Majeed 2018.

Study characteristics
Methods	Randomised, 'placebo'‐controlled clinical trial
Participants	This trial assessed the effects of rifaximin versus placebo for the prevention of hepatic encephalopathy in 120 people with cirrhosis and a history of at least 2 episodes of overt hepatic encephalopathy in the 6 months preceding the trial who were presumably free of hepatic encephalopathy at enrolment. However, the nature of the placebo is not provided. As the majority of participants received lactulose during the trial, the comparison is essentially rifaximin plus lactulose versus lactulose alone. There were 60 participants in each group. Age (mean ± SD) years Rifaximin plus lactulose 43.0 ± 8.6 Placebo plus lactulose 45.0 ± 9.2 Proportion of men (n: %) Both groups 78 (65%) Aetiology of cirrhosis Not reported
Interventions	Intervention: rifaximin (dose unknown) Control: placebo (no information provided) Co‐intervention: of the participants receiving placebo 91.2% also received lactulose during the trial; likewise 91.4% of the participants receiving rifaximin also received lactulose. Duration of treatment: rifaximin (128 ± 45.0)days; placebo (110 ± 61.2) days
Outcomes	Neuropsychiatric assessment Development of an episode of hepatic encephalopathy based on West Haven criteria
Inclusion period	January 2017 to June 2017
Outcomes included in meta‐analyses	Hepatic encephalopathy, adverse events
Country of origin	Single centre in Pakistan
Notes	Publication status: full paper Vested interests bias: no information provided Additional information: placebo‐controlled but details of blinding not provided Authors were contacted on 10 April 2021 for further information on the characteristics of the participants and interventions, conflicts of interest, blinding and randomisation status, concealment of allocation, handling of missing data, data on mortality and serious adverse events, and data on our secondary outcomes; still awaiting response.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote "The treatment allocation were applied randomly a bunch or patients were provided with rifaximin and others with Placebo".
Allocation concealment (selection bias)	Unclear risk	Quote "The treatment allocation were applied randomly a bunch or patients were provided with rifaximin and others with Placebo".
Blinding of participants and personnel (performance bias) All outcomes	High risk	No mention of blinding; no mention of the nature of the placebo
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention of blinding; no mention of the nature of the placebo
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information about intention to treat analysis. Unclear outcome follow‐up time: trial stopped when participants experienced an episode of HE, but unclear follow‐up for those that did not. Average duration was 128 days for rifaximin + NAD and 110 for NAD alone.
Selective reporting (reporting bias)	High risk	All outcomes listed on the trial registry have been included but details of the incidences of adverse events are only reported as percentages whereas the effect on the length of hospital stay is only reported as "rifaximin treatment also reduced the stay or risk of hospitalization due to HE".
Other bias	Low risk	No other bias identified
Overall bias assessment (mortality)	Unclear risk	No deaths are reported
Overall bias assessment (non‐mortality outcomes)	High risk	Attrition bias and blinding methods are unclear