Simple classification of COVID-19 patients

The research that has been reported in the literature compares patients as follows: (a) nonsevere/ severe; (b) non-intensive care unit (ICU)/ICU; (c) improvement/progression; (d) general/refractory; (e) common type/severe; (f) noninvasive mechanical ventilation (IMV)/ IMV; (g) good/poor outcomes; and (h) survivors/non-survivors. Although classifications are recommended based on radiological imaging, also clinical classification is urgently needed.5 Therefore, a uniform stratification of COVID-19 patients is necessary to standardize the future research studies and to enable meta-analyses that can more appropriately evaluate the data.