Clinical utility and risk of death according to age-adjusted D-dimer in patients with Covid-19

Abstract

OBJECTIVE: To determine the clinical utility and the risk of death associated with age-adjusted D-
dimer in patients with COVID-19 at hospitalization. MATERIAL: The electronic records of 1026
patients >18 years of age with a confirmed diagnosis of COVID-19 (RT-PCR, positive) and D-dimer, at
hospitalization at the Guillermo Almenara Irigoyen National Hospital (HNGAI-2020). METHODS: This
was an observational, retrospective, and analytical study. The risk of death associated with
conventional and age-adjusted D-dimer was estimated. The IBM SPSS statistical software, version 25,
was used. RESULTS: Mean D-dimer: 2.1 µg/ml (SD 1.6 µg/ml). The age-adjusted cutoff affected 3.3%
(34/1026 patients), all >60 years old and with D-dimer >0.5–1.0 µg/ml, with no change in patients with
D-dimer >1.0 µg/ml. The risk of death associated with D-dimer >1.0 µg/ml according to the
conventional cutoff was OR: 3.47 (CI: 2.28–5.26) and according to the age-adjusted cutoff: OR: 2.48
(CI: 1.73–3.55). CONCLUSIONS: Age-adjusted D-dimer is clinically useful for determining a more
precise cutoff in patients >50 years old. A D-dimer >1.0 µg/ml was significantly associated with the risk
of death at hospitalization for COVID-19, both in the conventional estimate and in the age-adjusted
estimate. However, an independent association cannot be established, or causality inferred, due to a
lack of multivariate analysis.
KEYWORDS: Covid-19, D-dimer, Mortality, Coronavirus.