Systematic Errors and Biases in “Systematic Review”on ““Waterpipe””

Source: "Peer-Reviewed" International Journal of Epidemiology.



This is a critique of Elie Akl et al (University of New York at Buffalo) “Systematic Review” of the Cochrane type on the “Effects of Waterpipe Tobacco Smoking on Health Outcomes” recently published in the International Journal of Epidemiology (IJE). The paper hypes the HAZARDS OF CANCER and the authors managed to select only the studies they saw relevant for their “assessment” of “health outcomes”, cancer in particular. As expected from antismoking researchers, they dismissed (details given in their “eligibility criteria”) the most relevant studies when they did not find a sufficient cancer risk… Amazingly, they mostly relied on studies led in China based on water pipes working with NO charcoal and in which tobacco is BURNT as in cigarettes, contrary to what the authors believed… This point is certainly not a detail because the chemistry of smoke is completely different and, as a consequence, the potential health effects…

As we pointed out elsewhere, the right place to discuss a controversial paper containing serious errors and biases is the journal in which it was published. Unfortunately, for political (and not scientific) reasons, this is not always possible. When confronted with this problem, the IJE, a journal which has apparently adopted a clear antismoking line, rejected a critique of the flawed paper. Interestingly, they accepted a Letter by Wasim Maziak, the author of the WHO flawed report and renown ““waterpipe”” antismoking researcher…

Following a necessary foreword, we offer a critique of the document.

READ ALSO (same critique published in the Chest journal) : Chaouachi K. More Rigor Needed in Systematic Reviews on “Waterpipe” (Hookah, Narghile, Shisha) Smoking. Chest May 2011 139:5 1250-1251. Doi:10.1378/chest.10-2864

Note: Elie Akl and his colleagues are actually publishing in several journals a series of biased “systematic reviews” on “”waterpipe”” smoking. The objective seems to recycle the famous fatal errors to be found in the former “”waterpipe”” antismoking literature (Wasim Maziak, Thomas Eissenberg, Kenneth Ward, Alan Shihadeh). A first critique was published [*]. A second one appeared in Chest, the journal of the American College of Chest Physicians [**]:

[*] Chaouachi K. [Comment]

Systematic Reviews” on ““Waterpipe”” (Shisha, Hookah, Narghile) Tobacco Smoking Should Not Recycle Old Errors. BMC Public Health 2010 (13 Aug).

[*] Chaouachi K.

More Rigor Needed in Systematic Reviews on “Waterpipe” (Hookah, Narghile, Shisha) Smoking.Chest 2011 (May);139(5):1250-1


As in the case of the US-American University of Beirut)’s unethical and highly politicised paper published in Atmospheric Environment (see Waterpipegate & Climategate knol), George Davey Smith, Editor of the International Journal of Epidemiology ( IJE ), has rejected (13 April 2010) the critique of the very serious errors to be found in Elie Akl and colleagues’ paper [

1]. His only “scientific argument” was that “[They] receive many more papers than [they] can publish”… Of course, this is not true since the same journal has published a flat Letter (with serious errors as usual) to the Editor by Wasim Maziak, head of the antismoking US-funded antismoking US-Syrian Center for Tobacco Studies (US-SCTS ) and author of theWHO flawed report on ““waterpipe”” smoking [2]… The Akl paper also concludes by citing this report for its “recommendations”….

We are convinced that the unethical anti-scientific decision was made by the designated “peer-reviewer” -or a member of the Editorial board of this journal- affiliated with Globalink , the world antismoking network of about 6,000 researchers/organisations around the world sponsored by the pharmaceutical industry (Pfizer laboratories among others). Indeed,

being a member of Globalink entails a notorious non-financial ideological competing interest.Editors of many biomedical journals of the world should be made aware of this tricky complex situation (de factoan invisible global Globalink conflict of Interest).

We have raised this issue in The Hague Speech ). Since the Globalink affiliation is never disclosed, editors blindly send manuscripts on tobacco peer-reviewers across the world (often via e-mail) without asking them to declare their antismoking Globalink condition as a striking competing interest. This is now a great stain on the credibility of many journals after the hypocrisy of the Farmington Consensus was exposed [


Paradoxically, the IJE is a member of COPE , the Committee on Publication Ethics defined as “a code of conduct for editors of biomedical journals”, “a suggested code of conduct for editors to guide them towards being fair to authors, researchers, and readers”… This remains a dream in tobacco research…

Interestingly again, there is one distinguished member among the regional Editors of the IJE: Robert West. Not only he is Editor-in-Chief of Addiction, a Farmingtonian antismoking journal [

3][4], but also a Globalink member. Notably also: “Robert West undertakes research and consultancy for companies that develop and manufacture smoking cessation medications. He has a share of a patent for a novel nicotine delivery device”[5][6]…


[1] Akl E, Gaddam S, Gunukula SK, Honeine R, Abou Jaoude P, Irani J. The effects of waterpipe tobacco smoking on health outcomes: a systematic review. International Journal of Epidemiology. Advance Access published online on March 4, 2010. Doi:10.1093/ije/dyq002

[2] Maziak W. The waterpipe—a global epidemic or a passing fad. Int. J. Epidemiol. published 25 March 2010. Doi: 10.1093/ije/dyq054

[3] Davies, John and Cameron, Douglas and Drucker, Ernest (2002) Damned and be unpublished. Addiction Research and Theory. ISSN: 1606-6359

[4] Davies J, Drucker E, Cameron D. The Farmington Consensus: Guilt by association. Addict. Res. & Theory. 2002;10(4):329-334.

