Staging of bronchiolitis obliterans syndrome using home spirometry.

Objectives: To compare the detection of bronchiolitis obliterans syndrome (BOS) in lung transplant recipients by clinic pulmonary function laboratory measurement and home spirometry.
Design: The subjects served as their own control group.
Setting: A university-based thoracic transplant center.
Subjects: Forty-five lung transplant recipients (26 women and 19 men; average +/- SD age, 47.7+/-11.4 years old at the time of transplantation). Lung function declined to at least BOS stage 1 in 17 of the 45 subjects.
Measurements: All subjects were participants in a home monitoring program utilizing home spirometry measurements. Clinic spirometry and home spirometry measurements were collected concurrently. The determinations of BOS staging were based on home and clinic FEV1 values using retrospective analysis and development of the home-based BOS staging algorithm.
Results: BOS stage 1 was detected an average of 341 to 276 days earlier with home spirometry than with clinic pulmonary function testing in the 17 subjects who had a pulmonary decline to BOS stage 1, depending on the persistence of the decline (1 day or 3 days, respectively). The difference in BOS detection time was statistically significant for both persistence requirements (p < 0.001).
Conclusions: Home spirometry detects pulmonary decline earlier than clinic spirometry; home spirometry can be a reliable and safe alternative to frequent pulmonary function testing in lung recipients.