Assessment of respiratory symptoms
A questionnaire regarding respiratory symptoms was developed by making minor modifications of the questionnaire of the International Study of Asthma and Allergies in Childhood.16 The parents/guardians completed the questionnaire at 6-month intervals. For perennial AR, the following question was used: “In the past 6 months, has your child consistently had a problem with sneezing, or a runny or blocked nose, even when he/she DID NOT have a cold or flu?” If the answer was “yes”, the parents further indicated each symptom, i.e., sneezing, runny nose, and/or blocked nose. For asthma, the core question was: “Has your child had wheezing or whistling in the chest in the last 6 months?”