Background: Factors contributing to either "complete" or "clinical" remission of asthma are important to know since there is no cure for the disease.
Methods: A cohort of 119 allergic asthmatic children was examined three times with a mean follow up of 30 years. They were aged 5-14 years at visit 1 (1966-9), 21-33 years at visit 2 (1983-6), and 32-42 years at visit 3 (1995-6). Complete remission of asthma at visit 3 was defined as no asthma symptoms, no use of inhaled corticosteroids, normal lung function (FEV1 >90% predicted), and no bronchial hyperresponsiveness (PC10 >16 mg/ml). Clinical remission was defined as no asthma symptoms and no use of inhaled corticosteroids.
Results: 22% of the group was in complete remission of asthma at visit 3 and a further 30% was in clinical remission (total 52%); 57% of subjects in clinical remission had bronchial hyperresponsiveness and/or a low lung function. Logistic regression analyses showed that a higher FEV1 in childhood and more improvement in FEV1 from age 5-14 to 21-33 were associated with both complete and clinical asthma remission at age 32-42.
Conclusions: Complete remission of asthma was present in a small subset of asthmatics while half the subjects showed clinical remission. Both complete and clinical remission were associated with a higher lung function level in childhood and a higher subsequent increase in FEV1. These results support the view that defining remission only on the basis of symptoms and medication use will overlook subjects with subclinical active disease and possibly associated airway remodelling.