Changes in pulmonary function and patient-reported outcomes during COVID-19 recovery: a longitudinal, prospective...

The aim of this study was to compare respiratory and patient-reported outcome measures (PROMs) between 3 and 6 months after symptom onset and to identify features that predict these changes.

This was a consecutive prospective cohort of 73 patients who were hospitalised with coronavirus disease 2019 (COVID-19). We evaluated the changes in pulmonary function tests and PROMs between 3 and 6 months and then investigated the associations between outcomes (change in diffusing capacity of the lung for carbon monoxide (D _LCO), dyspnoea and quality of life (QoL)) and clinical and radiological features.

There was improvement in forced vital capacity, total lung capacity and D _LCO between 3 and 6 months by 3.25%, 3.82% and 5.69%, respectively; however, there was no difference in PROMs. Reticulation and total computed tomography (CT) scores were associated with lower D _LCO % predicted at 6 months (coefficients; -8.7 and -5.3, respectively). The association between radiological scores and D _LCO were modified by time, with the degree of association between ground glass and D _LCO having decreased markedly over time. There was no association between other predictors and change in dyspnoea or QoL over time.

There is improvement in pulmonary function measurements between 3 and 6 months after COVID-19 symptom onset; however, PROMs did not improve. A higher reticulation and total CT score are negatively associated with D _LCO, but this association is attenuated over time. Lastly, there is a considerable proportion of patients with unexplained dyspnoea at 6 months, motivating further research to identify the underlying mechanisms.