Study design and patients
This was a prospective observational cohort study conducted from 20 July 2020 to 27 August 2020. A total of 101 confirmed COVID-19 cases by SARS-CoV-2 real-time polymerase chain reaction (PCR) from nasopharyngeal swabs were enrolled (53 non-hospitalized and 48 hospitalized cases). Inclusion criteria were: patients aged 13 years or older, both genders, confirmed mild COVID-19 infection in the non-hospitalized group, and confirmed moderate infection in patients hospitalized at the Royal Hospital (RH). Hospitalized patients were recruited within 48 hours of admission. Patients admitted directly to the ICU at the time of enrolment were excluded from the study. Mild cases were those who did not require admission to the hospital due to COVID-19 related illness or oxygen therapy. In contrast, moderate cases were identified as patients with hypoxemia </= 94% requiring oxygen support or those with one or more COVID-19 related organ involvement.
A specified clinical team was assigned to collect data and blood samples from the inpatients. Outpatients were approached through a daily list of confirmed COVID-19 patients provided by the Center of Operation Management for COVID-19 at the Ministry of Health, Oman. Telephonic calls were conducted to get patients’ consent to participate in the study after an explanation of the research idea. Patients in the community were visited by two designated researchers the next day. One nominated researcher-maintained communication to ensure the adherence of participants. Patients’ demographics and clinical characteristics were obtained from non-hospitalized patients directly or for hospitalized ones through electronic hospital records using a unified data collection form. Informed consent was obtained from all enrolled patients.