Figure 3.

Random Effects Meta-Analysis of the Association between Ever Use of Smokeless Waterpipe Smoking and Lung Cancer. The upper limit for one of the included studies65 was altered as we believe that the value reported in the paper is a typographical error. The CI reported in the published paper is 1.2 – 7.6 and we changed the upper limit to 27.6 to make the CI log symmetrical. We attempted to contact the authors to confirm this but were unsuccessful. The ORs fore each study are presented as squares, with the position of the square corresponding to the point estimate and the 95% CI shown by horizontal lines. (95% Cis for each study shown in the forest plot are obtained by back transformation using the calculated standard error shown in the analysis and do not always conform exactly to the stated confidence intervals in the paper). The area of the square Is inversely proportional to the variance in the OR. The diamond represents the pooled OR and it’s 95% CI