This cohort study examines trends in pneumonia mortality in Finland and the effects of a WHO recommendation restricting the registering of pneumonia as the underlying cause of death (COD) for several chronic diseases. All cases having pneumonia in any COD fields in 2000–2008 were extracted from the COD statistics. We examined trends in underlying-cause pneumonia mortality where pneumonia was also the immediate COD. Results are presented as age-specific and age-standardized rates. In the study period 2000–2008, there were 90 626 deaths with pneumonia in COD fields, while the underlying-cause pneumonia mortality rate decreased from 32 to 6/100 000 person-years. Immediate-cause pneumonia was less often chosen as underlying-cause towards 2008 suggesting an effect from changing coding practices. Changes in coding practices need to be considered when comparing different countries or time periods in pneumonia mortality.
