Definitions
Admission symptoms were investigated at the patient’s first visit by a
standardized list of questions based on the International Study of
Asthma and Allergies in Childhood (ISAAC)(5) using the German
questionnaire developed by Duhme et al. (1998)(6). Additional questions
were used as have been previously described in detail elsewhere(7).Wheezing not associated with colds was defined as a positive
response to the question: “Has your child had wheezing or whistling in
their chest in the past twelve months without a cold”. Wheezing
associated with colds had the same definition as the clinical evidence
of a viral cold(8). Ever had wheezing was defined as a positive
response to the question: “Has your child ever had wheezing or
whistling in their chest at any time in the past”(5). All symptoms were
reported by the children and confirmed by the parents or by a physician.
Children with at least one positive answer were declared as having
asthma-like symptoms.