Estimating non-fatal road casualties in a large French county, using the capture-recapture method.
BACKGROUND
Non-fatal road casualties are under-reported, with official figures coming from the police. In the French Rhône county, a road trauma registry constitutes a second source of reporting but its completeness needs to be assessed. We also wish to estimate an incidence rate of non-fatal road casualties that is corrected for under-count.


METHODS
Having two sources of reporting available, we can apply the capture-recapture method under certain conditions. To take into account different reporting probabilities among casualties, the capture-recapture analysis is stratified according to injury severity (New Injury Severity Score=NISS), road user type and human third party. To evaluate the sensitivity of the capture-recapture estimate on the number of matched casualties between the police file and the registry, three scenarios of record-linkage are considered.


RESULTS
For serious (NISS 9+) non-fatal road casualties, the police ascertainment rate is at most 57%, the registry ascertainment rate is at most 87%, and the aggregate ascertainment rate is at most 95%. The ascertainment-corrected incidence rate for serious (NISS 9+) non-fatal road casualties is at least 65 per 100,000.


CONCLUSIONS
The degree of completeness of the registry for serious casualties is rather high, though not satisfactory.
Amoros
Emmanuelle
E
Epidemiological Research and Surveillance Unit in Transport, Occupation and Environment UMRESTTE, French National Institute for Transport and Safety Research INRETS, Bron, F-69500, France. amoros@inrets.fr <amoros@inrets.fr>
Martin
Jean-Louis
JL
Laumon
Bernard
B
D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D001336:Automobiles / Q000706:statistics & numerical data*; D003625:Data Collection; D004812:Epidemiologic Methods; D005602:France / Q000453:epidemiology; D005843:Geography; D006801:Humans; D015994:Incidence; D015233:Models, Statistical; D011996:Records; D012042:Registries; D012680:Sensitivity and Specificity; D015599:Trauma Severity Indices; D014947:Wounds and Injuries / Q000453:epidemiology