Table 2

Measures of model calibration and discrimination in all admissions eligible for each model

Model
APACHE II
APACHE III
SAPS II
MPM II
ICNARC

Eligible admissions, n (percent)
8,344 (75.7)
9,021 (81.9)
8,220 (74.6)
7,267 (65.9)
10,285 (93.3)
AUC (95 percent CI)
0.73 (0.72, 0.75)
0.75 (0.74, 0.77)
0.81 (0.80, 0.82)
0.81 (0.79, 0.82)
0.82 (0.81, 0.83)
Hosmer-Lemeshow C*





     χ2(10)a
316
4542
162
99.5
94.6
     p value
<0.001
<0.001
<0.001
<0.001
<0.001
Cox's calibration regression





     Intercept (95 percent CI)
-0.23 (-0.29, -0.18)
0.44 (0.36, 0.52)
0.09 (0.03, 0.15)
0.27 (0.20, 0.34)
0.18 (0.12, 0.24)
     Slope (95 percent CI)
0.66 (0.62, 0.70)
0.58 (0.55, 0.62)
0.86 (0.82, 0.90)
1.00 (0.94, 1.05)
0.97 (0.93, 1.01)
     χ2(2)
262
2,045
74.8
84.8
66.3
     p value
<0.001
<0.001
<0.001
<0.001
<0.001
Brier's score
0.187
0.193
0.164
0.168
0.155

aNote that due to different sample sizes, the Hosmer-Lemeshow C*-statistic should not be directly compared between models. APACHE, Acute Physiology And Chronic Health Evaluation; AUC, area under the receiver operating characteristic curve; CI, confidence interval; ICNARC, Intensive Care National Audit & Research Centre; MPM, Mortality Probability Models; SAPS, Simplified Acute Physiology Score.

Hyam et al. Critical Care 2006 10(Suppl 2):S2   doi:10.1186/cc5066