Prevalence of upper and lower airway symptoms: the Skövde population-based study

This study was able to present representative data from Sweden as a whole and illuminates the epidemiological background of symptoms of the upper and lower airways. Current regular smokers, compared with non-smokers, had more problems with nasal blockage, cough and asthma. The relationship between the upper and lower airways was confirmed as regards airway symptoms.

Epidemiology of common respiratory symptoms is basic information in health care. This study has focused on the prevalence of upper and lower airway symptoms.

A random sample of 1900 age- and gender-stratified adults was recruited from a general population for this study, which included a structured interview about symptoms of nasal secretions and blockage, cough and asthma, and a clinical examination with nasal endoscopy, and peak nasal-inspiratory flow (PNIF). Smoking habits were evaluated by a questionnaire for current and previous smoking.

A response rate of 73% was achieved. The prevalence of various symptoms varied between age strata and gender. There was a statistically significant relationship between subjectively experienced nasal blockage and objectively observed nasal congestion. PNIF was negatively related to age and height and was increased in male gender. Smoking was most common among females and related to nasal blockage, cough and asthma, but not to nasal secretions. Significant relationships between the upper and lower airways were found.