Corrigendum: The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities.

[This corrects the article DOI: 10.3389/fphys.2019.00116.].

The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities.

The Poincaré plot is a geometrical technique used to visualize and quantify the correlation between two consecutive data points in a time-series. Since the dynamics of fluctuations in physiological rhythms exhibit long-term correlation and memory, this study aimed to extend the Poincaré plot by calculating the correlation between sequential data points in a time-series, rather than between two consecutive points. By incorporating this so-called lag, we hope to integrate a temporal aspect into quantifying the correlation, to depict whether a physiological system holds prolonged association between events separated by time. In doing so, it attempts to instantaneously characterize the intrinsic behavior of a complex system. We tested this hypothesis on three different physiological time-series: heart rate variability in patients with liver cirrhosis, respiratory rhythm in asthma and body temperature fluctuation in patients with cirrhosis, to evaluate the potential application of the extended Poincaré method in clinical practice. When studying the cardiac inter-beat intervals, the extended Poincaré plot revealed a stronger autocorrelation for patients with decompensated liver cirrhosis compared to less severe cases using Pearson's correlation coefficient. In addition, long-term variability (known as SD2 in the extended Poincaré plot) appeared as an independent prognostic variable. This holds significance by acting as a non-invasive tool to evaluate patients with chronic liver disease and potentially facilitate transplant selection as an adjuvant to traditional criteria. For asthmatics, employing the extended Poincaré plot allowed for a non-invasive tool to differentially diagnose various classifications of respiratory disease. In the respiratory inter-breath interval analysis, the receiver operating characteristic (ROC) curve provided evidence that the extension of the Poincaré plot holds a greater advantage in the classification of asthmatic patients, over the traditional Poincaré plot. Lastly, the analysis of body temperature from patients using the extended Poincaré plot helped identify inpatients from outpatients with cirrhosis. Through these analyses, the extended Poincaré plot provided unique and additional information which could potentially make a difference in clinical practice. Conclusively, the potential use of our work lies in its possible application of predicting mortality for the organ allocation procedure in patients with cirrhosis and non-invasively distinguish between atopic and non-atopic asthma.

The psychomotor vigilance task: Role in the diagnosis of hepatic encephalopathy and relationship with driving ability.

BACKGROUND & AIMS: Hepatic encephalopathy (HE) is a syndrome of decreased vigilance and has been associated with impaired driving ability. The aim of this study was to evaluate the psychomotor vigilance task (PVT), which is used to assess both vigilance and driving ability, in a group of patients with cirrhosis and varying degrees of HE. METHODS: A total of 145 patients (120 males, 59 ±â€¯10 years, model for end-stage liver disease [MELD] score 13 ±â€¯5) underwent the PVT; a subgroup of 117 completed a driving questionnaire and a subgroup of 106 underwent the psychometric hepatic encephalopathy score (PHES) and an electroencephalogram (EEG), based on which, plus a clinical evaluation, they were classed as being unimpaired (n = 51), or as having minimal (n = 35), or mild overt HE (n = 20). All patients were followed up for an average of 13 ±â€¯5 months in relation to the occurrence of accidents and/or traffic offences, HE-related hospitalisations and death. Sixty-six healthy volunteers evenly distributed by sex, age and education served as a reference cohort for the PVT. RESULTS: Patients showed worse PVT performance compared with healthy volunteers, and PVT indices significantly correlated with MELD, ammonia levels, PHES and the EEG results. Significant associations were observed between neuropsychiatric performance/PVT indices and licence/driving status. PVT, PHES and EEG results all predicted HE-related hospitalisations and/or death over the follow-up period; none predicted accidents or traffic offences. However, individuals with the slowest reaction times and most lapses on the PVT were often not driving despite having a licence. When patients who had stopped driving for HE-related reasons (n = 6) were modelled as having an accident or fine over the subsequent 6 and 12 months, PVT was a predictor of accidents and traffic offences, even after correction for MELD and age. CONCLUSIONS: The PVT is worthy of further study for the purposes of both HE and driving ability assessment. LAY SUMMARY: Hepatic encephalopathy (HE) is a complication of advanced liver disease that can manifest as excessive sleepiness. Some patients with HE have been shown to have difficulty driving. Herein, we used a test called the Psychomotor Vigilance Task (PVT), which measures sleepiness and can also be used to assess driving competence. We showed that PVT performance is fairly stable in healthy individuals. We also showed that PVT performance parallels performance in tests which are commonly used in cirrhotic patients to measure HE. We suggest that this test is helpful in quantifying HE and identifying dangerous drivers among patients with cirrhosis.

