MELD-GRAIL and MELD-GRAIL-Na Are Not Superior to MELD or MELD-Na in Predicting Liver Transplant Waiting List Mortality at a Single-center Level

John D Chetwood; Mark G Wells; Tatiana Tsoutsman; Carlo Pulitano; Michael D Crawford; Ken Liu; Simone I Strasser; Geoffrey W McCaughan; Avik Majumdar

doi:10.1097/TXD.0000000000001346

MELD-GRAIL and MELD-GRAIL-Na Are Not Superior to MELD or MELD-Na in Predicting Liver Transplant Waiting List Mortality at a Single-center Level

Transplant Direct. 2022 Jun 10;8(7):e1346. doi: 10.1097/TXD.0000000000001346. eCollection 2022 Jul.

Authors

John D Chetwood^{1

2}, Mark G Wells³, Tatiana Tsoutsman^{1

2}, Carlo Pulitano^{2

3}, Michael D Crawford^{2

3}, Ken Liu^{1

2

3

4}, Simone I Strasser^{1

2

3}, Geoffrey W McCaughan^{1

2

3

4}, Avik Majumdar^{1

2

3}

Affiliations

¹ AW Morrow Gastroenterology and Liver Centre, Royal Prince Alfred Hospital, Sydney, Australia.
² Central Clinical School, The University of Sydney, Sydney, Australia.
³ Australian National Liver Transplant Unit, Royal Prince Alfred Hospital, Sydney, Australia.
⁴ Liver Injury and Cancer Program, Centenary Institute, Sydney, Australia.

Abstract

Background: Controversy exists regarding the best predictive model of liver transplant waiting list (WL) mortality. Models for end-stage liver disease-glomerular filtration rate assessment in liver disease (MELD-GRAIL) and MELD-GRAIL-Na were recently described to provide better prognostication, particularly in females. We evaluated the performance of these scores compared to MELD and MELD-Na.

Methods: Consecutive patients with cirrhosis waitlisted for liver transplant from 1998 to 2017 were examined in this single-center study. The primary outcome was 90-d WL mortality. MELD, MELD-Na, MELD-GRAIL, and MELD-GRAIL-Na at the time of WL registration were compared. Model discrimination was assessed with area under the receiver operating characteristic curves and Harrell's C-index after fitting Cox models. Model calibration was examined with Grønnesby and Borgan's modification of the Hosmer-Lemeshow formula and by comparing predicted/observed outcomes across model strata.

Results: The study population comprised 1108 patients with a median age of 53.5 (interquartile range 48-59) y and male predominance (74.9%). All models had excellent areas under the receiver operating characteristic curves for the primary outcome (MELD 0.89, MELD-Na 0.91, MELD-GRAIL 0.89, MELD-GRAIL-Na 0.89; all comparisons P > 0.05). Youden index cutoffs for 90-d mortality were as follows: MELD, 19; MELD-Na, 22; MELD-GRAIL, 18; and MELD-GRAIL-Na, 17. Variables associated with 90-d mortality on multivariable Cox regression were sodium, bilirubin, creatinine, and international normalized ratio. There were no differences in model discrimination using Harrell's C-index. All models were well calibrated; however, divergence between observed and predicted mortality was noted with scores ≥25.

Conclusion: There were no demonstrable differences in discrimination or calibration of GRAIL-based models compared with MELD or MELD-Na in our cohort. This suggests that GRAIL-based models may not have meaningful improvements in discriminatory ability when applied to other settings.