International Journal of COPD (Feb 2017)
Is exposure to biomass smoke really associated with COPD?
Abstract
Vandana Das, Vanjare Nitin, Sundeep Salvi, Rahul Kodgule Department of Pulmonary Function Laboratory, Chest Research Foundation, Pune, Maharashtra, IndiaWe read the article by Balcan et al1 with great interest. The authors have reported a case–control study that included 115 females and looked at the association between exposure to biomass smoke and detection of COPD. Although the authors concluded a positive association, we are concerned about the issues related to the conduct of the study and discrepancies in the data reported. COPD cases in this study were defined based on pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio <0.70. However, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines define COPD based on post-bronchodilator FEV1/FVC ratio <0.70. Hence, many subjects detected to have COPD in this study may actually have had asthma, in which case, the findings of the study would not apply to the COPD population. Also the overall population included in the study was relatively younger (18–48 years). Use of a fixed ratio of FEV1/FVC is likely to lead to underdiagnosis of airflow limitation in this age group.2 Use of lower limits of normal would have been a better approach. Also, COPD is more common in age groups above 40 years. Therefore, we are not convinced about the selection of population with younger age. (Open PDF to read the full Letter)Authors’ replyBaran Balcan1Selcuk Akan2Aylin Ozsancak Ugurlu1Bahar Ozcelik Handemir3Berrin Bagcı Ceyhan4Sevket Ozkaya5 1Department of Pulmonary Medicine, Baskent University Faculty of Medicine, Istanbul, 2Department of Internal Medicine, Ankara Education and Teaching Hospital, Ankara, 3Department of Pulmonary Medicine, Irmet Hospital, Tekirdag˘, 4Department of Pulmonary Medicine, Marmara University Faculty of Medicine, 5Department of Pulmonary Medicine, Faculty of Medicine, Bahçeşehir University, Istanbul, Turkey According to GOLD guidelines, post-bronchodilator pulmonary function test results are taken into account to diagnose COPD. As this is a standard criterion according to GOLD, we did not mention it in the methodology section, though we used post-bronchodilator results. Moreover, it is known that in a standard spirometry test, the best of three attempts should be taken into consideration; therefore, we did not mention that the best of three attempts was taken. (Open PDF to read full Response) View original paper by Balcan and colleagues.
