Cash 2013.

Methods	Randomised clinical trial.
Participants	Country: UK. Number randomised: 21. Post‐randomisation dropouts: 8 (38.1%). Revised sample size: 13. Mean age: 55 years. Females: not stated. Symptomatic participants: not stated. AMA positive: 13 (100%). Responders: not stated. Mean follow‐up period (for all groups): all participants followed up for 12 months. Inclusion criteria Symptom status: not stated. AMA status: AMA‐positive participants only. Response status: not stated. Exclusion criteria Aged < 19 years or > 76 years. Cholesterol < 5 mmol/L. Known hypertension. Diabetes mellitus. History of cardiovascular disease. Already prescribed lipid‐lowering agents or hormonal preparations. Pregnancy.
Interventions	Participants were randomly assigned to 2 groups. Group 1: simvastatin (n = 7). Further details: simvastatin: 20 mg/day orally for 12 months. Group 2: placebo (n = 6).
Outcomes	None of the outcomes of interest reported.
Notes	Reasons for post‐randomisation dropouts: adverse effects.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: information not available.
Allocation concealment (selection bias)	Low risk	Quote: "Patient treatment randomization and allocation was performed independently by the Department of Research Pharmacology in the Royal Victoria Hospital at the initial baseline visit".
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The patients were blinded but the healthcare providers were not" (author's reply).
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "Outcome assessors were not blinded" (author's reply).
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: there were post‐randomisation dropouts.
Selective reporting (reporting bias)	High risk	Comment: neither mortality nor adverse events reported.
For‐profit bias	Low risk	Quote: "Financial support: The Royal Victoria Hospital Liver Support Group".
Other bias	High risk	Quote: "Patients were allowed to continue previous prescriptions for primary biliary cholangitis. It was not clear whether this was balanced across groups".