exact2x2: powerPaired2x2 – R documentation

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powerPaired2x2

Power for exact McNemar's test

Description

Calculate the power for the exact McNemar's test (i.e., exact2x2 with paired=TRUE) given the number of pairs and the probability of a positive response only in the test individual in the pair (pb), and the probability of a positive response only in the control individual in the pair (pc).

Usage

powerPaired2x2(pb, pc, npairs, sig.level = 0.05, 
   alternative = c("two.sided", "one.sided"), 
   strict = FALSE, nullOddsRatio = 1, errbound = 10^-6, ...)

Arguments

`pb`	probability of a (0,1) response for a pair, meaning negative response in the control individual and a positive response in the test individual
`pc`	probability of a (1,0) response for a pair, meaning positive response in the control individual and a negative response in the test individual
`npairs`	the number of pairs
`sig.level`	significance level (also called alpha-level)
`alternative`	either 'one.sided' or 'two.sided' (see `tsmethod` for two-sided method)
`strict`	use strict interpretation in two-sided case (i.e., TRUE allows rejections in the 'wrong' direction)
`nullOddsRatio`	null odds ratio, internally passed to `or` argument of `exact2x2` with `paired=TRUE`
`errbound`	error bound, `errbound=0` does exact calculation, when `errbound>0` then speed up calculations by not calculating outcomes at either extreme with tail probabilities less than errbound/2 which may underestimate power by at most errbound.
`...`	arguments passed to `exact2x2` (except these arguments cannot be passed this way: `or`, `alternative`, `conf.int`, `paired`, `plot`)

Details

When alternative='one.sided' then the test automatically picks the side that is most powerful.

Value

An object of class 'power.htest' with elements:

`power`	power
`npairs`	number of pairs
`pb`	probability of a (control,test)=(0,1) response for a pair
`pc`	probability of a (control,test)=(1,0) response for a pair
`sig.level`	significance level or alpha-level
`alternative`	either one-sided or two-sided
`nullOddsRatio`	null odds ratio (or boundary between null and alternative for one-sided tests)
`note`	notes about calculation (e.g., errbound value)
`method`	description of method

Examples

powerPaired2x2(.5,.3,npairs=20)

exact2x2

Exact Tests and Confidence Intervals for 2x2 Tables

v1.6.5

GPL-3

Authors

Michael P. Fay [aut, cre], Sally A. Hunsberger [ctb], Martha Nason [ctb], Erin Gabriel [ctb], Keith Lumbard [ctb]

Initial release

2020-08-02