Cross-sectional case-control studies (Blue)
The aim of this prospective cohort study was to analyse the incidence of post-acute COVID-19 syndrome (PCS) and its components, and to evaluate risk factors during the acute infection phase.
Adult patients who had recovered from COVID-19 (27th February to 29th April 2020) confirmed by PCR or subsequent seroconversion, who had had a systematic assessment 10-14 weeks after disease onset were included. PCS was defined as the persistence of at least one clinically relevant symptom, or abnormalities in spirometry or chest radiology. Outcome predictors were analysed by multiple logistic regression reporting OR and 95%CI. Two hundred seventy seven patients recovered from mild (34.3%) or severe (65.7%) forms of SARS-CoV-2 infection were evaluated 77 days (IQR 72-85) after disease onset. PCS was detected in 141 patients (50.9%; 95%CI 45.0-56.7%). Symptoms were mostly mild. Alterations in spirometry were noted in 25/269 (9.3%), and in radiographs in 51/277 (18.9%). No baseline clinical features behaved as independent predictors of PCS development.
The authors concluded that a post-acute COVID-19 syndrome was detected in half of COVID-19 survivors. Radiological and spirometric changes were mild and observed in less than 25% of patients. No baseline clinical features behaved as independent predictors of the development of post-acute COVID-19 syndrome.