Table 2.

Hurdle Models Predicting Likelihood and Quantity of Daily Alcohol Consumption

Predictors	Logistic Portion of Model			Count Portion of Model
	OR	95% CI	p	RR	95% CI	p
Intercept	0.23	0.18, 0.28	<0.001	4.27	3.97, 4.63	<0.001
Greek status	0.69	0.55, 0.85	<0.001	1.18	1.09, 1.27	<0.001
Sex	1.19	0.96, 1.47	0.128	0.83	0.77, 0.89	<0.001
Baseline drinks per weeka, z-score	1.15	1.02, 1.31	0.010	1.18	1.13, 1.22	<0.001
Baseline RAPI, z-score	1.06	0.95, 1.18	0.304	1.01	0.98, 1.05	0.484
Study period	1.04	1.00, 1.08	0.068	0.98	0.96, 0.99	0.004
Age, 21+	1.98	1.49, 2.55	<0.001	0.90	0.82, 0.98	0.018
Weekend	2.10	1.87, 2.34	<0.001	1.16	1.12, 1.20	<0.001
Person-mean positive expectancies	1.21	1.12, 1.32	<0.001	1.07	1.04, 1.11	<0.001
Daily deviation in positive expectancies	1.58	1.47, 1.70	<0.001	1.13	1.10, 1.15	<0.001
Person-mean negative expectancies	0.76	0.70, 0.83	<0.001	1.11	1.07, 1.13	<0.001
Daily deviation in negative expectancies	1.18	1.12, 1.28	<0.001	1.13	1.11, 1.15	<0.001

Note. OR = Odds Ratio; RR = Rate Ratio; CI = Credible Interval. Greek status was dummy-coded (0 = no Greek affiliation, 1 = fraternity or sorority affiliation). Sex was dummy-coded (0 = men, 1 = women).

^aDerived from the Daily Drinking Questionnaire conducted at baseline. RAPI = Rutgers Alcohol Problem Index. Study period was dummy-coded (0 for 1^st quarter of daily reporting to 3 for 4^th quarter of daily reporting). Weekend was dummy-coded (0 = Sunday to Wednesday, 1 = Thursday to Saturday).