Cost–utility analysis comparing hospital‐based intravenous immunoglobulin with home‐based subcutaneous immunoglobulin in patients with secondary immunodeficiency

Background and Objective Immunoglobulin replacement therapy ( IRT ) is often used to support patients with primary immunodeficiency disease ( PID ) and secondary immunodeficiency disease ( SID ). Home‐based subcutaneous immunoglobulin ( SCI g) is reported to be a cheaper and more efficient option compared to hospital‐based intravenous immunoglobulin ( IVI g) for PID . In contrast, there is little information on the cost‐effectiveness of IRT in SID . However, patients who develop hypogammaglobulinaemia secondary to other conditions ( SID ) have different clinical aetiology compared to PID . This study assesses whether SCI g provides a good value‐for‐money treatment option in patients with secondary immunodeficiency disease ( SID ). Methods A Markov cohort simulation model with six health states was used to compare cost‐effectiveness of IVI g with SCI g from a healthcare system perspective. The costs of treatment, infection and quality‐adjusted life years ( QALY s) for IVI g and SCI g treatment options were modelled with a time horizon of 10 years and weekly cycles. Deterministic and probabilistic sensitivity analyses were performed around key parameters. Results The cumulative cost for IVI g was A$151 511 and for SCI g A$144 296. The QALY s with IVI g were 3·07 and with SCI g 3·51. Based on the means, SCI g is the dominant strategy with better outcomes and at lower cost. The probabilistic sensitivity analysis shows that 88·3% of the 50 000 iterations fall below the nominated willingness to pay threshold of A$50 000 per QALY . Therefore, SCI g is a cost‐effective treatment option. Conclusion For SID patients in Queensland (Australia), the home‐based SCI g treatment option provides better health outcomes and cost savings.