Actual incidences of road casualties, and their injury severity, modelled from police and hospital data, France.
BACKGROUND
Nation-wide road casualty figures usually come from police data. In France, as in many developed countries, the reporting of fatalities is almost complete but the reporting of non-fatal casualties is rather low. It is moreover strongly biased. Valid estimates are needed.


METHODS
Using the capture-recapture method on police data and on a road trauma registry covering a large county of 1.6 million inhabitants, we estimate police under-reporting correction factors that account for unregistered casualties. These correction factors are then applied to the nation-wide police data, with standardization on under-reporting bias factors.


RESULTS
In 2004, whereas the police report 108,727 non-fatally injured, the estimation yields 400,200. Over the 1996-2004 study period, the average annual estimated incidence is 871/100,000 for all injured (3.4 times the police incidence), 232/100,000 for hospitalized, 103/100,000 for seriously injured (2.2 times the police incidence) and 12.6/100,000 for casualties with long-term major impairment. The incidence of seriously injured (NISS 9+) is 11.3/100,000 for pedestrians, 9.5/100,000 for cyclists, 36.3/100,000 for motorized two-wheel users and 42.5/100,000 for car users.


CONCLUSIONS
The estimated incidences are much higher than the police-based ones. This changes the scale of the road injuries issue. The risk of suffering a major impairment from a road crash is equal to the risk of being killed. Motorized two-wheel users experience a large burden of traffic casualties, much larger than that indicated by police data. The approach used can be reproduced in other countries, if an additional medical registration exists.
Amoros
Emmanuelle
E
University of Lyon 1 (UCBL) and French Institute for Public Health Surveillance (InVS), Lyon, F-69008, France. emmanuelle.amoros@inrets.fr
Martin
Jean-Louis
JL
Lafont
Sylviane
S
Laumon
Bernard
B
D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D003625:Data Collection / Q000379:methods*; D005260:Female; D005602:France / Q000453:epidemiology; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016495:Police / Q000706:statistics & numerical data*; D017678:Sex Distribution; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000453:epidemiology*