Measuring substance use disorder (SUD) and hospital use in commercial- and Medicaid-insured cancer patients in Washington (WA) state.

248 Background: Studies show that SUDs impact cancer risk, treatment, and survivorship and increase hospital use. We examined SUD in Medicaid enrollees with cancer in WA state, hypothesizing they had higher SUD diagnoses than commercial insurance enrollees and those with an SUD experienced more emergency department (ED) visits or inpatient (IP) stays during initial treatment. Methods: We linked WA state cancer registry records with claims data from two large commercial insurers and Medicaid. Eligibility criteria included patients < 65 diagnosed with a solid tumor between 2013-2023 who started systemic therapy within 6 months of diagnosis. SUD diagnoses within six months of cancer diagnosis are reported by alcohol, drug, and opioid use. Multivariate logistic regressions were used to evaluate the association between different types of SUDs and likelihood of hospital use (at least one ED visit or IP stay) in the 6 months following initiation of systemic therapy, after controlling for payer type, sex, race, ethnicity, age, marital status, stage, cancer group, area deprivation index, and diagnosis year. Results: Of the 12,714 patients receiving systemic therapy (7,956 Commercial, 4,758 Medicaid), 9.6% had an SUD diagnosis, most commonly alcohol-related (5.4%), followed by drugs and opioids (both 2.8%). SUD patients were less likely to be Asian and more likely to be male, living without a partner, diagnosed at a later stage, and living in more deprived areas. Medicaid patients had significantly higher rates of SUD at diagnosis compared to commercially insured patients (17.9% vs 4.6%), and for each type of substance use (alcohol 9.5% vs 4.8%, drug 6.2% vs 1.2%, and opioid 5.4% vs 2.1%). Overall, 46.6% of cancer patients used the hospital in the 6 months following systemic therapy initiation (68.5% patients with SUD, 44.3% patients without SUD). Hospital use was highest among Medicaid patients with an SUD (72.5%), with opioid-related cases leading (79.5%), followed by drug-related (73.6%) and alcohol-related SUDs (68.4%). In multivariate modeling, cancer patients with SUDs were significantly more likely to visit the hospital compared to those without SUDs, with the highest risk observed among patients with opioid-related SUDs (OR 2.62, 95% CI 2.01–3.42), followed by drug (OR 1.86, 95% CI 1.44–2.39) and alcohol (OR 1.57, 95% CI 1.32–1.86) related SUDs. Conclusions: Overall, more than 1 in 11 cancer patients in WA state under < 65 have a recorded SUD within 6 months of diagnosis; with the number for Medicaid-insured patients greater than 1 in 6. SUD is associated with significant excess risk for ED/IP admissions during treatment. Identification of SUD in patients with newly diagnosed cancer presents an opportunity to reduce unplanned ED visits and hospitalizations during treatment. Research directed at interventions to reduce this risk may provide substantial clinical and economic benefits.