The dangers of incense burning: COPD in Saudi Arabia

We read with great pleasure the letter to the editor written by Professor Al-Kassimi and we thank him for his interest in our paper “Chronic obstructive pulmonary disease: hospital and intensive care unit outcomes in the Kingdom of Saudi Arabia.”1 Our response to the queries raised by the comments 1 and 3 are shown below; comment 2 was simply the reiteration of limitations noted by ourselves in the discussion section of our paper. We agree with his concern that several forms of environmental smoke exposure may contribute towards COPD and this should have been better acknowledged in the discussion section of our paper. While we agree that smoking is one of the most studied COPD risk factors, the possibility of non-smokers developing this illness is not unheard of, as shown in epidemiological studies on this matter.2,3 In our opinion, classifying non-smokers as asthmatics in our study may not be an accurate representation of our patients. We acknowledge the concern raised by Professor Al Kassimi related to the mortality rates in our study being low secondary to inclusion of non-smokers who may not have had COPD to start with. Accordingly, in our study we have analyzed the results of smokers and non-smokers separately, as shown in Table 1. It is important to note that there were no statistically significant differences observed between smokers and non-smokers with regards to ICU or overall mortality. Therefore, we may conclude that the inclusion of non-smokers is unlikely to be the reason for lower mortality rates seen in our study. Table 1 The outcome of COPD patients admitted to the ICU