Prevalence and manifestations of obstructive lung disease in the city of Oslo.

A stratified random sample of 1209 subjects aged 16--69 was examined in Oslo, Norway in 1973--74 by a team of 11 chest physicians. They used information from a standardized interview and clinical examination, radiographs and ventilatory function tests to make a diagnostic decision. The within-observer agreement for the diagnosis bronchial asthma and the composite group obstructive lung disease (OLD) was 87% and 80%, respectively. More than 80% of maximal between-observer agreement was observed for these two entities. The point prevalence estimate of chest physicians' diagnosis of obstructive lung disease (OLD) was 5.5%, comprising bronchial asthma 1.4% and chronic obstructive lung disease (COLD) 4.1%. The prevalence of COLD increased with age, and it was four times more frequent in smokers/ex-smokers than in non-smokers. The prevalence of bronchial asthma showed no relation to age or smoking. Individuals aged 20--69 years with bronchial asthma, COLD and OLD, had 1 sec forced expiratory volumes of 83%, 71% and 74% of predicted values, respectively. A previous history of hay fever was reported five times more frequently by those with bronchial asthma than in the survey population. Disability pension was received by 15% of those with OLD.