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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. The condition is classified into four stages of severity: none, mild, moderate and severe.


A data frame containing 638 rows, grouped by patient, including histories of 204 patients. The first observation for each patient is defined to be stage 1, no BOS, at six months after transplant. Subsequent observations denote the entry times into stages 2, 3, 4, representing mild, moderate and severe BOS respectively, and stage 5, representing death.

ptnum(numeric)Patient identification number
time(numeric)Months after transplant
state(numeric)BOS state entered at this time


Papworth Hospital, U.K.


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 objects bos3 and bos4 contain the same data, but with mild/moderate/severe combined, and moderate/severe combined, to give 3 and 4-state representations respectively.


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.