Which heart rate variability index is an independent predictor of mortality in cirrhosis?

BACKGROUND: Liver cirrhosis is associated with reduced heart rate variability (HRV), which indicates impaired integrity of cardiovascular control in this patient population. There are several different indices for HRV quantification. The present study was designed to: 1) determine which of the HRV indices is best at predicting mortality in patients with cirrhosis; 2) verify if such ability to predict mortality is independent of the severity of hepatic failure. METHODS: Ten minutes electrocardiogram was recorded in 74 patients with cirrhosis. Heart rate fluctuations were quantified using statistical, geometrical and non-linear analysis. The patients were followed-up for 18months and information was collected on the occurrence of death/liver transplantation. RESULTS: During the follow-up period, 24 patients (32%) died or were transplanted for hepatic decompensation. Cox's regression analysis showed that SDNN (total HRV), cSDNN (corrected SDNN), SD1 (short-term HRV), SD2 (long-terms HRV) and spectral indices could predict survival in these patients. However, only SD2 and cSDNN were shown to be independent of MELD in predicting survival. The prognostic value of HRV indices was independent of age, gender, use of beta blockers, and the aetiology of liver disease. CONCLUSION: Two HRV indices were identified that could predict mortality in patients with cirrhosis, independently of MELD. These indices are potentially useful tools for survival prediction.

An educational tool for the prophylaxis of hepatic encephalopathy.

BACKGROUND: Providing structured information for the understanding of hepatic encephalopathy (HE) might be relevant to the prevention and management of the syndrome. The aim of our study was to design a brief, structured educational intervention and evaluate its usefulness in preventing HE-related hospitalisation over time. METHODS: Thirty-nine cirrhotic outpatients with a history of HE were enrolled and randomly assigned to an intervention (group A; n=20) or control group (group B; n=19). All of them underwent evaluation of HE (clinical and quantitative neuropsychiatric assessment) and completed the Questionnaire on the Awareness of Encephalopathy. A 15 min educational session was then provided to patients in group A, including basic information on the pathophysiology, hygienic and medical management of HE. RESULTS: No demographic/clinical differences were observed at baseline between the two groups. Similarly, there were no significant differences in HE-related information available at baseline between the two groups; knowledge of HE was limited in both. The intervention was highly effective in increasing patients' understanding of treatment of the condition (from 5% to 80%). The educational intervention also reduced the risk of developing an episode of HE over a period of 12 months. CONCLUSION: The educational intervention confirmed the poor knowledge of patients with previous HE about their condition, served as a tool to increase patients' awareness, and minimised HE-related readmission rates over a period of 1 year.

Abnormalities in the 24-hour rhythm of skin temperature in cirrhosis: Sleep-wake and general clinical implications.

BACKGROUND & AIMS: Sleep preparation/onset are associated with peripheral vasodilatation and a decrease in body temperature. The hyperdynamic syndrome exhibited by patients with cirrhosis may impinge on sleep preparation, thus contributing to their difficulties falling asleep. The aim of this study was the assessment of skin temperature, in relation to sleep-wake patterns, in patients with cirrhosis. METHODS: Fifty-three subjects were initially recruited, and 46 completed the study. Of the final 46, 12 were outpatients with cirrhosis, 13 inpatients with cirrhosis, 11 inpatients without cirrhosis and 10 healthy volunteers. All underwent baseline sleep-wake evaluation and blood sampling for inflammatory markers and morning melatonin levels. Distal/proximal skin temperature and their gradient (DPG) were recorded for 24 hours by a wireless device. Over this period subjects kept a sleep-wake diary. RESULTS: Inpatients with cirrhosis slept significantly less well than the other groups. Inpatients and outpatients with cirrhosis had higher proximal temperature and blunted rhythmicity compared to the other groups. Inpatients with/without cirrhosis had higher distal temperature values and blunted rhythmicity compared to the other groups. Inpatients and outpatients with cirrhosis had significantly lower DPG values compared to the other groups, and DPG reached near-zero values several hours later. Significant correlations were observed between temperature and sleep-wake variables and inflammatory markers. CONCLUSIONS: Alterations of distal/proximal skin temperature, their gradient and their time-course were observed in patients with cirrhosis, which may contribute to their sleep disturbances.

