LAUSR

Knowledge regarding deaths due to suicide, alcohol-related, or drug-related causes may be limited by inconsistent and/or restrictive case definitions, resulting in concerns regarding validity of findings and underestimates of burden. In this proof-of-concept study, we assessed varying case definitions (suicide, alcohol-related, drug-related mortality using underlying cause of death [UCOD] versus multiple cause of death [MCOD]) based on counts and rates among Colorado Veterans who died (2009-2020). Suicide, alcohol-related, or drug-related ICD-10 codes were identified, and two case definitions were compared: UCOD; qualifying ICD-10 code listed as the UCOD; and MCOD; qualifying ICD-10 code in any cause of death field. Of 109,314 decedents, the number and age-adjusted mortality rate (per 100,000 persons) significantly increased when including MCOD: UCOD, n=4,930 (110.3/100,000) versus MCOD, n= 6,954 (138.4/100,000). While rates of suicide mortality did not change, alcohol-related mortality doubled with the more inclusive case-definition: UCOD 1,752 (27.3/100,000) versus MCOD 3,847 (59.8/100,000). Alcohol use disorder codes accounted for 71% of additional alcohol-related deaths captured with the MCOD definition. Studies that rely on UCOD codes may be underestimating the burden of deaths, especially alcohol-related deaths. Increased effort is required to reevaluate current classifications of deaths associated with suicide, alcohol-use, or drug-use.