Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Hepatol. Nov 27, 2012; 4(11): 291-298
Published online Nov 27, 2012. doi: 10.4254/wjh.v4.i11.291
Is an estimated glomerular filtration rate better than creatinine to be incorporated into the end-stage liver disease score?
Yu-Wei Chen, Ching-Wei Chang, Chen-Wang Chang, Tsang-En Wang, Chih-Jen Wu, Han-Hsiang Chen
Yu-Wei Chen, Chih-Jen Wu, Han-Hsiang Chen, Department of Nephrology, Mackay Memorial Hospital, Taipei 10449, Taiwan
Yu-Wei Chen, Ching-Wei Chang, Chen-Wang Chang, Tsang-En Wang, Chih-Jen Wu, Han-Hsiang Chen, Mackay Medicine, Nursing and Management College, Taipei 10449, Taiwan
Ching-Wei Chang, Chen-Wang Chang, Tsang-En Wang, Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei 10449, Taiwan
Author contributions: Chen YW, Chang CW, Wu CJ and Chen HH designed the research; Chen YW, Chang CW and Chang CW performed the research; Chen YW and Chen HH contributed new reagents/analytic tools; Chen YW, Chang CW and Wang TE analyzed the data; and Chen YW wrote the paper.
Correspondence to: Dr. Yu-Wei Chen, Department of Nephrology, Mackay Memorial Hospital, No.92, sec. 2, Zhongshan N. Rd., Zhongshan Dist., Taipei 10449, Taiwan. yw.chen.mmh@gmail.com
Telephone: +886-2-25433535 Fax: +886-2-25433642
Received: December 7, 2011
Revised: August 17, 2012
Accepted: October 22, 2012
Published online: November 27, 2012

AIM: To incorporate estimated glomerular filtration rate (eGFR) into the model for end-stage liver disease (MELD) score to evaluate the predictive value.

METHODS: From January 2004 to October 2008, the records of 4127 admitted cirrhotic patients were reviewed. Patients who survived and were followed up as outpatients were defined as survivors and their most recent available laboratory data were collected. Patients whose records indicated death at any time during the hospital stay were defined as non-survivors (in-hospital mortality). Patients with incomplete data or with cirrhosis due to a congenital abnormality such as primary biliary cirrhosis were excluded; thus, a total of 3857 patients were enrolled in the present study. The eGFR, which was calculated by using either the modification of diet in renal disease (MDRD) equation or the chronic kidney disease epidemiology collaboration (CKD-EPI) equation, was incorporated into the MELD score after adjustment with the original MELD equation by logistic regression analysis [bilirubin and international normalized ratio (INR) were set at 1.0 for values less than 1.0].

RESULTS: Patients defined as survivors were significantly younger, had a lower incidence of hepatoma, lower Child-Pugh and MELD scores, and better renal function. The underlying causes of cirrhosis were very different from those in Western countries. In Taiwan, most cirrhotic patients were associated with the hepatitis virus, especially hepatitis B. There were 16 parameters included in univariate logistic regression analysis to predict in-hospital mortality and those with significant predicting values were included in further multivariate analysis. Both 4-variable MDRD eGFR and 6-variable MDRD eGFR, rather than creatinine, were significant predictors of in-hospital mortality. Three new equations were constructed (MELD-MDRD-4, MELD-MDRD-6, MELD-CKD-EPI). As expected, original MELD score was a significant predictor of in-hospital mortality (odds ratio = 1.25, P < 0.001). MELD-MDRD-4 excluded serum creatinine, with the coefficients refit among the remaining 3 variables, i.e., total bilirubin, INR and 4-variable MDRD eGFR. This model represented an exacerbated outcome over MELD score, as suggested by a decrease in chi-square (2161.45 vs 2198.32) and an increase in -2 log (likelihood) (2810.77 vs 2773.90). MELD-MDRD-6 included 6-variable MDRD eGFR as one of the variables and showed an improvement over MELD score, as suggested by an increase in chi-square (2293.82 vs 2198.32) and a decrease in -2 log (likelihood) (2810.77 vs 2664.79). Finally, when serum creatinine was replaced by CKD-EPI eGFR, it showed a slight improvement compared to the original MELD score (chi-square: 2199.16, -2 log (likelihood): 2773.07). In the receiver-operating characteristic curve, the MELD-MDRD-6 score showed a marginal improvement in area under the curve (0.909 vs 0.902), sensitivity (0.854 vs 0.819) and specificity (0.818 vs 0.839) compared to the original MELD equation. In patients with a different eGFR, the MELD-MDRD-6 equation showed a better predictive value in patients with eGFR ≥ 90, 60-89, 30-59 and 15-29.

CONCLUSION: Incorporating eGFR obtained by the 6-variable MDRD equation into the MELD score showed an equal predictive performance in in-hospital mortality compared to a creatinine-based MELD score.

Keywords: Liver cirrhosis, Estimated glomerular filtration rate, End-stage liver disease, Modification of diet in renal disease, Renal function