Mitchell 2001.

Methods	Study design: a double‐blind, randomised trial.
Participants	Country: Germany. Publication language: English. Inclusion criteria ‐ satisfying the cholangiographic criteria for the diagnosis of PSC; ‐ all patients had a liver biopsy with histological features compatible with the diagnosis and stable liver biochemical tests for three months before entry with a cholestatic enzyme pattern. Exclusion criteria ‐ age less than 18 or greater than 80 years; ‐ treatment with UDCA in the preceding year; ‐ previous bile‐duct surgery; ‐ dominant extrahepatic or bile duct stricture; ‐ previous choledocholithiasis; ‐ recurrent ascending cholangitis; ‐ previous history of variceal haemorrhage; ‐ decompensated liver disease; ‐ cholangiocarcinoma; ‐ active inflammatory bowel disease; ‐ and any features of a coexisting liver disease or an overlap syndrome. Participants ‐ UDCA group (n = 13) Mean age (years): 52 (range 22 to 79); Ratio of sex (M/F): 9/4; Concurrent IBD no. : 11 (84%); Symptoms: 6/13. ‐ Placebo group (n = 13) Mean age (years): 52 (range 28 to 74); Ratio of sex (M/F): 10/3; Concurrent IBD no. : 10 (70%); Symptoms: 5/13.
Interventions	UDCA group: ‐ Dose: 20 mg/kg body weight/day in two divided doses. ‐ Route: orally. ‐ Duration: two years. Placebo group: ‐ identical‐appearing capsules administered in the same quantity and manner.
Outcomes	Liver histological changes at the end of treatment; Endoscopic cholangiography changes at the end of treatment; Biochemical parameters at the end of treatment; Clinical symptoms changes at the end of treatment; and any adverse events.
Notes	Letter was sent to the authors in September 2010. No reply was received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	No information provided.
Allocation concealment?	Unclear risk	No information provided.
Blinding? All outcomes	Low risk	Quote: "...an identical‐appearing capsule administered in the same quantity and manner."
Incomplete outcome data addressed?	High risk	Follow‐up time: 2 years. Reasons for withdrawal are clearly stated for two patients. Two patients were not considered as withdrawn from study, but were not included in the analysis. One patient was not included in the analysis and no reasons were reported.
Free of selective reporting?	Low risk	Outcomes pre‐specified and required data reported.
Sample size calculation	High risk	Not stated and not used.
Intention‐to‐treat analysis	High risk	Stated but not used.