Drought Associations with All-Cause Mortality Rates in the United States

Little is known about the effect of drought on all-cause mortality, especially in higher income countries such as the United States. The aim of our study is to evaluate the associations between droughts and same-year all-cause mortality in adults in the United States from 1968-2014. This analysis was conducted by combining historical drought data with all-cause mortality data from 1968 to 2014 to determine any associations between changes in mortality with drought. The results of our study suggest that, for most demographic subgroups and across climate regions, there were limited significant associations between drought intensity as defined in this study with mortality rates within the same year in the contiguous United States over the period 1968-2014. Our results suggest that certain subgroups had possible health effects associated with drought events and the results of the metaregression suggests a possible relationship between the effects of drought severity on all-caused mortality with climate region, race, and age. The findings could indicate contextual heterogeneity in the effects of drought on mortality, possibly due to intersectional vulnerability, and either true null associations for most subgroups, or limitations in study design for observing the effects. This analysis could help public health officials understand the relationship of drought on health.