Prevalence of asthma in elderly Finns.

There is uncertainty about the prevalence of asthma even in countries in which extensive epidemiological surveys have been carried out and attention has been drawn to a probable increase in prevalence. A cross-sectional epidemiological survey of asthma in the population aged 64 years or over was carried out in the rural district of Lieto, Finland. All 1196 participants (488 men and 708 women, 93% of those eligible) were examined and individually assessed using a set of criteria for asthma. The prevalence of current asthma was 2.9% in the men and 3.8% in the women and it accounted for about 40% of the cumulative (life-time) prevalence of self-reported asthma. Current asthma was uncommon in men aged 75 years or over and no cases were found in men who smoked. Current asthma in women was associated with low social status, smoking and dusty working conditions in the past. The difference in prevalence between the men and women was greatest among the smokers, which may be due to a previous high mortality among elderly asthmatic men who had been smoking, or a lack of the typical characteristics of asthma in men with long histories of smoking. The prevalence of asthma was similar to that obtained earlier in Finland and elsewhere.