Sex assigned at birth may modify health‐related quality of life in children treated with peanut oral immunotherapy

Background The high burden of peanut allergy underscores the need for treatment options that improve patient health‐related quality of life (HRQL). However, the modifying effect of sex assigned at birth on treatment‐related outcomes remains poorly understood. We sought to investigate whether sex modifies treatment effect on the change in overall and subdomain HRQL during the PPOIT‐003 trial. Methods PPOIT‐003 was a multicenter, randomized controlled trial in 201 children with peanut allergy (aged 1–10) allocated to combined probiotic and peanut oral immunotherapy (PPOIT), peanut oral immunotherapy alone (OIT), or placebo. Participant HRQL was measured with the Food Allergy Quality of Life–Parent Form (FAQLQ‐PF) at baseline, end‐of‐treatment, and 12 months post‐treatment. Multivariable linear regression with an interaction term was used to investigate the relationship between treatment and HRQL in males ( N = 128, 63.68%) and females ( N = 73, 36.32%). Results Sex‐modification of total FAQLQ‐PF scores was present between baseline to end of 12 month follow‐up ( p = .008). In this time, improvement in FAQLQ‐PF scores was significantly better in active compared to placebo groups for males (PPOIT vs. Placebo: −1.003 [95% CI: −1.571, −0.436]; OIT vs. Placebo: −1.250 [95% CI: −1.805, −0.695]), but not for females where improvement also occurred in the placebo group (PPOIT vs. Placebo: −0.148 [95% CI: −0.914, 0.617]; OIT vs. Placebo: 0.252 [95% CI: −0.547, 1.052]). Separate analysis of study phases revealed sex effect modification was greater during treatment than during post‐treatment follow‐up in domains related to food anxiety ( p = .037) and emotional impact of allergy ( p = .063). Conclusion Sex modifies HRQL outcomes during peanut OIT. Greater understanding of the biological and psychosocial drivers of post‐treatment HRQL will facilitate personalized management approaches.