PREVALENCE OF POSSIBLE UNDIAGNOSED ASTHMA AND ASSOCIATED MORBIDITY AMONG URBAN SCHOOLCHILDREN

Objective: The extent to which urban children endure the symptoms and consequences of asthma without a physician diagnosis has not been well studied. Our objective was to obtain an estimate of the prevalence of possible undiagnosed asthma in a population of urban schoolchildren. Design and methods: A population-based cross-sectional study was condu cted in urban schoolchildren, grades 3 to 5. Undiagnosed asthma was de fined as caretaker report of symptoms and/or bronchial hyperresponsive ness, defined as a 15% or greater drop in baseline forced expiratory v olume in 1 second, after exercise challenge. Results: A total of 230 c hildren (61% of those eligible) participated in the study. Forty child ren (17.4%; 95% Confidence interval (CI) = 12.5% to 22.3%) had reports of a physician diagnosis of asthma. Of these, 33 (14.3%; (95% CI = 9. 8% to 18.9%) reported wheezing in the past 12 months. Among the remain ing 189 eligible children, 11 (5.8%; 95% CI = 2.5% to 9.2%) met study criteria for undiagnosed asthma based on bronchial hyperresponsiveness (BHR). Another 16 (8.5%; 95% CI = 4.5% to 12.4%) met study criteria f or undiagnosed asthma through modified American Thoracic Society sympt om criteria. Overall, 27 children (27/189; 14.3%) fulfilled criteria f or undiagnosed asthma. Children identified as having undiagnosed asthm a were compared with children who had no BHR and no symptoms and who d id not report a physician diagnosis of asthma (children without asthma ). Children with BHR were more likely to have a report of allergies an d eczema than children without asthma, odds ratios (OR) = 8.5 (95% CI = 2.4 to 30.7) and 6.4 (95% CI = 1.1 to 38.1), respectively. Children meeting symptom criteria were more likely to have a report of allergie s, OR = 6.2 (95% CI = 2.0 to 19.1), and bronchitis, OR = 6.7 (95% CI = 2.0 to 22.4), and were also more likely to report sleep disruption, O R = 7,1 (95% CI = 2.3 to 21.8) and missed physical education classes, OR = 15.0 (95% CI = 4.8 to 46.7), compared with children without asthm a. Conclusions: We estimated a prevalence of 14.3% for possible undiag nosed asthma among urban schoolchildren, grades 3 to 5, through careta ker report of symptoms or BHR postexercise challenge. Children with un diagnosed asthma repelted more atopic disease than children without as thma. In addition, children meeting symptom criteria for asthma report ed more bronchitis, sleep disruption, and missed physical education cl asses than did those without asthma. These results suggest that rates of undiagnosed asthma may be high in this predominantly black school-a ge population.