Figure 2
Forest plot for tonsillectomy exposure occurring at ≤ 20 years of age. Forest plot of 12 included studies reporting tonsillectomy in those ≤ 20 years of age in cases with multiple sclerosis and controls. Horizontal lines, 95% CIs of each study; squares, odds ratios of each individual study (the size represents the weight that the study was given in the meta-analysis); diamond, the pooled summary estimate; solid vertical line, null value. OR > one favoured the control group.