Optimal Timing
OR = 1.00 (reference)
OR at 24h
OR at 48h
Risk Cluster
Purpose
This is a research tool for exploring optimal anticoagulation timing in patients with traumatic brain injury (TBI). It models the optimal timing for VTE prophylaxis initiation to minimize mortality from bleeding or thrombotic events after TBI.
This tool is for research purposes only and should not be used to guide clinical decision-making.
Authors
Methodology
Data Source
This tool uses data from the National Trauma Data Bank (NTDB) , the largest trauma registry in the United States. The NTDB collects data from over 900 trauma centers nationwide, providing comprehensive information on patient demographics, injury characteristics, treatments, and outcomes.
Selection Criteria
- ICU patients with traumatic brain injury (TBI diagnosed via AIS coding)
- 30-day mortality as the primary outcome
- Patients censored at 30 days post-injury
Statistical Approach
- Inverse Probability of Treatment Weighting (IPTW) - to account for confounding by indication
- Marginal Structural Model (MSM) - to estimate causal effects of treatment timing
- B-spline timing curves (df=3) - to flexibly model the relationship between initiation time and outcome
- Effect modification - timing effects vary by patient GCS and age (not ISS)
Patient Clustering
K-means clustering (k=3) based on GCS, Age, ISS, and bleeding history variables (prior anticoagulation, cirrhosis, stroke, bleeding disorder) to identify risk groups with similar baseline characteristics.