asthma: Asthma repeated measures dataset from Littell et al. (2002)
Description
This dataset was used by Littell (2002) to demonstrate repeated measures analyses. The effect of two asthma drugs and a placebo were measured on 24 asthmatic patients. Each patient was randomly given each drug using an approach to minimize carry-over effects. Forced expiratory volume (FEV1), the volume of air that can be expired after taking a deep breath in one second, was measured. FEV1 was measured hourly for eight hours following application of the drug. A baseline measure of FEV1 was also taken 11 hours before application of the treatment.
Format
The dataframe has 11 columns:
- PATIENT
- The subjects (there were 24 patients).
- BASEFEV1
- A numerical variable; the baseline forced expiratory volume.
- FEV11H
- Forced expiratory volume at 11 hours.
- FEV12H
- Forced expiratory volume at 12 hours.
- FEV13H
- Forced expiratory volume at 13 hours.
- FEV14H
- Forced expiratory volume at 14 hours.
- FEV15H
- Forced expiratory volume at 15 hours.
- FEV16H
- Forced expiratory volume at 16 hours.
- FEV17H
- Forced expiratory volume at 17 hours.
- FEV18H
- Forced expiratory volume at 18 hours.
- DRUG
- A factor with three levels
"a" = a standard drug treatment, "c" = the drug under development, and "p" = a placebo.
Source
Littell, R. C., Stroup, W. W., and R. J. Fruend (2002) SAS for Linear Models. John
Wiley and Associates.