National trends and demographic disparities in mortality involving co-listed chronic obstructive pulmonary disease and substance use disorders among U.S. adults aged ≥65 years: A population-based serial cross-sectional CDC WONDER analysis, 1999 to 20

Chronic obstructive pulmonary disease (COPD) and substance use disorders (SUDs) frequently coexist, yet national mortality patterns involving both conditions among older adults remain incompletely characterized. We evaluated temporal, demographic, geographic, and substance-specific patterns in U.S. death records co-listing COPD and SUDs among adults aged ≥65 years. We conducted a descriptive serial cross-sectional analysis of Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research multiple cause of death data from 1999 to 2020. Eligible records included deaths among adults aged ≥65 years in which COPD (International Classification of Diseases, 10th revision J41-J44) and SUDs (F10-F19) were both recorded in the Multiple Cause of Death fields. Age-adjusted mortality rates (AAMRs) were calculated overall and by sex, race/ethnicity, census region, urbanization, and state; age-group analyses used age-specific crude mortality rates. Joinpoint regression estimated annual percent changes and average annual percent changes. Secondary analyses examined individual F10 to F19 categories, with a sensitivity analysis excluding tobacco/nicotine-related disorders (F17). Among 1,524,216 qualifying deaths, the overall AAMR increased from 25.5/100,000 in 1999 to 213.2 in 2020, peaking at 219.0 in 2017. Males had higher pooled AAMRs than females (216.98 vs 132.54). The highest pooled racial/ethnic AAMR occurred among non-Hispanic American Indian or Alaska Native adults (191.99), followed closely by non-Hispanic White adults (188.68). The Midwest had the highest regional AAMR, while nonmetropolitan counties had higher AAMRs than metropolitan counties (232.82 vs 152.03). Tobacco/nicotine-related disorders accounted for the predominant substance-specific burden. Excluding F17 yielded an average annual percent change of 2.19% (95% confidence interval, 1.37-3.02). In the overall F10 to F19 analysis, mortality involving co-listed COPD and SUDs increased markedly during the earlier study period before stabilizing, whereas temporal trajectories differed across individual substance categories. Substantial demographic, geographic, and substance-specific heterogeneity was observed. Findings are descriptive and should not be interpreted causally.