Original article
Pancreas, biliary tract, and liver
Combined Scores from the EncephalApp Stroop Test, Number Connection Test B, and Serial Dotting Test Accurately Identify Patients With Covert Hepatic Encephalopathy

https://doi.org/10.1016/j.cgh.2019.11.018Get rights and content

Background & Aims

The EncephalApp Stroop test is a high-sensitivity but low-specificity test that has been used to identify patients with covert hepatic encephalopathy (CHE). We aimed to develop a new strategy to detect CHE, combining EncephalApp Stroop test score with scores from subtests of the psychometric hepatic encephalopathy scoring system (PHES).

Methods

We performed a survey of 569 adult volunteers (229 men) in 9 communities in Shanghai, China, administering the EncephalApp Stroop test to determine the range of scores in the general population. Data from the standard PHES, including the number connection test-A, number connection test-B (NCT-B), line tracing test, serial dotting test (SDT), and digit symbol test, were used as the reference standard for diagnosis of CHE. A combination of the EncephalApp Stroop with subtests of the PHES was used to establish a new strategy for CHE diagnosis. We validated our findings using data from 160 patients with cirrhosis from 5 centers China.

Results

We determined the range of EncephalApp Stroop test scores for the volunteers of different decades of age, education levels, and sexes. Age, education level, and sex were independently associated with EncephalApp Stroop test scores. A combination of scores from the EncephalApp Stroop test, the NCT-B, and the SDT identified patients with CHE with the highest level of accuracy, when the standard PHES was used as the reference standard. A combination of scores of 187 sec for the EncephalApp Stroop test and below –1 for the NCT-B or below –1 for the SDT identified patients with CHE with an area under the curve (AUC) of 0.86, 81.0% sensitivity, and 91.9% specificity, and 87.5% accuracy. In the validation cohort, these cutoff scores identified patients with CHE with an AUC of 0.88, 97.1% sensitivity, 79.3% specificity, and 86.9% accuracy. The average time to calculate this score was 374±140 sec, compared 424±115 sec for the entire PHES.

Conclusion

Scores from the EncephalApp Stroop test, NCT-B, and SDT identify patients with CHE with approximately 87% accuracy, and in a much shorter time than the standard PHES. This score combination could be a valid and convenient method for identifying patients with CHE. chictr.org.cn number, ChiCTR-EDC-17012007, ChiCTR1800019954.

Section snippets

Study Population

Healthy subjects were enrolled in an epidemiological survey study from 9 communities in Shanghai, China. The inclusion criteria were healthy volunteers above 18 years of age. The exclusion criteria were similar to our previous study.9 Those subjects who had an alcohol intake of more than 30 g/d in men or 20 g/d in women were excluded as well.

To determine the new strategy for CHE diagnosis, the data reported in our previous study were reanalyzed to develop a 2-step method by means of a

Range of Scores for the EncephalApp Stroop Test in the General Population

In total, 569 volunteers were enrolled to determine the range of scores of the EncephalApp Stroop test in the general population, including 229 (40.2%) men and 340 (59.8%) women, from 18 to 67 years of age, with education levels ranging from 2 to 23 years (Supplementary Table 1). As shown in Supplementary Figure 1, the average OnTime was significantly longer than OffTime (82 ± 21 seconds vs 73 ± 19 seconds; P < .001), and the number of On runs was obviously higher than the number of Off runs

Discussion

Although a series of psychometric and neurophysiological tests reflecting the subtle neuropsychological impairments in cognitive function, attention, psychomotor speed, and information processing speed have been applied in the diagnosis of CHE,2 the proportion of cirrhotic patients who underwent routine tests for CHE remains very low in practice. Our present study collected the range of EncephalApp Stroop test scores in China and established a novel strategy for CHE diagnosis with high

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      Testing with PHES or EncApp_ST alone, or a PHES plus EncApp_ST combination, is equivalent to diagnosing covert HE and predicting overt HE development [20]. In contrast, a multicenter Chinese survey showed that combined scores from the EncApp_ST, NCT-B, and SDT identified patients with covert HE with approximately 87% accuracy, and in a much shorter time than the standard PHES [21]. In our study, the PHES was performed as a gold standard method to select patients with MHE.

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    Conflicts of interest The authors have no conflicts to disclose.

    Funding This work was supported by the Top-Level Clinical Discipline Project of Shanghai Pudong (PWYgf2018-04), the Science and Technology Guidance Plan of Shanghai Science and Technology Commission (19411970500), the Emerging Advanced Technology Joint Research Project of Shanghai Hospital Development Center (SHDC12016103), and the Shanghai Natural Science Fund (16ZR1436400).

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