Select this option on the Statistic tab in a Rate session to calculate the standard errors and confidence intervals for the rates.
Standard errors and confidence intervals are always calculated if trends are being calculated and the Weighted Least Squares method of APC calculation is being used, or, in a Rate session, if Include Rate Ratios on Last Row Variable Groupings is marked.
If trends are being calculated and this option is selected, the option to show p-values for APC significance testing will be available. If this option is selected and you are calculating an age-adjusted statistic, the option to use the Tiwari et al. modification will be available.
The degree of confidence is equal to one minus the p-value. For example, a p-value equal to 0.05 yields 95% confidence intervals.