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.

Prospectively planned cost-effectiveness analysis alongside a randomised control trial.

The Royal Children’s Hospital, Melbourne, Australia.

56 children with peanut allergy aged 1–10 years at recruitment.

A daily dose of probiotic Lactobacillus rhamnosus CGMCC 1.3724 (NCC4007) and peanut oral immunotherapy administered for 1.5 years.

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).

Healthcare cost per patient over 10 years was higher for PPOIT compared with placebo ($A9355 vs $A1031, p

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).

Australian New Zealand Clinical Trials Registry ACTRN12608000594325; Post-results.