Frequency of thromboprophylaxis and incidence of in-hospital venous thromboembolism in a cohort of emergency department patients.

OBJECTIVE

Prior work suggests that in-hospital pulmonary and venous thromboembolism (VTE) could be decreased if the rate of prophylaxis for VTE in high-risk patients were increased at the time of admission. Our objective was to quantify the rate of thromboprophylaxis and incidence of in-hospital VTE, based upon risk of VTE, in a cohort of patients admitted through the emergency department (ED).

METHODS

We performed a prospective cohort study at an urban ED with >100,000 visits. All medical patients >17 years admitted from the ED were prospectively identified on a random sample of days for one year. Using a structured data form we collected each patient's risk factors for VTE, and prophylaxis measures. We computed a validated risk score of each patient, with a score >or=4 high-risk (HR) and a score <4 low risk (LR). The main outcome was VTE during the hospitalization, diagnosed after admission from ED.

RESULTS

Of 4732 patients, VTE was diagnosed during hospitalization in 44 (0.9%). 437 (9%) patients were HR for VTE and HR patients had significantly higher frequency of VTE vs. LR patients, 1.8 vs. 0.8% (95% CI for difference of 1% = 0.1-3%). Only 36% of HR patients received thromboprophylaxis. There were no significant differences in the frequency of observed inpatient VTE events between patients who were prescribed prophylaxis compared with those who were not prescribed prophylaxis in either risk group.

CONCLUSION

These data suggest only a modest opportunity for ED-based policy for thromboprophylaxis in admitted medical patients.