Higher Admission D-Dimer Values Are Associated With an Increased Risk of Nonroutine Discharge in Neurosurgery Patients

Background D-dimers are serum acute-phase proteins with a role in mediating inflammation that may be used as biomarkers for the prediction of deep vein thrombosis. Recent studies have shown that D-dimers can be used to predict prognosis and stratify risk in neurosurgical patients; however, a comparative analysis across diagnostic subtypes has yet to be performed. Methods A bioinformatics analysis evaluated neurosurgical patients with admission D-dimer levels between 2008 and 2017. Nonroutine disposition (e.g., skilled nursing facility, rehabilitation, other hospital, mortality) was primarily evaluated. Results A total of 1,854 patients (mean age 55.1±18.2 years, 55.4% male; mean admission D-dimer 4.83±7.78 μg/ml) were identified. Patient diagnoses included vascular (27.1%), trauma (16.4%), multiple diagnoses (15.7%), spine (15.6%), tumor (13.0%), and other (12.2%) causes. Univariate analysis showed that older age (p=0.0001), higher American Society of Anesthesiologists (ASA) score (p=0.0001), lower Glasgow Coma Scale (GCS) score (p=0.0001), diagnosis type (p=0.0001), longer length of stay (LOS) (p=0.0001), higher infection rate (p=0.0001), surgery in the past year (p=0.02), and higher D-dimer levels (3.4±4.9 vs. 5.4±8.7 μg/ml, p=0.0001) were associated with nonroutine disposition. Multivariate logistic regression showed that elevated D-dimers were independently associated with a greater relative risk of nonroutine disposition (relative risk [RR] 1.026, 95% CI 1.02-1.033, p=0.0001). Conclusions Elevated admission D-dimer values were independently associated with a 3% increased risk of nonroutine disposition per D-dimer unit after accounting for other factors. These results suggest that D-dimer values may help in stratifying patient risk models despite clinical heterogeneity. Further refinement of neurosurgical patient risk models using clinical variables and biomarkers may aid in resource allocation and early warning.