The effect of preinjury anticoagulation on mortality in trauma patients: A systematic review and meta-analysis.

Objectives: To assess the effect of preinjury anticoagulation on mortality in trauma patients.

Methods: A search of electronic information sources was conducted to identify all observational studies comparing preinjury anticoagulation with no preinjury anticoagulation in trauma patients. The primary outcome measure was overall mortality (overall mortality, in-hospital mortality and 30-day mortality). The secondary outcome measures included the length of hospital stay, length of intensive care unit (ICU) stay, incidence of intracranial haemorrhage (ICH), and need for operation. Fixed effect or random effects modelling was applied as appropriate to calculate pooled outcome data.

Results: Nineteen comparative studies enrolling a total of 1,365,446 patients were included. Preinjury anticoagulation was associated with higher risk of overall mortality (OR 2.12, 95%CI 1.79 - 2.51, p < 0.00001), in-hospital mortality (OR 2.04, 95%CI 1.66 - 2.52, p < 0.00001), ICH (OD 1.99, 95%CI 1.61 - 2.45, p < 0.00001), and shorter length of hospital stay (MD 0.50, 95%CI 0.03 - 0.97, p = 0.04) in comparison to no preinjury anticoagulation. We found no difference between the two groups in 30-day mortality (OR 1.61, 95%CI 0.91 - 2.85, p = 0.10), length of ICU stay (MD 0.62, 95%CI -0.13 - 1.36, p = 0.11), and need for operation (OR 1.73, 95%CI 0.71 - 4.20, p = 0.23). The quality of the available evidence was moderate.

Conclusion: Preinjury anticoagulation is a significant predictor of mortality in trauma patients. Future studies should focus on strategies required to reduce such a significant risk of mortality in these high-risk patients. This may include adaptation of primary, secondary and tertiary trauma surveys for patients on preinjury anticoagulation.