Figure. Participant Recruitment and Retention.

Baseline surveys (N = 1423) were completed from March 2019 through February 2020. Six- and 12-month follow-up surveys were administered electronically at the respective intervals from baseline. As of September 2020, all participants had been eligible for 6-month follow-up, and approximately half of the sample was eligible for 12-month follow-up.

^aTwo schools enrolled in spring 2019 were revisited in fall 2019 to enroll new samples of ninth-grade students.

^bOf these 536 follow-up responses, 51 were collected prior to March 20, 2020, and 485 were collected after the stay-at-home order. For this analysis, the 51 pre–stay-at-home responses were included with the spring 2019 cohort.

^cThis retention percentage calculated among the 711 participants enrolled in spring 2019; the remaining 712 students enrolled in fall 2019 were not yet eligible for 12-month follow-up.

^dThis retention percentage refers to participants in the entire cohort who completed at least one 6- or 12-month follow-up survey through September 2020. Some participants completed both a 6- and 12-month follow-up survey.