Geographic Clusters of Alzheimer's Disease Mortality Rates in the USA: 2008-2012

IMPORTANCE: The results identified geographic clusters of high and low Alzheimer's disease (AD)-related mortality across the contiguous United States. These clusters identify specific geographic groupings of counties that allow researchers to narrow the focus to identify some of the biopsychosocial variables contributing to increased or decreased AD mortality. OBJECTIVES: To determine the extent to which geographic clusters exist where AD mortality significantly differs from the national average. Such knowledge could further future research in a more focused study of variables that are contributing to these differences. DESIGN: Age adjusted AD mortality rates were analyzed with a spatial cluster analysis using the disease surveillance software SatScanTM. RESULTS: Three large clusters had elevated age-adjusted AD mortality of at least 60% above the national average. These clusters were in Washington State, Iowa, and North and South Dakota. Below average AD mortality was observed in several areas including New York City, and parts of Arizona, California, Arkansas and Texas. CONCLUSION AND RELEVANCE: This study demonstrates the use of disease surveillance methodology in identifying geographic patterns of unusually high or low AD mortality rates in the USA. Such results provide supporting evidence of appropriate locations to test interventions with the goal to reduce AD mortality.