Setting: Evidence is accumulating that there has been an increase in the adult population burden of obstructive lung disease. Has this increased the burden of symptoms? It is possible that diagnostic efficiency has improved, so that milder asthma cases are being diagnosed.
Objective: To investigate changes in symptom burden by asthma diagnosis, age and sex.
Design: We performed two postal cross-sectional studies among adults aged 15-70 years in Oslo, Norway, in 1972 and again in 1998/1999 (total = 39998). Changes in 11 self-reported respiratory symptoms were investigated.
Results: The prevalence of having at least one symptom increased from 50% to 60% (P < 0.001), and the distribution of symptoms showed an overall increase. Nine symptoms increased in prevalence. The increase was largest among the young and females, and was present in both those with and those without asthma. For any given number of reported symptoms, asthma prevalence was higher in 1998 than in 1972, suggesting increased case finding.
Conclusion: There has been an increase in the population burden of respiratory symptoms matching the observed increase in young adult asthma, together with a probable increase in the clinical willingness to give an asthma diagnosis.