[5] UK Centre for Tobacco Control Studies

[6] West R. Co-ownership of Patent.


The Letter Sent to the International Journal of Epidemiology

[The Buffalo biased flow chart for the confusionist erroneous so-called “systematic review” (not part of the Letter)]

Akl et al’ systematic review on the health outcomes of ““waterpipe”” smoking poses two main problems and contains a certain number of errors and biases. 1

The first problem is that the authors have extensively relied on studies run in China. However, they did not realise that the Chinese water pipes work with no charcoal but with tiny bowls of plain tobacco (no molasses) that are directly burnt as a cigarette. Among other striking differences, the temperature is therefore much higher than in the modern fashionable shisha which has got all antismoking researchers of the world concerned. As a consequence, and leaving aside the particular environment (mines polluted with arsenic and radon), such studies provide no relevant information for the public health issue at stake: shisha smoking, i.e. smoking of moassel (a heated flavoured tobacco (or no-tobacco)-molasses mixture in which the charcoal is separated from the product by an aluminium foil) with all the chemical consequences glossed over in the mainstream ““waterpipe”” literature of the past eight years.

The second problem is that Akl et al refrained, without giving the least explanation, from citing or discussing the two most relevant studies on hookah smoking and cancer ever published on this issue. 2,3 These studies are based on a fine selection of exclusive/ever hookah smokers who have been using, for decades, huge amounts of tobacco in their pipes: each time in the bowl the tobacco-weight equivalent of up to 60 cigarettes. Its authors used CEA as a cancer biomarker and found a weaker association than that in cigarette smoking even more noticeable when taking into account the long and daily duration of exposure and the impressive amount of tobacco. 4 By contrast, moassel generally involves about 15 g of a tobacco-molasses mixture in which the percentage of tobacco does not go in excess of a few grams. Furthermore, and concerning USA and Europe, all studies show that this last fashionable product is used on average only but a few times a week. The dismissal of such a work is even more surprising that a dose-response relationship, viewed as a criterion of quality, is obvious in the case of these studies. Not only was the discrimination between ever cigarette smokers and ever hookah smokers strictly observed, but the findings of the second study 3 confirm those of the previous one. 2 Furthermore, no only are they in agreement with the great majority of reports and studies of the past decades -pointing to a weaker risk of cancer (including animal studies)- but they also are in correspondence with the results of a recent study on blood metabolites of tobacco smoke carcinogens in patrons of a hookah lounge in Germany. 4

Other errors. While the authors stress that there would be a need for “a critical review of the literature”, it is amazing that they have actually dismissed all existing published critiques of the papers they have selected. Just to take one example in relation to cancer, Maziak et al.’s paper (“Tobacco smoking using a waterpipe…”) published in the Tobacco Control journal, contains a series of serious errors that deserved minimal caution. This paper actually credited several authors for the opposite of their findings concerning the association between shisha smoking and diverse types of cancer (lung, bladder).4

Akl et al also credit Sukumar and Subramanian for statements about temperatures which are not to be found in their study. 5 The clarification about the differences between shisha smoking and cigarette smoking as far as temperatures are concerned, and the importance of considering the Maillard chemical reaction, were first published in a transdisciplinary doctoral thesis, in several peer-reviewed publications including the two studies on hookah smoking and cancer, the critique of the WHO report in which the experts did not make the least distinction, not only between cigarette smoke and shisha smoke, but also between different types of water pipes. 6

Akl et al did not realise that in the Tunisian study by Hsairi et al, cigarette smoking was described the main use of tobacco (94%). In their conclusion, the authors emphasised that among youth, shisha smoking was used as a substitute to cigarettes (original: «comme succédané de la cigarette parmi les jeunes»). In other words, the subjects were not exclusive shisha smokers as in the Pakistani studies. As for controls, it is noteworthy that their were using on average +/– 5 daily cigarettes. 7 The same goes for the Indian study by Gupta et al. in which data are missing concerning hookah, not to mention the fact that no information is provided on the simultaneous use of cigarettes and, most importantly, bidis and smokeless tobacco. 8

Since Akl et al stressed on the need to keep critical when reviewing this literature, they should have noted that in their main study about pregnancy, Nuwayhid et al emphasised that the main problem was the fact that they did not distinguish between the diverse type of smoking products. 9

