Obstructive lung disease in northern Sweden: respiratory symptoms assessed in a postal survey.

The prevalence of respiratory symptoms in 6,610 adults (3,372 men and 3,238 women); 35-36, 50-51 and 65-66 yrs of age, living in selected areas of Norrbotten, northern Sweden, were assessed in a postal survey. Response rates were identical in men and women, and at least one respiratory symptom was reported by 41% of each sex. Twenty two percent reported sputum production, and 14% reported wheezing. Despite differences in smoking habits and in the different age groups, the prevalence of symptoms did not differ between the sexes, or between urban and rural areas. Symptoms were as common in people living in the rural interior as in the industrialized coastal area. Present or past history of asthma was reported by 323 (5.9%) subjects, whilst 234 (4.1%) subjects stated that they had chronic bronchitis or emphysema. Less than half of the subjects who reported attacks of breathlessness together with wheezing stated that they had at any time had asthma. Whilst the exact prevalence of had asthma. Whilst the exact prevalence of at any time had asthma and chronic bronchitis cannot be assessed from this postal survey, its results indicate that the prevalence of asthma may be higher in northern Sweden than has been reported from the south of Sweden.