Is the MVV:FEV₁ ratio useful for assessing spirometry validity?

The ratio between the maximal voluntary ventilaion (MVV) and the forced expiratory volume in one second (FEV₁) has been proposed as an indicator of the adequacy of a subject's efforts in disability determinations and other spirometry applications. Data from a large population of industrial workers tested in a university pulmonary function laboratory were examined and a smaller clinical population was used to validate the conclusions. The MVV:FEV₁ ratio was not affected to a clinically significant degree by age, degree of functional abnormality, or administration of an aerosolized bronchodilator. The ratio was too variable to be of use in determining whether an individual's results are reliable, but the determination of the average ratio for a large group of subjects may be useful in evaluating the overall performance of a spirometry laboratory.