SUMMARY OF FINDINGS FOR THE MAIN COMPARISON [Explanation]

Waterpipe intervention compared with a control for waterpipe cessation
Outcomes	Impact	Number of Participants (Studies)	Certainty of the evidence (GRADE)*	Comments
Prolonged Cessation	(Dogar 2014) RR 2.48 (95% CI: 1.36 to 3.83) for 25 weeks cessation (Lipkus 2011) RR 1.46 (95% CI: 0.81 to 2.62) for 6 months (Mohlman 2013) RR 3.25 (95% CI: 1.19 to 2.12) for 12 months cessation	200 (1) 91 (1) 540 (1)	⊕○○○ very low	The studies were not pooled as the interventions were not sufficiently similar in design and participant demographics. There is no pooled effect estimate
CI: Confidence interval; RR: Risk Ratio
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.

^*The certainty of the evidence was very low as all the studies had at least one high risk of bias in accordance with the GRADE framework (see Figure 2).