An earlier study reported a tight linear fit between national adult HIV prevalence and the percentage of children living in a household with at least one HIV-positive adult. MEASURE Evaluation extended this analysis to all existing DHS data sets with HIV testing, to determine the feasibility of using regression modeling to estimate the size of two priority groups: (1) children living with at least one adult who is HIV-positive, and (2) orphans and coresident children living with at least one adult who is HIV-positive.