The full set of exposure variables was then reduced to a parsimonious model containing the top 11 exposure features with the most predictive power: time on ART, appointment month, time since last viral load (VL) test, VL test result, proportion of visits attended >3 days late, CD4 count at screening, age, travel time to clinic, total number of TB symptoms, year first tested positive, and number of others living with client in their house. Here, CD4 is linked to tuberculosis.