Phase-specific costs of care in diffuse large B-cell lymphoma in Ontario, Canada.
Authors: Truong Judy , Cheung Matthew , Seung Soo Jin , Dharma Christoffer , Cheng Stephanie Y. , Earle Craig , Singh Simron , Mittmann Nicole 
Published: June 2022

e18840 Background: This Canadian study analyzes real-world data to estimate phase-specific costs and health care resource utilization for patients with diffuse large B-cell lymphoma (DLBCL). Methods: A cohort of adult patients diagnosed with DLBCL were identified between 2003-2014 from the Ontario Cancer Registry (OCR) and linked to treatment data from Cancer Care Ontario and other provincial administrative health care databases. Health system costs and resource utilization were determined for four defined phases of care in which index date was defined as the OCR diagnosis date, including: pre-diagnosis (90 days prior to index date), initial treatment (index date to 6 months), follow-up (end of treatment phase to beginning of end-of-life or completion of cohort follow-up) and end-of-life (last 6 months of life for patients who died). Costs (Canadian dollars in 2014) and resource utilization were normalized to 30-days. Results: There were 5,392 individuals (53% males; median age 64 years (IQR 53-74)) diagnosed with DLBCL. The median follow-up was 1,903 days (IQR 1,194-2,882) from index date. At follow-up completion, 4,015 (74.5%) individuals were alive. Total mean 30-day cost was $1,175 (±2,267) in pre-diagnosis, $9,166 (±5,581) during initial treatment, $1,462 (±2,757) during follow-up, and $7,965 (±7,104) during end-of-life. The total 30-day cost for inpatient care was $3,864 (±5,013) during treatment (n = 3,362 hospitalized during treatment) and $5,045 (±5,908) for end-of-life (n = 1,367 hospitalized during end-of-life). For home care, the mean 30-day costs were $528 (±512) during initial treatment (n = 3,508, 65% of cohort) and $725 (±884) during end-of-life (n = 1,211, 23% of cohort). Mean 30-day cost of cancer medication was $80 (±455) in pre-diagnosis, $3,115 (±1,236) during initial treatment, $232 (±712) during follow-up, and $305 (±694) during end-of-life. A subset of 239 individuals had autologous stem cell transplantation (ASCT) for relapsed/refractory DLBCL. For the ASCT subgroup, the mean total 30-day cost was $11,653 (±4632) in pre-ASCT phase, $1,542 (±2961) in post-ASCT phase, and $14,094 (±12,845) in end-of-life phase for those that subsequently died (n = 118). A further subset of 52 individuals had relapsed and proceeded to third-line therapy. The total mean total 30-day cost was $8,288 (±8,943) in the first 6-month follow-up, $2,584 (±4,000) in the post 6-month follow-up, and $14,999 (±9,443) in end-of-life phase for those that died (n = 29). Conclusions: Total mean 30-day cost was highest in initial treatment phase and end-of-life phases following a U-shaped pattern. Inpatient care was the cost driver across all phases. Individuals who required ASCT had significantly increased costs. Home care was less frequently accessed during end-of-life phase compared to initial treatment phase (23% vs. 65%). These findings can help allocate appropriate resources throughout the different phases of cancer care.