The animal naming test: An easy tool for the assessment of hepatic encephalopathy.

Screening for hepatic encephalopathy (HE) that does not cause obvious disorientation or asterixis (minimal HE [MHE]/grade 1 HE) is important. We examined if the animal naming test (ANT1 ) (maximum number of animals listed in 1 minute) is useful in this context. In total, 208 healthy controls, 40 controls with inflammatory bowel disease, and 327 consecutive patients with cirrhosis underwent the ANT1 . Patients were tested for MHE by the psychometric HE score, and 146 were assessed by electroencephalography; 202 patients were followed up regarding the occurrence of overt HE and death. In the healthy controls, ANT1 was influenced by limited education (<8 years) and advanced age (>80 years, P < 0.001). Using an age and education adjusting procedure, the simplified ANT1 (S-ANT1 ) was obtained. An S-ANT1 of <10 animals was abnormal. Of the patients, 169 were considered unimpaired, 32 as having HE ≥grade 2, and 126 as having MHE/grade 1 HE. This group had lower S-ANT1 than unimpaired patients (12 ± 0.4 versus 16 ± 0.7, P < 0.001) and higher S-ANT1 than those with HE ≥grade 2 (4 ± 0.9). In grade 1 HE the S-ANT1 was lower than in MHE. Following receiver operating characteristic analysis (Youden's index), 15 animals produced the best discrimination between unimpaired and MHE/grade 1 HE patients. Thus, a three-level score (0 for S-ANT1 ≥15, 1 for 10 ≤ S-ANT1 < 15, 2 for S-ANT1 <10) was obtained. This score was correlated both to the psychometric HE score (P < 0.0001) and to electroencephalography (P = 0.007). By sample random split validation, both S-ANT1 and its three-level score showed prognostic value regarding the 1-year risk of overt HE and death. No inflammatory bowel disease control had S-ANT <15. CONCLUSION: The S-ANT1 is an easily obtainable measure useful for the assessment of HE. (Hepatology 2017;66:198-208).

Neuropsychiatric performance in patients with cirrhosis: Who is "normal"?

In patients with cirrhosis a normal neuropsychiatric performance has been traditionally defined by the absence of any degree of hepatic encephalopathy and/or the absence of psychometric or neurophysiological abnormalities, compared with data from the healthy population. As the understanding and management of end-stage liver disease continues to change, it is our impression that the concept of normal neuropsychiatric performance also needs updating. This review explores novel and more pragmatic interpretations of neuropsychiatric "normality" compared with top personal performance, in terms of risk of overt hepatic encephalopathy or brain failure and in relation with events such as liver transplantation, decompensation, acute-on-chronic liver failure and transjugular intrahepatic portosystemic shunt placement.

Neuropsychiatric performance and treatment of hepatitis C with direct-acting antivirals: a prospective study.

BACKGROUND: Since direct-acting antivirals (DAAs) have been approved for the treatment of hepatitis C virus (HCV) infection, a small series of patients with new-onset neuropsychiatric alterations have been referred to us. We therefore set out to study neuropsychiatric function in relation to DAAs prospectively. METHODS: Ten patients with cirrhosis and 12 post-liver transplant (post-LT) patients were enrolled. All underwent wake electroencephalography (EEG) and a neuropsychological evaluation (paper and pencil battery, simple/choice reaction times, working memory task) at baseline, at the end of treatment with DAAs and after 6 months. At the same time points, full blood count, liver/kidney function tests, quantitative HCV RNA, ammonia and immunosuppressant drug levels were obtained, as appropriate. RESULTS: Patients with cirrhosis were significantly older than post-LT patients (65±12 vs 55±7 years; P<0.05). Neuropsychological performance and wake EEG were comparable in the two groups at baseline. At the end of a course of treatment with DAAs, a significant slowing in choice reaction times and in the EEG (increased relative delta power) was observed in patients with cirrhosis, which resolved after 6 months. In contrast, no significant changes over time were observed in the neuropsychiatric performance of post-LT patients. No significant associations were observed between neuropsychiatric performance and stand-alone/combined laboratory variables. CONCLUSION: Some degree of neuropsychiatric impairment was observed in relation to treatment with DAAs in patients with cirrhosis, but not in post-LT patients, suggesting that the former may be sensitive to mild DAA neurotoxicity.

