or.midp: Odds ratio estimation and confidence intervals using mid-p...

In epitools: Epidemiology Tools

Description

Calculates odds ratio by median-unbiased estimation and exact confidence interval using the mid-p method (Rothman 1998).

Usage

or.midp(x, conf.level = 0.95, byrow = TRUE, interval = c(0, 1000))

Arguments

x	input data can be 2x2 matrix or vector of length 4
conf.level	confidence level (default is 0.95)
byrow	integer vectors are read in row-wise (default)
interval	interval for the uniroot that finds the odds ratio median-unbiased estimate and mid-p exact confidence interval for oddsratio.midp

Details

Calculates odds ratio by median-unbiased estimation and exact confidence interval using the mid-p method (Rothman 1998, p. 251).

This function expects the following 2x2 table struture:

              exposed   not exposed
    disease  	 a1	    a0	      			
    no disease   b1	    b0
  

or a numeric vector of the form c(a1, a0, b1, b0).

This function is used by oddsratio.midp.

Value

x	table that was used in analysis
data	same table as x but with marginal totals
estimate	median unbiased odds ratio
conf.level	confidence level used

Author(s)

Tomas Aragon, [e-mail], http://www.phdata.science

References

Kenneth J. Rothman and Sander Greenland (1998), Modern Epidemiology, Lippincott-Raven Publishers

See Also

oddsratio

Examples

##rothman p. 243
z1 <- matrix(c(12,2,7,9),2,2,byrow=TRUE)
z2 <- z1[2:1,2:1]
##jewell p. 79
z3 <- matrix(c(347,555,20,88),2,2,byrow=TRUE)
z4 <- z3[2:1,2:1]
or.midp(z1)
or.midp(z2)
or.midp(z3)
or.midp(z4)

Example output

$x
     [,1] [,2]
[1,]   12    2
[2,]    7    9

$estimate
[1] 6.880701

$conf.int
[1]  1.276258 60.721998

$conf.level
[1] 0.95

attr(,"method")
[1] "median-unbiased estimate & mid-p exact CI"
$x
     [,1] [,2]
[1,]    9    7
[2,]    2   12

$estimate
[1] 6.880701

$conf.int
[1]  1.276258 60.721998

$conf.level
[1] 0.95

attr(,"method")
[1] "median-unbiased estimate & mid-p exact CI"
$x
     [,1] [,2]
[1,]  347  555
[2,]   20   88

$estimate
[1] 2.732458

$conf.int
[1] 1.683370 4.648361

$conf.level
[1] 0.95

attr(,"method")
[1] "median-unbiased estimate & mid-p exact CI"
$x
     [,1] [,2]
[1,]   88   20
[2,]  555  347

$estimate
[1] 2.732458

$conf.int
[1] 1.683370 4.648361

$conf.level
[1] 0.95

attr(,"method")
[1] "median-unbiased estimate & mid-p exact CI"

epitools documentation built on March 26, 2020, 9:14 p.m.