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

• Published in: Transplantation Direct
• Main Authors: John D. Chetwood, MBBS(Dist), DTM&H, Mark V. Wells, BSc, Tatiana Tsoutsman, PhD, Carlo Pulitano, MD, PhD, FRACS, Michael D. Crawford, MBBS, FRACS, M.Med, Ken Liu, BSc(Med), FRACP, Simone I. Strasser, MBBS, MD, FRACP, FAASLD, Geoffrey W. McCaughan, MBBS, PhD, FRACP, FAHMS, Avik Majumdar, MPHTM, PhD, FRACP
• Format: Article
• Language: English
• Published: Wolters Kluwer 2022-07-01
• Online Access: http://journals.lww.com/transplantationdirect/fulltext/10.1097/TXD.0000000000001346

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.