Akl et al. BMC Public Health 2011, 11:244 http://www.biomedcentral.com/1471-2458/11/244 R E S E A R C H A R T I C L E Open Access The prevalence of waterpipe tobacco smoking among the general and specific populations: a systematic review Elie A Akl1,2,3*, Sameer K Gunukula1,2, Sohaib Aleem1,4, Rawad Obeid5, Philippe Abou Jaoude1, Roland Honeine1 and Jihad Irani6 Abstract Background: The objective of this study was to systematically review the medical literature for the prevalence of waterpipe tobacco use among the general and specific populations. Methods: We electronically searched MEDLINE, EMBASE, and the ISI the Web of Science. We selected studies using a two-stage duplicate and independent screening process. We included cohort studies and cross sectional studies assessing the prevalence of use of waterpipe in either the general population or a specific population of interest. Two reviewers used a standardized and pilot tested form to collect data from each eligible study using a duplicate and independent screening process. We stratified the data analysis by country and by age group. The study was not restricted to a specific context. Results: Of a total of 38 studies, only 4 were national surveys; the rest assessed specific populations. The highest prevalence of current waterpipe smoking was among school students across countries: the United States, especially among Arab Americans (12%-15%) the Arabic Gulf region (9%-16%), Estonia (21%), and Lebanon (25%). Similarly, the prevalence of current waterpipe smoking among university students was high in the Arabic Gulf region (6%), the United Kingdom (8%), the United States (10%), Syria (15%), Lebanon (28%), and Pakistan (33%). The prevalence of current waterpipe smoking among adults was the following: Pakistan (6%), Arabic Gulf region (4%-12%), Australia (11% in Arab speaking adults), Syria (9%-12%), and Lebanon (15%). Group waterpipe smoking was high in Lebanon (5%), and Egypt (11%-15%). In Lebanon, 5%-6% pregnant women reported smoking waterpipe during pregnancy. The studies were all cross-sectional and varied by how they reported waterpipe smoking. Conclusion: While very few national surveys have been conducted, the prevalence of waterpipe smoking appears to be alarmingly high among school students and university students in Middle Eastern countries and among groups of Middle Eastern descent in Western countries. Background Tobacco smoking using waterpipe - also known as nar- guileh, hookah and shisha - is traditional to region of the Middle East (Figure 1) [1]. The waterpipe device heats the tobacco using charcoal, filters the resulting smoke in a bowl of water, and directs it to a rubber pipe for inhalation [2]. The type of tobacco smoked, and the shape, the size, and the appearance of the waterpipe device vary across regions [3]. * Correspondence: elieakl@buffalo.edu 1Department of Medicine, State University of New York at Buffalo, NY, USA Full list of author information is available at the end of the article A recent systematic review found that waterpipe tobacco smoking was significantly associated with lung cancer, respiratory illness, low birth weight and period- ontal disease [4]. An association with bladder cancer, nasopharyngeal cancer, esophageal cancer, oral dysplasia or infertility was not ruled out [4]. Another systematic review found that waterpipe tobacco smoking negatively affects lung function and may be as harmful as cigarette smoking [5]. In spite of these deleterious health effects, waterpipe smoking is widely believed to be a less harm- ful form of tobacco smoking, [6] and a safer alternative to cigarette smoking [7-9]. © 2011 Akl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.