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Trial registered on ANZCTR


Registration number
ACTRN12618001990213
Ethics application status
Approved
Date submitted
4/12/2018
Date registered
12/12/2018
Date last updated
12/12/2018
Date data sharing statement initially provided
12/12/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Can early introduction of dietary allergen reduce the prevalence of infant food allergy? The EarlyNuts population-based study
Scientific title
A population-based cross-sectional study of age at introduction of allergenic foods and food allergy in infants
Secondary ID [1] 296580 0
NHMRC Project Grant 1146769
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
IgE-mediated food allergy 310381 0
Peanut allergy 310382 0
Egg allergy 310383 0
Tree nut allergy 310384 0
Cashew allergy 310385 0
Cow's milk allergy 310386 0
Condition category
Condition code
Inflammatory and Immune System 309102 309102 0 0
Allergies

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Exposures: Age at introduction of allergenic foods (peanut, egg, tree nuts and cow's milk). Participants will be recruited from council-led immunisation centres in Melbourne on the day of their 12 month immunisation (eligible age range is 11-15 months of age). Parents will complete a questionnaire which collects data on infant diet including age at introduction of allergenic foods as well as data on other risk factors for food allergy including family history of allergy, parent ethnicity, pet ownership, number of siblings and infant history of eczema.
Intervention code [1] 312893 0
Not applicable
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 308073 0
Proportion of infants with IgE-mediated food allergy to peanut, egg, cashew or cow's milk. Infants will undergo a skin prick test on the day of recruitment to peanut, egg, cashew and cow's milk to test for IgE sensitisation to these foods. Any infants with a detectable reaction on skin prick test to one or more foods will be invited to a study clinic at the Royal Children's Hospital Melbourne for follow up, including an oral food challenge if required, to determine their food allergy status. Food allergy will be defined as either a positive oral food challenge, or a recent history of objective symptoms (assessed by study doctor) consistent with an IgE-mediated reaction within 1 hour of ingestion of the food, in an infant with evidence of IgE sensitisation to that food (positive skin prick test).
Timepoint [1] 308073 0
1 year of age
Primary outcome [2] 308074 0
Proportion of infants consuming allergenic foods (peanut, egg, cow's milk and cashew) in the first year of life. Assessed using study-specific questionnaire.
Timepoint [2] 308074 0
1 year of age
Secondary outcome [1] 353881 0
Proportion of infants sensitised to peanut, egg, cow's milk or cashew on skin prick test
Timepoint [1] 353881 0
1 year of age
Secondary outcome [2] 353882 0
Parent-reported reactions to peanut, egg, cow's milk and cashew occurring in the community in the first year of life. Assessed using researcher administered, study-specific questionnaire.
Timepoint [2] 353882 0
1 year of age

Eligibility
Key inclusion criteria
Infants aged 11-15 months attending council-led immunisation sessions in Melbourne, Australia
Minimum age
11 Months
Maximum age
15 Months
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Parent or guardian must be able to provide informed consent in English

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Random sample
Timing
Both
Statistical methods / analysis
Baseline data on food allergy prevalence is available from the HealthNuts population-based study of 5,300 12 month old infants (2007-2011). HealthNuts found:
- 3.0% population prevalence of challenge-confirmed peanut allergy
- 28% of infants consuming peanut in the first year of life

We modelled the expected reduction in population peanut allergy prevalence due to early peanut introduction and calculated this to be at least 40% (Koplin J et al. J Allergy Clin Immunol. 2016; 138(4):1131-1141.).

A sample size of 2,000 infants in the current study provides:
• 81% power to detect a 40% decrease in peanut allergy prevalence (from 3% to 1.8%); and
• 95% power to detect a 5% increase in proportion of infants eating peanut before 12 months

We will also formally explore the contribution of changes in the population distribution of age at allergen introduction to changes in food allergy prevalence over time, by using causal mediation analysis to partition the total change in food allergy prevalence between the two studied time points into:
- An indirect effect: An effect attributable to the influence of year of recruitment - original (2008) or new (2018) - on earlier allergen introduction; and
- A direct effect: An effect of year of recruitment that occurs through any other pathways that do not involve factors that influence the age of introduction of allergenic foods.

We will adjust for potential changes over time in other environmental factors and population factors that might influence food allergy risk, such as parental migration status and pet ownership.

We will examine the association between age at introduction of allergenic foods and food allergy using multivariable logistic regression models, as we have done in our previous work with egg allergy (Koplin J et al. J Allergy Clin Immunol. 2010;126(4):807-13). This model will include covariates previously shown to confound diet-allergy associations: parent-reported child reactions to other foods, eczema, family history of allergy and parent country of birth.

We will also examine the age at introduction of allergenic foods separately for high and low risk infants. The population prevalence of early allergen introduction will be estimated as the observed prevalence among the complete group of 2000 infants for each food of interest (egg, peanut, tree nuts, cow’s milk), and separately in specific high risk subgroups (e.g. family history of food allergy, Asian-born parents, infants with eczema).

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 301159 0
Government body
Name [1] 301159 0
National Health and Medical Research Council
Address [1] 301159 0
National Health and Medical Research Council Level 1, 16 Marcus Clarke Street Canberra ACT 2601 GPO Box 1421 Canberra ACT 2601
Country [1] 301159 0
Australia
Funding source category [2] 301160 0
Other
Name [2] 301160 0
Murdoch Children's Research Institute
Address [2] 301160 0
Royal Children’s Hospital, Flemington Rd, Parkville VIC 3052
Country [2] 301160 0
Australia
Primary sponsor type
Other
Name
Murdoch Children's Research Institute
Address
Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Rd, Parkville VIC 3052
Country
Australia
Secondary sponsor category [1] 300779 0
None
Name [1] 300779 0
Address [1] 300779 0
Country [1] 300779 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301905 0
Royal Children's Hospital Melbourne Human Research Ethics Committee
Ethics committee address [1] 301905 0
Royal Children's Hospital, Flemington Rd, Parkville VIC 3052
Ethics committee country [1] 301905 0
Australia
Date submitted for ethics approval [1] 301905 0
Approval date [1] 301905 0
09/09/2016
Ethics approval number [1] 301905 0
36160

Summary
Brief summary
The EarlyNuts study will recruit a population-based sample of 2.000 12-month-old infants in Melbourne, Australia, to:
1) Measure the current prevalence of challenge-proven peanut, cashew, egg and cow's milk allergy;
2) Measure current practices around introduction of allergenic foods (peanut, egg, tree nuts and cow’s milk) to infants in the population; and
3) Measure the association between age at introduction of allergenic foods and the development of allergy to these foods.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 88506 0
Dr Jennifer Koplin
Address 88506 0
Population Allergy, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Rd, Parkville, VIC 3052, Australia
Country 88506 0
Australia
Phone 88506 0
+61 3 8341 6236
Fax 88506 0
Email 88506 0
jennifer.koplin@mcri.edu.au
Contact person for public queries
Name 88507 0
Ms Sasha Odoi
Address 88507 0
Population Allergy, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Rd, Parkville, VIC 3052, Australia
Country 88507 0
Australia
Phone 88507 0
+61 3 8341 6236
Fax 88507 0
Email 88507 0
earlynuts@mcri.edu.au
Contact person for scientific queries
Name 88508 0
Dr Jennifer Koplin
Address 88508 0
Population Allergy, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Rd, Parkville, VIC 3052, Australia
Country 88508 0
Australia
Phone 88508 0
+61 3 8341 6236
Fax 88508 0
Email 88508 0
jennifer.koplin@mcri.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Undecided
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results