Methodological issues in comparing injury incidence across countries.

The primary objective was to describe the methodological challenges and devise solutions to compare injury incidence across countries. The research design was a mixed methods study, consisting of a consultation with an expert group and comparison of injury surveillance systems and data from ten European countries. A subset of fractures, selected radiologically verifiable fractures and a method of checking the national representativeness of sample emergency department data were devised and are proposed for further development. These methodological considerations and developments will be further refined and tested and should prove useful tools for those who need to compare injury incidence data across countries.