Risk factors for and prediction of mortality in critically ill medical–surgical patients receiving heparin thromboprophylaxis

Annals of Intensive Care

Table 3 Comparing three models in model performance for 60-day hospital mortality in the derivation and validation dataset and for 60-day ICU mortality in the whole dataset

Model performance	Goodness-of-fit		C index	SMR (95 % CI)
Model performance	p value^a	AIC	C index	SMR (95 % CI)
Hospital mortality—derivation set (n = 1891)
Model 1 (including APACHE II scores only)	0.68	5704	0.58	1.003 (0.959–1.050)
Model 2 (including the other risk factors only)^b	0.16	5359	0.62	1.002 (0.956–1.049)
Model 3 (including both the other risk factors and APACHE II scores)^c	0.90	5329	0.64	1.006 (0.961–1.052)
Hospital mortality—validation set (n = 1855)
Model 1 (including APACHE II scores only)	0.37	5912	0.60	0.933 (0.890–0.978)
Model 2 (including the other risk factors only)^b	0.80	5765	0.59	1.019 (0.972–1.067)
Model 3 (including both the other risk factors and APACHE II scores)^c	0.88	5567	0.64	1.011 (0.966–1.060)
ICU mortality—the whole set (n = 3746)
Model 1 (including APACHE II scores only)	0.75	8180	0.61	1.003 (0.972–1.036)
Model 2 (including the other risk factors only)^d	0.24	7821	0.58	1.001 (0.969–1.034)
Model 3 (including both the other risk factors and APACHE II scores)^e	0.74	7778	0.64	1.004 (0.972–1.038)

AIC Akaike information criterion, SMR standardized mortality ratio
^aBased on Groennesby and Borgan test
^bThe other risk factors included BMI, medical admission, inotropes or vasopressors and acetylsalicylic acid or clopidogrel
^cModel 3 consisted of BMI, medical admission, inotropes or vasopressors, acetylsalicylic acid or clopidogrel, APACHE II score and the interaction between BMI and APACHE II score
^dThe other risk factors included BMI, medical admission and invasive mechanical ventilation
^eModel 3 consisted of BMI, medical admission, invasive mechanical ventilation and APACHE II score