the number of people living with HIV by year, single-year age band, subnational unit, and gender, as well as the number of people eligible to transition, actually transitioning, and eligible to switch or be on TLD. The Pediatric HIV Transition Model is a valuable tool for informing target-setting, forecasting, and planning for treatment and care programs for young people's transitions in care.