ecg: Two-period crossover trial study on cerebrovascular...

In ALA: Data sets and examples for the book "Applied Longitudinal Analysis"

Description

The dataset consists of safety data from a crossover trial on the disease cerebrovascular deficiency.

Usage

data(ecg)

Format

A data frame with 14 observations on the following 4 variables.

id

a factor with 67 levels

sequence

a factor with levels P->A and A->P, indicating treatment sequence (placebo to active and active to placebo, respectively

period

a factor with levels 1 and 2

ecg

a factor (ECG response) with levels normal and abnormal

Details

The response variable is not a trial endpoint but rather a potential side effect. In this two-period crossover trial, comparing the effects of active drug to placebo, 67 patients were randomly allocated to the two treatment sequences, with 34 patients receiving placebo followed by active treatment, and 33 patients receiving active treatment followed by placebo. The response variable is binary, indicating whether an electrocardiogram (ECG) was abnormal (1) or normal (0). Each patient has a bivariate binary response vector.

Note

Original variable names have been adapted to R conventions. Data were reshaped from wide to long format and the response named ecg. Variable ID was added to identify individuals.

Source

http://biosun1.harvard.edu/~fitzmaur/ala

References

Jones B, Kenward MG (1989) Design and Analysis of Cross-over Trials. London: Chapman and Hall/CRC Press.

Examples

str(ecg)
summary(ecg)

ALA documentation built on May 2, 2019, 5:39 p.m.