Prediction of Risk of Death for Patients Starting Dialysis: A Systematic Review and Meta-Analysis

Abstract

Background and objectives: Dialysis is a preference-sensitive decision where prognosis may play an important role. Although patients desire risk prediction, nephrologists are wary of sharing this information. We reviewed the performance of prognostic indices for patients starting dialysis to facilitate bedside translation.

Design, setting, participants, & measurements: Systematic review and meta-analysis following the PRISMA guidelines. We searched Ovid MEDLINE, Ovid Embase, Ovid Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus for eligible studies of patients starting dialysis published from inception to December 31, 2018.

Selection criteria: Articles describing validated prognostic indices predicting mortality at the start of dialysis. We excluded studies limited to prevalent dialysis patients, AKI and studies excluding mortality in the first 1-3 months. Two reviewers independently screened abstracts, performed full text assessment of inclusion criteria and extracted: study design, setting, population demographics, index performance and risk of bias. Pre-planned random effects meta-analysis was performed stratified by index and predictive window to reduce heterogeneity.

Results: Of 12,132 articles screened and 214 reviewed in full text, 36 studies were included describing 32 prognostic indices. Predictive windows ranged from 3 months to 10 years, cohort sizes from 46 to 52,796. Meta-analysis showed discrimination area under the curve (AUC) of 0.71 (95% confidence interval, 0.69 to 073) with high heterogeneity (I²=99.12). Meta-analysis by index showed highest AUC for The Obi, Ivory, and Charlson comorbidity index (CCI)=0.74, also CCI was the most commonly used (ten studies). Other commonly used indices were Kahn-Wright index (eight studies, AUC 0.68), Hemmelgarn modification of the CCI (six studies, AUC 0.66) and REIN index (five studies, AUC 0.69). Of the indices, ten have been validated externally, 16 internally and nine were pre-existing validated indices. Limitations include heterogeneity and exclusion of large cohort studies in prevalent patients.

Conclusions: Several well validated indices with good discrimination are available for predicting survival at dialysis start.

Keywords: Acute Kidney Injury; Area Under Curve; Bias; Cohort Studies; Comorbidity; Humans; Nephrologists; Patient Selection; Prevalence; Prognosis; Renal Dialysis; Risk; dialysis; mortality; mortality risk; peritoneal dialysis.

Graphical abstract

Figure 1.

Flow diagram of the literature search and selection.

Figure 2.

Meta-analysis of discrimination score of mortality prediction by index for those where three or more results were available. Weights are from random-effects analysis. 95% CI, 95% confidence interval; K-W, Kahn-Wright.

Figure 3.

Meta-analysis by predictive window, categorized to within 3 months, within 6 months, 1–5 years, or >5 years. Weights are from random-effects analysis. 95% CI, 95% confidence interval; ACPI, age-comorbidity prognostic index; AROii, Analyzing Data, Recognizing Excellence, and Optimizing Outcomes; ESRD-SI, End stage Renal Disease Severity Index; HEC, hospice eligibility criteria; K-W, Kahn-Wright; mCCI-IHD, Modified Charlson comorbidity index (CCI) - Intermittent Hemodialysis; mCCI-IPD, Modified CCI Intermittent Peritoneal Dialysis; NYHA, New York Heart Association; RMRC, Registre de Malalts Renals de Catalunya.