To the Editor.
—In reference to Gilbert and Auchincloss'1 study of 211 patients, they found that approximately half of the patients having a restrictive defect based on a spirogram alone did not have such a defect identified by the older criteria requiring total lung capacity (TLC) measurement. We recently retrospectively evaluated the medical records for the past five years of 83 patients at the Fresno (Calif) Veterans Administration Medical Center who were diagnosed as having a mild restrictive ventilatory defect due to a variety of causes based on the criteria of a combination of a low vital capacity (60% to 79% of the predicted value) and a normal (≥75%) ratio of 1-s forced expiratory volume to forced vital capacity alone. The predicted values of the vital capacity were obtained from the study by Schmidt et al.2 All 83 patients also had total lung capacity measured either by helium
Baylor P, King M, Mahanty H. What Is a Restrictive Defect?. Arch Intern Med. 1987;147(4):797. doi:10.1001/archinte.1987.00370040179036