Abstract: 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). 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.

Plain-language summary: We searched for controlled trials in the Cochrane Tobacco Addiction Review Group specialized register, in June 2015. We also searched a number of electronic databases, including MEDLINE, EMBASE, PsycINFO and CINAHL, using a variety of names and spellings for waterpipe use ('waterpipe' or 'narghile' or 'arghile' or 'shisha' or 'goza' or 'narkeela' or 'hookah' or 'hubble bubble'). We searched for published and unpublished trials in any language, and especially in areas where waterpipe use is widespread. We identified three studies that tested behavioural methods to help waterpipe smokers to quit. Two were waterpipe-specific interventions and one was a non-specific tobacco intervention.One small, pilot study was set in the USA, and delivered a Powerpoint presentation online to 91 college students who were using waterpipe. One study was a secondary analysis of data from 264 waterpipe smokers who were part of a trial that enrolled people suspected of having tuberculosis from 33 healthcare clinics in Pakistan. Clinics were randomly assigned to deliver a behavioural intervention versus control (usual care), or a behavioural intervention plus medication (bupropion) versus control (usual care). The third study, set in Egypt, targeted both cigarette and waterpipe smokers, and was a community-based programme. In all three trials, the percentage of participants who stopped smoking waterpipe was higher in the intervention groups than in the control groups, although this was a statistically significant finding in only two of the trials. People who received either behavioural treatment or behavioural treatment plus buproprion were more likely to quit waterpipe smoking at six months follow-up than those who received usual care. Men smoking waterpipe in the Egyptian study were more likely to have quit at one year follow-up in the intervention villages than in the control villages. These studies provide support to suggest that cessation interventions may help waterpipe smokers to quit. However, further larger studies are needed to build on this. The trials were all rated at very low quality of evidence, as they were relatively small studies, with at least one high risk of bias.