Characterization of Confirmed and Suspected COVID-19 Pneumonia Patients in a Retrospective Cohort Study in Wuhan

Abstract Background: A methodical comparison of confirmed and suspected COVID-19 patients has not been previously reported. Therefore, we thoroughly analyzed the demographic and clinical characteristics between these groups to identify mortality risk factors.Methods: A retrospective cohort of 1,276 hospitalized COVID-19 pneumonia patients at Tongren Hospital (Wuhan, China; January 27 to March 3, 2020) was studied. Cox regression analyses were performed to evaluate multiple mortality risk factors. Results: Both cohorts of confirmed (n=797) and suspected (n=479) patients exhibited typical demographic, clinical, and radiological characteristics. Treatment methods were consistent and both groups shared similarities in many demographic and clinical characteristics: age (≥65, 45.9% vs 41.8%, P=0.378) and lung disease (12.5% vs 14.6%, P=0.293). However, confirmed patients exhibited more severe disease manifestations than those in suspected patients: a higher incidence of fever (65.4% vs 58.0%, P<0.01), lower lymphocyte count (1.12×109/L vs 1.22×109/L, P=0.022), higher C-reactive protein (CRP) (11.60 mg/L vs 7.61mg/L, P=0.021), and more severe radiographic manifestations (lung infection incidence, 3.8% vs 3.0%, P=0.014; ground-glass opacity lesion incidence, 2.3% vs 2.0%, P=0.033). The dynamic profiles of lymphocytes, monocytes, D-dimer, and CRP, clearly delineated confirmed patients from suspected patients exhibiting critical illness. Cox regression analysis demonstrated that lung disease (adjusted hazard ratio 8.972, 95% CI: 3.782-21.283), cardiovascular disease (3.083, 1.347-7.059), neutrophil count (1.189, 1.081-1.307), age (1.068, 1.027-1.110), and ground-glass opacity lesions (1.039, 95% 1.013-1.065), were the main risk factors for mortality in confirmed patients; lung disease (14.725, 2.187-99.147), age (1.076, 1.004-1.153), and CRP level (1.012, 95% CI 1.004-1.020) were the primary factors in suspected patients.Conclusions: Suspected patients with serious illness should seek medical attention to reduce mortality. Multiple factors must be assessed to determine the mortality risk and the appropriate treatment.