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. 2014 Oct 15;31(20):1721–1732. doi: 10.1089/neu.2014.3361

FIG. 2.

FIG. 2.

Calibration tests for the original IMPACT and APACHE II models for 6-month mortality (left) and unfavorable outcome (right) prediction. The H-L calibration plots to the left (with a loess smoother curve fitted between the groups) and the GiViTI calibration belts to the right for 6-month mortality and neurological outcome, respectively. The GiViTI belt shows risk intervals of significant under- and overprediction when the 95% confidence interval does not encompass the diagonal bisector line (black line, indicating perfect calibration). The APACHE II model showed good calibration for mortality (p=0.099), but not neurological outcome (p<0.001) prediction. Both the IMPACT core and extended models showed poor calibration by both tests (p<0.05). The IMPACT lab was the only model showing good calibration for both mortality (p=0.054) and neurological outcome (p=0.078) prediction. IMPACT, International Mission for Prognosis and Analysis of Clinical Trials; APACHE II, Acute Physiology and Chronic Health Evaluation II; H-L, the Hosmer-Lemeshow Ĉ-test; GiViTI, Italian Group for the Evaluation of Interventions in Intensive Care Medicine.