R: Ashina's crossover trial

ashina {ISwR} | R Documentation

## Ashina's crossover trial

### Description

The `ashina` data frame has 16 rows and 3 columns. It contains data from a crossover trial for the effect of an NO synthase inhibitor on headaches. Visual analog scale recordings of pain levels were made at baseline and at five time points after infusion of the drug or placebo. A score was calculated as the sum of the differences from baseline. Data were recorded during two sessions for each patient. Six patients were given treatment on the first occasion and the placebo on the second. Ten patients had placebo first and then treatment. The order of treatment and the placebo was randomized.

### Usage

    ashina

### Format

This data frame contains the following columns:

`vas.active`

  a numeric vector, summary score when given active substance.

`vas.plac`

  a numeric vector, summary score when given placebo treatment.

`grp`

  a numeric vector code, 1: placebo first, 2: active first.

### Source

Original data.

### References

M.Ashina et al. (1999), Effect of inhibition of nitric oxide synthase on chronic tension-type headache: a randomised crossover trial. Lancet 353, 287–289

### Examples

    plot(vas.active~vas.plac,pch=grp,data=ashina)
    abline(0,1)

[Package ISwR version 2.0-7 Index]