Changes in certification of diabetes with cardiovascular diseases increased reported diabetes mortality in Australia and the United States

ObjectiveThis paper seeks to better understand diabetes-related mortality in Australia and the United States through analysis of the impact of certification practices of diabetes as a multiple cause of death, specifically with cardiovascular diseases (CVDs).Study Design and SettingVital registration multiple cause of death data in Australia and the United States since 1999 are used to examine trends in the ratio of diabetes reported in Part I (underlying cause) and Part II (associated cause) of the death certificate, when CVDs are also reported.ResultsUnderlying cause of death (UCOD) statistics mask the magnitude of diabetes-related mortality. In both countries, since 1999 there has been an increase in the ratio of diabetes deaths in Part I vs. Part II where CVD deaths, including ischemic heart disease and cerebrovascular diseases, are also reported. In Australia, diabetes reported as an UCOD would be 12% lower in 2006 if the ratio from 1999 was applied.ConclusionThe increasing likelihood of physicians to report diabetes in Part I reflects the subjectivity of diabetes death certification. There is a need for specific guidelines on death certification of diabetes with cardiovascular conditions, relating to its reporting as an underlying or associated cause.