StEroids in hospitaLized patiEnts With Covid-19 in The Netherlands.

Rationale: In patients with COVID-19 admitted to the hospital, large heterogeneity exists in patients, timing and dosing of steroid therapy. It is unclear how to treat patients who fail dexamethasone therapy. High-dose steroids are prescribed mainly in patients with the most severe disease, which may be too late given the potential escalation of pathophysiological pathways in these patients. Objectives: The main objective is to determine the most optimal form, timing and dosing of steroid therapy to reduce the morbidity and mortality of patients admitted to the hospital for COVID-19. This objective will be addressed in 4 work packages (WP): * WP-1A-ward admission: What is the effect of higher dose steroids upon hospital admission on clinical deterioration and what would be the optimal timing of increasing steroid dosage? * WP1B-ward late: Do high-dose steroids, compared to no steroids, improve outcomes in dexamethasone-unresponsive COVID-19 patients on the ward after dexamethasone 6 mg/day for 10 days? * WP2-ICU admission: Do high-dose steroids, compared to 6 mg/day dexamethasone or its equivalent, improve outcomes in patients admitted to the ICU with moderate/severe C-ARDS? * WP3-ICU late: Do high-dose steroids, compared to no steroids, improve outcomes in ICU patients with moderate/severe C-ARDS after dexamethasone 6 mg/day for 10 days? * WP4-biobank: Can biomarkers help predict outcomes after (high dosed) steroid therapy? Study design: Retrospective observational multicenter study in the Netherlands. Study population: Adult patients (≥ 18 years) hospitalized with COVID-19 will be included, more specifically: Intervention (if applicable): Not applicable (retrospective study design). Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Given the retrospective nature of the study, no burden, risks or benefits for the patient are associated with participation. The target population of this study is specific to h