Persistent disparities despite declining carbon monoxide mortality in the United States: a nationwide analysis, 1999–2023

Background Carbon monoxide (CO) poisoning remains a preventable cause of mortality. However, emerging evidence suggests that recent progress in prevention may not be equitably experienced across the population groups in the United States. Long-term national assessments of disparities in CO mortality are inadequate. Objectives This study sought to identify trends in CO poisoning mortality, assess disparities, and inform future studies. Methods We conducted a descriptive epidemiological study, using national mortality data from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) for 1999–2023. The study population included adults aged 25 years and older, with 47,160 deaths identified. Age-adjusted mortality rates were calculated, and trends were assessed using joinpoint regression to estimate annual and average annual percent change (APC and AAPC), with 95% confidence intervals (CIs). Analyses were stratified by sex, race and ethnicity, age group, geographic region and urban–rural status. All analyses represent primary use of these data. Results National age-standardized mortality declined over the study period (AAPC −3.02%; 95% CI − 4.58 to −1.43), but the decline slowed after 2010. Mortality among Hispanic adults increased substantially after 2016, with signs of trend reversal among non-Hispanic Black adults. Mortality in non-metropolitan areas remained approximately 1.8 times higher than in metropolitan areas, with evidence suggesting that prior declines may have stalled. Conclusion Declines in CO poisoning mortality have slowed in the United States, with some evidence of recurrent annual fluctuations, accompanied by widening racial, ethnic, and geographic differences.