Work productivity among patients with metastatic breast cancer in the United States.

Objective: To characterize workplace productivity measures in patients with metastatic breast cancer (mBC) using line of therapy (LOT) and first line (1 L) regimen.

Methods: A retrospective cohort study was conducted using IBM's MarketScan Commercial Claims and Encounters (CCAE) and Health and Productivity Management (HPM) databases. The cohort included patients diagnosed with mBC who initiated 1 L treatment between 2/3/2015 and 6/30/2018. Productivity was measured using days absent from work and short- and long-term disability (STD, LTD) claims by LOT and 1 L regimen (any cyclin-dependent kinase 4/6 inhibitor [CDK4/6i], endocrine monotherapy, chemotherapy only, or other anti-cancer therapy [OACT]). LOT was defined using regimen-based progression.

Results: Overall, 548 patients were included; 148, 129, 145, and 126 received endocrine monotherapy, CDK4/6i, chemotherapy only, and OACT, respectively. The rate of LTD increased significantly by 3.1 and 2.6 times from 1 L to second line (2 L) and from 2 L to subsequent lines, respectively. Patients receiving 1 L chemotherapy had 2.4- and 2.7-times odds of using STD and LTD compared to patients receiving 1 L CDK4/6i.

Conclusions: Regimen-based disease progression is associated with increased use of STD and LTD. Patients with a 1 L regimen of chemotherapy have significantly higher odds of using STD or LTD than patients using 1 L CDK4/6i.