The cost-effectiveness of a questionnaire as a screening test for chronic obstructive pulmonary disease among the Bangkok elderly.

This study aimed to explore the cost-effectiveness of using a questionnaire as a screening test for Chronic Obstructive Pulmonary Disease (COPD) among the Bangkok elderly residing around Siriraj Hospital. The gold standard used for diagnosing COPD followed the guidelines of the Thoracic Society of Thailand. The questionnaire consisted of 10 questions on smoking status, respiratory symptoms and previous history of pulmonary tuberculosis. There were 3,094 elderly who participated, completed the questionnaire, and underwent spirometry as well as chest radiography in the community. The results showed that elderly individuals who are smokers (> 0.5 pack-year) or have ever experienced sudden cough with chest oppression or dyspnea when the weather changes or who have expectorated more than two tablespoons of sputum would be suspected of having COPD with a sensitiviy of 81.4 per cent (95% CI 79.4-83.4), specificity of 62.2 per cent (95% CI 60.4-64.0) false negative rate 1.2 per cent (95% CI 0.7-1.7) and false positive rate 38 per cent (95% CI 35.3-40.7) and subsequently required spirometry and chest X-ray for definitive diagnosis. The test needed to screen 17 elderly individuals to detect one COPD case at a cost of 1,538 baht. This questionnaire is also a self-assessment tool for COPD screening among the elderly in order to encourage them to seek for early medical attention and it is recommended that this should be publicized via the mass media.