LAUSR

6595 Background: Depression and anxiety are common among cancer patients and can worsen outcomes. We studied the occurrence of depression and anxiety in three common cancers to investigate whether healthcare costs were greater for cancer patients with two mental health disorders (MHD), depression and anxiety, compared to patients without MHD. Methods: This retrospective analysis used deidentified medical and pharmacy claims from a large national U.S. health insurer. Patients were Medicare Advantage enrollees ≥65 years diagnosed with breast, colorectal, or prostate cancer and continuously enrolled from 1/2018–12/2019. We determined statistically whether the annual prevalence of the two MHDs varied by cancer types. Total costs and costs exclusive of MHD-related expenses in five sub-categories were compared: inpatient, emergency room, non-inpatient medical, professional, and pharmacy. Costs from 2019 claims were presented as per-patient per-month (PPPM). Direct depression- and anxiety-related costs were from claims with depression/anxiety diagnoses or drugs. The impact of MHDs on 2019 healthcare spending was examined using multiple linear regression, controlling for demographic and clinical characteristics. LASSO was used for variable selection. Mann-Whitney U tests compared differences in costs by service types between patients with and without MHDs. Results: Of 19,304 study patients, 8,916 (46%) had coexisting depression or anxiety: (i) 4% depression only; (ii) 27% anxiety only; (iii) 7% depression and anxiety; and (iv) 8% were on antidepressant without MHDs diagnoses. There were significant differences in the rates of MHDs between the three cancer groups, with the highest frequency in breast cancer ( breast vs colorectal. 56% vs 49%, p < 0.0005 ; breast vs prostate. 56% vs 38%, p < 0.0005; colorectal vs prostate. 49% vs 38%, p < 0.0005). After excluding the MHDs-related costs (PPPM mean = $44), the monthly spending was 54% higher for patients with MHDs ($2,184 MHDs vs. $1,406 non-MHDs). After adjusting for covariates, the PPPM costs were 23%–58% higher for the MHD-cohort vs. the non-MHD cohort for each cancer type ( non-MHD vs. with depression only, CI 13%–34%, p < 0.0001; non-MHD vs. with anxiety only, CI 40%-52%, p < 0.0001; non-MHD vs. with depression and anxiety, CI 48%-70%, p < 0.0001; non-MHD vs. with antidepressant only, CI 28%-45%, p < 0.0001). Higher costs in MHD-cohort were observed in all cost categories (p < 0.0001). Conclusions: We found high prevalence of MHDs in patients diagnosed with cancer. Analyses showed that total spending was significantly higher in individuals with cancer and MHD for all cost categories. Explanations for higher costs are unclear, as costs remain high even after adjusting for MHD-related care costs. Research on specific healthcare services driving higher costs and the risk factors for depression and anxiety is needed to address broader MHDs to improve cancer care.