TABLE 2.

2 × 2 contingency table

Group	Death within 3 days	Not death within 3 days
Not surprised	Group A; 636	Group B; 543
Surprised	Group C; 38	Group D; 194
Sensitivity	94.3% (95% CI: 92.7%–95.8%)	Positive predictive value	53.9% (95% CI: 53.0%–54.7%)
Specificity	26.3% (95% CI: 24.8%–27.6%)	Negative predictive value	83.6% (95% CI: 78.7%–87.7%)

Group A: "Patients who physicians answered "not surprised" and actually die within three days". Group B: "Group that lived longer than expected (defined as "Lived longer group"): patients who physicians answered "not surprised" and did not actually die within three days". Group C: "Patients who physicians answered "surprised" and actually die within three days". Group D: "Patients who physicians answered "surprised" and did not actually die within three days".

Abbreviation: CI, Confidence interval.