Relationship of D-dimer with severity and mortality in SARS-CoV-2 patients : A meta-analysis

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic. Many studies have shown that several laboratory parameters are related to disease severity and mortality in SARS-CoV-2 cases. This meta-analysis aimed to determine the relationship of a prognostic factor, D-dimer, with disease severity, need for intensive care unit (ICU) care, and mortality in SARS-CoV-2 patients.

A systematic search for all observational studies and trials involving adult patients with SARS-CoV-2 that had any data related to D-dimer on admission was conducted using PubMed, Science Direct, Scopus, ProQuest, and MedRxiv databases. We performed random-effects inverse-variance weighting analysis using mean difference (MD) of D-dimer values for outcomes such as disease severity, mortality, and need for ICU care.

A total of 29 studies (4,328 patients) were included in this meta-analysis, which revealed a higher mean of D-dimer levels on admission in severe patients than in nonsevere patients (MD = 0.95, [95% confidence interval (CI): 0.61-1.28], P < .05; I²  = 90%). The nonsurvivor group had a higher pooled MD of D-dimer values on admission (MD = 5.54 [95% CI: 3.40-7.67], P < .05; I²  = 90%). Patients who needed ICU admission had insignificantly higher D-dimer values than patients who did not need ICU admission (MD = 0.29, [95% CI: -0.05 to 0.63], P = .10; I²  = 71%).

Elevated D-dimer levels on admission were associated with an increased risk of disease severity and mortality in patients with SARS-CoV-2 infection.