The Prognosis in Palliative care Study II (PiPS2): A prospective observational validation study of a prognostic tool with an embedded qualitative evaluation.

P C Stone,A Kalpakidou,V Vickerstaff,D Finlay,R Z Omar,K Spencer,C Todd,V Keeley,J Griffiths,P Buckle,Tim Luckett

doi:10.1371/journal.pone.0249297

Abstract

BackgroundPrognosis in Palliative care Study (PiPS) models predict survival probabilities in advanced cancer. PiPS-A (clinical observations only) and PiPS-B (additionally requiring blood results) consist of 14- and 56-day models (PiPS-A14; PiPS-A56; PiPS-B14; PiPS-B56) to create survival risk categories: days, weeks, months. The primary aim was to compare PIPS-B risk categories against agreed multi-professional estimates of survival (AMPES) and to validate PiPS-A and PiPS-B. Secondary aims were to assess acceptability of PiPS to patients, caregivers and health professionals (HPs).Methods and findingsA national, multi-centre, prospective, observational, cohort study with nested qualitative sub-study using interviews with patients, caregivers and HPs. Validation study participants were adults with incurable cancer; with or without capacity; recently referred to community, hospital and hospice palliative care services across England and Wales. Sub-study participants were patients, caregivers and HPs. 1833 participants were recruited. PiPS-B risk categories were as accurate as AMPES [PiPS-B accuracy (910/1484; 61%); AMPES (914/1484; 61%); p = 0.851]. PiPS-B14 discrimination (C-statistic 0.837) and PiPS-B56 (0.810) were excellent. PiPS-B14 predictions were too high in the 57–74% risk group (Calibration-in-the-large [CiL] -0.202; Calibration slope [CS] 0.840). PiPS-B56 was well-calibrated (CiL 0.152; CS 0.914). PiPS-A risk categories were less accurate than AMPES (p<0.001). PiPS-A14 (C-statistic 0.825; CiL -0.037; CS 0.981) and PiPS-A56 (C-statistic 0.776; CiL 0.109; CS 0.946) had excellent or reasonably good discrimination and calibration. Interviewed patients (n = 29) and caregivers (n = 20) wanted prognostic information and considered that PiPS may aid communication. HPs (n = 32) found PiPS user-friendly and considered risk categories potentially helpful for decision-making. The need for a blood test for PiPS-B was considered a limitation.ConclusionsPiPS-B risk categories are as accurate as AMPES made by experienced doctors and nurses. PiPS-A categories are less accurate. Patients, carers and HPs regard PiPS as potentially helpful in clinical practice.Study registrationISRCTN13688211.

Highlights

Patients with advanced incurable cancer, their relatives and clinical teams often want to know how long patients will survive
Prognosis in Palliative care Study (PiPS)-B risk categories are as accurate as agreed multi-professional estimates of survival (AMPES) made by experienced doctors and nurses
Unlike prognoses made at diagnosis, or prior to starting systemic anti-cancer therapies (SACT) [3], those made in a palliative care context usually rely on subjective judgments of clinicians, which show a wide variation in reported accuracy [4]

Summary

Introduction

Patients with advanced incurable cancer, their relatives and clinical teams often want to know how long patients will survive. The Palliative Prognostic (PaP) score, widely used in palliative cancer care, classifies patients into risk groups based on 30-day survival probabilities [5]. One limitation of PaP is that scores are heavily influenced by the weighting given to clinical predictions of survival (CPS). This can make PaP challenging to use when clinicians are unsure about survival times. The Prognosis in Palliative care Study (PiPS) predictor models were developed by members of our own group to provide prognostic estimates that do not rely on clinicians’ intuition [6]. Prognosis in Palliative care Study (PiPS) models predict survival probabilities in advanced cancer. Secondary aims were to assess acceptability of PiPS to patients, caregivers and health professionals (HPs)

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Results

Conclusion