- subject
A factor with 234 levels: 1, 2, 3, 4, 6, ..., 240
- treat.f
A factor with 2 levels: Placebo, Active
- visual0
An integer vector with values ranging from 20 to 85
- miss.pat
A factor with 8 levels: ----, ---X, --X-, --XX, -XX-, ..., X-XX
- time.f
A factor with 4 levels: 4wks, 12wks, 24wks, 52wks
- time
A numeric vector with values 4, 12, 24, 52
- visual
An integer vector with values ranging from 3 to 85
- tp
A numeric vector with values 1, 2, 3, 4 corresponding to time points 4, 12, 24, 52, respectively