Figure 2. Comparative ROC curves for universal and site-specific algorithms: The universal algorithm (yellow) is evaluated using data from 137 848 patients across 373 sites in Geita and Kagera, Tanzania (2018–2021) and applied to 6679 patients (2018–2023.5) with a viral load threshold of 1000 copies/mL. The algorithm (blue) is assessed on 12 690 patients (2018–2021) and tested on 6769 patients (2018–2023.5) at clinic A and clinic B, using the same viral load threshold. The algorithm (green) is trained on 5883 clinic A patients (2018–2021) and applied to 3384 clinic A patients (2018–2023.5) and trained on 6214 clinic B patients (2018–2021) and applied to 2926 clinic B patients (2018–2023) separately, using the same viral load threshold. ROC, receiver operating characteristic.