R: Marked improvement of psoriasis after application of...

liarozole {MCPAN} | R Documentation

## Marked improvement of psoriasis after application of liarozole

### Description

In a placebo controlled clinical trial, patients with psoriasis were randomly assigned to a placebo group and three dose groups (50 mg, 75 mg, and 150 mg). Variable of primary interest was the proportion of patients with marked improvement of psoriasis. This data.frame mimics how raw data could have been represented in a larger data frame.

### Usage

    data(liarozole)

### Format

A data frame with 137 observations on the following 2 variables.

Improved

  a factor with levels `n`, `y`, for "no" and "yes"

Treatment

  a factor with levels `Dose150`, `Dose50`, `Dose75`, `Placebo`

### Details

For illustrative purpose only. Number of successes recalculated from proportions presented in the publication, while the number of patients in group `Dose50` was not exactly clear.

### Source

Berth-Jones J, Todd G, Hutchinson PE, Thestrup-Pedersen K, Vanhoutte FP: Treatment of psoriasis with oral liarozole: a dose-ranging study. British Journal of Dermatology 2000; 143: 1170-1176.

### Examples

    data(liarozole)
    head(liarozole)
    # create a contingency table:

    table(liarozole)

    # the order of the groups is alpha-numeric,
    # and "y" for success is of higher order than
    # to change the order:

    liarozole$Treatment<-factor(liarozole$Treatment,
     levels=c("Placebo", "Dose50", "Dose75", "Dose150"))

    liarozole$Improved<-factor(liarozole$Improved,
     levels=c("y", "n"))

    tab<-table(liarozole)
    tab

    # Approximate simultaneous confidence intervals
    # for the differences  pDose-pPlacebo:

    LCI<-binomRDci(tab, type="Dunnett",
    alternative="greater", method="ADD1")

    LCI

    plot(LCI, main="Proportion of patients
     with marked improvement")

    # Perform a test on increasing trend
    # vs. the placebo group:

    Ltest<-binomRDtest(tab, type="Williams",
    alternative="greater", method="ADD1")

    summary(Ltest)

[Package MCPAN version 1.1-21 Index]