A low-cost, user-friendly electroencephalographic recording system for the assessment of hepatic encephalopathy.

UNLABELLED: Electroencephalography (EEG) is useful to objectively diagnose/grade hepatic encephalopathy (HE) across its spectrum of severity. However, it requires expensive equipment, and hepatogastroenterologists are generally unfamiliar with its acquisition/interpretation. Recent technological advances have led to the development of low-cost, user-friendly EEG systems, allowing EEG acquisition also in settings with limited neurophysiological experience. The aim of this study was to assess the relationship between EEG parameters obtained from a standard-EEG system and from a commercial, low-cost wireless headset (light-EEG) in patients with cirrhosis and varying degrees of HE. Seventy-two patients (58 males, 61 ± 9 years) underwent clinical evaluation, the Psychometric Hepatic Encephalopathy Score (PHES), and EEG recording with both systems. Automated EEG parameters were calculated on two derivations. Strong correlations were observed between automated parameters obtained from the two EEG systems. Bland and Altman analysis indicated that the two systems provided comparable automated parameters, and agreement between classifications (normal versus abnormal EEG) based on standard-EEG and light-EEG was good (0.6 < κ < 0.8). Automated parameters such as the mean dominant frequency obtained from the light-EEG correlated significantly with the Model for End-Stage Liver Disease score (r = -0.39, P < 0.05), fasting venous ammonia levels (r = -0.41, P < 0.01), and PHES (r = -0.49, P < 0.001). Finally, significant differences in light-EEG parameters were observed in patients with varying degrees of HE. CONCLUSION: Reliable EEG parameters for HE diagnosing/grading can be obtained from a cheap, commercial, wireless headset; this may lead to more widespread use of this patient-independent tool both in routine liver practice and in the research setting. (

A Model for Predicting Development of Overt Hepatic Encephalopathy in Patients With Cirrhosis.

BACKGROUND & AIMS: Overt hepatic encephalopathy (HE) affects patients' quantity and quality of life and places a burden on families. There is evidence that overt HE might be prevented pharmacologically, but prophylaxis would be justified and cost effective only for patients at risk. We aimed to identify patients with cirrhosis at risk for overt HE. METHODS: We collected data from October 2009 through December 2012 for 216 consecutive patients with cirrhosis (based on liver biopsy, 96 patients with minimal HE), admitted to the Gastroenterology Unit at the University of Rome. Patients were followed up and evaluated for an average of 14.7 ± 11.6 months; development of overt HE was recorded. We analyzed end-stage liver disease scores, shunt placement, previous overt or minimal HE, psychometric hepatic encephalopathy score (PHES), and levels of albumin, bilirubin, creatinine, and sodium to develop a prediction model. We validated the model in 112 patients with cirrhosis seen at the University of Padua and followed up for 12 ± 9.5 months. RESULTS: During the follow-up period, 68 patients (32%) developed at least 1 episode of overt HE. Based on multivariate analysis, the development of overt HE was associated with previous HE, minimal HE (based on PHES), and level of albumin less than 3.5 g/dL (area under curve [AUC], 0.74). A model that excluded minimal HE but included albumin level and previous HE also identified patients who would develop overt HE (AUC, 0.71); this difference in AUC values was not statistically significant (P = .104). Both models were validated in the independent group of patients (3 variables: AUC, 0.74; 95% confidence interval, 0.66-0.83; and 2 variables: AUC, 0.71; 95% confidence interval, 0.63-0.78). CONCLUSIONS: We developed and validated a model to identify patients with cirrhosis at risk for overt HE based on previous HE, albumin levels, and PHES. If PHES was not available, previous HE and albumin levels still can identify patients at risk. Psychometric evaluation is essential for patients with no history of HE. These findings should aid in planning studies of pharmacologic prevention of overt HE.

Prognostic benefit of the addition of a quantitative index of hepatic encephalopathy to the MELD score: the MELD-EEG.

