ratesci (version 0.2-0)

pairbinci: Skewness-corrected confidence intervals for comparisons of paired binomial

Description

Score-based confidence intervals for the rate (or risk) difference ("RD"), rate ratio ("RR") or for odds ratio ("OR"), for paired binomial data. [For paired Poisson rates, use the tdasci function with distrib="poi", with pairs as strata.]. This function applies the stratified TDAS method for RD and RR. For OR, an interval is produced based on transforming a SCAS interval for the single proportion.

Usage

pairbinci(x, contrast = "RD", level = 0.95, delta = NULL)

Arguments

x

A numeric vector object specified as c(a,b,c,d) where: a is the number of pairs with the event (e.g. success) under both conditions (e.g. treated/untreated, or case/control) b is the count of the number with the event on condition 1 only c is the count of the number with the event on condition 2 only d is the number of pairs with no event under both conditions (Note the order of a and d is only important for contrast="RR".) Note for data in columns of success/failure, use the tdasci function instead (not recommended for contrast="OR")

contrast

Character string indicating the contrast of interest: "RD" = rate difference (default), "RR" = rate ratio, "OR" = odds ratio.

level

Number specifying confidence level (between 0 and 1, default 0.95).

delta

Number to be used in a one-sided significance test (e.g. non-inferiority margin). 1-sided p-value will be <0.025 iff 2-sided 95% CI excludes delta. NB: can also be used for a superiority test by setting delta=0.

References

Laud PJ. Equal-tailed confidence intervals for comparison of rates. Pharmaceutical Statistics [in press]. Fagerland MW, Lydersen S, Laake P. Recommended tests and confidence intervals for paired binomial proportions. Statistics in Medicine 2014; 33(16):2850<U+2013>2875

Examples

 
  #Data example from Agresti-Min 2005
  pairbinci(c(53,16,8,9),contrast="RD")
  pairbinci(c(53,16,8,9),contrast="RR")
  pairbinci(c(53,16,8,9),contrast="OR")