Validation of a Self‐Administered Questionnaire on Asthmatic Symptoms and Atopy in House Painters

Abstract

Validation of a Self‐Administered Questionnaire on Asthmatic Symptoms and Atopy in House Painters: Gunilla Wieslander, et ai. Department of Occupational and Environmental Medicine, Uppsala University—The aim of this study was to validate questions on asthmatic symptoms and atopy among Swedish house painters. Clinical investigations were performed in 44 male painters, selected by stratified sampling from a larger group of 415 painters. Symptoms were recorded by means of a self‐administered questionnaire. Clinical examinations were performed after an exposure free weekend, and included dermal prick test to nine common allergens, dynamic spirometry, and methacholine challenge test (MCT). Atopy was defined as at least one positive skin prick test to common allergens. A forced expiratory volume in one second (FEVd below 80% of normal values were considered a sign of impaired lung function. A cumulative dose of methacholine below 8 mg causing a 20% decrease in FEVt (PD20) was considered a sign of bronchial hyperresponsiveness (BHR). Sensitivity and specificity for different questions was calculated. Most single airway symptom had a good sensitivity for severe BHR, defined as a PD2o below 0.5 mg of methacholine. For milder BHR, however, sensitivity was below 50% for most single symptoms, except the question on nonspecific hyperreactivity symptoms. By combining the symptoms to a symptom score predicable of BHR, a high sensitivity could be obtained for both mild BHR and severe BHR. Most single questions on respiratory symptoms had high specificity, but low sensitivity, as predictors of impaired FEV‐,. Sensitivity for impaired FEV‐, was improved by constructing another symptom score, predictable of FEVt. The assessment of a history of atopy by five questions on asthma, hay fever and eczema in childhood was significantly related to atopy verified by a positive dermal prick test (79% sensitivity and 75% specificity). There was also a significant relation between self‐reported hay fever and positive prick test to pollen extracts (52% sensitivity and 90% specificity). In conclusion, our questions on airway symptoms and atopy are related to clinical signs of BHR, impaired FEV1# and atopy respectively. By combining different symptoms to symptom scores, the problem with low sensitivity of single questions on airway symptoms and atopy can be reduced.