A62-04 Comparison of Home Spirometry to Office Spirometry in Children and Young Adults Post Hematopoietic Stem Cell Transplant in the Transpire Research Study

Rationale Pulmonary complications post hematopoietic stem cell transplant (post-HSCT) are prevalent, affecting 25% to 60% of children. One of the most common pulmonary complications is bronchiolitis obliterans syndrome (BOS). During early phases of BOS patients may be asymptomatic and only diagnosed through pulmonary function tests (PFTs). Early and accurate diagnosis of lung injury is key to improving survival. Lung function parameters are part of the criteria for the diagnosis of BOS and are routinely performed in the pulmonary function laboratory.We have previously reported that home spirometry is feasible and useful for following indices over time in children post-HSCT. Herin, we report on home spirometry compared to office spirometry of our TRANSPIRE cohort. Methods TRANSPIRE is an ongoing multicenter prospective cohort study of pulmonary complications in pediatric and young adults post-HSCT. Home spirometry was studied at three sites in eligible participants, defined as those with the ability to do acceptable and repeatable, or at least consistently usable, spirometry by American Thoracic Society standards in the clinical pulmonary function laboratory. Patients were initiated on Day 100 post-HSCT and actively monitored for 6 months. Home spirometry data was compared to office spirometry. Only results that were done within 30 days of each other were used for analysis. Linear regression analysis and Bland-Altman plots were used for analysis. Results There were 1415 home spirometry measurements from 27 patients. Thirty-five paired home-office spirometry measurements were available for analysis. Race neutral z-scores were calculated for FEV1, FVC, and FEV1/FVC. Coefficient values for FEV1, FVC, and FEV/FVC were 0.101, 0.145, and 0.298. Only FEV1/FVC had a p value < 0.05. For all indices office and home spirometry values were comparable when values were within normal z-score ranges but were different at abnormal z-score ranges. Bland-Altman plot data showed similar results with no significant difference in values and means when values were between normal z-scores. Conclusion When comparing home spirometry to office spirometry in our cohort of subjects post-HSCT, results were comparable only for values that were within normal z-scores ranges. Differences between home and office spirometry outside of normal z-scores may be a result of severity of lung disease affecting subject effort or changes in home spirometry device performance at different severities of lung disease. Abnormal home spirometry measurements may be helpful to identify subjects that need to have office spirometry performed to verify accuracy of home spirometry results and whether medical intervention is needed. This abstract is funded by: NIH