Filling Gaps and Adjusting Discontinuities: Transition to ICD-10 Revision in Poland

Agnieszka Fihel, University of Warsaw

Long-term mortality series by single causes of death allow for the analysis of epidemiologic tendencies and health policy impacts within a population. Establishing such long-term continuous series requires linking subsequent WHO International Classification of Diseases (ICD) revisions, which cannot be based exclusively on nominal categories of causes of death, but also on coding practices observed in each country. This paper presents such reconstruction of cause-of-death mortality series for Poland since 1980, that is when the ICD-9 and ICD-10 have been in use. The implementation of ICD-10 revision took place in 1997 under unique circumstances, namely strike of medical doctors. One of its form was neglecting the duty of reporting the underlying cause of death, which applied in years 1997-1998 to over 20% death certificates. Therefore, the analysis includes also restoration of mortality data by single causes of death at the local and country level.