BACKGROUND & AIMS: A slowed electroencephalogram (EEG) is indicative of the presence of hepatic encephalopathy (HE). Since HE is not reflected in the MELD score and is an important prognostic parameter, we assess the prognostic benefit of the addition of an EEG-based HE index to the MELD. METHODS: Three hundred and ninety-two patients with cirrhosis underwent EEG and automated determination of its mean dominant frequency (MDF). MELD was calculated at the time of EEG recording. Patients were monitored for up to 18 months in relation to the occurrence of death/transplantation. The prognostic value of the stand-alone/combined MELD and MDF was calculated using standard survival analysis techniques. Patients transplanted for hepatic decompensation were considered dead on the day of transplantation, those transplanted for hepatocellular carcinoma were censored. The findings were validated using a split-sample technique (reference group: n = 256; test group: n = 136). During the follow-up period, 107 patients died/were transplanted for hepatic decompensation. RESULTS: Both MELD and MDF predicted mortality on Kaplan-Meier analysis, and both were independent predictors of mortality on a Cox model. Based on Cox regression parameters, a novel prognostic index was devised, as follows: MELD-EEG = 0.087*MELD-0.306*MDF. On ROC curve analysis, MELD-EEG had higher prognostic accuracy in predicting 12- and 18-month mortality compared to MELD (P = 0.016 and P = 0.018, respectively). In addition, it had better sensitivity and reduced the misclassification rate for given levels of specificity. On validation, no significant differences were observed between the reference/test groups. CONCLUSIONS: The addition of an automatically obtained EEG-based index improves the prognostic accuracy of the MELD score.

Covert hepatic encephalopathy: agreement and predictive validity of different indices.

AIM: To investigate the agreement and prognostic value of different measures of covert hepatic encephalopathy (CHE). METHODS: One-hundred-and-thirty-two cirrhotic outpatients underwent electroencephalography (EEG), paper-and-pencil psychometry (PHES) and critical flicker frequency, scored on the original/modified (CFFo/CFFm) thresholds. Eighty-four patients underwent Doppler-ultrasound to diagnose/exclude portal-systemic shunt. Seventy-nine were followed-up for 11 ± 7 mo in relation to the occurrence of hepatic encephalopathy (HE)-related hospitalisations. RESULTS: On the day of study, 36% had grade I HE, 42% abnormal EEG, 33% abnormal PHES and 31/21% abnormal CFFo/CFFm. Significant associations were observed between combinations of test abnormalities; however, agreement was poor (Cohen's κ < 0.4). The prevalence of EEG, PHES and CFFo/CFFm abnormalities was significantly higher in patients with grade I overt HE. The prevalence of EEG and CFFm abnormalities was higher in patients with shunt. The prevalence of EEG abnormalities was significantly higher in patients with a history of HE. During follow-up, 10 patients died, 10 were transplanted and 29 had HE-related hospitalisations. Grade I HE (P = 0.004), abnormal EEG (P = 0.008) and abnormal PHES (P = 0.04) at baseline all predicted the subsequent occurrence of HE; CFF did not. CONCLUSION: CHE diagnosis probably requires a combination of clinical, neurophysiological and neuropsychological indices.

Sleep-wake abnormalities in patients with cirrhosis.

A considerable proportion of patients with cirrhosis exhibit insomnia, delayed sleep habits, and excessive daytime sleepiness. These have been variously attributed to hepatic encephalopathy and impaired hepatic melatonin metabolism, but the understanding of their pathophysiology remains limited and their treatment problematic. Sleep is regulated by the interaction of a homeostatic and a circadian process. The homeostatic process determines sleep propensity in relation to sleep-wake history, thus the need to sleep increases with the duration of the waking period. The circadian process, which is marked by the 24-hour rhythm of the hormone melatonin, is responsible for the alternation of high/low sleep propensity in relation to dark/light cues. Circadian sleep regulation has been studied in some depth in patients with cirrhosis, who show delays in the 24-hour melatonin rhythm, most likely in relation to reduced sensitivity to light cues. However, while melatonin abnormalities are associated with delayed sleep habits, they do not seem to offer a comprehensive explanation to the insomnia exhibited by these patients. Fewer data are available on homeostatic sleep control: it has been recently hypothesized that patients with cirrhosis and hepatic encephalopathy might be unable, due to excessive daytime sleepiness, to accumulate the need/ability to produce restorative sleep. This review will describe in some detail the features of sleep-wake disturbances in patients with cirrhosis, their mutual relationships, and those, if any, with hepatic failure/hepatic encephalopathy. A separate section will cover the available information on their pathophysiology. Finally, etiological treatment will be briefly discussed.

