[Confusion about MRC dyspnea scales in Japan--which MRC dyspnea scale should we employ?]

Though the Hugh-Jones dyspnea scale has been widely used in Japan, the British Medical Research Council (MRC) dyspnea scale and/or modified MRC dyspnea scales have been used in many other countries. One of these modified MRC dyspnea scales was translated into Japanese and appeared in both the "Japanese Manual of Respiratory Rehabilitation (2003)" and the "Japanese Standards for the Diagnosis and Care of Patients with Chronic Obstructive Pulmonary Disease (2004)" which were published by the Japanese Respiratory Society. Subsequently, the MRC dyspnea scale appeared in a textbook and in review articles published in Japan. However, this dyspnea scale, which was translated into Japanese, is not used by the British Thoracic Society, American Thoracic Society, European Respiratory Society, Canadian Respiratory Society, or Global Initiative for Chronic Obstructive Lung Disease (GOLD). The Japanese version of the MRC dyspnea scale has two serious problems: 1) normal healthy subjects have to be classified into dyspnea grade 0 or grade 1, and 2) incorrect Japanese translation of the scale. The Japanese Respiratory Society has to decide which MRC dyspnea scale should be employed, with a well-thought-out translation.