Healthcare utilization and costs in frail versus non-frail patients with diffuse large B-cell lymphoma

Half of older patients with diffuse large B-cell lymphoma (DLBCL) receiving curative-intent treatment are frail. Understanding differences in healthcare utilization including costs between frail and non-frail patients can inform appropriate models of care. A retrospective cohort study was conducted using population-based data in Ontario, Canada. Patients >66 years with DLBCL who received frontline curative-intent chemo-immunotherapy between 2006-2017 were included. Frailty was defined using a cumulative deficit-based frailty index. Healthcare utilization and costs were grouped into five phases: (1) 90 days preceding first treatment; (2) early treatment (0 to +90 days after starting treatment); (3) late treatment (+91 to +180 days); (4) follow-up (+181 to -181 days prior to death); (5) end-of-life (last 180 days before death). Costs were standardized to 30-day intervals (2019 Canadian dollars). 5,527 patients were included (median age 75 years (IQR 70-80), 48% female). 2,699 (49%) patients were classified as frail. Median costs (IQR) for frail vs. non-frail patients per 30-days based on phase of care were: (1)$5,683 (3,065-10,322) vs. $2,586 (1,656-4,721); (2)$13,090 (10,385-16,809) vs. $11,256 (9,107-13,976); (3)$5,734 (3,347-8,904) vs. $4,883 (2,845-7,543; (4)$1,138 (552-2,397) vs. $686 (350-1,425); (5)$11,413 (5,845-21,381) vs. $9,089 (4,844-15,793), p<0.0001 in all phases. In multivariable modelling, frail patients had higher rates of emergency department visits and hospitalizations and increased costs compared to non-frail patients through all phases except end-of-life. During end-of-life, a substantial portion of patients [84% (N=2569)] required admission to hospital; 27% (N=684) of whom required ICU admission. Future work could assess whether certain hospitalizations are preventable, particularly for patients identified as frail.