Quality of home spirometry performance amongst adults with cystic fibrosis

Bell, J.; Sivam, S.; Dentice, R.; Dwyer, T.; Jo, H.; Lau, E.; Lee, W. Y.; Munoz, P.; Shah, K.; Taylor, N.; Visser, S.; Yozghatlian, V.; Wong, K.

Objectives: Spirometry is usually performed under the supervision of a trained respiratory scientist to ensure acceptability and repeatability of results as outlined by the 2019 American Thoracic Society and European Respiratory Society Statement. With increased telehealth consultations during the COVID-19 pandemic, remote monitoring of lung function is encouraged at cystic fibrosis (CF) centres. We aimed to evaluate the quality of spirometry performance by adult CF patients with and without observation by a trained respiratory scientist. Methods: A cross-sectional study was conducted between February-September 2020. 74 adults from the Royal Prince Alfred Hospital Adult CF clinic were recruited and instructed to perform spirometry without supervision within 24 hours of their remote CF clinic consultation. Spirometry was repeated at their consultation, supervised by a respiratory scientist using video conferencing. The same portable spirometer was used during both encounters. Spirometry grade was recorded from their portable devices and severity of obstruction (mild: FEV1 >80%, moderate: FEV1 50–80%, severe: FEV1 <50%) was obtained from their supervised encounter. Results: 15, 30 and 29 participants with mild, moderate and severe obstruction respectively participated in the study (total n = 74, mean age 37 ± 11 years, 50% female). The majority of patients achieved ATS/ERS grade A (excellent) or B (very good) spirometry quality with (95%) and without supervision (91%) independent of lung function severity or age. Participants with poorer grades (C-F) either experienced technical difficulties with their devices or failed to perform a sufficient number of manoeuvres. No patients required carer assistance to perform spirometry remotely. Conclusion: For a large proportion of adult CF patients, unsupervised portable spirometry produces acceptable and repeatable results. Ongoing monitoring for technical difficulties may be needed.