Characteristic	n (%)
Sex: female	904 (52.7)
Age (y), mean ± SD	37.7±16.1
18–23	435 (25.4)
24–29	258 (16.0)
30–39	359 (20.9)
40–49	304 (17.7)
≥50	360 (21.0)
Education
Less than high school	520 (30.3)
High school graduate	434 (25.3)
More than high school	761 (44.4)
Missing	1 (0.0)
Income ($)
0–20,000	625 (37.2)
20,001–$40,000	513 (30.6)
40,001–$60,000	298 (17.8)
≥60,000	242 (14.4)
Missing	38 (2.2)
Driver of the car	1215 (70.8)
Days in hospital (d), mean ± SD	1.6±4.1
0	1249 (73.0)
1–2	175 (10.2)
3–7	175 (10.2)
>7	113 (6.6)
Missing	4 (0.0)
Accident caused
Fracture any bones
No	1263 (73.6)
Yes	362 (21.1)
Uncertain	90 (5.3)
Missing	1 (0.0)
Loss of consciousness
No	855 (50.0)
Yes	473 (27.6)
Do not know	386 (22.5)
Missing	2 (0.0)
Amnesia
No	1059 (61.7)
Yes	393 (22.9)
Do not know	264 (15.4)
Confusion
No	505 (29.5)
Yes	1019 (59.5)
Do not know	190 (11.1)
Missing	2 (0.0)
Pain intensity baseline, mean ± SD∗
Neck	6.1±2.9
Headache	5.7±3.4
Back	4.1±3.6
Mid back	3.8±3.6
Arm	3.1±3.5
Hand	1.7±2.9
Abdomen, chest, groin	3.2±3.7
Face	2.4±3.4
Leg	3.2±3.6
Foot	1.1±2.6
Prior health
Excellent	738 (43.0)
Very good	567 (33.0)
Good	332 (19.3)
Fair/poor	79 (4.6)
Health now
Excellent/very good	154 (9.0)
Good	385 (22.4)
Fair	682 (39.8)
Poor	494 (28.8)

∗ Item missing for pain questions up to 25 (1.5%).