Performance of the model for end-stage liver disease score for mortality prediction and the potential role of etiology

Bakground & aims Although discrimination of the model for end stage liver disease (MELD) is generally considered acceptable, its calibration is still unclear. In a validation study, we assessed the discrimination and calibration performance of 3 versions of the model: original MELD-TIPS, used to predict survival after transjugular intra-hepatic portosystemic shunt (TIPS); classic MELD-Mayo; MELD-UNOS, used by United Network for Organ Sharing (UNOS). Recalibration and model updating were also explored. Methods 776 patients submitted to elective TIPS (TIPS cohort), and 445 unselected patients (non-TIPS cohort) were included. Three, 6 and 12-month mortality predictions were calculated by the 3 MELD versions: discrimination was assessed by c-statistics and calibration by comparing deciles of predicted and observed risks. Cox and Fine and Grey models were used for recalibration and prognostic analyses. Results Major patient characteristics in TIPS/non-TIPS cohorts were: viral etiology 402/188, alcoholic 185/130, NASH 65/33; mean follow-up± SD 25±9/19±21months; 3-6-12 month mortality were respectively, 57-102-142/31-47-99. C-statistics ranged from 0.66 to 0.72 in TIPS and 0.66 to 0.76 in non-TIPS cohorts across prediction times and scores. A post-hoc analysis revealed worse c-statistics in non-viral cirrhosis with more pronounced and significant worsening in non-TIPS cohort. Calibration was acceptable with MELD-TIPS but largely unsatisfactory with MELD-Mayo and -UNOS whose performance improved much after recalibration. A prognostic analysis showed that age, albumin, and TIPS indication might be used for a MELD updating. Conclusions In this validation study the MELD performance was largely unsatisfactory, particularly in non-viral cirrhosis. MELD recalibration and candidate variables for a MELD updating are proposed. Lay summary While discrimination performance of the Model for End Stage Liver Disease (MELD) is credited to be fair to good, its calibration, the correspondence of observed to predicted mortality, is still unsettled. We found that application of 3 different versions of the MELD in two independent cirrhosis cohorts yielded largely imprecise mortality predictions particularly in non-viral cirrhosis and propose a validated model recalibration. Candidate variables for a MELD updating are proposed.