Figure 15

Forest plot of ex smoking of any product and emphysema. Table 10 presents the results of a main meta-analysis for emphysema based on 17 relative risk (RR) and 95% confidence interval (CI) estimates for ex smoking of any product (or cigarettes if any product not available). The individual study estimates are shown numerically and graphically on a logarithmic scale. The weights (inverse-variance) are also shown numerically, expressed as a percentage of the overall weight. The studies are sorted in order of sex within study reference (REF). In the graphical representation individual RRs are indicated by a solid square, with the area of the square proportional to the weight. Arrows indicate where the CI extends outside the range allocated. Also shown are the combined random-effects estimates. These are represented by a diamond of standard height, with the width indicating the 95% CI.