Table 1.

Descriptive statistics for all time-varying covariates and primary study variables by wave; fall 2015-spring 2019 (N = 1277)

	Fall 2015	Spring 2016	Fall 2016	Spring 2017	Spring 2018	Spring 2019
Age (mean [SD])	21.33 (1.60)	21.79 (1.61)	22.31 (1.60)	22.79 (1.60)	23.82 (1.61)	24.84 (1.58)
Past 30-day cannabis (%)	38.06	39.93	38.45	39.78	35.87	34.61
Past 14-day binge drinking (%)	42.29	44.71	43.77	43.07	41.50	36.26
Past 30-day # of other tobacco (mean [SD])	0.76 (0.90)	0.74 (0.92)	0.66 (0.88)	0.67 (0.88)	0.58 (0.83)	0.46 (0.78)
Impulsivity (mean [SD])	2.50 (0.97)	2.49 (0.98)	2.47 (0.96)	2.47 (0.98)	2.49 (0.94)	2.42 (0.97)
Sensation-seeking (mean [SD])	3.48 (0.93)	3.47 (0.92)	3.46 (0.91)	3.40 (0.90)	3.46 (0.90)	3.42 (0.92)
Peer ENDS use (mean [SD])	2.16 (0.90)	2.09 (0.87)	1.99 (0.86)	1.95 (0.82)	2.17 (0.87)	2.35 (0.86)
ENDS use frequency (mean [SD])	3.29 (7.34)	3.35 (7.67)	2.88 (7.26)	2.85 (7.29)	4.21 (8.72)	5.44 (9.98)