Identifying disproportionate burden through the spatial covariance of two acute deaths of despair : firearm suicide and opioid overdose

Objectives: To evaluate the spatial covariance in two acute deaths of despair outcomes, firearm suicides and opioid overdoses, to better understand how these two public health crises intersect across US counties. The identification of communities which share similar risk for both outcomes as well as those with a disproportionate burden of one outcome compared to the other will allow for more effective resource allocation and targeted intervention strategies. Methods: CDC NVSS county-level detailed mortality data from 2013-2017 was used to classify deaths due to firearm suicide and opioid overdose. Local county standardized mortality ratios were smoothed using a Bayesian BYM model to reduce the influence of extreme, variable rates due to small numbers. The smoothed standardized mortality ratios for these two acute deaths of despair within each county were intersected to classify counties by their shared and distinct cause-specific burden of death compared to the US average risk. Results: There is significant heterogeneity in the incidence of firearm suicide and opioid overdose deaths at the county-level compared to the US average risk of death (3.48 firearm suicide deaths per 10,000 people and 7.66 opioid overdose deaths per 10,000 people). The burden of mortality from these preventable causes reveals a distinct spatial pattern of intersection and avoidance, creating a uneven landscape of risk across the United States. Conclusions: Spatial Bayesian smoothing techniques are crucial tools for making valid inferences regarding risk in small areas. Recognizing the shared or disproportionate burden of these two acute deaths of despair in a community can guide the development and refinement of programs designed to prevent them. To intervene to reduce deaths, a welfare geography approach should be used to equitably allocate shared resources to address the specific mediating pathways from despair to firearm suicide or opioid overdose deaths.