Table 3.

Association of variables related to sleep with risk of crash in which a road user (driver, passenger, pedestrian) was injured. Adjusted odds ratio and 95% confidence intervals for multivariate model.

Variables	Unadjusted oddsa (95%CI)	Adjusted oddsb (95%CI)
Sleepiness scale for TRIP
1. Felt active, wide awake	1.0	1.0
2–4. Not fully alert, difficulty staying awake, sleepy	3.1 (2.03–4.84)	5.7 (2.67–12.28)
Amount of sleep in the previous 24 hc
≥6 h	1.0	1.0
<6 h	4.6 (1.83–11.46)	5.9 (1.66–20.85)
Number of nights of adequate sleep in the previous weekd
≥1 night of adequate sleep	1.0	1.0
No night of adequate sleep	1.7 (0.51–5.43)	1.1 (0.18–7.09)
≥2 obstructive sleep apnoea symptomse
No	1.0	1.0
Yes	3.5 (1.49–8.16)	2.9 (0.61–13.57)
Shift workf
No	1.0	1.0
Yes	1.0 (0.46–2.04)	0.4 (0.10–1.80)
Hours paid work per week (>60 h)
No	1.0	1.0
Yes	1.2 (0.54–2.82)	0.4 (0.05–2.82)

^aAdjusted for sampling design.

^bLogistic regression analysis included age, sex, ethnicity, income, self-reported alcohol use, vehicle type, vehicle speed prior to survey/crash, day and time of survey/crash.

^cNumber of hours slept.

^dNumber of nights of adequate sleep (mostly between 11 p.m. and 7 a.m. for 7 h or more).

^eWitnessed reports of symptoms of obstructive sleep apnoea (regular loud snoring, breathing pauses, and choking).

^fInvolving paid work starting before 6 a.m. or finishing after midnight whether permanent, rotating or on call.