COVID-19, Coronavirus, Cytokine release syndrome, Tocilizumab, Adult, Aged, Aged, 80 and over, Antibodies, Monoclonal, Humanized, COVID-19, Cohort Studies, Female, Hospitalization, Humans, Male, Middle Aged, Receptors, Interleukin-6, Respiratory Insufficiency, Retrospective Studies, SARS-CoV-2, Treatment Outcome, COVID-19 Drug Treatment