​Summary: To compare adolescents’ substance use and physical activity behaviors before and after stay-at-home restrictions.

Ongoing prospective cohort study of tobacco use behaviors among ninth- and tenth-grade students enrolled at eight public high schools in Northern California from March 2019 to February 2020 and followed up from September 2019 to September 2020. Race/ethnicity was self-classified from investigator-provided categories and collected owing to racial/ethnic differences in tobacco and substance use. In California, a COVID-19 statewide stay-at-home order was imposed March 19, 2020. In this study, 521 six-month follow-up responses were completed before the order and 485 were completed after the order.

The prevalence of substance use (ie, past 30-day use of e-cigarettes, other tobacco, cannabis, and alcohol) and physical activity (active ≥5 days/week) was compared at baseline and follow-up. A difference-in-difference approach was used to assess whether changes from baseline to 6-month follow-up varied if follow-up occurred after the stay-at-home order, adjusting for baseline behaviors and characteristics.

Findings: Of 1,423 adolescents enrolled at baseline, 1,006 completed 6-month follow-up. E-cigarette use declined from baseline to 6-month follow-up completed before the stay-at-home order and 6-month follow-up completed after the stay-at-home order, but the extent of decline did not differ statistically between groups responding before versus after the stay-at-home order.

In contrast, being physically active was unchanged from baseline if follow-up was before the order but declined sharply from baseline if follow-up was after the order, indicating a pronounced difference in change from baseline after the stay-at-home order. Overall in the cohort, reported use of other tobacco, cannabis, and alcohol did not differ meaningfully before and after the order.

In this cohort, a reduction in e-cigarette use occurred independently of COVID-19 stay-at-home restrictions, but persistent cannabis and alcohol use suggest continued need for youth substance use prevention and cessation support. Declining physical activity during the pandemic is a health concern.

This study uses 2020 California Health Interview Survey (CHIS) data.

Read the Publication:

• Journal Article: Adolescents’ Substance Use and Physical Activity Before and During the COVID-19 Pandemic