Figure 1.

Flow chart with an overview of study steps. Patients were classified into three groups of mild, moderate, and severe disease. Treatment regimen and admission/discharge criteria were according to Iran's national guideline for novel coronavirus infection. The definition of mild, moderate, and severe disease was as below according to the national guideline: Patients with a flu-like syndrome with/without fever, who did not have any signs of infiltration in lung imaging were classified as having mild disease. The moderate group was defined as symptomatic patients with pulmonary infiltration or at least one of the admission criteria, as explained in figure. The severe group constituted patients who have at least one of the following criteria: (1) reduced consciousness; (2) respiratory rate ≥30; (3) blood pressure (BP) BP <90/60; (4) multilobular infiltration; (5) hypoxemia