Patients' perceptions compared with objective ratings of asthma severity

Optimal asthma management requires accurate assessment of asthma severity.

To compare patients' perceptions of their asthma severity with that obtained by using the guidelines published by the National Asthma Education and Prevention Program's Expert Panel and with functional impairment measured by spirometry and numeric criteria of the American Thoracic Society.

We enrolled 323 patients age 18 to 50 years who were members of the Kaiser Foundation Health Plan for > or = 1 year in a randomized control trial of an asthma education program. Each had a confirmed diagnosis of bronchial asthma and had been receiving antiasthma medication for > or = 1 year. Patients rated the severity of their asthma. Office spirometry was performed, and, using the Mini-Wright peak flow meter, patients kept 2-week diaries of at-home recordings of morning and evening peak expiratory flow rates.

A statistically significant association was noted between patients' perceptions of asthma severity and both medication severity rating (P < .001) and diurnal variation rating (P = .003) and evening peak expiratory flow rate percentage (P = .019). In comparison with a severity composite based on criteria of the National Asthma Education Program, 54% of patients accurately estimated asthma severity, 27% overestimated, and 20% underestimated severity.

A clinically significant proportion of asthmatic patients substantially underestimate disease severity and thereby may be at risk of increased mortality or morbidity.