The dermatology dataset is derived from a randomized clinical trial that compared a test treatment with a control for managing skin conditions stanish_1978winr. This trial enrolled 172 patients—88 in the test group and 84 in the placebo group—across six clinics. These patients were assessed at three follow-up visits, where the degree of improvement in their skin condition was measured on a five-point scale: 1 for rapidly improving, 2 for slowly improving, 3 for stable, 4 for slowly worsening, and 5 for rapidly worsening. Due to Clinic 9 enrolling only four patients, data from Clinics 8 and 9 were combined, a decision supported by these clinics having the smallest sample sizes in their strata. The primary baseline variable recorded was the stage of disease at the start of the study, categorized as 3 for fair, 4 for poor, and 5 for exacerbation. This dataset also features missing data at follow-up visits, progressively increasing from 2% (3 missing observations) at the first visit to 9% (16 missing) at the second, and 17% (30 missing) at the third visit.
skinA data frame with 11 variables.
INV: Investigator identification number (5,6,8,9,10,11)
ID: Participant ID
center: Treatment center
center2: Treatment center that pools centers 3 and 4 due to small sample size
TRT: 1 = Test drug, 2 = Placebo
STAGE: Initial stage of disease (3 = Fair, 4 = Poor, 5 = Exacerbation)
R1: Response at Time 1; NA if missing
R2: Response at Time 2; NA if missing
R3: Response at Time 3; NA if missing
Stage4: 1 if Stage 4, 0 otherwise
Stage5: 1 if Stage 5, 0 otherwise