Table 3

Characteristics of visibly injured drivers, time of crash, and passenger presence

Characteristic	Value	Controls	Cases	Crude odds ratio	95% CI	Adjusted odds ratio*	95% CI
*Odds ratios obtained from logistic model containing all variables in table.
CI, confidence interval.
Driver and crash characteristics
Driver age	16	4648	3963	1.27	1.20 to 1.34	1.37	1.29 to 1.45
	17	7520	5061	(ref)	–	(ref)	–

Driver sex	Male	6171	5396	1.45	1.37 to 1.53	1.25	1.18 to 1.33
	Female	5997	3628	(ref)	–	(ref)	–

Driver alcohol use	Yes	42	813	28.59	20.93 to 40.01	21.62	15.75 to 29.69
	No	12126	8211	(ref)	–	(ref)	–

Time of crash	4 pm–5:59 pm	2079	1310	0.96	0.88 to 1.04	0.93	0.86 to 1.01
	6 pm–7:59 pm	1632	1032	0.96	0.88 to 1.05	0.92	0.84 to 1.01
	8 pm–9:59 pm	1162	836	1.09	0.99 to 1.20	1.00	0.91 to 1.11
	10 pm–11:59 pm	770	820	1.62	1.45 to 1.80	1.30	1.16 to 1.46
	Midnight–1:59 pm	279	529	2.88	2.47 to 3.35	1.86	1.58 to 2.19
	2 am–3:59 am	89	274	4.67	3.65 to 6.02	2.78	2.14 to 3.61
	4 am–5:59 am	25	182	11.05	7.23 to 17.55	9.29	6.02 to 14.34
	6 am–3:59 pm	6132	4041	(ref)	–	(ref)	–

Passenger characteristics	No of passengers
Driving alone	None	5598	4449	(ref)	–	–	–

Male teenage only	1	1337	1226	1.15	1.06 to 1.26	1.03	0.94 to 1.12
	2	411	389	1.19	1.03 to 1.38	1.00	0.86 to 1.17
	3 or more	183	218	1.49	1.22 to 1.84	1.27	1.03 to 1.57

Female teenage only	1	1533	969	0.80	0.73 to 0.87	0.85	0.77 to 0.93
	2	388	235	0.76	0.64 to 0.90	0.79	0.67 to 0.94
	3 or more	166	91	0.69	0.53 to 0.90	0.69	0.53 to 0.90

Mix of male and female teenage	2	299	238	1.00	0.84 to 1.20	0.96	0.80 to 1.15
	3 or more	341	364	1.34	1.15 to 1.57	1.20	1.03 to 1.41

Young adult (ages 20–29)	1	256	164	0.81	0.66 to 0.99	0.71	0.57 to 0.88
	2 or more	29	13	0.56	0.27 to 1.12	0.31	0.14 to 0.67

Mature adult (ages 30+)	1	521	128	0.31	0.25 to 0.38	0.30	0.25 to 0.37
	2 or more	51	9	0.22	0.10 to 0.46	0.22	0.11 to 0.46

Mix of young and mature adult	2 or more	24	5	0.26	0.08 to 0.70	0.25	0.09 to 0.67

Children only	1	209	108	0.65	0.51 to 0.83	0.71	0.56 to 0.91
	2 or more	59	36	0.77	0.49 to 1.18	0.90	0.59 to 1.38

Mix of teen and adults	2	190	97	0.64	0.50 to 0.83	0.57	0.44 to 0.74
	3 or more	151	101	0.84	0.65 to 1.09	0.57	0.43 to 0.76

Mix of teen and children	2	124	66	0.67	0.49 to 0.91	0.75	0.55 to 1.02
	3 or more	97	71	0.92	0.67 to 1.27	0.95	0.70 to 1.31

Other mix	2 or more	201	47	0.28	0.16 to 0.46	0.31	0.22 to 0.43

Total	–	12168	9024	–	–	–	–