Bowker-test

Install required packages

coin

wants <- c("coin")
has   <- wants %in% rownames(installed.packages())
if(any(!has)) install.packages(wants[!has])

Bowker test

Using mcnemar.test()

categ <- factor(1:3, labels=c("lo", "med", "hi"))
drug  <- rep(categ, c(30, 50, 20))
plac  <- rep(rep(categ, length(categ)), c(14,7,9, 5,26,19, 1,7,12))
cTab  <- table(drug, plac)
addmargins(cTab)

     plac
drug   lo med  hi Sum
  lo   14   7   9  30
  med   5  26  19  50
  hi    1   7  12  20
  Sum  20  40  40 100

mcnemar.test() automatically runs the Bowker test for tables with more than 2 rows/columns

mcnemar.test(cTab)

    McNemar's Chi-squared test

data:  cTab
McNemar's chi-squared = 12.272, df = 3, p-value = 0.006508

Using symmetry_test() from package coin

library(coin)
symmetry_test(cTab, teststat="quad", distribution=approximate(nresample=9999))

    Approximative General Symmetry Test

data:  response by
     conditions (drug, plac) 
     stratified by block
chi-squared = 12.139, p-value = 0.0017

Detach (automatically) loaded packages (if possible)

try(detach(package:coin))
try(detach(package:survival))

Get the article source from GitHub

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