  Temporal inference from laboratory testing results and their triangulation
with clinical outcomes as described in the associated unstructured text from
the providers notes in the Electronic Health Record (EHR) is integral to
advancing precision medicine. Here, we studied 181 COVIDpos and 7,775 COVIDneg
patients subjected to 1.3 million laboratory tests across 194 assays during a
two-month observation period centered around their SARS-CoV-2 PCR testing
dates. We found that compared to COVIDneg at the time of clinical presentation
and diagnostic testing, COVIDpos patients tended to have higher plasma
fibrinogen levels and similarly low platelet counts, with approximately 25% of
patients in both cohorts showing outright thrombocytopenia. However, these
measures show opposite longitudinal trends as the infection evolves, with
declining fibrinogen and increasing platelet counts to levels that are lower
and higher compared to the COVIDneg cohort, respectively. Our EHR augmented
curation efforts suggest a minority of patients develop thromboembolic events
after the PCR testing date, including rare cases with disseminated
intravascular coagulopathy (DIC), with most patients lacking the platelet
reductions typically observed in consumptive coagulopathies. These temporal
trends present, for the first time, fine-grained resolution of COVID-19
associated coagulopathy (CAC), via a digital framework that synthesizes
longitudinal lab measurements with structured medication data and neural
network-powered extraction of outcomes from the unstructured EHR. This study
demonstrates how a precision medicine platform can help contextualize each
patients specific coagulation profile over time, towards the goal of informing
better personalization of thromboprophylaxis regimen.
