The relation between chronic respiratory symptoms and ventilatory capacity in adults.

In the clinical setting, a patient's chronic respiratory complaints often provide the first clue of underlying lung disease. Chronic symptoms may themselves be important or may complement objective measures of spirometry in assessing respiratory status. This chapter focuses on one aspect of chronic symptom reporting--the efficacy of standardized symptom questionnaires in respiratory epidemiology--and reviews the reliability of reported symptoms as well as evidence for the relation between chronic symptoms and diminished ventilatory capacity as measured by spirometry.