The effect of death certification and coding practices on observed differences in respiratory disease mortality in 8 E.E.C. countries.

National differences in respiratory disease mortality have been observed in eight member countries of the European Economic Community (E.E.C.). To investigate the extent to which death certification and coding practices explain such differences, a representative sample of certifying doctors in each country was asked to complete specimen death certificates for a bank of ten written case histories. The certificates from each country were coded firstly by their own offices and subsequently by the W.H.O. Reference Centre in the U.K. Large within- and between-country differences in the coded causes of death were found. Some of these differences were due to variations in the ways doctors certify deaths, others to the way certificates are coded in each country. These discrepancies explain part of the between-country differences in mortality in some disease categories. Comparisons of mortality statistics for respiratory diseases between different countries should therefore be viewed with caution. There is a need for further standardisation of death certification and coding practices in the E.E.C.