OBJECTIVES: Major depressive disorder (MDD) is a common comorbidity linked to poorer outcomes in cancer patients, but MDD’s impact on healthcare costs for cancer populations is poorly understood. We examined healthcare costs among cancer patients with and without MDD and assessed the impact of MDD on healthcare spending.

METHODS: Retrospective analyses were conducted using medical and pharmacy claims from a large national U.S. health insurer. Patients were Medicare Advantage enrollees ≥65 years old diagnosed with LC (≥2 claims with ICD10 C34 ≥30 days apart) between 1/2017 and 12/2019. Continuous enrollment from 1/2018 to 12/2019 was required. MDD cohort inclusion required ≥1 claim with a MDD diagnosis (ICD10 F32 or F33) and ≥1 pharmacy claim for antidepressant medications with ≥30 days supply in 2019. Costs of 2019 claims were captured and presented as per-patient per-month (PPPM) costs. Direct depression-related costs were from claims with MDD diagnosis or antidepressant drug. The impact of MDD-cohort healthcare spending in 2019 was examined with multiple linear regression, controlling for demographic and clinical characteristics. LASSO was used for variable selection.

RESULTS: Of 8,084 study patients, 1,251 (15.5%) had coexisting MDD. After excluding the depression-related costs (PPPM mean=$98 and median=$29), MDD-cohort patients incurred higher monthly spending compared to those without ($3,994 MDD vs. $3,237 non-MDD). After adjusting for covariates, the PPPM costs excluding depression-related costs were 16% (95% CI: 1.08–1.26; p<0.001) higher for MDD-cohort vs. non-MDD cohort.

CONCLUSIONS: After accounting for MDD-related expenditures, MDD in elderly LC patients is associated with overall increased healthcare costs. Future research will identify specific factors associated with increasing costs for promoting innovative ways to improve and coordinate care for this population.