Turner 1994.

Methods	Double‐blind, placebo controlled randomised clinical trial with parallel group design (two interventions groups). Trial duration: 2 years. Follow‐up: 5 patients receiving ursodeoxycholic acid and 4 placebo withdrew.
Participants	Country: UK. Number of patients randomised: 46, mean age 57 years (96% females). Inclusion criteria: ‐ liver biopsy compatible with PBC; ‐ positive AMA; ‐ abnormal liver function tests; ‐ no medication within six months of trial entry. Exclusion criteria: ‐ none listed.
Interventions	Patients were randomly assigned to receive: Intervention group 1: ursodeoxycholic acid 10mg/kg/day (mean actual dose (+/‐SD): 11.4+/‐0.9 mg/kg/day), n = 22; Intervention group 2: placebo, n = 24.
Outcomes	Mortality. Liver transplantation. Symptoms. Liver biochemistry. Liver histology. Quality of life.
Notes	Data for the following outcomes were extracted from the preliminary report of the included trial (Myszor 1990): ‐ pruritus score; ‐ serum bilirubin; ‐ serum alkaline phosphatases; ‐ serum aspartate aminotransferase. Number of patients randomised 34, follow‐up 1 year.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The trial is described as randomised, but the method of sequence generation was not specified.
Allocation concealment (selection bias)	Unclear risk	The trial was described as randomised but the method used to conceal the allocation was not described, so that intervention allocations may have been foreseen in advance of, or during, enrolment.
Blinding (performance bias and detection bias) All outcomes	Low risk	The trial was described as blinded, the parties that were blinded, and the method of blinding was described, so that knowledge of allocation was adequately prevented during the trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The numbers and reasons for dropouts and withdrawals in all intervention groups were described.
Selective reporting (reporting bias)	Low risk	Pre‐defined, or clinically relevant and reasonably expected outcomes are reported on.
Other bias	Unclear risk	It was reported that trial medications were generously donated by Thames Laboratories, Wrex‐ham, Wales.