In this study, the investigator examined epidemiological and demographic characteristics, risk factors and 28-day mortality of patients admitted to the intensive care unit with the diagnosis of coronavirus disease 2019 pneumonia.

The patients with intensive care requirements were admitted from emergency department and coronavirus disease 2019 wards to our units. The criteria for intensive care requirement was identified as oxygen saturation<90%, partial oxygen pressure<70 mmHg, respiratory rate> 30/min or PaO2/FiO2(partial oxygen pressure/fraction of inspired oxygen) <300 despite conventional oxygen treatment of 5lt/min. Primary objective was the effect of defined data on 28-day mortality, and secondary objective was the impact of lymphocyte count, lactate dehydrogenase, ferritin, D-dimer and procalcitonin levels, and SOFA(Sequential Organ Failure Assessment) score on prognosis, which are among the risk factors determined by previous studies. All data were evaluated and recorded using the standardized International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) case report forms, complemented by electronic records of the hospital, nurse observation records, and missing information was completed by telephone interviews with patients' relatives.

Inclusion Criteria:

• The study was planned retrospectively, cross-sectionally and observationally with 193 patients hospitalized between 16 March 2020 and 15 May 2020 in five different coronavirus disease 2019 intensive care units in two campuses of our hospital.

Exclusion Criteria:

• Health workers, patients hospitalized less than 24 hours, patients with negative polymerase chain reaction tests, and patients who returned to intensive care unit after discharge were excluded from the study.

The study was planned retrospectively, cross-sectionally and observationally with 193 patients hospitalized between 16 March 2020 and 15 May 2020 in five different coronavirus disease 2019 intensive care units in two campuses of our hospital.