Guan WJ, Liang WH, Zhao Y, et al. - Given the worldwide rapid evaluation of the coronavirus disease 2019 (COVID-19) outbreak, the risk of serious adverse outcomes was examined in patients with coronavirus disease 2019 (COVID-19) by stratifying the comorbidity status. From 575 hospitals in 31 province/autonomous regions/provincial municipalities across mainland China, 1,590 laboratory-confirmed hospitalized patients between December 11, 2019 and January 31, 2020 provided data for this work. The composite endpoints consisting of admission to intensive care unit, or invasive ventilation, or death were analyzed.  The study population had 16.0% severe cases. At least one comorbidity was evident in 399 (25.1%) cases. Hypertension (16.9%) was the most prevalent comorbidity, followed by diabetes (8.2%). Two or more comorbidities were reported in 130 (8.2%) patients. Observations revealed poorer clinical outcomes in patients with any comorbidity, vs those without, among laboratory-confirmed cases of COVID-19. Poorer clinical outcomes were also reported in correlation with a greater number of comorbidities.