Analysing multiple causes of death: which methods for which data? An application to the cancer-related mortality of France and Italy

Multiple cause of death (MCOD) data have been used to recalculate mortality levels attributed to a given condition, and to determine the most frequent associations of causes involving this condition. In this article, we begin with a description of how the MCOD data is collected, and we discuss data quality. After presenting the main indicators specifically developed to analyse these data, we provide a concrete illustration of the method based on a comparison of cancer-related mortality in Italy and France. The results for the two countries are strikingly similar. The change in mortality levels is modest for most anatomic sites: cancer is often selected as the underlying cause of death (UCD). The most notable exception (cancer of the prostate) potentially exemplifies future trends, with more effective treatments and increased incidence of this disease among elderly people due to population ageing, cancers may more often play a contributing role in mortality. For all anatomic sites, the reporting of a neoplasm as both underlying and contributing cause of death is a feature of cancer-related mortality. We then categorize all other associations into five patterns (‘degeneration of the contributing cause’, ‘risk factor for the UCD’, ‘common cause’, ‘consequence/complication of the UCD’ and ‘symptom of the UCD’) that reflect current medical knowledge