Background:The definition or diagnosis of asthma is a challenge for both clinicians and epidemiologists. Symptom history is usually supplemented with tests of bronchial hyperresponsiveness (BHR) in spite of their uncertainty in improving diagnostic accuracy. Methods: To assess the interrelationship between respiratory symptoms, BHR, and clinical diagnosis of asthma, the respiratory symptoms of 1633 schoolchildren were screened using a questionnaire (response rate 81.2%) and a clinical study was conducted in a subsample of 247 children. Data from a free running test and a methacholine inhalation challenge test were available in 218 children. The diagnosis of asthma was confirmed by a paediatric allergist. Results: Despite their high specificity (>0.97), BHR tests did not significantly improve the diagnostic accuracy after the symptom history: area under the receiver operator characteristic (ROC) curve was 0.90 for a logistic regression model with four symptoms and 0.94 for the symptoms with free running test and methacholine inhalation challenge results. On the other hand, BHR tests had low sensitivity (0.35-0.47), whereas several symptoms had both high specificity (>0.97) and sensitivity (>0.7) in relation to clinical asthma, which makes them a better tool for asthma epidemiology than BHR. Conclusions: Symptom history still forms the basis for defining asthma in both clinical and epidemiological settings. BHR tests only marginally increased the diagnostic accuracy after symptom history had been taken into account. The diagnosis of childhood asthma should not therefore be overlooked in symptomatic cases with no objective evidence of BHR. Moreover, BHR should not be required for defining asthma in epidemiological studies.

RSV bronchiolitis was associated with a restrictive pattern of lung function. Early atopy and maternal smoking during pregnancy may play a role in the development and persistence of BHR.

A questionnaire aimed at screening and identifying patients with asthmatic symptoms was sent to the parents of 2011 children aged 7 to 12 years; 1633 (81%) returned the questionnaire. A clinical examination was given to 165 symptomatic and 82 non-symptomatic children. The children were classified into three groups: 1, clinical asthma (n = 43); 2, other symptoms from lower airways (OSLA) (n = 34); 3, healthy children (n = 170). The prevalences of asthma and OSLA in the whole source population (n = 1633) were then estimated based on these figures. The lifetime prevalence of asthma was 4.0%. All children with asthma were either symptomatic or on continuous maintenance therapy during the preceding 12 months. The lifetime prevalence of OSLA was 5.0%, with 3.0% being symptomatic during the preceding 12 months. Asthma was more common in boys (5.0%) than in girls (2.8%). The respective figures for OSLA were 6.2 and 3.7%. The occurrence of asthma as well as respiratory symptoms suggestive of asthma was more common than previously observed in this area.

P Pr re ev ve en nt ti iv ve e t th he er ra ap py y f fo or r a as st th hm ma a i in n c ch hi il ld dr re en n; ; a a 9 9--y ye ea ar r e ex xp pe er ri ie en nc ce e i in n E Ea as st te er rn n F Fi in nl la an nd d The data on maintenance drugs in children with asthma from five years (1985, 1987, 1989, 1991 and 1993) were retrospectively retrieved from the computerized registers. The reliability of the data for the diagnosis and basic treatment of asthma was checked by one of the authors, who compared the data with the patient cards from the hospital.The number of children with doctor-diagnosed asthma increased continuously during the surveillance period. The proportion of children receiving preventive medication increased concomitantly; this increase was most pronounced between 1987 and 1989. The most common preventive drug was sodium cromoglycate; its use increased from 14% in 1985 to 58% in 1993. The use of inhaled steroids remained stable at 17-19% in all surveillance years.Our treatment policy is in accordance with the international consensus statement published in 1989; however, the change towards preventive medication occurred before its publication. Eur Respir J., 1995Respir J., , 8, 1318