The economic value of self-administered subcutaneous immunoglobulin G (SCIg) in Canada: a scoping review

Subcutaneous immunoglobulin (SCIg) is a treatment available in Canada for patients requiring antibody replacement. While standard-of-care involves in-hospital intravenous Ig (IVIg) treatment, SCIg allows for home-based administration and fewer clinic visits, representing a common treatment choice. This study summarized the economic value of SCIg vs. IVIg treatment in Canada.

A scoping review was conducted using Medline and Embase, supplemented by grey literature searches. Eligibility criteria were clinical studies and economic evaluations reporting cost and healthcare resource use (HCRU) outcomes of SCIg or IVIg treatment in Canada (any condition). Types and estimates of costs (Canadian dollars [CAN$]), cost-effectiveness, and HCRU were summarized. Estimates from economic models were inflated to 2025 CAN$ and standardized as cost savings per-patient per-year.

From 824 database abstracts and 10 grey literature citations, 21 eligible articles were included; articles without Canadian economic data for IVIg or SCIg were excluded. Lower costs and HCRU were reported for SCIg vs. IVIg (n=7 studies), where reductions in total cost ranged from $1,795 to $5,386/patient/year (uninflated). Staffing time and lost productivity were also lower; SCIg required 45-57 fewer nursing hours/patient/year, and 51-82 fewer parental hours/patient/year. Lower costs with SCIg were driven by reduced infusion materials, staff time, transportation to clinics, and lost productivity. Across economic models, annual cost savings were substantial after switching patients from IVIg to SCIg; post-inflation estimates averaged from $1,947 to $7,152 per patient. In a cost-utility analysis, SCIg was less costly while providing greater quality-adjusted life-years than hospital-based IVIg, even when hospital/staff costs for IVIg were lowered by 50%.

SCIg represents an important treatment option both for alleviating burden to the Canadian healthcare system and for patients. Substantial cost savings were estimated by switching from IVIg to SCIg. These findings provide evidence to support healthcare decision-making from an economic perspective.