The influence of environmental factors on sleep quality in hospitalized medical patients.

INTRODUCTION: Sleep-wake disturbances are common in hospitalized patients but few studies have assessed them systematically. The aim of the present study was to assess sleep quality in a group of medical inpatients, in relation to environmental factors, and the switch to daylight-saving time. METHODS: Between March and April 2013, 118 consecutive inpatients were screened and 99 (76 ± 11 years; hospitalization: 8 ± 7 days) enrolled. They slept in double or quadruple rooms, facing South/South-East, and were qualified as sleeping near/far from the window. They underwent daily sleep assessment by standard questionnaires/diaries. Illuminance was measured by a luxmeter at each patient's eye-level, four times per day. Noise was measured at the same times by a phonometer. Information was recorded on room lighting, position of the rolling shutters and number/type of extra people in the room. RESULTS: Compliance with sleep-wake assessment was poor, with a range of completion of 2-59%, depending on the questionnaires. Reported sleep quality was sufficient and sleep timing dictated by hospital routine; 33% of the patients reported one/more sleepless nights. Illuminance was generally low, and rolling shutters half-way down for most of the 24 h. Patients who slept near the window were exposed to more light in the morning (i.e., 222 ± 72 vs. 174 ± 85 lux, p < 0.05 before the switch; 198 ± 72 vs. 141 ± 137 lux, p < 0.01 after the switch) and tended to sleep better (7.3 ± 1.8 vs. 5.8 ± 2.4 on a 1-10 scale, before the switch, p < 0.05; 7.7 ± 2.3 vs. 6.6 ± 1.8, n.s. after the switch). Noise levels were higher than recommended for care units but substantially comparable across times/room types. No significant differences were observed in sleep parameters before/after the switch. CONCLUSION: Medical wards appear to be noisy environments, in which limited attention is paid to light/dark hygiene. An association was observed between sleep quality and bed position/light exposure, which is worthy of further study.

Quantifying memory in complex physiological time-series.

In a time-series, memory is a statistical feature that lasts for a period of time and distinguishes the time-series from a random, or memory-less, process. In the present study, the concept of "memory length" was used to define the time period, or scale over which rare events within a physiological time-series do not appear randomly. The method is based on inverse statistical analysis and provides empiric evidence that rare fluctuations in cardio-respiratory time-series are 'forgotten' quickly in healthy subjects while the memory for such events is significantly prolonged in pathological conditions such as asthma (respiratory time-series) and liver cirrhosis (heart-beat time-series). The memory length was significantly higher in patients with uncontrolled asthma compared to healthy volunteers. Likewise, it was significantly higher in patients with decompensated cirrhosis compared to those with compensated cirrhosis and healthy volunteers. We also observed that the cardio-respiratory system has simple low order dynamics and short memory around its average, and high order dynamics around rare fluctuations.

Excessive daytime sleepiness and hepatic encephalopathy: it is worth asking.

The relationship between hepatic encephalopathy (HE) and the sleep-wake disturbances exhibited by patients with cirrhosis remains debated. The aim of this study was to examine the usefulness of sleep-wake interview within the context of HE assessment. One-hundred-and-six cirrhotic patients were asked three yes/no questions investigating the presence of difficulty falling asleep, night awakenings and daytime sleepiness. All underwent formal HE assessment, quantitative electroencephalography and standardised psychometry. Fifty-eight were monitored for 8 ± 6 months in relation to the occurrence of HE. Patients complaining of daytime sleepiness (n = 75, 71 %) had slower EEGs than those who did not report it (relative alpha power: 37 ± 19 vs. 48 ± 17 %, p < 0.05). In addition, daytime sleepiness was associated with the presence of portal-systemic shunt (79 vs. 57 %, p < 0.05) and HE history (72 vs. 45 %, p < 0.05). Finally, the absence of excessive daytime sleepiness had a Negative Predictive Value of 92 % (64-100) in relation to the development of HE during the follow-up period. These data support the appropriateness of adding a yes/no question on the presence of excessive daytime sleepiness to routine assessment of patients with cirrhosis, to help identify those who do not need further, formal HE screening.