PURPOSE : To identify the proportion of Emergency Department (ED) visits in cancer patients associated with a mental and substance use disorder (MSUD) and the subsequent healthcare costs.

METHODS : Nationally representative data on ED visits from 2009 to 2018 was obtained from the Nationwide Emergency Department Sample (NEDS). We identified cancer-related visits with or without a MSUD using the Clinical Classifications Software diagnoses documented during the ED visit. Survey-adjusted frequencies and proportions of ED visits among adult cancer patients with or without a MSUD was evaluated. Survey-adjusted multivariable logistic regression models were used to examine demographic and clinical predictors of the presence of an MSUD and the likelihood of hospital admission for patients with a primary MSUD.

RESULTS : Among 54,004,462 ED visits with a cancer diagnosis between 2009 and 2018, 11,803,966 (22%) were associated with a MSUD. Compared to a primary diagnosis of cancer, patients who presented to the ED with a chief complaint of MSUD were more likely to be female (54% vs. 49%), younger (median: 58 vs. 66), more likely to have Medicaid insurance, and more likely to be discharged home. The three most common MSUD diagnoses among cancer patients were alcohol-related disorders, anxiety disorders, and depressive disorders. The total costs associated with a primary MSUD from 2009 to 2018 was $3,133,432,103, of which alcohol-related disorders claimed the largest majority. Younger age (OR per 10-year increase: 0.86, 95% CI: 0.85, 0.86) and female sex (OR: 1.34, 95% CI: 1.33-1.35) were associated with higher odds of having an MSUD.

CONCLUSIONS : Our findings demonstrate a high burden of psychiatric and substance use illness in the cancer population and provide the rationale for early psychosocial intervention to support these patients.