Intravenous versus subcutaneous immunoglobulin in patients with haematological malignancies: time-driven activity-based costing.

purposeProphylactic immunoglobulin (Ig) is used to prevent infections in patients with hypogammaglobulinaemia due to haematological malignancies (HM). Ig can be administered intravenously (IVIg) in hospital or self-administered subcutaneously (SCIg) at home, using different dosing regimens but with comparable effectiveness. In Australia, Ig product costs alone were AU$915.7 million in 2022/2023, 60% of the national blood budget. However, the total cost of IVIg and SCIg, including administration costs, remains uncertain.

methodsWe conducted a prospective, time-driven, activity-based costing study to compare the costs of providing IVIg and SCIg to patients with HM from an Australian healthcare perspective. Ig product, consumables, equipment, and in-hospital costs were included. Analyses were conducted assuming full adherence and using (1) published prices for IVIg and SCIg, which excluded plasma fractionation costs to the Australian government, and (2) equivalent average weighted price for IVIg and SCIg, including plasma fractionation costs.

resultsAnnual IVIg product cost per patient was lower than that for SCIg under both costing scenarios: (1) AU$10,012 and (2) AU$5895, driven by higher SCIg doses. The costs of treating a patient with IVIg for a year were (1) AU$9936 and (2) AU$5787 lower than with SCIg, mainly due to higher SCIg product costs. When only in-hospital administration costs were considered (excluding Ig product and SCIg home consumables), SCIg treatment was AU$1019 less costly than IVIg.

conclusionOur results indicated higher annual direct costs per patient treated with SCIg than IVIg, despite higher in-hospital costs associated with IVIg administration. Further research, including understanding costs to patients, is warranted.