A Comparison of the Assessment of Simple Bronchitis (Chronic Mucus Hypersecretion) by Measurements of Sputum Volume and by Standardized Questions on Phlegm Production
Seven hundred and ninety-two working men were asked questions 6, 8 and 10 on phiegm production from the Medical Research Council's Standardized Questionnaire on Respiratory Symptoms in eight successive summers, and three measurements of early morning sputum volume were made on the same men every six months over the same period. The findings were related to simultaneous measurements of forced expiratory volume in one second (FEV), smoking habits and frequency of chest illnesses and chest colds, to find the best way of scoring the replies and the sputum measurements as indices of chronic mucus hypersecretion. It was found that the best way of scoring the questions is to allocate marks of 2, 1 and 1 respectively to questions 6, 8 and 10 giving a total score, ranging from 0 to 4, which has good reproducibility. The best index from the sputum measurements was given by the simple proportion of bottles containing some sputum, ignoring its volume. Chronic mucus hypersecretion appears to have been estimated rather more accurately by the phlegm score than by the proportion of bottles containing some sputum, and since this method is less laborious, it is the method of choice.