title: [Interpretation of spirometry: distinguishing prevalence from function].
abstract: To interpret spirometric data, it helps if (a) we make a distinction between prevalence and function; and (b) consider the test result within its clinical context. The reference values recently described by the Global Lung Function Initiative provide both predicted values and the fifth percentile for a set of spirometric parameters. The use of the fifth percentile to distinguish 'normal' from 'abnormal' has the advantage that the percentage of healthy subjects who are incorrectly classified as 'abnormal' is known. With respect to function, a score based on the spread of spirometric parameters in the healthy population does not appear to be appropriate. Instead, there are good reasons to evaluate the severity of the functional impairment by mapping the lung function parameters on a scale from 0 to 100% of the predicted value.
authors.affiliation: Medisch Centrum Alkmaar, afd. Longziekten, Alkmaar.
authors.forename: Joost G
authors.initials: JG
authors.lastname: van den Aardweg
mesh_terms: D000328:Adult; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D015995:Prevalence; D012016:Reference Values; D013147:Spirometry; D014797:Vital Capacity