[The usefulness of COPD questionnaire for screening COPD subjects].

To evaluate the usefulness of the COPD questionnaire of the International Primary Care Airways Group (IPAG) for screening the subjects with COPD in a given cohort, the questionnaires were given to subjects aged 40 or older, regardless of smoking habit at a general health check-up program in 4 institutions (Miyagi, Osaka, Okayama and Fukuoka) of the Japan Anti-tuberculosis Association (JATA) prefectural branch from April 1, 2007 to March 31, 2008. The questionnaires scores of 11,166 participants were collated with their FEV1/FVC, with their agreement. The prevalence of cases at high-risk of COPD receiving a score of 17 or more was 27.5%, and airflow limitation defined as FEV1/FVC < 70% was found in 6.5% among these cases, i.e. 2.7% among all subjects. The area under the curve of the receiver operating characteristic (AUC-ROC), sensitivity, and specificity were 0.755, 0.666, and 0.736, respectively. Airflow limitation was observed more frequently in those older than 59, more than 24 pack-years, and frequent wheezes but not in those of cough affected by weather, sputum in the morning, and allergies. Among 4 institutions, sensitivities of airflow limitation varied from 0.581 to 1.000 and these were remarkably elevated to 0.702 and more by excluding the subjects with P x Y0-14. This questionnaire seemed to be effective using a cut-off level of 17 for screening cases at high risk of COPD.