Prevalence, severity and determinants of asthma in Danish five-year-olds.
BACKGROUND
The prevalence of asthma and wheeze is increasing.


OBJECTIVE
To study the annual and cumulative prevalence of asthma and wheeze in 5-y-old Danish children.


METHODS
We obtained data on 3052 (82.0% of eligible) Danish children by a postal parental questionnaire including ISAAC questions regarding respiratory symptoms and our own questions on sociodemography and tobacco exposure.


RESULTS
"Wheeze ever" was reported in 38.3%, "doctor-diagnosed asthma ever" in 10.5%, "childhood bronchitis ever" in 30.0%, "current wheeze" (<12 mo) in 19.7%, and being "severe" (>3 episodes) in 3.9% of the children. Current wheeze was associated with male gender (OR 1.63, 95% CI 1.35-1.96), low parental post-primary education (OR 1.29, 95% CI 1.02-1.63 for <3 y vs > or =3 y) and current maternal smoking (OR 1.69, 95% CI 1.39-2.04). "Severe current wheeze" was recognized as asthma in six and childhood bronchitis in three of 10 cases. Nearly all diagnosed asthmatics had suffered wheeze, two-thirds recently.


CONCLUSIONS
We found a high prevalence of asthma and wheeze in Danish late-preschool children, associated with male gender, current maternal tobacco smoking and low parental post-primary education. The majority of children with current wheeze had an early onset, and severe early symptoms tended to persist. Used with consideration, the label "childhood bronchitis" seems purposeful.
Hermann
Christian
C
Research Unit and Department for General Practice, University of Copenhagen, Copenhagen, Denmark. c.hermann@dadlnet.dk
De Fine Olivarius
Niels
N
Høst
Arne
A
Begtrup
Kamilla
K
Hollnagel
Hanne
H
D001249:Asthma / Q000453:epidemiology*; D001991:Bronchitis / Q000453:epidemiology; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D015995:Prevalence; D012135:Respiratory Sounds; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology