Development and Validation of the PaP Score Nomogram for Terminally Ill Cancer Patients

SIMPLE SUMMARY: The Accurate prediction of survival in a palliative care setting is vitally important for clinical, organizational and ethical reasons. Several prognostic tools have been developed to provide reliable estimates of survival in terminally ill cancer patients. We previously developed and validated the Palliative Prognostic (PaP) score, a prognostic tool that assigns patients to three different risk groups according to a 30-day survival probability: group A, >70%; group B, 30–70%; and group C, <30%. As the PaP score does not provide the individual prediction of the survival probability but only probability windows, the present work focuses on the development and validation of the PaP score as a nomogram in order to provide individualized prediction of survival at 15, 30 and 60 days. The nomogram improved the performance of the original PaP score while also maintaining its key feature of simplicity. ABSTRACT: The validated Palliative Prognostic (PaP) score predicts survival in terminally ill cancer patients, assigning patients to three different risk groups according to a 30-day survival probability: group A, >70%; group B, 30–70%; and group C, <30%. We aimed to develop and validate a PaP nomogram to provide individualized prediction of survival at 15, 30 and 60 days. Three cohorts of consecutive terminally ill cancer patients were used: one (n = 519) for nomogram development and internal validation, and a second (n = 451) and third (n = 549) for external validation. Multivariate analyses included dyspnea, anorexia, Karnofsky performance status, clinical prediction of survival, total white blood count and lymphocyte percentage. The predictive accuracy of the nomogram was determined by Harrell’s concordance index (95% CI), and calibration plots were generated. The nomogram had a concordance index of 0.74 (0.72–0.75) and showed good calibration. The internal validation showed no departures from ideal prediction. The accuracy of the nomogram at 15, 30 and 60 days was 74% (70–77), 89% (85–92) and 72% (68–76) in the external validation cohorts, respectively. The PaP nomogram predicts the individualized estimate of survival and could greatly facilitate clinical care decision-making at the end of life.