Effect of simvastatin allocation on major coronary events by year of follow-up. Rate ratios (RR: black squares with area proportional to the amount of "statistical information" in each subdivision) comparing outcome among patients allocated simvastatin to that among those allocated placebo are plotted, along with their 95% confidence intervals (CI: horizontal lines). For relevant subtotals, the result and its 95% CI is represented by a diamond, with the overall proportional reduction and statistical significance given alongside. Squares or diamonds to the left of the solid vertical line indicate benefit with simvastatin (with nominal significance of at least two-sided P < 0.05 when the horizontal line or diamond does not overlap the vertical line). The broken vertical lines indicate the overall rate ratios.