Local-level Association of Social Deprivation and Serious Injuries in Washington State: An Ecological Cross-sectional Study

Background Injuries, a major source of morbidity and mortality, are associated with social determinants of health. To inform strategic prioritization and targeting of injury prevention resources, there is a need to better understand the relationship between specific community-level factors and serious injuries. Methods We conducted an ecological cross-sectional study in ZIP Code Tabulation Areas (ZCTAs) level in Washington State. Community-level risk was assessed through Social Deprivation Index (SDI) (i.e., a composite score that measures deprivation using American Community Survey (ACS) demographic data). Serious injury was defined as injury hospitalization or death. Negative binomial regression was used to examine the relationship between SDI score and injury incidence and pattern. Results SDI score, nonfatal injury hospitalization and death all showed substantial variation across ZCTAs. Compared to communities with the lowest SDI quintile (i.e., lower deprivation), communities with the highest deprivation quantile had higher nonfatal all-cause injury hospitalization incidence rate (IRR=1.38, 95% CI: 1.18,1.6), unintentional injury rates (IRR=1.29, 95% CI: 1.11, 1.50), interpersonal injury rates (IRR=5.22, 95% CI: 3.04, 8.90), and self-inflicted injury rates (IRR=1.69, 95% CI: 1.16, 2.46). Similarly, communities with the highest quantile also had higher all-cause injury mortality rate (MRR=1.79, 95% CI: 1.27, 2.51), unintentional injury mortality rate (MRR=1.96, 95% CI: 1.29, 2.95), homicides (MRR=4.17, 95% CI: 1.63, 10.4), and suicides (MRR=1.23, 95% CI: 0.78, 1.94). Conclusion We observed a positive relationship between SDI score and serious injury at the ZCTA level. Community deprivation indices such as SDI may be a valuable tool for injury prevention targeting at the local level.