Cost-effectiveness analysis of probiotic peanut oral immunotherapy (PPOIT) versus placebo in Australian children with peanut allergy alongside a randomised trial

Abstract

Objective To compared the cost-effectiveness of coadministration of a probiotic adjuvant with peanut oral immunotherapy (PPOIT) with placebo (no treatment) in children with peanut allergy. Design Prospectively planned cost-effectiveness analysis alongside a randomised control trial. Setting The Royal Children's Hospital, Melbourne, Australia. Participants 56 children with peanut allergy aged 1-10 years at recruitment. Intervention A daily dose of probiotic Lactobacillus rhamnosus CGMCC 1.3724 (NCC4007) and peanut oral immunotherapy administered for 1.5 years. Main outcomes measures Costs were considered from a healthcare system perspective and included costs of treatment delivery and adverse events. Effectiveness outcomes included rate of sustained unresponsiveness (SU) and quality-adjusted life years (QALYs). The cost-effectiveness of PPOIT versus placebo was analysed using patient-level data. Time horizon was 10 years from commencement of PPOIT treatment, comprising 1.5 years of treatment (actual data), 4 years of post-treatment follow-up (actual data), and 4.5 years of extrapolation thereafter (modelling). Results Healthcare cost per patient over 10 years was higher for PPOIT compared with placebo ($A9355 vs $A1031, p<0.001). Over half of the per patient healthcare cost (53%) in the PPOIT group was attributable to treatment delivery, while the remaining cost was attributable to adverse events. Both measures of effectiveness were superior in the PPOIT group: the average SU rate over 10 years was 54% for PPOIT versus 6% for placebo (p<0.001); QALYs over 10 years were 9.05 for PPOIT versus 8.63 for placebo (p<0.001). Overall, cost per year of SU achieved was $A1694 (range $A1678, $A1709) for PPOIT compared with placebo, and cost per additional QALY gained was $A19 386 (range $A19 024, $A19 774). Conclusions Cost per QALY gained using PPOIT compared with no treatment is approximately $A20 000 (£10 000) and is well below the conventional value judgement threshold of $A50 000 (£25 000) per QALY gained, thus deemed good value for money ($A1= £0.5 approximately). Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12608000594325; Post-results.