title: [Age-and, education-corrected number connection test and digit symbol test in diagnosis of minimal hepatic encephalopathy].
abstract: OBJECTIVE
  To determine the age-and education-corrected control values for the number connection test (NCT) and digit symbol test (DST) psychometric measures to increase their accuracy for diagnosis of minimal hepatic encephalopathy (MHE).
  
  
  METHODS
  The NCT Part A (NCT-A) and DST were administered to 843 healthy volunteers (age range:16-65 years; education:more than 1 year) and 429 patients with liver cirrhosis (with Child-Pugh classification of liver function). The normal values were defined as the mean ± 2 standard deviations (2SD);MHE was defined by abnormal results on at least one psychometric test. The statistical significance of differences in MHE diagnosis according to the various control values (age and education-corrected or not) was assessed by the chi-square test and logistic regression analysis.
  
  
  RESULTS
  NCT-A and DST were found to be influenced by age (standard coefficient 0.405, P =0.000 and standard coefficient-0.527, P =0.000 respectively) and education (standard coefficient-0.347, P =0.000 and standard coefficient 0.405, P =0.000 respectively). Among the 120 patients with liver cirrhosis who were diagnosed with MHE (27.97%), 113 had abnormal NCT-A results (26.34%), 54 had abnormal DST results (12.59%),and 47 had abnormal results on both tests (10.96%). Among these 120 MHE-positive patients, 21 were classified as Child-Pugh A (19.81%), 46 as Child-Pugh B (23.71%), and 53 as Child-Pugh C (41.09%);the MHE-positive rate was significantly greater in the patients with Child-Pugh C classification than those with either Child-Pugh B or Child-Pugh A (P < 0.01). Logistic analysis showed that when the control data was corrected for age and education, the MHE diagnosis was related with liver function (P =0.000), regardless of age (P =0.328) and education (P =0.563). When the control data was uncorrected, the MHE diagnosis was not only influenced by liver function (P =0.000) but also by age (P =0.000) and education (P =0.005).
  
  
  CONCLUSIONS
  Age and education-corrected control values can increase the accuracy of MHE diagnosis by NCT-A and DST.
authors.affiliation: Department of Gastroenterology, Dongfeng Hospital, Hubei Medicial College, Shiyan Hubei 442000, China.
authors.forename: Liangcheng
authors.initials: L
authors.lastname: Hao
authors.forename: Yangqian
authors.initials: Y
authors.lastname: Hu
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Hou
mesh_terms: D017677:Age Distribution; D006501:Hepatic Encephalopathy; D006801:Humans; D008103:Liver Cirrhosis; D011594:Psychometrics