Additional analyses
We perform three additional analyses, which are detailed in the Supporting Information. First, to validate the implementation of the high-touch model, we analyze interview, call, and contact statistics across full-time contact tracers to confirm that high-touch contact tracers indeed had a greater degree of interaction and guidance with clients than standard contact tracers. We perform Second, we analyze the “pilot phase” of the high-touch program, which ran from January 6, 2021 until the randomized trial began on February 15, 2021. During this time period, the high-touch team was smaller and was only assigned cases from 12 ZIP Codes, with no randomization. We perform a difference-in-differences analysis, using other ZIP Codes as a control group, and we find substantially identical results of the program impact on referral and uptake rates (see Third, to gather qualitative data on client outcomes and contact tracer experiences from the program, we administered a survey to all high-touch contact tracers active in November 2021. We then identify common themes in the responses (see 