Mayo Clinic primary biliary cirrhosis data used as example code

The dataset originates from the Mayo Clinic trial on primary biliary cirrhosis (PBC) of the liver, carried out from 1974 to 1984. It includes data from 424 PBC patients who were referred to the Mayo Clinic within this decade and met the eligibility requirements for a randomized placebo-controlled trial of D-penicillamine. However, only the initial 312 cases from the dataset were enrolled in the randomized trial. Thus, the dataset specifically pertains to these 312 patients, for whom the data is largely complete.

Usage

data(pbc3)

Format

A data frame with 1945 observations on the following 27 variables:

id: patients identifier; in total there are 312 patients.
years: number of years between registration and the earlier of death, transplantation, or study analysis time.
status: a factor with levels alive, transplanted and dead.
drug: a factor with levels placebo and D-penicil.
age: at registration in years.
sex: a factor with levels male and female.
year: number of years between enrollment and this visit date, remaining values on the line of data refer to this visit.
ascites: a factor with levels No and Yes.
hepatomegaly: a factor with levels No and Yes.
spiders: a factor with levels No and Yes.
edema: a factor with levels No edema (i.e. no edema and no diuretic therapy for edema), edema no diuretics (i.e. edema present without diuretics, or edema resolved by diuretics), and edema despite diuretics (i.e. edema despite diuretic therapy).
serBilir: serum bilirubin in mg/dl.
serChol: serum cholesterol in mg/dl.
albumin: albumin in mg/dl.
alkaline: alkaline phosphatase in U/liter.
SGOT: SGOT in U/ml.
platelets: platelets per cubic ml/1000.
prothrombin: prothrombin time in seconds.
histologic: histologic stage of disease.
status2: a numeric vector with the value 1 denoting if the patient was dead, and 0 if the patient was alive or transplanted.
status3: a numeric vector with the value 1 denoting if the patient was dead or transplanted, and 0 if the patient was alive.
status4: a numeric vector with the value 1 denoting if the patient was transplanted, and 0 if the patient was dead. Used for competing risks.
status5: a numeric vector with the value 2 if the patient was transplanted, 1 denoting if the patient was dead, and 0 if the patient was alive. Used for competing risks with censored.
Tyears1: a numeric vector with a transformed value of time-to-event outcome.
Tyears2: a numeric vector with a transformed value of time-to-event outcome.
Tyears3: a numeric vector with a transformed value of time-to-event outcome.
Tyears4: a numeric vector with a transformed value of time-to-event outcome.

Source

pbc.

References

Fleming T, Harrington D. Counting Processes and Survival Analysis. 1991; New York: Wiley.

Therneau T, Grambsch P. Modeling Survival Data: Extending the Cox Model. 2000; New York: Springer-Verlag.