Predictors for Long COVID and Differences in Long COVID Symptoms, Findings on Chest Imaging and Pulmonary Function between Hospitalized COVID-19 Patients with versus without Intensive Care Unit Admission

Abstract

<b><i>Introduction:</i></b> Many COVID-19 survivors suffer from persisting sequelae after acute disease. This is referred to as long COVID. The objectives of this study were to assess factors associated with long COVID and to analyze differences in persistent symptoms, findings on chest imaging, and pulmonary function between intensive care unit (ICU) and non-ICU hospitalized patients. <b><i>Methods:</i></b> We conducted a retrospective study including patients hospitalized with COVID-19. Patients were stratified into ICU patients and non-ICU patients. We analyzed the outcomes of patients who were in clinical follow-up 6 months after discharge with persistent symptoms, radiological and/or functional abnormalities. Logistic regression was used to examine the association between long COVID and patient characteristics. <b><i>Results:</i></b> A total of 549 patients were included. Eighty-one ICU patients (66%) and 146 (34%) non-ICU patients had persistent symptoms or abnormalities on chest imaging or lung function test minimally 6 months after discharge. Significantly more ICU patients had residual fibrotic abnormalities on chest CT and functional impairment. Female gender, myocardial infarction, OSAS, low PCO₂ at admission, and longer hospital stay were associated with a higher risk of developing long COVID. Diabetes and treatment with tocilizumab were associated with a lower risk of developing long COVID. <b><i>Conclusion:</i></b> Of the patients hospitalized for COVID-19, 34–66% suffered from persistent symptoms, residual abnormalities on chest imaging, or reduced lung function at around 6 months after discharge. While persistent sequelae were more frequent in ICU patients, admission to the ICU was not found to be an independent risk factor for developing long COVID.