Value of psychometric hepatic encephalopathy score in the diagnosis of minimal hepatic encephalopathy in patients with liver cirrhosis

Objective To investigate the value of psychometric hepatic encephalopathy score (PHES) in the diagnosis of minimal hepatic encephalopathy (MHE) and related influencing factors, as well as the prevalence rate of MHE among patients with liver cirrhosis and related risk factors. Methods A total of 138 patients with liver cirrhosis aged ≥18 years, who were hospitalized in China-Japan Union Hospital of Jilin University from April 2011 to April 2012, were enrolled as liver cirrhosis group, and 108 individuals who underwent physical examination during the same period of time, patients' family members, and adult volunteers without liver disease were enrolled as normal control group. PHES was determined for all subjects. The influencing factors for the scores on each scale were analyzed, the value of this score in the diagnosis of MHE was evaluated, and the risk factors for MHE were identified. The t-test or the Wilcoxon rank-sum test was used for comparison of continuous data between two groups, and the chi-square test was used for comparison of categorical data between two groups.Pearson correlation was used to analyze the correlation between continuous variables, and multivariate linear stepwise regression and logistic regression were used to analyze related factors. Results There were no significant differences in age, education level, drinking, smoking, and occupation between the two groups (all P > 0. 05) . In the normal control group, age and years of education had a linear correlation with PHES, and PHES decreased with the increase in age (r =-0. 259) and the reduction in education level (r = 0. 693) . The formulas of the expected normal reference values of each test associated with age and education level were established as follows: number connection test-A (NCT-A) = 30. 70 + 0. 631 × age-1. 504 × years of education, modified number connection test-BC (NCT-BC) = 54. 93 + 1. 134 ×age-2. 574 × years of education, digit symbol test (DST) = 29. 90-0. 332 × age + 2. 670 × years of education, line-tracing test (LTT) = 48. 82 + 0. 496 × age-1. 120 × years of education, serial dotting test (SDT) = 54. 35 + 0. 402 × age-1. 266 × years of education. For the comparison of test results with corresponding expected normal reference values in the patients with liver cirrhosis, there were significant differences between the patients with stage I overt hepatic encephalopathy (OHE) and those without OHE in PHES (-5. 5 (-2. 0 to-7. 0) vs-10. 0 (-7. 5 to-13. 0) , Z = 3. 65, P < 0. 01) and prevalence rate of MHE (52. 5% vs 80. 0%, χ2= 4. 19, P < 0. 05) . The logistic regression analysis showed that the prevalence rate of MHE was significantly associated with Child-Pugh class (odds ratio = 2. 30, 95%confidence interval: 1. 46-3. 79, P < 0. 01) . Conclusion PHES helps with the early diagnosis of MHE, but it is influenced by age and education level, Child-Pugh class is an important risk factor for the prevalence rate of MHE.