Psychological factors and asthma quality of life: a population based study

Abstract
Background: Reports of psychological conditions in asthmatic subjects have been limited to certain population groups or convenience samples. A study was undertaken of the prevalence of psychological distress in asthma in the general population and its associations with quality of life. Methods: The WANTS Health and Well-being Survey is a population household interview survey of adults (age ⩾18) in Western Australia, the Northern Territory, and South Australia. Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to two questions: “Have you ever been told by a doctor that you have asthma?” and “Do you still have asthma?” determined current doctor-diagnosed asthma. Other items included the SF-12, the Kessler-10 index of psychological distress, questions on feelings of lack of control in different areas of life, and on mental health conditions. Results: From the available sample of 10 080, 7619 interviews were completed (participation rate 74.8%), with 834 people reporting current doctor-diagnosed asthma (11.2%). Psychological distress was more frequent in those with asthma (17.9% v 12.2%, pv 31.2%, pv 10.8%, pv 24.3%, pr = 0.73, adjusted r2 = 0.54). Conclusion: These results, from a representative population sample, show that psychological distress and decreased feelings of control are common in asthma and are significantly associated with physical health status.