Eriksson 1997.

Methods	Multicenter double‐blind, placebo controlled randomised clinical trial with parallel group design (two interventions groups). Trial duration 2 years. Follow‐up: 8 patients from the ursodeoxycholic acid and 7 patients from the placebo withdrew. Patients were stratified into symptomatic and asymptomatic.
Participants	Country: Sweden. Number of patients randomised: 116, from six centres in Sweeden, mean age 57 years (85.5% females). Inclusion criteria: PBC defined as chronic cholestatic liver disease of more than six months duration with histology typical of or compatible with PBC plus at least two of the following: ‐ positive anti‐mitochondrial antibodies; ‐ alkaline phosphatases > 1.5 times the upper reference value; ‐ IgM > 1.5 times the upper reference value during the year preceding the entry into the trial. Exclusion criteria: ‐ patients with severe end‐stage liver disease; ‐ diuretic‐resistant ascites; ‐ repeated variceal bleeding in spite of sclerosing treatment; ‐ patients waiting for liver transplantation; ‐ pregnancy; ‐ alcohol or drug abuse.
Interventions	Patients were randomly assigned to receive: Intervention group 1: 500 mg ursodeoxycholic acid (˜7.7 mg/kg/day) as two capsules in the evening, n = 60; Intervention group 2: placebo, n = 56.
Outcomes	Mortality. Liver transplantation. Symptoms ‐ pruritus, fatigue, ascites, jaundice. Liver biochemistry and bile acids. Histology ‐ portal inflammation, spill‐over, interface hepatitis, bile duct proliferation, portal fibrosis. Quality of life.
Notes	At 24 months, 32 of 49 patients allocated to placebo and still remaining in the trial were switched to ursodeoxycholic acid and 42 of 52 patients allocated to ursodeoxycholic acid and still remaining in the trial continued with ursodeoxycholic acid. Anti‐hepatitis C virus tests not performed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sequence generation was achieved using a randomisation list which was produced for every clinic.
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	Described as 'double‐blind', and placebo looked identical to ursodeoxycholic acid, but details on taste and smell not given. However outcome assessment was blinded and the possible non‐blinding of others unlikely to introduce bias.
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	Low risk	Trial appears to be free of information that could put it at risk of bias.