Association of deep-vein thrombosis (DVT) with missed doses of prophylactic antithrombotic medications in ICU patients: a case-control study.

BACKGROUND

Medications for prevention of venous thromboembolism (VTE) are routinely prescribed in critically ill patients.

OBJECTIVE

To identify any association between missed doses of VTE prophylaxis medications and acute, in-hospital deep-vein thrombosis (DVT).

METHODS

Case-control study in hospitalized adult patients at high risk for developing VTE, defined as an ICU length of stay (LOS) of at least 24 hours. Cases were defined as patients with acute DVT during hospitalization, and controls were patients with no documented DVT. Multivariate logistic regression was used to assess the odds of acute DVT in patients with any missed dose of prophylactic antithrombotic medication.

RESULTS

Of 920 patients, 59 (6.4%) experienced an acute, in-hospital DVT. Overall, 64% of patients missed at least 1 dose of VTE prophylaxis medication, and 33% missed more than 3 doses. In the univariate analysis, there was no significant association between any missed dose of prophylaxis medication and acute DVT (odds ratio [OR] = 0.96; CI = 0.56-1.7). Multivariate logistic regression modeling confirmed no association between missed doses of pharmacological VTE medications and acute DVT (OR = 0.69 [0.39-1.2]; P = 0.21). Prolonged hospital LOS was associated with increased odds of acute DVT (LOS = 4-6 days; OR = 0.75 [0.21-2.6]; LOS = 7-13 days; OR = 2.3 [0.9-5.9]; and LOS = ≥14 days; OR = 6.4 [2.6-15.9]).

CONCLUSION

We found no evidence of a relationship between any missed dose of prophylactic antithrombotic medication and development of acute DVT. The odds of acute DVT increased in patients with prolonged hospital LOS.