Using the diagnostic model based on routine laboratory tests to distinguish patients infected with SARS-CoV-2 from those infected with influenza virus

Abstract Background The differential diagnosis between novel coronavirus pneumonia patients (NCPP) and influenza patients (IP) remains a challenge in clinical practice. Methods Between January 2018 and March 2020, 1027 NCPP and 1140 IP were recruited from Tongji hospital. Blood routine examination, biochemical indicators, and coagulation function analysis were performed in all participants simultaneously. Results There was no sex predominance in NCPP. The NCPP were frequently encountered in the sixth and seventh decades of life. The mean age of NCPP (56 ± 16 years) was higher than IP (47 ± 17 years), but without statistical difference. Although most results of routine laboratory tests between NCPP and IP had no significant difference, some laboratory tests showed an obvious change in NCPP. We observed that NCPP had significantly decreased white blood cells, alkaline phosphatase, and d-dimer, compared with IP. However, the results of lactate dehydrogenase, erythrocyte sedimentation rate and fibrinogen were significantly increased in NCPP compared with those in IP. The diagnostic model based on combination of eighteen routine laboratory indicators showed an area under the curve of 0.796 (95% CI, 0.777 to 0.814), with a sensitivity of 46.93% and a specificity of 90.09% when using a cutoff value of 0.598. Conclusions Some routine laboratory results had statistical difference between NCPP and IP. A diagnostic model based on combination of routine laboratory results provides an adjunct approach in the differential diagnosis between NCPP and IP.