Table 4 Predictors of persistent neck pain—multivariable models.

Exposure	Relative risk (95% CI)
	Model 1: aetiological model	Model 2: overall model	Model 3: weighted model*
Age in years (quintiles)†
17–24	1.0	1.0	1.0
24–30	0.8 (0.4 to 1.4)	0.8 (0.4 to 1.4)	0.8 (0.4 to 1.6)
30–37	1.3 (0.8 to 2.1)	1.1 (0.7 to 1.8)	1.1 (0.7 to 2.0)
37–47	1.2 (0.8 to 2.0)	1.3 (0.8 to 2.1)	1.3 (0.7 to 2.2)
47–68	1.5 (0.9 to 2.4)	1.5 (0.9 to 2.5)	1.6 (0.9 to 2.7)
Sex†
Male	1.0	1.0	1.0
Female	1.0 (0.8 to 1.4)	1.0 (0.7 to 1.4)	1.0 (0.7 to 1.4)
General Health Questionnaire (tertiles)
0–3	1.0	1.0	1.0
4–8	2.1 (1.4 to 3.3)	1.6 (0.99 to 2.5)	1.5 (0.9 to 2.4)
9–12	2.4 (1.5 to 3.7)	1.3 (0.8 to 2.1)	1.3 (0.8 to 2.1)
Pre‐collision, one month period prevalence of widespread body pain
No	1.0	1.0	1.0
Yes	2.1 (1.3 to 3.4)	1.9 (1.1 to 3.2)	1.9 (1.1 to 3.3)
Own vehicle
Car	1.0	1.0	1.0
Other	2.0 (1.2 to 3.3)	1.8 (1.04 to 3.2)	1.7 (0.9 to 3.2)
Number of other symptoms (tertiles)‡
0–3	–	1.0	1.0
4–5	–	1.2 (0.8 to 2.0)	1.3 (0.8 to 2.1)
6–10	–	2.0 (1.2 to 3.2)	2.0 (1.2 to 3.3)
Initial Neck Disability Index score (tertiles)‡
0–14	–	1.0	1.0
15–22	–	1.2 (0.8 to 1.9)	1.2 (0.7 to 1.9)
⩾22	–	1.9 (1.2 to 2.9)	1.7 (1.1 to 2.7)

*Model weighted back to original age/sex distribution of all invited patients.

†Forced into models.

‡Not included in model 1.