A time of diagnosis/place of birth interaction would indicate an exposure at a heterogeneous time after birth, with a constant latent period.
Thus a time of birth/place of birth interaction would suggest a transient environmental exposure affecting children in-utero or shortly after birth and that there is a variable latent period between exposure and diagnosis.
In addition to sex, age, history of allergies, family history of allergies, premature birth, early respiratory infection, and high-risk birth, an interaction term (living on a farm that raised swine and added antibiotics to feed) was independently associated with asthma/medication for wheeze, current wheeze (p = 0.06), and cough with exercise.
This approach allowed us to study whether BMI differed according to age group and birth cohort and whether there was an age group-by-birth cohort interaction.
Birth weights in all datasets were influenced (P < 0.001) by effects of flock, birth type, dam age class, lamb sex, and dam age class × birth type interaction.
This 'place of birth'*'country' interaction effect totally explained the between-country differences in self-related satisfaction.
The significance of each potential risk factor (Main Effect) is shown as well as a test for differences by birth cohort (Interaction).
CI = confidence interval; SGA = small for gestational age; PTB = preterm birth; The interaction term between alcohol intake during pregnancy and maternal education was not significant (p-values for interaction ranged from 0.104 to 0.669).
Multivariable linear regression models were constructed adjusting for potential confounders including current BMI, age, race, and age of first live birth, and interaction terms were generated for the genotype of each SNP compared to a baseline genotype.
The birth weight gene interaction in relation to type 2 diabetes was tested in one study based on nine diabetes risk alleles, which showed that the individuals with the lowest birth weight and the most high-risk genotypes had the greatest risk of type 2 diabetes (32).
