Table 3.
PPI better than CPS N (%)1 | CPS better than PPI N (%)1 | NRI (from CPS to PPI)2(95% CI) | P-value | |
---|---|---|---|---|
Died within 30 days | 19 (58) | 14 (42) | 67% (31%, 103%) | 0.0005 |
Alive after 30 days | 123 (76) | 39 (24) | ||
Died within 100 days | 43 (47) | 48 (53) | 20% (−9%, 48%) | 0.19 |
Alive after 100 days | 55 (63) | 33 (37) |
Abbreviations: CI, confidence interval; CPS, clinician prediction of survival; NRI, net reclassification improvement; PPI, palliative prognostic index
We applied logistic regression modeling to compute the probability of an outcome of interest (e.g. death within 30 or 100 days) for each prognostication approach (i.e. CPS or PPI). We then compared the outcomes for each approach. Each cell shows the number of patients in which the probability of having the outcome based on one prognostication approach is closer to predicting the outcome than the other approach, along with the row percentage in parenthesis.
The percentage of subjects who were correctly reclassified using PPI instead of CPS. A positive value indicates better discrimination.