Background: Waterpipe tobacco smoking is a traditional method of tobacco use, especially in the Eastern Mediterranean Region (EMR), but its use is now spreading worldwide. Recent epidemiological data, for example, show that waterpipe smoking has become the most prevalent tobacco use method among adolescents in the EMR, and the second most prevalent in the US. Waterpipes are used socially, often being shared between friends or family at home, or in dedicated bars and cafes that provide waterpipes to patrons. Because the smoke passes through a reservoir of water, waterpipe tobacco smoking is perceived as being less harmful than other methods of tobacco use. At least in some cultures, women and girls are more likely to use a waterpipe than to use other forms of tobacco, and it is popular among younger smokers. Accumulating evidence suggests that some waterpipe smokers become addicted, have difficulty quitting, and experience similar health risks as cigarette smokers.

Objectives: To evaluate the effectiveness of tobacco cessation interventions for waterpipe users.

Search methods: We searched the Cochrane Tobacco Addiction Review Group specialized register in June 2015. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL , using variant terms and spellings ('waterpipe' or 'narghile' or 'arghile' or 'shisha' or 'goza' or 'narkeela' or 'hookah' or 'hubble bubble'). We searched for trials, published or unpublished, in any language, and especially in regions where waterpipe use is widespread.

Selection criteria: We sought randomized, quasi-randomized or cluster-randomized controlled trials of smoking cessation interventions for waterpipe smokers of any age or gender. The primary outcome of interest was abstinence from tobacco use, measured at six months post-cessation or longer, regardless of whether abstinence was biochemically verified. We included interventions that were pharmacological (for example, nicotine replacement therapy (NRT) or bupropion) or behavioural, or both, and could be directed at individual waterpipe users or at groups of users. We only included tobacco cessation interventions, and did not consider trials of prevention of uptake.

Data collection and analysis: Two review authors assessed abstracts of the studies retrieved by the search strategy, for possible inclusion in the review. We retrieved full-text articles for all abstracts that any of the authors believed might be suitable. Two review authors then extracted data and assessed trial quality independently in accordance with standard Cochrane Collaboration methodologies. We aimed to pool groups of studies that we considered to be sufficiently similar, provided there was no evidence of substantial statistical heterogeneity, and aimed to estimate a pooled risk ratio (RR) using the Mantel-Haenszel fixed-effect method. Where meta-analysis was not possible, we presented summary and descriptive statistics.

Main results: Our search retrieved 1311 unique citations, of which 1289 were excluded after title and abstract screening. Of the remaining 22, we excluded 19 because they were empirical studies that were not randomized, quasi-randomized or cluster-randomized controlled trials (n = 12), because they were review articles (n = 3), because they described protocols only (n = 2), they were conducted among cigarette smokers only (n = 1), or they had only a three-month follow-up (n = 1).We identified three controlled trials which tested cessation interventions for waterpipe smokers. Studies were carried out in Egypt (Mohlman 2013), Pakistan (Dogar 2014), and the US (Lipkus 2011). One was a randomized controlled trial and two were cluster-randomized trials. Two studies tested individual-level interventions, and one tested a community-level intervention. Two studies included only behavioural interventions, and one study (Dogar 2014) included two intervention groups: one behavioural, and the other behavioural with bupropion. The Lipkus and Mohlman studies delivered waterpipe-specific interventions, and the Dogar study delivered a non-specific tobacco intervention. Due to study variation we did not pool results, and intervention effects are reported descriptively. Compared to control groups, waterpipe smoking cessation rates were higher in the intervention groups in all three studies, with a significant difference in two studies. For the Dogar study, the RRs for waterpipe smoking abstinence at 25 weeks among waterpipe-only smokers were 2.2 (95% confidence interval (CI) 1.3 to 3.8; 180 participants) in the behavioural group, and 2.5 (95% CI 1.3 to 4.7; 84 participants) in the behavioural plus bupropion group. In our analysis we have combined both groups, to give a RR of 2.28 (95% CI 1.36 to 3.83; 200 participants). The Mohlman study delivered a RR in male waterpipe-smokers at one year in favour of the intervention of 3.25 (95% CI 1.19 to 8.89).

Authors' conclusions: Although the literature on waterpipe cessation interventions remains sparse, the reviewed studies provide a basis for developing interventions in this area. The lack of statistically significant effects in one of the three studies is not unexpected, given the small and pilot nature of the studies. The studies highlight important design and content issues that need to be considered for future cessation trials in waterpipe smokers. These include building on the vast experience developed in the study of smoking cessation interventions in cigarette smokers, whilst including components and assessment tools that address the specific aspects of waterpipe smoking, such as its social dimension, unique experiences, and cues.