Volume 142, Issue 4, Pages 744-753 (April 2012) Cigarette Smoking Increases Risk of Barrett's Esophagus: An Analysis of the Barrett's and Esophageal Adenocarcinoma Consortium  Michael B. Cook, Nicholas J. Shaheen, Lesley A. Anderson, Carol Giffen, Wong–Ho Chow, Thomas L. Vaughan, David C. Whiteman, Douglas A. Corley  Gastroenterology  Volume 142, Issue 4, Pages 744-753 (April 2012) DOI: 10.1053/j.gastro.2011.12.049 Copyright © 2012 AGA Institute Terms and Conditions

Figure 1 Forest plots of the relationship between increasing categories of cigarette smoking and Barrett's esophagus compared with (A) population-based controls and (B) GERD controls. Each study's estimate is represented by the corresponding black square with the arms representing 95% CIs. The gray box overlaying each estimate represents the weight that it contributes to the pooled estimate. The pooled estimates are designated by the diamonds that follow each subgroup; the widths of the diamonds represent the 95% CIs. KPNC, Kaiser Permanente Northern California; UNC, University of North Carolina. Gastroenterology 2012 142, 744-753DOI: (10.1053/j.gastro.2011.12.049) Copyright © 2012 AGA Institute Terms and Conditions

Figure 2 Spline plots of the relationship between increasing categories of cigarette smoking and Barrett's esophagus compared with (A) population-based controls and (B) GERD controls. The solid line represents the estimate of the OR, and the broken lines on either side represent 95% CIs. Gastroenterology 2012 142, 744-753DOI: (10.1053/j.gastro.2011.12.049) Copyright © 2012 AGA Institute Terms and Conditions