Olsson 2005.

Methods	Randomised clinical trial.
Participants	Country: Sweden/Norway. Number randomised: 219. Post‐randomisation drop‐outs: 21 (9.6%). Revised sample size: 198. Mean age: 43 years. Females: 58 (29.3%). Separate data for the subgroup with ulcerative colitis: no. Inclusion criteria: Diagnosis of primary sclerosing cholangitis based on cholangiography. Age between 18 and 70 years. Body weight lower than 115 kg. Expected survival longer than 1 year. Exclusion criteria: Earlier treatment with UDCA. Planned pregnancy within the forthcoming 5 years. Alcohol abuse and other forms of abuse. Hepatitis B or hepatitis C infection. Follow‐up: 60 months.
Interventions	Participants were randomly assigned to 1 of 2 groups. Group 1: moderate‐dose UDCA (17‐23 mg/kg/d) over the period of follow‐up of the study (n = 97). Group 2: placebo (250 mg gelatin capsules containing microcrystalline cellulose, cornstarch, and magnesium stearate) over the period of follow‐up of the study (n = 101).
Outcomes	1. Mortality. 2. Proportion of participants with any type of adverse events. 3. Cholangiocarcinoma. 4. Liver transplant. 5. Quality of life.
Notes	Reasons for post‐randomisation drop‐out: Participants who did not attended any follow‐up visit. Participants who never took capsules.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: This information was not available.
Allocation concealment (selection bias)	Low risk	Quote: "The trial code was kept at the pharmacies in the hospitals. The code was not broken until data from all patients had been collected".
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "We conducted a randomized, double‐blind, placebo controlled, multicenter….At that time we had recruited 219 patients (121 from Sweden, 77 from Norway, and 21 from Denmark) who were randomized to either UDCA (in a daily dose of 17–23 mg/kg of body weight divided in 2 doses) or placebo in identical 250‐mg gelatin capsules containing microcrystalline cellulose".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "We conducted a randomized, double‐blind, placebo controlled, multicenter….At that time we had recruited 219 patients (121 from Sweden, 77 from Norway, and 21 from Denmark) who were randomized to either UDCA (in a daily dose of 17–23 mg/kg of body weight divided in 2 doses) or placebo in identical 250‐mg gelatin capsules containing microcrystalline cellulose".
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: Post‐randomisation drop‐outs may be related to the treatment that participants received.
Selective reporting (reporting bias)	Low risk	Comment: No published protocol was available; mortality and liver transplant were reported.
For‐profit bias	High risk	Quote: "Supported by Dr Falk Pharma GmbH". Comment: The trial was funded by a party with vested interest in the results (this company produces UDCA).
Other bias	Low risk	Comment: no other bias.