Validation of the Caprini Venous Thromboembolism Risk Assessment Model in Critically Ill Surgical Patients

Appropriate risk stratification for venous thromboembolism (VTE) is essential to providing appropriate thromboprophylaxis and avoiding morbidity and mortality.To validate the Caprini VTE risk assessment model in a previously unstudied high-risk cohort: critically ill surgical patients.We performed a retrospective cohort study of 4844 adults (≥18 years old) admitted to a 20-bed surgical intensive care unit in a large tertiary care academic hospital during a 5-year period (July 1, 2007, through June 30, 2012).The main study outcome was VTE (defined as patients with deep vein thrombosis or pulmonary embolism) that occurred during the patient's initial hospital admission.The study population was distributed among risk levels as follows: low, 5.3%; moderate, 19.9%; high, 31.6%; highest, 25.4%; and superhigh, 14.9%. The overall incidence of inpatient VTE was 7.5% and increased with risk level: 3.5% in low-risk patients, 5.5% in moderate-risk patients, 6.6% in high-risk patients, 8.6% in highest-risk patients, and 11.5% in superhigh-risk patients. Patients with Caprini scores greater than 8 were significantly more likely to develop inpatient VTE events when compared with patients with Caprini scores of 7 to 8 (odds ratio [OR], 1.37; 95% CI, 1.02-1.85; P = .04), 5 to 6 (OR, 1.35; 95% CI, 1.16-1.57; P < .001), 3 to 4 (OR, 1.30; 95% CI, 1.16-1.47; P < .001), or 0 to 2 (OR, 1.37; 95% CI, 1.16-1.64; P < .001). Similarly, patients with Caprini scores of 7 to 8 were significantly more likely to develop inpatient VTE when compared with patients with Caprini scores of 5 to 6 (OR, 1.33; 95% CI, 1.01-1.75; P = .04), 3 to 4 (OR, 1.27; 95% CI, 1.08-1.51; P = .005), or 0 to 2 (OR, 1.38; 95% CI, 1.10-1.74; P = .006).The Caprini VTE risk assessment model is valid. This study supports the use of individual risk assessment in critically ill surgical patients.