The data are from a randomized clinical trial to compare a test treatment to placebo for a respiratory disorder, and listings of the data appear in Stokes et al. (2000, chap. 15, pp. 495-496) and Koch et al. (1990). The variables are as follows:
data(resp)A data frame with 111 observations and 9 variables.
centera factor vector for two centers
treatmenta factor with levels A and P for active and placebo treatments, respectively
sexa factor with levels F and M for female and male, respectively
agea numeric vector for age
baselinea numeric vector for patient global ratings of symptom control according to 5 categories (4 = excellent, 3 = good, 2 = fair, 1 = poor, 0 = terrible) at baseline measurement
visit1a numeric vector for patient global ratings of symptom control at visit 1 with same categories as baseline
visit2a numeric vector for patient global ratings of symptom control at visit 2 with same categories as baseline
visit3a numeric vector for patient global ratings of symptom control at visit 3 with same categories as baseline
visit4a numeric vector for patient global ratings of symptom control at visit 4 with same categories as baseline
Stokes, M. E., Davis, C. S., and Koch, G. G. (2000), Categorical Data Analysis using the SAS System, Cary: SAS Publishing.
Koch, G. G., Carr, G. J., Amara, I. A., Stokes, M. E., and Uryniak, T. J. (1990), "Categorical Data Analysis," in Statistical Methodology in Pharmaceutical Sciences, ed. D. A. Berry, New York: Marcel Dekker, pp. 291-475.