対症例対照研究(Matched Case-Control Study) Mantel-Haenszel のオッズ比計算スクリプト

calcMHRatio.R

calcMHRatio <- function(mymatrix, alpha=0.05)
{
  caseExposedControlUnexposed <- mymatrix[1, 2]
  caseUnexposedControlExposed <- mymatrix[2, 1]
  MHRatio <- caseExposedControlUnexposed / caseUnexposedControlExposed
  print(paste("Mantel-Haenszelのオッズ比 =", MHRatio))
  # 信頼区間の計算
  confidenceLevel <- (1 - alpha) * 100
  sigma <- sqrt((1 / caseExposedControlUnexposed) + (1 / caseUnexposedControlExposed))
  # sigmaは,オッズ比の対数の推定値の標準誤差
  z <- qnorm(1 - (alpha / 2))
  lowervalue <- MHRatio * exp(-z * sigma)
  uppervalue <- MHRatio * exp( z * sigma)
  print(paste(confidenceLevel, "% confidence interval = [", lowervalue,", ",uppervalue,"]"))
}