Data from the Mayo Clinic trial in primary biliary cirrhosis (PBC) of the
liver. This dataset was obtained from the survival package:
the variables copper and trig from survival::pbc were
merged into survival::pbcseq and several categorical variables were
re-coded.
Survival outcome and id
- id
case number
- futime
number of days between registration and the earlier of death, transplantation, or end of follow-up
- status
status at endpoint ("censored", "transplant" or "dead")
Baseline covariates
- trt
D-pen (D-penicillamine) vs placebo
- age
in years
- sex
male or female
- copper
urine copper (\(\mu\)g/day)
- trig
triglycerides (mg/dl)
Time-varying covariates
- day
number of days between enrolment and this visit date; all measurements below refer to this date
- albumin
serum albumin (mg/dl)
- alk.phos
alkaline phosphatase (U/liter)
- ascites
presence of ascites
- ast
aspartate aminotransferase (U/ml)
- bili
serum bilirubin (mg/dl)
- chol
serum cholesterol (mg/dl)
- edema
"no": no oedema, "(un)treated": untreated or successfully treated 1 oedema, "edema": oedema despite diuretic therapy
- hepato
presence of hepatomegaly (enlarged liver)
- platelet
platelet count
- protime
standardised blood clotting time
- spiders
blood vessel malformations in the skin
- stage
histologic stage of disease (4 levels)
Examples
summary(PBC)
#> id futime status trt age
#> Min. : 1.0 Min. : 41 censored :1073 D-pen :967 Min. :26.28
#> 1st Qu.: 61.0 1st Qu.:2055 transplant: 147 placebo:978 1st Qu.:41.79
#> Median :126.0 Median :2963 dead : 725 Median :48.87
#> Mean :135.4 Mean :2941 Mean :49.26
#> 3rd Qu.:203.0 3rd Qu.:3819 3rd Qu.:56.15
#> Max. :312.0 Max. :5225 Max. :78.44
#>
#> sex day ascites hepato spiders
#> male : 237 Min. : 0 no :1716 no :952 no :1311
#> female:1708 1st Qu.: 192 yes : 169 yes :932 yes : 576
#> Median : 750 NA's: 60 NA's: 61 NA's: 58
#> Mean :1145
#> 3rd Qu.:1838
#> Max. :5152
#>
#> edema bili chol albumin
#> no :1401 Min. : 0.100 Min. : 55.0 Min. :1.17
#> (un)treated: 379 1st Qu.: 0.800 1st Qu.: 235.0 1st Qu.:3.11
#> edema : 165 Median : 1.400 Median : 281.0 Median :3.44
#> Mean : 3.672 Mean : 320.5 Mean :3.39
#> 3rd Qu.: 3.900 3rd Qu.: 349.2 3rd Qu.:3.70
#> Max. :41.000 Max. :1775.0 Max. :8.01
#> NA's :821
#> alk.phos ast platelet protime stage
#> Min. : 73 Min. : 6.2 Min. : 40.0 Min. : 9.0 1: 95
#> 1st Qu.: 737 1st Qu.: 72.0 1st Qu.:165.0 1st Qu.:10.1 2:266
#> Median : 1072 Median : 107.0 Median :228.0 Median :10.8 3:612
#> Mean : 1382 Mean : 122.7 Mean :233.7 Mean :11.0 4:972
#> 3rd Qu.: 1636 3rd Qu.: 155.0 3rd Qu.:290.2 3rd Qu.:11.5
#> Max. :13862 Max. :1205.0 Max. :991.0 Max. :36.0
#> NA's :60 NA's :73
#> copper trig
#> Min. : 4.00 Min. : 33
#> 1st Qu.: 38.00 1st Qu.: 83
#> Median : 65.00 Median :105
#> Mean : 84.54 Mean :122
#> 3rd Qu.:105.00 3rd Qu.:151
#> Max. :588.00 Max. :598
#> NA's :8 NA's :206