The dangers of incense burning: COPD in Saudi Arabia

Correspondence: Feisal A Al-Kassimi PO Box 94357, Riyadh 11693, Saudi Arabia Tel +966 1 467 1521 Fax +966 1 467 1246 Email [email protected] To the editor We read with great interest the article titled “Chronic obstructive pulmonary disease: hospital and intensive care unit outcomes in the Kingdom of Saudi Arabia” and we would like to make the following comments on its methodology: 1. The fact that 37% of this chronic obstructive pulmonary disease (COPD) population are never-smokers is a cause for concern as they may be asthmatic or cases of bronchiectasis. The so-called never-smoker COPD has been largely attributed to asthma. It is true that regular and heavy exposure to biomass, in the absence of smoking, may induce COPD. However, this is limited to poor countries in which biomass is used, on a regular basis, for daily cooking. Interestingly, the authors attribute the COPD to incense burning and not using biomass for cooking. The 1994 study they quote as evidence for the presence of COPD attributed to incense burning in Saudi Arabia concluded that the culprit was biomass burning for cooking and not incense (as offered in the initial hypothesis of the study they quote). The burning of incense (a relatively expensive commodity) is practiced in Saudi Arabia for ceremonial or brief social occasions, and has never been proven to induce COPD, let alone severe COPD sending the patient to the intensive care unit (ICU). 2. The authors have quite rightly stated that “the problem of the misdiagnosis of asthma and COPD is common.” As previously stated, the never-smoker patients in their study may be asthmatic. The situation is compounded by the fact that the pulmonary function tests were unavailable in some patients. Further, COPD cannot be diagnosed solely on the basis of “compatible physical examination.” 3. We believe that to ensure reliable findings, two things could have been done: a. excluding from analysis all patients without spirometry (unless they are called back for testing after discharge); and b. never-smoker cases should have been excluded or, alternatively, analyzed separately as a subgroup. It is possible that the unusually low rates of ICU mortality in the whole group was the product of inadvertently including never-smoker asthmatics or bronchiectasis cases with a more favorable outcome than COPD.