M. Kilpelainen et al., Validation of a new questionnaire on asthma, allergic rhinitis, and conjunctivitis in young adults, ALLERGY, 56(5), 2001, pp. 377-384
Background: Epidemiologic data on asthma and allergies among adults are mai
nly based on questionnaires: this study validates the questions on asthma,
allergic rhinitis, and conjunctivitis of a new Finnish questionnaire.
Methods: To validate questions used in a country-wide study among universit
y students aged 18-25 years, we examined 150 subjects who had ever reported
asthma or wheezing, and 140 without asthma symptoms. Questions were valida
ted in relation to current diseases including
1) symptoms detected during the preceding year at the physician's interview
2) objective measurements, such as methacholine challenge, skin prick tests
, and specific IgE.
Data were adjusted for original proportions of "asthmatics" and "nonasthmat
ics" in the questionnaire study.
Results: Questions;on "reported asthma" and "doctor-diagnosed asthma" had g
ood positive predictive value (PPV) and specificity in diagnosing current a
sthma. The question on "attacks of shortness of breath with wheezing", and
especially the question on "cough with wheezing" were most sensitive. Quest
ions on "allergic nasal symptoms" and "allergic eye symptoms" that were "re
lated to pollen or animals" were sensitive, but a further question on docto
r's diagnosis yielded higher specificity and PPV.
Conclusions: Diagnosis-based questions were found suitable for risk-factor
studies, because of their good specificity and PPV, and symptom-based quest
ions for screening, because they were highest in sensitivity.