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Longitudinal monitoring of asthma in the clinic using respiratory oscillometry
Author(s) -
Cottee Alice M.,
Seccombe Leigh M.,
Thamrin Cindy,
Badal Tanya,
King Gregory G.,
Peters Matthew J.,
Farah Claude S.
Publication year - 2021
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1111/resp.14053
Subject(s) - medicine , spirometry , concordance , asthma , exhaled nitric oxide , pulmonary function testing , cohort , longitudinal study , physical therapy , cardiology , pathology
Background and objective Asthma guidelines emphasize the importance of assessing lung function and symptoms. The forced oscillation technique (FOT) and its longitudinal relationship with spirometry and symptoms are unresolved. We examined concordance between longitudinal spirometry, FOT and symptom control, and determined FOT limits of agreement in stable asthma. Methods Over a 3‐year period, adults with asthma attending a tertiary clinic completed the asthma control test (ACT), fraction of exhaled nitric oxide (FeNO), FOT and spirometry. Analysis included between‐visit concordance for significant change using Cohen's kappa ( κ ) and stable asthma FOT limits of agreement. Results Data ( n = 186) from 855 visits (mean ± SD 4.6 ± 3.0 visits), 114 ± 95 days apart, were analysed. Between‐visit concordance was moderate between reactance at 5 Hz ( X 5) and forced expiratory volume in 1 s (FEV 1 ) ( κ = 0.34, p = 0.001), and weak between ACT and FEV 1 ( κ = 0.18, p = 0.001). Change in FeNO did not correlate with lung function or ACT ( κ < 0.05, p > 0.1). Stable asthma between visits ( n = 75; 132 visits) had reduced lung function variability, but comparable concordance to the entire cohort. Limits of agreement for FEV 1 (0.42 L), resistance at 5 Hz (2.06 cm H 2 O s L −1 ) and X 5 (2.75 cm H 2 O s L −1 ) in stable asthma were at least twofold greater than published values in health. Conclusion In adults with asthma, there is moderate concordance between longitudinal change in FOT and spirometry. Both tests relate poorly to changes in asthma control, highlighting the need for multi‐modal assessment in asthma rather than symptoms alone. The derivation of longitudinal FOT limits of agreement will assist in its clinical interpretation.