Tobacco Use Disorder Among Patients With Smoking-related Chronic Medical Disease: Association With Comorbid Substance Use Disorders.

INTRODUCTION: Very little is known of the behavioral vulnerabilities of patients diagnosed with smoking-related chronic medical illness who continue to smoke, potentially worsening morbidity and mortality risks. This study explores the association of tobacco use disorder (TUD) among those with smoking-related chronic medical illnesses with other substance use disorders (SUDs) and risk factors.
METHODS: Among veterans with smoking-related chronic medical illnesses identified from the National Veterans Health Administration administrative records from fiscal year 2012, we compared the characteristics of those with a diagnosis of TUD (International Classification of Diseases, 9th edition code 305.xx; n = 519,918), and those without such a diagnosis (n = 2,691,840). Using multiple logistic regression, we further explored the independent association of factors associated with TUD.
RESULTS: SUD prevalence was markedly higher among those with TUD (24.9% vs 5.44%), including alcohol use disorder (20.4% vs 4.3%) and drug use disorder (13.5% vs 2.6%), compared with nonsmokers. On multiple logistic regression analyses, alcohol use disorder (odds ratio [OR] 2.94, 95% confidence interval [CI] 2.90-2.97) and drug use disorder (OR 1.97, 95% CI 1.94-1.99) were independently associated with current TUD diagnosis. Having any single SUD was associated with considerably high odds of having TUD (OR 3.32, 95% CI 3.29-2.36), and having multiple SUDs with even further increased risk (OR 4.09, 95% CI 4.02-4.16).
CONCLUSIONS: A substantial proportion of people with TUD diagnosis despite concurrent smoking-related medical illnesses are also likely to have other comorbid SUDs, complicating efforts at smoking cessation, and requiring a broader approach than standard nicotine-dependence interventions.