TABLE 3—

Sequential Logistic Regression of DWI in the Past Month Among 11th-Grade Students: NEXT Generation Study, United States, 2010–2011

Covariate	Model 1, ORa (95% CI)	Model 2, ORa (95% CI)	Model 3, ORa (95% CI)
Binge drinking in last 30 d
No (Ref)	1.00	1.00	1.00
Yes	11.96*** (7.71, 18.58)	5.75*** (3.28, 10.09)	3.17** (1.53, 6.54)
Illegal drug use in the past y
No (Ref)		1.00	1.00
Yes		7.80*** (3.81, 16.00)	5.91*** (2.64, 13.23)
Risky driving			1.25*** (1.12, 1.39)
Secondary tasks while driving			1.09 (0.92, 1.29)

Note. CI = confidence interval; DWI = driving while intoxicated; OR = odds ratio. Model 1 includes binge drinking in last 30 days and covariates; model 2 includes model 1 variable plus illegal drug use in the past year and covariates; model 3 includes model 2 variables plus risky driving and secondary tasks while driving and covariates. Risky driving and secondary task engagement are continuous variables. The total sample size was n = 880 (those who had an independent driver’s license, not a learner’s permit). Goodness-of-fit statistics were as follows: for model 1, χ² = 283373.68, df = 6; for model 2, χ² = 400079.35, df = 7, Δχ² = 116705.67 (P < .001), Δdf = 1, compared with model 1; for model 3, χ² = 543920.79, df = 9, Δχ² = 143841.44 (P < .001), Δdf = 2, compared to model 2.

^aControlling for race/ethnicity, gender, and driving days in the past 30 days.

**P < .01; ***P < .001.