Long-term changes in adult asthma prevalence.
There has been an increase in asthma prevalence among children. Little evidence is available regarding long-term changes in asthma prevalence in adults. Two cross-sectional studies were performed among adults aged 15-70 yrs in Oslo, Norway, in 1972 and again in 1998-1999 (n=39,998). A postal self-completed questionnaire was used. Exactly the same questions and survey methods were used in both studies. In 1998-1999, additional telephone follow-up was included for postal nonresponders. The crude prevalence of ever having had a doctor's diagnosis of asthma increased from 3.4 to 9.3%. The prevalence of wheezing increased from 17.8 to 25.8% and attacks of breathlessness from 12.6 to 16.7%. After controlling for smoking, the risk of asthma among those aged <40 yrs had tripled. The increase in asthma was 50% greater in females than males. The prevalence of symptoms increased less than asthma diagnosis. Wheezing increased by 50% in those aged <40 yrs, with smaller increases at greater ages. The increase in symptoms was seen among both asthmatics and nonasthmatics. There has been a large increase in the prevalence of asthma diagnosis and asthma-like symptoms in adults. The increase is less pronounced among those aged >40 yrs.
Brogger
J
J
Dept of Thoracic Medicine, Institute of Medicine, University of Bergen, Norway. jan.brogger@med.uib.no
Bakke
P
P
Eide
G E
GE
Johansen
B
B
Andersen
A
A
Gulsvik
A
A
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology*; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D011336:Probability; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects; D011795:Surveys and Questionnaires; D014505:Urban Population