Table 1 shows the past-30-day prevalence of substance use across the repeated surveys. Collapsing data across all three surveys (n = 3,159), 8.0% of youth ever reported use of any substance, 3.4% ever reported use of alcohol, and 3.6% ever reported use of nicotine. Rates of substance use remained stable across the three surveys during the pandemic, from May to August 2020 (Table 1). Among those endorsing use, most youth (72%) indicated 1–2 days of use in the past month (Figure S3), and most youth (76%) indicated the use of a single substance. Twenty percent of those endorsing alcohol use also used nicotine; 21% of those endorsing nicotine use also used alcohol; and other overlaps were infrequent (<8%). Among endorsements of nicotine use, 42% were of vaping from an electronic nicotine delivery system; 20% of smoking a tobacco cigarette; 20% of using smokeless tobacco, chew, or snus; and 17% of smoking a tobacco cigar, hookah, or pipe. Among endorsements of cannabis use, 38% were of smoking flower, 14% of smoking oils or concentrates, 16% of vaping flower, 16% of vaping
