Table 2.
Discriminatory ability and relative performance of CPS, PPI
Concordance index (95% CI) | AUC (95% CI) for 30-day survival | AUC (95% CI) for 100-day survival | IDI for 30-day survival3 | IDI for 100-day survival3 | |
---|---|---|---|---|---|
CPS | 0.58 (0.47, 0.68) | 0.58 (0.47, 0.68) | 0.62 (0.54, 0.70) | -- | -- |
PPI | 0.62 (0.51, 0.73) | 0.76 (0.66, 0.85) | 0.64 (0.56, 0.72) | -- | -- |
Difference between PPI and CPS4 | 0.2 (0.15, 0.25) 1 | 0.18 (0.09, 0.27) 2 | 0.03 (−0.06, 0.12)2 | 0.15 (0.08, 0.21) | 0.03 (−0.01, 0.07) |
P-value | <0.0001 | 0.0001 | 0.58 | <0.0001 | 0.1478 |
Abbreviations: CPS, clinician prediction of survival; PPI, palliative prognostic index; CI, confidence interval; AUC, area under the receiver-operating characteristics curve; IDI, integrated discrimination improvement
A positive value indicates better discrimination for concordance index
A positive value indicates better discrimination for AUC
The relative change in slope is shown based on the integrated discrimination improvement. A positive value indicates better discrimination for PPI compared to CPS
The difference between PPI and CPS is a statistical comparison that calculates A-B and the appropriate standard deviation for this difference. A p-value <0.05 indicates that the difference between PPI and CPS were significantly significant