Health Information Technology for COVID-19 Testing in Schools (SCALE-UP Counts)

Intervention: Randomization of parent/student participants will take place upon enrollment in the study. Participants are assigned to either usual care (UC), text messaging (TM), or text messaging plus health navigation (TM+HN).

Participants included are those who did not opt-out of the study. Participants eligible for Randomization will either be assigned to 1) Usual Care (control, approximately 20% of participants), 2) Text Message (TM, approximately 40% of participants), or 3) Text Message plus Health Navigation (TM+HN, approximately 40% of participants).

Usual Care participants will only receive unidirectional and fixed public service announcement-type text messaging on COVID-19 testing every 3 weeks (e.g., recommendation to obtain COVID-19 testing if exposed or experience symptoms; information on testing options through the school or district).

TM consists of a more intensive, bidirectional text message prompt asking if a participant has COVID-19 symptoms or if a participant has been exposed to a person that has tested positive for COVID-19, or if the participant has interest in preemptive testing. If a participant responds yes, they will receive a TM prompt for immediate testing and to re-test. Participants will be provided with information on testing options for COVID-19. After 24 hours, the participant will be asked if they tested and what their results are. After 3 days, participants will be prompted to re-test. If a participant had interest in preemptive testing, they will be asked if testing was completed after 7 days. Testing and re-testing prompts will be adjusted through the study to mirror public health guidance on testing strategies.

TM+HN consists of the same intervention as TM with the addition of health navigation services based on participant non-compliance. Participants will be evaluated as non-compliant if they had reported symptoms, contact, or interest in testing and then stop responding to text messages or respond that they did not test. Health navigator (HN) calls will be conducted using Motivation and Problem Solving (MAPS). MAPS is an empirically validated proactive coaching approach used to address barriers and motivate participants to utilize testing options if they are experiencing COVID-19 symptoms, have been exposed to someone that has tested positive for COVID-19, or reported interest in preemptive testing.

Assessments: The study team will collect survey data from parents at pre- and post-intervention as well as throughout the trial. COVID-19 test results of participants will be collected through self-report as well as through results reported to the "Ellume" testing app. Additionally, the study team will conduct stakeholder interviews with students, parents, and staff on ways to improve the interventions to better meet their needs and preferences.

Addendum to study allocation ratio: Change of allocation for participants eligible for Randomization

• The study's allocation ratio was changed on 7/20/22. The original allocation ratio for the study was 20% usual care with the remaining 80% randomly assigned equally to the TM and TM+HN groups. The new allocation ratio was 50% randomly assigned to control with the remaining 50% randomly assigned equally to the TM and TM+HN groups. The reason for the change in allocation ratio is that the study team observed low numbers of participants reporting any COVID-19 testing. Thus, in order to optimize statistical power to be able to compare the control group to both experimental groups (TM and TM+HN) together in end-of-study analyses, the allocation ratio was changed. For schools that were enrolled in the study prior to this allocation ratio change, individuals in that school who had already been assigned a study condition maintained their original assignment. To account for this change in allocation, we will adjust for the allocation ratio for when the participant was randomized, within the model.

Addendum to outcome measures timeline: Change of survey timeline of outcomes for eligible participants

• The survey distribution timeline was changed 9/27/22. The 6-month survey was not distributed (due to an electronic distribution error) and the timing of this survey was changed to 9 months post intervention enrollment. Additionally, the 1-month survey was only distributed in Year 1 of the study. Newly enrolled participants in Year 2 (as of 8/1/22) did not receive the 1-month survey. The purpose of the 1-month survey was to complete an early assessment of the intervention to determine if any changes were needed based on participant feedback, and thus was not needed in the second year of the study. Enrolled participants that did not complete the baseline survey were sent a follow up survey at the end of the study to collect demographic and other outcomes data. A final survey distributed at the end of the study was also added in order to assess accessibility, feasibility, and other outcomes.