Mortality Statistics and their Contribution to Improving the Knowledge of Rare Diseases Epidemiology: The Example of Hereditary Ataxia in Europe.

Official mortality statistics provide population-based data and serve to improve epidemiological knowledge of rare diseases (RDs), by helping with the description of the natural history of the disease. They are an important complement of registries and estimates of disease burden and costs. At the same time, they heighten both the visibility of these diseases and the interest in their study and the search for treatments that may increase survival. This chapter contains a European analysis of hereditary ataxia mortality, which considers the time trend in different countries and the geographical variability in risk of death. Despite the limitations of applying this data source to RDs, mortality statistics share criteria which facilitate international comparisons and are of great utility for obtaining sufficiently uniform and robust time series for analysis of low-prevalence diseases.