Allison 1986.

Methods	Randomised clinical trial.
Participants	Country: UK. Number randomised: 17. Post‐randomisation drop‐outs: 6 (35.3%). Revised sample size: 11. Mean age: 52 years. Females: 3 (27.3%). Ulcerative colitis: no. Inclusion criteria: Primary sclerosing cholangitis of the intrahepatic ducts. Exclusion criteria: Biliary bypass procedure. Follow‐up: 3 months after completion of 2‐week treatment.
Interventions	Participants were randomly assigned to 1 of 2 groups. Group 1: continuous nasobiliary irrigation with normal saline plus hydrocortisone (100 mg/d) for 2 weeks (n = 6). Group 2: continuous nasobiliary irrigation with saline alone (1 L/d) for 2 weeks (n = 5).
Outcomes	1. Mortality. 2. Proportion of participants with any type of adverse events. 3. Proportion of participants with severe adverse events. 4. Number of any type of adverse events. 5. Number of severe adverse events. 6. Liver transplantation.
Notes	Reasons for post‐randomisation drop‐out: "technical failures": Endoscopic retrograde cholangiopancreatography failure (n = 2). Nasobiliary tube insertion failure (n = 2). Nasobiliary tubes fell out of the biliary tree during lavage (n = 2).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were randomised by sealed envelope to receive continuous nasobiliary irrigation with either normal saline alone or normal saline plus hydrocortisone. [.] The randomisation code was blocked to ensure an approximately equal number of patients in each group at any stage of the trial".
Allocation concealment (selection bias)	Low risk	Quote: "Patients were randomised by sealed envelope". Comment: "Opaque sealed envelopes manually shuffled" (trial author's reply).
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Patients and interpreters blinded to allocation" (trial author's reply).
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Patients and interpreters blinded to allocation" (trial author's reply).
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 transplantation were reported.
For‐profit bias	Low risk	Comment: "Patients were cared for and followed within normal NHS founded hospital stay. No additional grants were sought" (trial author's reply).
Other bias	Low risk	Comment: no other bias.