ABSTRACT
It is not clear whether D-dimer can be an independent predictor of coronavirus disease 2019 (COVID-19) mortality, and the cut-off of D-dimer for clinical use remains to be determined. Therefore, a comprehensive analysis is still necessary to illuminate the clinical significance of plasma D-dimer in COVID-19 mortality. We searched PubMed, Embase, Cochrane Library, and Scopus databases until November 2020. STATA software was used for all the statistical analyses. The identifier of systematic review registration was PROSPERO CRD42020220927. A total of 66 studies involving 40,614 COVID-19 patients were included in our meta-analysis. Pooled data showed that patients in high D-dimer group had poor prognosis than those in low D-dimer group [OR = 4.52, 95% CI = (3.61, 5.67), P < 0.001; HR = 2.81, 95% CI = (1.85, 4.27), P < 0.001]. Sensitivity analysis, pooled data based on different effect models and the Duval and Tweedie trim-and-fill method did not change the conclusions. Subgroup analyses stratified by different countries, cutoffs, sample size, study design, and analysis of OR/HR still keep consistent conclusions. D-dimer was identified as an independent predictor for COVID-19 mortality. A series of values including 0.5 µg/ml, 1 µg/ml, and 2 µg/ml could be determined as cutoff of D-dimer for clinic use. Measurement and monitoring of D-dimer might assist clinicians to take immediate medical actions and predict the prognosis of COVID-19.
ABSTRACT
INTRODUCTION: The ongoing worldwide pandemic of coronavirus disease 2019 (COVID19) has posed a huge threat to global public health. However, the issue as to whether routine blood tests could be used to monitor and predict the severity and prognosis of COVID19 has not been comprehensively investigated so far. OBJECTIVES: This study aimed to provide an overview of the association of markers in the routine blood test with the severity of COVID19. METHODS: PubMed, Embase, Cochrane Library, Wanfang, and China National Knowledge Infrastructure (CNKI) databases were searched to identify studies reporting data on markers in the routine blood test and the severity of COVID19, published until March 20, 2020. The STATA software was used for metaanalysis. RESULTS: A total of 15 studies with 3090 patients with COVID19 were included in this analysis. Patients in the nonsevere group, compared with those in the severe group, had lower counts of white blood cells (weighted mean difference [WMD], -0.85 [×109/l]; 95% CI, -1.54 to -0.16; P = 0.02) and neutrophils (WMD, -1.57 [×109/l]; 95% CI, -2.6 to -0.54; P = 0.003), greater counts of lymphocytes (WMD, 0.29 [×109/l]; 95% CI, 0.22-0.36; P <0.001) and platelets (WMD, 19.05 [×109/l]; 95% CI, 3.04-35.06; P = 0.02), and a lower neutrophiltolymphocyte (NLR) ratio (WMD, -2.48; 95% CI, -3.81 to -1.15; P <0.001). There was no difference in the monocyte count (WMD, 0.01 [×109/l]; 95% CI, -0.01 to 0.03; P = 0.029) between these 2 groups. Sensitivity analysis and metaanalysis based on standard mean difference did not change the conclusions regarding neutrophils, lymphocytes, and NLR, but yielded inconsistent results for white blood cells and platelets. CONCLUSIONS: Severe patients had more neutrophils, higher NLR level, and fewer lymphocytes than non-severe patients with COVID-19. Measurement of these markers might assist clinicians to monitor and predict the severity and prognosis of COVID-19.