date. In these analyses, a similar proportion of patients with self-reported abstinence had positive PEth as in the full sample (15% vs. 12%) and this group also showed significantly increased risk of mortality, corroborating results from the full sample. Additionally, previous research using AUDIT-C trajectory models indicates that self-report of alcohol use varies little over time in this population.45 We were also limited by sample size in our ability to use the combined alcohol measure in the modeling of mortality risk among patients who self-reported any alcohol use. Finally, due to the observational nature of our study, we cannot establish causality.
