RELIABILITY AND VALIDITY OF SPIROMETRY MEASUREMENTS IN A PAPERLESS HOME MONITORING DIARY PROGRAM FOR LUNG TRANSPLANTATION

Objective: To demonstrate that home spirometry measurements are reliab le and valid and can be used as part of a home measurement monitoring system by lung transplant recipients. Design: Longitudinal, observatio nal. Setting: University medical center. Subjects: Eighteen patients w ho have undergone lung transplantation; age range was 24 to 63 years ( mean of 49.5 years). Outcome Measures: Reliability and validity of for ced expiratory Volume at 1 second (FEV(1)) and forced vital capacity ( FVC). Intervention: Recording of spirometry. Vital signs, and symptom measures at home each day by use of a paperless electronic diary/spiro meter instrument. Results: Day-to-day variability as measured by the s tandard deviation ranged from 0.013 L to 0.202 L for FVC and 0.015 L t o 0.117 L for FEV(1), The correlation between the two best forced expi ratory maneuvers on any given day was 0.98 for both FVC and FEV(1), wi th percent differences between the measurements of 2% for FVC and 3% f or FEV(1). The correlation between measurements performed in the pulmo nary function laboratory and measurements done by the patient at home on the same day was 0.94 for FVC and 0.99 for FEV(1). Conclusions: Thi s evaluation demonstrated that home measurements are bath reliable (i. e., repeatable) and valid when compared with the ''gold standard'' of the pulmonary function laboratory. The home monitoring program has bee n well accepted by patients, is easy to use, and provides data compara ble to that collected during clinic visits.