Table 4.

Factors associated with guideline concordance: multilevel logistic regression

Three-level model	Odds ratio (95% CI)	P value
Patient factors
Surgical admission	1.09 (0.68, 1.75)	0.718
APACHE II score (10-point increase)	1.49 (1.17, 1.89)	0.001
Cancera	3.22 (1.81, 5.72)	<0.001
History of venous thromboembolism	3.94 (1.46, 10.66)	0.007
Body mass index (10-point increase)	1.32 (1.05, 1.65)	0.018
Daily factorsb
Any dialysis	0.79 (0.45, 1.40)	0.422
Invasive mechanical ventilation	1.83 (1.32, 2.52)	<0.001
Vasopressors or inotropes	1.26 (0.90, 1.78)	0.184
Site factors
Dedicated thrombosis consulting service	1.91 (0.95, 3.86)	0.069
Preprinted orders including thromboprophylaxis	1.00 (0.51, 1.98)	0.989

Results of the multilevel logistic regression model examining determinants of guideline concordance (use of any pharmacological thromboprophylaxis unless contraindications exist). The three levels are center, patient, and ICU-day. There were 10,540 patient-days (10,154 with concordance, 386 without), n = 1,533 patients. Body mass index values were missing for 402 of the 1,935 patients enrolled in the study. These patients were therefore excluded from the regression analysis. APACHE, Acute Physiology and Chronic Health Evaluation; CI, confidence interval. ^aCancer refers to lymphoma, metastatic cancer, leukemia, multiple myeloma, active solid malignancy, or history of solid malignancy. ^bDaily factors reflect exposure in the preceding 3 days.