Home-Based Subcutaneous Infusion of Immunoglobulin for Primary and Secondary Immunodeficiencies: A Health Technology Assessment.

Background: There are currently two methods used to administer immunoglobulin: intravenous (IV) infusion, the conventional method, and subcutaneous (SC) infusion, a newer alternative. The aim of this assessment was to compare administration of SC immunoglobulin at home with IV immunoglobulin in hospital with respect to benefits, harm, and costs. We also investigated the lived experiences of patients, looking at their quality of life, satisfaction, opinions, and preferences.

Methods: We searched the literature for studies that compared home-based SC infusion with hospital- or clinic-based IV infusion of immunoglobulin in the treatment of primary and secondary immunodeficiency in adults and children. Two review authors reviewed the abstracts and full text of the relevant studies, and abstracted the data.We also performed a review of the economic literature comparing SC infusion at home versus IV infusion of immunoglobulin in a hospital or outpatient clinic in patients with primary or secondary immunodeficiency disorders. We also performed a budget impact analysis to estimate the 5-year cost burden of funding home-based SC infusion programs. All costs were reported in 2017 Canadian dollars.This health technology assessment followed a consultation plan for public engagement. We focused on interviews to examine the lived experience of patients with immunodeficiency, including those having experience of intravenous and/or subcutaneous immunoglobulin treatment.

Results: Sixteen studies met the inclusion criteria. The annual rate of serious bacterial infection per patient did not differ. The annual rate of all infections per patient was relatively lower with home-based SC infusion than with hospital-based IV infusion. Both methods provided an adequate blood (serum) level of immunoglobulin and the pooled mean difference in immunoglobulin level favoured home-based SC infusion. Severe adverse reactions were rare with either method. The risk of adverse events such as fever or headache were higher with IV, while SC infusion sometimes caused infusion site reactions such as swelling, redness, or pain. Where reported, incidence of hospitalization, antibiotic use, and missed days from work or school either did not differ or were lower for SC infusion. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) of evidence for these outcomes was determined to be low.The scores for quality of life and treatment satisfaction either did not differ between the two methods or were significantly higher for some domains with home-based SC infusion. The three important concerns of patients in Ontario regarding home-based programs are loss of supervision, cost, and frequent injections.We identified four economic studies with six analyses (five cost-minimization and one cost-utility). All six analyses suggested that home-based infusion has lower costs, with one also showing greater effectiveness. Results of the budget impact analysis suggest that funding home-based SC infusion program would yield savings of about $0.4 million in the first year, and about $1.6 million by year 5. The total savings from funding home-based SC infusion are approximately $5.0 million over 5 years. Greater savings are indicated when the analysis is conducted from the societal perspective.In speaking directly with patients and their caregivers we found that immunodeficiency reduces quality of life. Intravenous treatment was said to be effective but consumed time and induced side-effects.

Conclusions: The best available evidence suggests that home-based SC infusion is safe and effective, with clinical outcomes that are comparable to the clinical outcomes of hospital IV infusion. The quality of evidence is low, however, meaning that we cannot be certain about these findings. The shift from hospital-based IV to home-based SC has the potential to reduce the health care costs due to savings in nursing time in Ontario. Patients and caregivers expressed preference for home-based SC treatment as it reduces treatment burden and improves overall quality of life.