Table 1 Outcome variables as defined based on questionnaires
Allergy-related condition | Time point(s) | Questions used to define cases |
|---|---|---|
Asthma (ever) | 2 years | “Has the child ever been diagnosed with asthma by a doctor” |
Asthma (current) | 6 years | As asthma (ever) AND “Has the child been treated with tablets, inhalation medications or other treatments for wheezing, tightness in the chest or asthma during the last 12 months? |
Wheeze (ever) | 2 years | “Has the child ever had whistling in the chest?” AND “Has the child ever had episodes of wheezing or tightness in the chest? |
Wheeze (current) | 6 years | As for wheeze (ever) AND “Has the child had whistling, rattling or tightness in the chest in the past 12 months? |
ARC (ever) | 2 & 6 years | “Has the child ever had hay fever, sneezing or itchy-watery eyes? |
Eczema (ever) | 2 & 6 years | “Has the child ever had eczema?” AND “Has the child ever had an itchy rash which came and went over at least six months? |
Eczema (current) | 6 years | As for eczema (ever) AND “Has the child during the last 12 months used medications, balms, creams, tablets or herbal medicines for eczema? |