Confidence intervals for comparisons of two binomial rates. This convenience wrapper function produces a selection of the methods below as appropriate for the odds ratio contrast (OR), with or without continuity adjustment.
SCAS (skewness-corrected asymptotic score)
Miettinen-Nurminen, Gart and unadjusted Asymptotic Score methods
MOVER-R Wilson
MOVER-R Jeffreys
Approximate normal (Woolf/Gart) methods (strongly advise this is not used for any purpose but included for reference)
Arguments
- x1, x2
Numeric vectors of numbers of events in group 1 & group 2 respectively.
- n1, n2
Numeric vectors of sample sizes (for binomial rates) or exposure times (for Poisson rates) in each group.
- level
Number specifying confidence level (between 0 and 1, default 0.95).
- std_est
logical, specifying if the crude point estimate for the contrast value should be returned (TRUE, default) or the method-specific alternative point estimate consistent with a 0% confidence interval (FALSE).
- cc
Number or logical (default FALSE) specifying (amount of) continuity adjustment. Numeric value between 0 and 0.5 is taken as the gamma parameter in Laud 2017, Appendix S2 (
cc = TRUEtranslates to 0.5 for 'conventional' Yates adjustment).- precis
Number (default 8) specifying precision (i.e. number of decimal places) to be used in root-finding subroutine for the score confidence intervals. (Note other methods use closed-form calculations so are not affected.)
References
Laud PJ. Equal-tailed confidence intervals for comparison of rates. Pharmaceutical Statistics 2017; 16:334-348. (Appendix A.4)
Author
Pete Laud, p.j.laud@sheffield.ac.uk