Early introduction of peanut reduces peanut allergy across risk groups in pooled and causal inference analyses.
Level 1 - systematic review of randomized trials
Pooled individual participant data analysis of two randomized controlled trials
PubMed 36435990 · doi:10.1111/all.15597
What was done
Researchers conducted a pooled analysis of individual participant data from two randomized controlled trials (the LEAP and EAT studies) under the European Union-funded iFAAM project. They compared intention-to-treat (ITT), per-protocol (PP), and causal inference models to evaluate the efficacy and effectiveness of early peanut introduction in preventing peanut allergy across different risk strata, including baseline eczema severity, baseline peanut sensitization, ethnicity, and age of introduction.
What was found
Pooled ITT analysis showed a 75% reduction in peanut allergy (p < .0001) in infants randomized to early peanut introduction, with protection observed across all eczema severities, baseline sensitization statuses, and ethnicities. Earlier age of introduction correlated with greater effectiveness. Pooled PP analysis demonstrated a 98% risk reduction (p < .0001). Causal inference modeling showed an 89% average treatment effect relative risk reduction (p < .0001) overall, and a 100% reduction in peanut allergy among children without eczema (p = .004).
Why it matters
This confirms that the preventive benefit of early peanut introduction is not restricted to high-risk infants with severe eczema or egg allergy, but extends to low-risk and standard-risk infants across diverse ethnic groups, reinforcing guidance for early dietary introduction.
Limits
The abstract does not report the total pooled sample size (n), absolute event rates, confidence intervals, or specific numerical age thresholds defining earlier introduction. The analysis is limited to data from two specific randomized trials.