Abstract
Many road accident casualties are not reported to the police and therefore do not appear in national casualty statistics. In addition, injury severity may be mis-classified by the police within reported casualties. To enable the Department of Transport to assess the costs of road accidents and identify and prioritise road casualty reduction measures, accurate information on the number and type of casualties occurring is required. This report summarises the results of a study to link casualties from a national sample of hospitals with police casualty records to provide information on the relative differences between reported and unreported casualties and the extent to which casualties are mis-classified within national accident data. (A)