The longitudinal impact of probiotic and peanut oral immunotherapy on health-related quality of life

Background: We previously reported that probiotic and peanut oral immunotherapy (PPOIT) was effective at inducing sustained unresponsiveness compared with placebo in a double-blind, placebo-controlled randomized trial. This study evaluated the impact of PPOIT on health-related quality of life (HRQL). Method: Fifty-one participants (PPOIT 24; placebo 27) from the PPOIT trial completed Food Allergy Quality of Life Questionnaire (FAQLQ-PF) and Food Allergy Independent Measure (FAIM) at pre-treatment, end-of-treatment and 3 months after end-of-treatment. A total of 42 participants (20 PPOIT; 22 placebo) completed measures at 12 months post-treatment. Changes over time in PPOIT and placebo groups were examined by repeated-measures analysis of variance and paired t tests. Results: Probiotic and peanut oral immunotherapy was associated with significant improvement in FAQLQ-PF (F = 3.63, P =.02), with mean difference 0.8 at 3 months post-treatment (P =.05) and 1.3 at 12 months post-treatment (P =.005), exceeding the 0.5 minimal clinically important difference for FAQLQ-PF. For FAIM, mean difference was 0.5 (P =.03) at 3 months and 0.4 (P =.04) at 12 months post-treatment. In placebo group, post-treatment FAQLQ and FAIM remained unchanged from pretreatment. Improvement in FAQLQ-PF and FAIM scores related specifically to acquisition of sustained unresponsiveness rather than to receiving PPOIT treatment or participation in the trial. Conclusions: Probiotic and peanut oral immunotherapy has a sustained beneficial effect on psychosocial impact of food allergy at 3 and 12 months after end-of-treatment. Treatment was not associated with reduced HRQL relative to baseline in either PPOIT or placebo groups, indicating that PPOIT was well tolerated and psychological well-being was not negatively impacted. Improved HRQL was specifically associated with acquisition of sustained unresponsiveness.