Database	Time span	Search strategy
Cochrane Central Register of Controlled Trials (CENTRAL) (Wiley)	Issue 2, 2017.	#1 MeSH descriptor: [Liver Cirrhosis, Biliary] explode all trees #2 (primary biliary cholangitis or PBC) #3 #1 or #2
MEDLINE (OvidSP)	January 1947 to February 2017.	1. exp Liver Cirrhosis, Biliary/ 2. (primary biliary cholangitis or PBC).ti,ab. 3. 1 or 2 4. randomized controlled trial.pt. 5. controlled clinical trial.pt. 6. randomized.ab. 7. placebo.ab. 8. drug therapy.fs. 9. randomly.ab. 10. trial.ab. 11. groups.ab. 12. 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 13. exp animals/ not humans.sh. 14. 12 not 13 15. 3 and 14
Embase (OvidSP)	January 1974 to February 2017.	1. exp primary biliary cholangitis/ 2. (primary biliary cholangitis or PBC).ti,ab. 3. 1 or 2 4. exp crossover‐procedure/ or exp double‐blind procedure/ or exp randomized controlled trial/ or single‐blind procedure/ 5. (((((random* or factorial* or crossover* or cross over* or cross‐over* or placebo* or double*) adj blind*) or single*) adj blind*) or assign* or allocat* or volunteer*).af. 6. 4 or 5 7. 3 and 6
Science Citation Index Expanded (Web of Knowledge)	January 1945 to February 2017.	#1 TS=(primary biliary cholangitis or PBC) #2 TS=(random* OR rct* OR crossover OR masked OR blind* OR placebo* OR meta‐analysis OR systematic review* OR meta‐analys*) #3 #1 AND #2
World Health Organization International Clinical Trials Registry Platform Search Portal (apps.who.int/trialsearch/Default.aspx)	February 2017.	Condition: "primary biliary cholangitis" or PBC
ClinicalTrials.gov	February 2017.	Interventional Studies | "primary biliary cholangitis" OR PBC | Phase 2, 3, 4