Table 1 Traffic crash deaths attributed to each risk factor, US, 1982–2001.

Risk factor	Affected population	All deaths in affected population	Deaths attributed to each risk factor
		Count	Count	Rate*	(%)†
Alcohol	All traffic deaths	858 741	366 606	7.15	43
No seat belt	Vehicle occupants	641 114	259 239	5.06	40
No air bag	Vehicle front seat occupants	564 124	31 377	0.61	6
No motorcycle helmet	Motorcycle riders	63 811	12 095	0.24	19
No bicycle helmet	Bicycle riders	16 473	10 552	0.21	64
All five risk factors	All traffic deaths	858 741	528 105‡	10.30	61

*Rates per 100 000 person‐years.

†(%)  =  100 × attributed deaths/deaths in affected population.

‡Count attributed to all five risk factors is less than the sum of the five individual counts because many persons were at risk from more than one factor.