All-cause deaths and North Atlantic accumulated cyclone energy: understanding the relationship based on county-level income and education levels

Abstract North Atlantic hurricanes have intensified in the past decades, resulting in excess deaths especially among lower-income populations who tend to have elevated mortality rates in coastal regions. Yet the effects of hurricane intensity on mortality rates by income and education levels has not been understood. This population-based study used the North Atlantic accumulated cyclone energy (ACE) index to examine the effects on all-cause mortality (20–84 years) by county-level income and college education level stratification (high and low) in the southeastern United States from 2014–2022. We found that an extreme (≥ 160×104 kt2) ACE period (in comparison to normal ACE period) was associated with all-cause mortality by a rate ratio (RR) of 1.056 (P < 0.001) times. The relationship between ACE index and all-cause mortality was found to be linear. Furthermore, when stratified by income and education levels, only those counties with high-income and high-education were found to have significant associations between above (≥ 126×104 kt2) ACE (in comparison to normal ACE period) and mortality (RR 1.056, P = 0.0008). All other combinations of income and education levels were found to have insignificant associations with mortality during above normal intensity hurricane years. This appears to be explained by the geographic concentration of high income and high education counties along the coasts as compared to the more inland location of low income and low education countries, thus increasing the exposure to impacts of hurricane events. This is the first study to denote that hurricane effects vary based on a combination of income and education levels. Further investigations are needed to identify the effects of hurricanes on cause-specific events based on income and education levels in the United States.