PBC {gmvjoint}

Primary biliary cirrhosis data

Description

Primary biliary cirrhosis (PBC) data. PBC is a chronic liver disease which affects the bile ducts of the liver, complications of which can ultimately lead to death. The longitudinal profile of numerous biomarkers were observed for 312 patients at the Mayo Clinic between 1974 and 1984 with patients assigned to either the active (D-penicillamine, n=154 (50.6 placebo treatment arm (Murtaugh 1994). The data is publicly available in numerous places, including joineRML and survival. The presence of many longitudinal biomarkers of clinical interest as well as an event-time has lead to the PBC data becoming widely used in literature.

Usage

data('PBC')

Format

data.frame with 312 patients and 19 variables:

id

Subject identifier

survtime

Survival time in years

drug

Binary indicator covariate: was the patient assigned active (drug=1) or placebo?

sex

Binary indicator covariate: Takes value 1 if the subject is female, and zero if male.

time

Time of visit (0=baseline).

ascites

Binary response variable. Takes value 1 if accumulation of fluid in abdomen ("ascites") present.

hepatomegaly

Binary response variable. Takes value 1 if enlarged liver ("hepatomegaly") present.

spiders

Binary response variable. Takes value 1 if malformed blood vessels in skin ("hepatomegaly") present.

edema

Factor variable describing edema therapy, see pbcseq.

serBilir

Serum bilirubin (measured in mg/dl).

serChol

Serum cholesterol (measured in mg/dl).

album

Serum albumin (measured in mg/dl).

alkaline

Alkaline phosphotase (measured in U/liter).

SGOT

Aspartate aminotransferase (measured in U/liter).

platelets

Platelet count per cubic ml/1000.

histologic

Histologic stage of disease, see pbcseq.

status

Survival status, status=1 if the subject experienced mortality and =0 if censored.

age

Standardised age at baseline visit.

Details

Nine longitudinal biomarkers exist with varying degrees of completeness in the data.

Source

pbcseq

References

Murtaugh PA, Dickson ER, Van Dam GM, Malinchoc M, Grambsch PM, Langworthy AL, Gips CH. Primary biliary cirrhosis: Prediction of short-term survival based on repeated patient visits. Hepatology 1994; 20(1); 126-134.