1. Definition of improved manifestations of hepatic encephalopathy.

Trial	Type of hepatic encephalopathy	Neuropsychiatric assessment	Definition of overall improvement
Amodio 1997	Minimal	Number Connection Test and Brainstem Auditory Evoked Response.	Investigators did not define or assess the number of participants with an overall improvement.
Barbaro 1998	Overt	Mental status assessed using a clinical scale (Table 3), Modified Glasgow Coma Scale (Table 3), and electroencephalography (Table 4).	Improvement in clinical scores or electroencephalography.
Cadranel 1995	Overt	Mental status assessed using a clinical scale (Table 3), and electroencephalography (Table 4).	Improvement in clinical score or electroencephalography.
Dursun 2003	Minimal or overt	Mental status assessed using a clinical scale (Table 3), Number Connection Test results, and electroencephalography (Table 4).	Improvement based on the clinical score and Number Connection Test results.
Giger‐Mateeva 1999	Minimal	Number Connection Test and brainstem auditory evoked response.	Not defined. The investigators included a post‐hoc subjective assessment of alertness.
Gooday 1995	Minimal	Simple and complex reaction time, verbal memory, psychomotor speed, short‐term and working memory.	Improvement in psychomotor speed evaluated using change in reaction time; Investigators did not define or assess the number of participants with overall improvement. .
Gyr 1996	Overt	Mental status (Table 3), and electroencephalography (Table 4).	Clinically relevant improvement defined as a 2‐point improvement in clinical score at any time during treatment compared with baseline. The investigators also reported improvement defined using the clinical scale score (mean for all individual observations).
Hermant 1991	Overt	Glasgow Coma Scale (Table 3), and electroencephalography.	A 2‐point improvement in the Glasgow Coma Score and electroencephalography.
Klotz 1989	Overt	Clinical assessment (score not described).	Improvement in clinical status
Lacetti 2000	Overt	Mental status (scale not specified) and Glasgow Coma Scale (Table 3).	Investigators originally classified participants as Grade III to IV coma. Method of assessment not stipulated. The trial report defined 'clinically relevant improvement' as primary outcome defined as a 3‐point improvement in Glasgow Coma Score.
Li 2009	Overt	Glasgow Coma Scale (Table 3), and electroencephalography	Improvement in the Glasgow Coma Score of ≥ 3 points.
Pomier‐Layrargues 1994	Overt	Modified Glasgow Coma Score (Table 3), and electroencephalography.	Improvement in ≥ 2 items on modified Glasgow Coma Score within 1 hour after the end of treatment.
Van der Rijt 1995	Overt	Clinical scale (Table 3).	A ≥ 1 point decrease in severity of hepatic encephalopathy.
Zhu 1998	Overt	Clinical scale (Table 3).	Overall improvement in hepatic encephalopathy based on clinical grade.

RCT: randomised clinical trial.