A series of measurements of the forced expiratory volume in one second (FEV1) from lung transplant recipients, from six months onwards after their transplant.
A data frame containing 5896 rows. There are 204 patients, the rows are grouped by patient number and ordered by days after transplant. Each row represents an examination and containing an additional covariate.
ptnum | (numeric) | Patient identification number. |
days | (numeric) | Examination time (days after transplant). |
fev | (numeric) | Percentage of baseline FEV1. A code of 999 indicates the patient's date of death. |
acute | (numeric) | 0/1 indicator for whether the patient suffered an acute infection or rejection |
| within 14 days of the visit. |
A baseline "normal" FEV1 for each individual is calculated using measurements from the first six months after transplant. After six months, as presented in this dataset, FEV1 is expressed as a percentage of the baseline value.
FEV1 is monitored to diagnose bronchiolitis obliterans syndrome (BOS), a long-term lung function decline, thought to be a form of chronic rejection. Acute rejections and infections also affect the lung function in the short term.
Jackson, C.H. and Sharples, L.D. Hidden Markov models for the onset and progression of bronchiolitis obliterans syndrome in lung transplant recipients Statistics in Medicine, 21(1): 113--128 (2002).