Monitoring Huntington's Disease Mortality across a 30-Year Period: Geographic and Temporal Patterns

Abstract

Background: Huntington's disease (HD) is a progressive neurodegenerative condition characterized by chorea, dystonia, behavioral disturbances and cognitive decline. The aim of this study is to assess temporal and spatial changes on mortality attributable to HD over 30 years in Spain. Methods: HD data were extracted from the nationwide mortality registry for the period 1984-2013. Annual and 5-year gender- and age-specific rates adjusted for the standard European population were calculated. Geographic analysis was performed by districts from 1999 through 2013, and then estimated standardized mortality ratios (SMRs) and smoothed SMRs. Results: There were 1,556 HD-related deaths across the study period. An increasing trend in age-adjusted HD mortality was in evidence, specifically from 1994 through 1998. On a year-by-year basis, age-adjusted mortality rates increased from 0.076 per 100,000 population in 1984 to 0.157 in 2013. Geographical differences among districts were evident in specific areas and in the southwest of Spain with a significantly higher HD mortality risk. Conclusion: HD mortality rising trends in Spain might be attributable to improvements in diagnosis leading to a rise in prevalence. Geographical variability in HD mortality could be related to regional differences in disease prevalence, health-care disparities, or other factors which call for in-depth assessment in future studies.