Epidemiology of asthma: severity matters.
Chest 2002 Jan; 121(1):6-8
How should asthma be defined in population studies? The question is deceptively simple, and its answer remains elusive. Since questionnaires are the most practical tools to use in screening populations for asthma, much attention has focused on developing survey definitions of asthma based on questionnaires. In general, the approach to validating such definitions has been to assess the ability of individual questions and combinations of questions to predict which individuals in a population have either clinical diagnoses of asthma or nonspecific bronchial hyperreactivity (BHR) to agents such as histamine or methacholine. Unfortunately, physicians' diagnoses of asthma and BHR are not particularly good "gold standards" for identification of asthma. It is likely that a physician's diagnosis of asthma underdetects subclinical mild asthma. Thus, using it as a "gold standard" will tend to underestimate the specificity of a questionnaire. In contrast, BHR is present in many people without asthma. Therefore, use of BHR as a "gold standard" will underestimate sensitivity.
Bronchial-asthma; Questionnaires; Humans; Respiratory-system-disorders; Pulmonary-system-disorders
Dr. Weissman, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, MS L-4218, Morgantown, WV 26505, USA
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease