Asthma patients will be recruited from the Respiratory Medicine clinic at the Hospital for Sick Children. A member of the medical team in the Asthma Clinic, known to the patient, will introduce the study, and obtain permission for the patient/caregiver to meet with study personnel. Subjects will then be approached by the Principal investigator or her delegate. They will be informed that enrolment is voluntary and that they can withdraw from the study at any time.