Study Design, Setting, and Participants

The current multicenter, prospective, observational clinical trial was conducted in three hospitals (Koç University Hospital [KUH], Koç Healthcare American Hospital [KHAH], and Marmara University Hospital [MUH]) in Istanbul, Turkey. All participants were referred to the hospitals between March 10 and June 22, 2020 (KUH and KHAH) and between April 17 and June 21, 2020 (MUH) (Figure 1). Inclusion into the study started on April 16, 2020. Inclusion criteria were as follows: 1) being an adult with a diagnosis of COVID-19, 2) having the ability to read and speak, and 3) signed informed consent. Demographic data, comorbidities, clinical symptoms, laboratory and radiological findings, treatment, and outcomes were prospectively collected from the electronic health records per June 26, 2020. The participants answered to the BQ (see below), which was administered in the outpatient clinic, in hospital, or shortly after the hospital discharge between April 21 and July 7, 2020, blinded to the clinical outcomes. The clinical, laboratory, and radiological investigations are planned to be repeated, and polysomnographic, echocardiographic, and lung function evaluations will be performed within 12 months after the initial COVID-19 onset.

Flow of patients through the study. COVID-19 = coronavirus disease; ICU = intensive care unit.

The Koç University Committee on Human Research approved the study protocol (approval nr 2020.140.IRB1.030; 04.15.2020), and written informed consent was provided from all participants. The trial was registered with ClinicalTrials.gov.