| bos {flexsurv} | R Documentation |
Bronchiolitis obliterans syndrome after lung transplants
Description
A dataset containing histories of bronchiolitis obliterans syndrome (BOS) from lung transplant recipients. BOS is a chronic decline in lung function, often observed after lung transplantation.
Format
A data frame containing a sequence of observed or censored transitions to the next stage of severity or death. It is grouped by patient and includes histories of 204 patients. All patients start in state 1 (no BOS) at six months after transplant, and may subsequently develop BOS or die.
bosms3 contains the data for a three-state model: no BOS, BOS or
death. bosms4 uses a four-state representation: no BOS, mild BOS,
moderate/severe BOS or death.
id | (numeric) | Patient identification number |
from | (numeric) | Observed starting state of the transition |
to | (numeric) | Observed or potential ending state of the transition |
Tstart | (numeric) | Time at the start of the interval |
Tstop | (numeric) | Time at the end of the interval |
time | (numeric) | Time difference Tstart-Tstop |
status
| (numeric) | 1 if the transition to state to was observed, or
0 if the transition to state to was censored (for example, if the
patient was observed to move to a competing state) |
trans | (factor) | Number of the transition from-to in the set of
all ntrans allowed transitions, numbered from 1 to ntrans. |
Details
The entry time of each patient into each stage of BOS was estimated by clinicians, based on their history of lung function measurements and acute rejection and infection episodes. BOS is only assumed to occur beyond six months after transplant. In the first six months the function of each patient's new lung stabilises. Subsequently BOS is diagnosed by comparing the lung function against the "baseline" value.
The same data are provided in the msm package, but in the native format of msm to allow Markov models to be fitted. In flexsurv, much more flexible models can be fitted.
Source
Papworth Hospital, U.K.
References
Heng. D. et al. (1998). Bronchiolitis Obliterans Syndrome: Incidence, Natural History, Prognosis, and Risk Factors. Journal of Heart and Lung Transplantation 17(12)1255–1263.