International comparability of coding cancer data: present state and possible improvement by ICD-10

These are only a few of the major findings of this international death certificate study but they should be enough to make epidemiologists and statisticians wary of international mortality figures and to realize that the World Health Organization must put some effort into improving the rules for selecting the underlying cause of death and to training the users to use them in a uniform manner; otherwise the huge and costly effort of revising the ICD-9 into ICD-10 will have been in vain because the mortality figures will not be internationally comparable.