key: cord-0876160-7tdd0t0e
authors: Li, Chenghong; Hu, Bingzhu; Zhang, Zhu; Qin, Wei; Zhu, Ziyang; Zhai, Zhenguo; Davidson, Bruce L; Wang, Chen
title: D‐dimer triage for COVID‐19
date: 2020-06-07
journal: Acad Emerg Med
DOI: 10.1111/acem.14037
sha: cab62418dddf66768cbb293c60dc564974e7fd08
doc_id: 876160
cord_uid: 7tdd0t0e

Coagulopathy and elevated D‐dimer levels were recognized as prognostic factors early in Wuhan, China as accompanying more severe COVID‐19 patient cases. We sought to determine the accuracy of normal vs elevated D‐dimer blood levels at presentation, day 1, and on day 3 for predicting 28‐day survival in a large cohort of consecutive PCR‐proven COVID‐19 patients, to help with patient triage, reassurance, and follow‐up management.

 The authors each report no potential or actual conflict of interest.

C.L., Z.G.Z., B.D. and C.W. had the idea for and designed the study and had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. C.L., Z.Z., W.Q,. B.D. and Z.G.Z. drafted the paper. C.L., Z.Z., B.H., Z.G.Z., C.W. and B.D. did the analysis, and all authors critically reviewed for important intellectual content and gave final approval for the version to be published. C.L., B.H., W.Q., Z.Y.Z. collected data.

This article is protected by copyright. All rights reserved Coagulopathy and elevated D-dimer levels were recognized as prognostic factors early in Wuhan, China as accompanying more severe COVID-19 patient cases. We sought to determine the accuracy of normal vs elevated D-dimer blood levels at presentation, day 1, and on day 3 for predicting 28-day survival in a large cohort of consecutive PCR-proven COVID-19 patients, to help with patient triage, reassurance, and follow-up management. This is an observational study of a cohort of consecutive patients presenting to Affiliated Hospital of Jianghan University, Wuhan, from January 10 through February 28, 2020. Before data collection, we Clinicians delivered care appropriate to the level of illness, including intensive care, assisted ventilation, and circulatory and other support such as hemodialysis. The primary outcome was 28-day survival.

Of 761 PCR-confirmed COVID-19 patients admitted, 749 had presenting day 1 D-dimer levels available.

The 28-day mortality was 78 in the 749-patient cohort, 10.4% (95% CI, 8.3-12.8%). D-dimer levels at day 1 were normal in 586 of 671 survivors but elevated in 36 of 78 non-survivors, for a survival sensitivity of 87% (95% CI, 86-89%), positive predictive value 93% (95% CI, 92-95%), specificity 46% (95% CI, 36-57%), negative predictive value 30% (95% CI, 23-36%). Figure 1 shows 28-day survival for normal vs elevated D-dimer values in this population.

Day 3 D-dimer values, available for 598 cohort patients (80%), were normal in 408 28-day survivors and 10 who died. They were elevated in 130 28-day survivors and 50 who died. Thus, a normal value was strongly associated with survival: sensitivity 76% (95% CI, 75-77%), positive predictive value 98% (95% CI, 96-99%), specificity 83% (95% CI, 72-91%), negative predictive value 28% (95% CI, 24-30%).

Survival odds with a normal day 1 D-dimer were 5.9 (95% CI, 3.6-9.7%); for a normal day 3 D-dimer, Accepted Article survival odds were 15.6 (95% CI, 7.7-31.8%).

Association of coagulopathy with COVID-19 is now widely reported (1, 2) . In the United States and elsewhere, rapid results of PCR coronavirus testing are not widely available and a positive swab result does not inform prognosis. In this cohort of 100% COVID-19 patients, a day 1 and particularly a day 3 normal D-dimer had high precision for predicting 28-day survival. Similar to how D-dimer is used to assist diagnosis of deep vein thrombosis and pulmonary embolism, a normal result supports the decision to triage a patient to watchful waiting as opposed to hospital admission. For symptomatic COVID-19 suspects awaiting swab results but ill enough to require hospitalization, elevated D-dimer levels could be presumptively diagnosed as COVID-19 and triaged as higher risk, Those with normal D-dimer level and without another reason for hospitalization could be managed expectantly as outpatients with reassurance and appointment for follow-up day 3 D-dimer level, while other etiologies were also considered.

Evaluation of subjective outpatient deterioration could be assisted by an on-site, real-time, commercially available point-of-care D-dimer determination. While qualitative bedside tests may be somewhat less accurate than quantitative ones(3), real-time D-dimer testing can even be performed in the field and has been reported to be helpful in expediting emergency department evaluation of pulmonary embolism (4, 5) .

We speculate that field D-dimer testing may be similarly useful to make prehospital decisions about transport of patients with suspected COVID-19.

Our results differ from previous reports (6, 7) . Because D-dimer assays have different upper limits of normal and a multiple of some level from one assay is not necessarily proportional to that of another(6), we used the upper limit of normal as the cut-off to allow generalization as universally as possible. We assess D-dimer in the largest number yet of COVID-19 PCR-confirmed consecutive cohort patients yet prospectively reported, rather than selecting patients. We include day 3 data, available for 80% of our cohort. These advantages allow tighter precision of the survival positive predictive value and other accuracy values, reduce possible selection bias, and allow insight for day 3 follow-up with interpretation of those D-dimer level results.

A normal D-dimer on presentation is highly predictive of survival, a day 3 normal value even more so.

This readily available information can help guide physicians with triage and follow-up, reassure patients, and help to bring confidence to identifying those patients warrant closest surveillance.

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Excluding venous thromboembolism using point of care D-dimer tests in outpatients: a diagnostic meta-analysis

Implementation of a rapid whole blood D-dimer test in the emergency department of an urban academic medical center: impact on ED length of stay and ancillary test utilization

Qualitative point-of-care D-dimer testing compared with quantitative D-dimer testing in excluding pulmonary embolism in primary care

D-dimer levels on admission to predict in-hospital mortality in patients with COVID-19

Clinical course and risk factors for mortality of adult inpatients with

This article is protected by copyright. All rights reserved