Table 3 Model adjustment and performance

 Khwannimit and Bhurayanontachai (2011) [51]

Recalibration (first-level customisation): customised APACHE II logit = –7.7206 + (APACHE II score × 0.2013) + new diagnostic category weight (Appendix I [51])

0.936 (0.925–0.947) (entire population n = 2022)

0.936 (0.925–0.947) (validation dataset n = 1011)

C statistic χ² = 104.2 (p = 0.001), H statistic

χ² = 113.1 (p < 0.001)

C statistic χ² = 16.1 (p = 0.09),

H statistic χ² = 14.1 (p = 0.17)

 Eapen et al. (1997) [30]

Variable adjustment: GCS excluded

Not evaluated

0.6068

Not reported

Not reported

 Hashmi et al. (2016) [77]

Modelling technique adjustments: APACHE II calculated automatically by software which uses manually entered values using the logit equation = –4.063 + (APACHE II) × 0.181

0.823 (0.76–0.88)

(manual calculation)

0.827 (0.77–0.88)

(software calculation)

χ² = 11.76 (p = 0.16)

χ² = 5.46 (p = 0.71)

 Nimgaonkar et al. (2004) [35]

Modelling technique adjustments: Artificial Neural Network (ANN 22) model

trained on an Indian patient dataset using all 22 APACHE II variables

0.77

0.87 (p < 0.002)

H statistic

χ² = 123.5 (p < 0.05)

H statistic χ² = 22.4 (p < 0.05)

 Nimgaonkar et al. (2004) [35]

Modelling technique adjustments: Artificial Neural Network (ANN 15) model trained on an Indian patient dataset using 15 APACHE II variables

0.77

0.88 (p < 0.001)

ANN 15

H statistic

χ² = 123.5 (p < 0.05)

H statistic

χ² = 27.7 (p < 0.05)

 Khwannimit and Bhurayanontachai (2011) [51]

Recalibration (first-level customisation): customised SAPS II logit = –10.1779 + 0.0719 (SAPS II score) + 1.4891 × ln(SAPS II score + 1)

0.914 (0.901–0.928) (entire population n = 2022)

0.919 (0.900–0.938) (validation dataset n = 1011)

C statistic

χ² = 124.9 (p < 0.001),

H statistic

χ² = 97.5 (p < 0.001)

C statistic

χ² = 8.6 (p = 0.57),

H statistic

χ² = 9.6 (p = 0.48)

 Zhao et al. (2013) [50]

Variable adjustment: 1. Underlying disease variables excluded

2. Admission type variables excluded

0.776 (95% CI 0.750–0.802) at admission, 0.826 (95% CI 0.803–0.850) at 24 hours

Not reported: correlation was suggested between the simplified SAPS II score at each time point and outcome with OR of 1.109 (p = 0.000), regardless of the diagnosis

Not reported

Not reported

 Khwannimit and Bhurayanontachai (2011) [51]

Recalibration (first-level customisation): customised SAPS 3 logit = –33.4249 + ln(SAPS 3 score +1) × 7.8699

0.913 (0.899–0.924) (entire population n = 2022)

0.917 (0.897–0.937)

(validation dataset n = 1011)

C statistic

χ² = 170 (p < 0.001),

H statistic

χ² = 79.9 (p < 0.001)

C statistic

χ² = 8.2 (p = 0.61),

H statistic

χ² = 79.9 (p < 0.001)

 Riviello et al. (2016) [43]

MPM (0) III