Representativeness

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Representativeness

The UN definition of a road crash is that it "occurred or originated on a way or street open to public traffic, which resulted in one or more persons being killed or injured, and in which at least one moving vehicle was involved".

Theoretically a crash database would contain all crashes on public roads. In practice, however, the registration rate depends on a crash's severity (the severer the better) and the vehicles involved. Somebody who falls from his bicycle and breaks a leg meets the requirements of the definition entirely. However, it is experienced as being accidental, 'someone fell', but not as a 'road crash'. That is why single vehicle crashes involving cyclists are almost entirely missing in the crash database.

The incompleteness of the registration is mainly because:

not all crashes are reported to the police;
the police do not register all reported crashes and send them to AVV.

Registration rate and severity: the more severe the injury, the higher the registration rate

		1996	1997	1998	1999	2000	2001	2002	2003	2004	2005
Killed	Registration rate	94%	94%	93%	92%	93%	92%	92%	94%	91%	92%
	Real number	1,251	1,235	1,149	1,186	1,166	1,083	1,069	1,088	881	817
	Registered	1,180	1,163	1,066	1,090	1,082	993	987	1,028	804	750
In-patients	Registration rate	62%	58%	63%	64%	63%	62%	60%	57%	52%
	Real number	19,410	20,210	18,620	19,410	18,300	17,820	18,420	18,660	18,420
	Registered	11,964	11,717	11,733	12,387	11,505	11,028	11,018	10,596	9,487	9,401
A&E dept.	Registration rate	18%	16%	16%	15%	13%	15%	14%	10%
	Real number	91,100	108,000	105,000	116,000	117,000	92,000	91,000	97,000
	Registered	16,381	16,795	16,989	16,828	14,996	13,884	12,580	9,970	10,883

Registration rate by injury severity.

Registration rate by transport mode and injury severity

Crashes are more frequently registered:

the severer they are,
if motor vehicles are involved: the average registration rate of in-patients is 60%, but of casualties in/on motor vehicles i.e. cars, lorries, motorbikes, and moped riders the registration is higher than 80%. The registration rate of casualties among cyclists and pedestrians is far below 60%. The registration of cyclists and pedestrians in collision with motor vehicles is also more complete than if absolutely no motor vehicles at all were involved.

	Registration rate
Mode of transport	Killed (CBS 2000)	In-patients (NPR 2000)	A&E (ISS 2000)	Other injury (AIN 97/98)
Car/lorry/motorbike	95%	84%	25%	38%
Moped	96%	67%	14%	26%
Bicycle	88%	33%	4%	13%
Pedestrian	94%	55%	21%
Total	93%	60%	13%	24%

Registration rate of traffic casualties by mode of transport and severity.

The source of the 'Other injury' is the telephone survey entitled Accidents in the Netherlands 1997/98 (Den Hertog et al, 2000) Therefore the figures differ from the permanent registration that is used in all the other table data. Cyclists have by far the lowest registration rate, irrespective of the severity category.

The real or actual registration rate is determined by comparing the Road Crash Registration with other sources.

See further in Causes of Death, National Patient Register , Injury Surveillance System , Accidents and Exercise in the Netherlands.

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