In The Netherlands, there are two registrations of road accident casualties being admitted to hospital. There are the databases of the Basic Data Department of the Netherlands Transport Research Centre (AVV/BG; police registration) and the Prismant database (hospital registration). For a long time now, there has been a considerable difference in the numbers registered in the two databases. An estimation of the total, annual number of hospitalised road accident casualties (the target population) can be made by linking the two databases. The first test of such a linking was made in 1987; for 1985. The results were very promising, so this was repeated in 1997, for 1992 and 1993. A new method was used also involving matching those records that did not entirely agree. Based on this 1992-1993 linking, an estimation of the 'real' numbers was made, not only for these two years, but also for 1994-1997, using extrapolation. This report presents the results of the 1992-1997 linking, with addition of 1985 and 1986. The results of all the years so matched provides a good picture of the course of the registration rates of the two different registrations. Practically the same 'real' numbers of road accident in-patients was obtained for 1992 and 1993 as for after the linking of 1997. The numbers for the whole series deviate slightly from those resulting from the earlier extrapolation. It would seem that the registration rate of AVV/BG declined slightly less than had previously been supposed.
Samenvatting