Concerning the only non-water pipe specific study about infertility by Inhorn, Akl et al did not note the striking result that, after adjustment for

“water pipe smoking, tea drinking, marital duration, husband’s age, husband’s education”, the O.R. for cigarette smoking does NOT vary (0.5, CI: 0.2-1.3) whereas the O.R. for water pipe smoking (type not specified), when adjusted for the same confounding factors (“cigarette smoking” obviously instead of “water pipe smoking”), shows the following variation: 1.8 (CI: 0.8-4.1) to 2.5 (CI: 1.0-6.3).10

Akl et al support their claim that shisha smoke would contain metals and cancer-causing chemicals with studies from the US-American University of Beirut. In fact, the sound first peer-reviewed studies on the above issues were published long before in Saudi Arabia and found negative results. 11,12

Less importantly, Akl et al credit Chaouachi for stating that shisha smoking would be “traditional of the eastern Mediterranean region”. On the contrary, this author has early established as early as 1997 that it is a serious misrepresentation to focus exclusively on this region. Indeed, shisha smoking has been a centuries-old tradition in many other regions of the world, particularly in Africa and Asia. 13 The geographical distribution of shisha use is something and the recent antismoking research (mainly by the US-Syrian Centre for Tobacco Studies and the US-American University of Beirut), actually based in the “Eastern Mediterranean”, is something else.

Finally, and in contrast with Akl et al’s recommendation, we believe that no sound conclusion can be drawn so far from the WHO report in its present form because of its serious flaws and errors. 6 The same goes for the so-called “standardized questionnaire” by Maziak et al (ref.45) which no scientific consensus has been reached in spite of its striking weak points. What is needed is further independent sound studies on this issue. Similarly and most importantly, a radical critique of the so-called “standardized” “waterpipe” smoking machine” behind the world confusion remains an urgent priority. 14



1 Akl E, Gaddam S, Gunukula SK, Honeine R, Abou Jaoude P, Irani J. The effects of waterpipe tobacco smoking on health outcomes: a systematic review. International Journal of Epidemiology. Advance Access published online on March 4, 2010. Doi:10.1093/ije/dyq002

2 Sajid KM, Chaouachi K, Mahmood R. Hookah smoking and cancer. Carcinoembryonic Antigen (CEA) levels in exclusive/ever hookah smokers. Harm Reduct J 2008 24 May;5(19). doi:10.1186/1477-7517-5-19

3 Sajid KM, Parveen R, Durr-e-Sabih, Chaouachi K, Naeem A, Mahmood R, Shamim R. Carcinoembryonic antigen (CEA) levels in hookah smokers, cigarette smokers and non-smokers. J Pak Med Assoc 2007;57(12):595-9.

4 Chaouachi K, Sajid KM. A critique of recent hypotheses on oral (and lung) cancer induced by water pipe (hookah, shisha, narghile) tobacco smoking. Med Hypotheses 2009 (online: 24 Dec). Doi:10.1016/j.mehy.2009.11.036

5 Sukumar A, Subramanian R. Elements in hair and nails of residents from a village adjacent to New-Delhi—influence of place of occupation and smoking-habits. Biological Trace Element Res 1992;34:99–105.

6 Chaouachi K. A Critique of the WHO’s TobReg “Advisory Note” entitled: “Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators.Journal of Negative Results in Biomedicine 2006 (17 Nov); 5:17. Doi:10.1186/1477-5751-5-17

7 Hsairi M, Achour N, Zouari B, Ben Romdhane H, Achour A, Maalej M, Nacef T. Facteurs étiologiques du cancer bronchique primitif en Tunisie. Tunis Med 1993; 71: 265–268.

8 Gupta D, Boffetta P, Gaborieau V, Jindal S K. Risk factors of lung cancer in Chandigarh, India. Indian J Med Res 2001; 113: 142–150.

9 Nuwayhid IA, Yamout B, Azar G, Kambris M, Narghile (Hubble-Bubble) Smoking, Low Birth Weight, and other Pregnancy Outcomes, Am J Epidemiol 1998;148 (4):375-83.

10 Inhorn MC, Buss KA. Ethnography, epidemiology and infertility in Egypt. Soc Sci Med. 1994;39(5):671-686.

11 El-Aasar AM, El-Merzabani MM, Studies on Jurak Smoke. I. The organic constituents of jurak smoke. Journal of King Abdulaziz University (Science) 1991; 3: 169-81.

12 El-Aasar AM, El-Merzabani MM, Ba-Akel H. Studies on Jurak Smoke: II. The metallic constituents of jurak paste and jurak smoke. Journal of King Abdulaziz University (Science) 1991; 3: 183-8.

13 Chaouachi K. Public health intervention for narghile (hookah, shisha) use requires a radical critique of the related “standardised” smoking machine. Journal of Public Health [Springer Berlin/Heidelberg] 2009; 17(5): 355-9. Doi: 10.1007/s10389-009-0272-7.