Addressing COVID-19 Testing Disparities in Vulnerable Populations Using a Community JITAI (Just in Time Adaptive Intervention) Approach: RADx-Underserved Populations (RADxUP) Phase III

The Phase III study design focuses on vulnerable communities selected to intervention and control conditions and takes advantage of the fact that these communities were randomized to conditions using methods to ensure balanced arms. In Phase III, the investigators will combine the two intervention conditions [Testing Navigation Intervention (TNI) and Facilitated Self-Sampling Intervention (FSSI), and will receive the Multilevel Community network-informed Just-In-Time-Adaptive Intervention (MC-NET-JITAI). The study will include PBGs from each of the two intervention conditions in Phase II; they will be matched to the comparison PBGs on variables such as size, vaccination and testing rates, and the disparities index with the control group. The intervention will last 8 weeks; individuals will be recruited and asked to complete a survey.

Participants who live in a PBG randomized to the intervention arm will be invited to participate in the trial for that arm. In each of the selected intervention PBGs, individuals will be selected via convenience sampling procedures. Recruitment of participants to the MC-NET-JITAI will take place at the participant's home or at one of the community organizations that our participants look to and interact with around COVID-19 topics identified through the social network data. Community Health Workers (CHW) will consent and enroll participants in the MC-NET-JITAI from the randomized PBGs. MC-NET-JITAI will include CHWs providing the participant with a batch of 4 rapid antigen tests that can be shared with people in the household or other close contacts if needed, a COVID-19 resource flier tailored to the study region and updated information about COVID-19 testing and vaccination. The intervention will consist of enhanced behavioral and educational text messages, up to three messages each week, providing updates on COVID-19 testing and vaccination. The text messages will include digitally delivered intervention content such as a video with low-literacy instructions for administering the rapid antigen tests, guidance if they tested positive (e.g., quarantine, notify contacts, wearing a mask), and other relevant strategies and content focused on increasing COVID-19 testing and vaccination. The CHWs will also be available by phone to the participants for any follow-up questions. CHW will follow up via text, email and/or phone with the participants during the two months post-enrollment. In addition to the intervention, the participants will be asked to complete the pre and post-test surveys. Post surveys will be administered online, over the phone, or in person two months after the initial intervention. Study data will be compared to historical control data from the previous phase II Embedded Study.