Risk indices predicting graft use, graft and patient survival in solid pancreas transplantation: a systematic review

Jonathan E H Ling,John Kanellis,Timothy Coughlan,Kevan R Polkinghorne

doi:10.1186/s12876-021-01655-2

Abstract

BackgroundRisk indices such as the pancreas donor risk index (PDRI) and pre-procurement pancreas allocation suitability score (P-PASS) are utilised in solid pancreas transplantation however no review has compared all derived and validated indices in this field. We systematically reviewed all risk indices in solid pancreas transplantation to compare their predictive ability for transplant outcomes.MethodsMedline Plus, Embase and the Cochrane Library were searched for studies deriving and externally validating risk indices in solid pancreas transplantation for the outcomes of pancreas and patient survival and donor pancreas acceptance for transplantation. Results were analysed descriptively due to limited reporting of discrimination and calibration metrics required to assess model performance.ResultsFrom 25 included studies, discrimination and calibration metrics were only reported in 88% and 38% of derivation studies (n = 8) and in 25% and 25% of external validation studies (n = 12) respectively. 21 risk indices were derived with mild to moderate ability to predict risk (C-statistics 0.52–0.78). Donor age, donor body mass index (BMI) and donor gender were the commonest covariates within derived risk indices. Only PDRI and P-PASS were subsequently externally validated, with variable association with post-transplant outcomes. P-PASS was not associated with pancreas graft survival.ConclusionMost of the risk indices derived for use in solid pancreas transplantation were not externally validated (90%). PDRI and P-PASS are the only risk indices externally validated for solid pancreas transplantation, and when validated without reclassification measures, are associated with 1-year pancreas graft survival and donor pancreas acceptance respectively. Future risk indices incorporating recipient and other covariates alongside donor risk factors may have improved predictive ability for solid pancreas transplant outcomes.

Highlights

Risk indices such as the pancreas donor risk index (PDRI) and pre-procurement pancreas allocation suitability score (P-PASS) are utilised in solid pancreas transplantation no review has compared all derived and validated indices in this field
We compared the predictive ability of all current risk indices derived for use in solid pancreas transplantation via a systematic review
This systematic review of risk indices derived for use in solid pancreas transplantation found that despite 21 risk indices being derived, only P-PASS and PDRI were externally validated and are in use today [6, 7]

Summary

Introduction

Risk indices such as the pancreas donor risk index (PDRI) and pre-procurement pancreas allocation suitability score (P-PASS) are utilised in solid pancreas transplantation no review has compared all derived and validated indices in this field. We systematically reviewed all risk indices in solid pancreas transplantation to compare their predictive ability for transplant outcomes. Ling et al BMC Gastroenterol (2021) 21:80 transplantation within the USA [7] They are not widely used as external validation studies have reported varying association with their intended outcomes [8,9,10,11]. Other risk indices have been derived for use in pancreas transplantation have not been validated widely in external cohorts [12, 13]. We compared the predictive ability of all current risk indices derived for use in solid pancreas transplantation via a systematic review. This would guide future work in incorporating a risk index into the Australian and New Zealand pancreas transplant protocol, as no index is currently used to guide solid pancreas transplantation locally [5, 14]

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Conclusion