D2.203 - Awareness of and adherence to advice on early introduction of food allergens: is it preventing food allergy? Protocol for EarLY Food Allergens iNTroduction (ELYFANT) study

Food allergy affects ~5% of children in the UK. An increase in the prevalence of food allergy has been driven by environmental factors and prevention is key. The landmark LEAP and EAT trials demonstrated that the timely introduction of food allergens in infancy can prevent some food allergies but introducing multiple allergens is challenging. The aim of this study is to assess awareness and uptake of revised UK guidance on early food allergen introduction and its impact on the prevalence of food allergy.

Parents who have taken part in the 2023 Infant Feeding Survey (IFS) in England have agreed to complete two further questionnaires: one when their child is 15-17 months old, and one when their child is 22-24 months old. Questionnaires were designed by the study team and include questions about the child’s diet and whether they have developed food allergy or any related conditions, such as eczema or asthma.

Data analysis will consist of descriptive statistics to describe the population with a focus on sources of advice, and timing (early vs. late), frequency and reasons for introduction of common food allergens (cow’s milk, eggs, peanuts, tree nuts, fish, sesame, wheat). We will identify risk factors for food allergy (e.g. presence/absence of eczema) and assess how these factors associate with early/late food allergen introduction using logistic regression methods. We will estimate the prevalence of food allergy and co-morbidities (eczema, wheeze/asthma) in this population and compare it with previous estimates.

Approximately 2,500 mothers completed the last 2023 IFS questionnaire. We estimate ~2,000 will complete our first questionnaire and ~1,600 will complete our second questionnaire. Based on an estimated sample size of 2,000 mothers, we may be able to detect an absolute minimum difference of 0.8%, that is a decline in prevalence from a baseline prevalence of 2% to 1.2%, at 80% power.

This study will provide information on parents’ awareness of and adherence to the latest guidance on early food allergens introduction in England.  We will also explore whether there is any evidence that the new guidance is preventing food allergy in children.