OBJECTIVES: Persistent symptoms on short-term follow-up after infection with COVID-19 are common, but long-term consequences have been insufficiently studied. The aim of this study was to characterize pulmonary function and ongoing symptoms 12 months after hospitalization with COVID-19.

METHODS: This prospective multicenter study included 222 patients hospitalized with PCR-confirmed COVID-19 in the Central Denmark Region. Disease severity was stratified using WHO Clinical Progression Scale. Clinical characteristics, pulmonary function test (PFT), 6-minute walk test (6MWT), and patient-reported outcome measures were collected at follow-up 3 and 12 months after discharge. Outcome measures from follow-up 3 months after discharge have previously been published.

RESULTS: A total of 179 (81%) patients completed the 12-month follow-up. Median age was 60 years (IQR 51, 69) and 58% were male patients. At 12-month follow-up 49.7% had a normal diffusion capacity for carbon monoxide (DLCO), while 39.4% had DLCO < 80%. The 6MWT distance increased significantly (29 m 95% CI 19, 40; p < 0.01). An mMRC score of 0 was reported by 51% and an mMRC ≥ 2 by 20%. The frequency and severity of fatigue, depression, and anxiety did not improve over time.

CONCLUSIONS: The study found that impaired DLCO percentage is common 12 months after hospitalization with SARS-CoV-2 and reduction in DLCO percentage is associated to dyspnea.