Nawaz 2015.

Study characteristics
Methods	Randomised, double‐blind, placebo‐controlled clinical trial
Participants	This trial assessed the effects of rifaximin versus placebo in the prevention of hepatic encephalopathy, over a 6‐month period, in 150 people with cirrhosis and a history of 2 or more episodes of overt hepatic encephalopathy in the preceding 6 months. As it is highly likely, but not stipulated, that these participants would be taking prophylactic lactulose, this comparison is effectively rifaximin plus lactulose versus lactulose alone. There were 75 participants in each group. Age (mean ± SD) years Rifaximin: 46.7 ± 2.4 Placebo: 44.3 ± 3.6 Proportion of men (n: %) Rifaximin: 80 (53.3) Placebo: 77 (51.2) Aetiology of cirrhosis Hepatitis C virus and hepatitis B virus primarily The second most common aetiology was alcohol.
Interventions	Intervention: rifaximin 550 mg twice daily Control intervention: placebo twice daily ‐ no details provided Co‐intervention: all participants were permitted to use lactulose as standard of care. Duration of treatment: 6 months or until the first episode of hepatic encephalopathy
Outcomes	Neuropsychiatric assessment No information provided on methods for assessing hepatic encephalopathy but likely to be West Haven criteria.
Inclusion period	2014
Outcomes included in meta‐analyses	Hepatic encephalopathy
Country of origin	Single centre in Pakistan
Notes	Publication status: abstract only Vested interests bias: no conflicts of interest declared by the authors. Additional information: planned publication of full paper in future Authors contacted for further information 12 April 2021, response received 14 August 2021. Further information received included characteristics of participants, date of the study, conflicts of interest, randomisation methods, concealment of allocation, methods of blinding, handling of incomplete outcome data, trial registration status, publication status and data on our primary and secondary outcomes.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	All participants randomised by simple lottery method in a 1:1 manner
Allocation concealment (selection bias)	Low risk	Allocation concealed: codes allocated to both the groups were concealed from both the researcher and the participants.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote from author: "it was a double‐blind placebo‐controlled trial, both the participants and the researchers were blinded, it was done by allocating codes to the drug and placebo."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote from author: "it was a double‐blind placebo‐controlled trial, both the participants and the researchers were blinded, it was done by allocating codes to the drug and placebo."
Incomplete outcome data (attrition bias) All outcomes	High risk	Participants lost to follow‐up were excluded from the analyses. No intention‐to‐treat analysis.
Selective reporting (reporting bias)	High risk	Published as an abstract, in which only data on hepatic encephalopathy were reported. Although further information was received from the study authors on mortality and adverse events, its completeness is uncertain.
Other bias	Low risk	No other bias detected
Overall bias assessment (mortality)	High risk	High risk of attrition and reporting bias
Overall bias assessment (non‐mortality outcomes)	High risk	High risk of attrition and reporting bias