Table 2.

Demographic, sleep, and drinking characteristics.

Characteristics		Ineligible upon web screening	Eligible upon web screening but not enrolled	Enrolled	Test statistic		P value
					F test (df)	Chi-square (df)
Number of participants, n		592a	290	27	N/Ab	N/A	N/A
Age (years), mean (SD)		21.1 (2.3)	21.2 (2.1)	20.3 (1.7)	2.352 (908)	N/A	.10
Sex (female), n (%)		392 (66.2)	223 (76.9)c	16 (59.3)d	N/A	11.8 (2)	.003
Smartphone, n (%)
	iPhone	509 (86.0)	264 (91.0)	24 (88.9)	N/A	4.6 (2)	.10
	Android	83 (14.0)	26 (9.0)	3 (11.1)	N/A	N/A	N/A
Sleep quality on 1-5 scale, mean (SD)		2.8 (0.9)	2.7 (0.8)c	2.5 (0.9)	5.411 (827)	N/A	.005
AUDIT-Ce on 0-12 scale, mean (SD)		All below high-risk cutoffs (<5 women and <7 men)	6.6 (1.5)	8.0 (1.6)d	19.032 (316)f	N/A	<.001
Heavy drinking episodes in the past 14 days, mean (SD)		0.5 (0.8)	2.6 (2.3)c	5.1 (1.9)c,d	299.243 (908)f,g	N/A	<.001
Drinks per week, mean (SD)		3.9 (4.5)	13.7 (8.6)c	28.1 (27.4)c,d	288.710 (908)f,g	N/A	<.001

^a81 volunteers from this group were excluded from the analysis of sleep quality because they chose not to answer this question. They were nonetheless counted as completed surveys because sleep quality did not affect study eligibility.

^bN/A: not applicable.

^cDifferent than ineligible upon web screening (Bonferroni-adjusted Q<.05).

^dDifferent than eligible upon web screening but not enrolled (Bonferroni-adjusted Q<.05).

^eAUDIT-C: consumption questions of the Alcohol Use Disorders Identification Test.

^fAdjusted for sex.

^gAdjusted for age.