Database	Time span	Search strategy
The Cochrane Hepato‐Biliary Group Controlled Trials Register	Date will be given at review status.	lamivudin* AND 'chronic hepatitis b'
Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library	Latest issue.	#1 MeSH descriptor Lamivudine explode all trees in MeSH products #2 lamivudin* in All Fields in all products #3 (#1 OR #2) #4 MeSH descriptor Hepatitis B, Chronic explode all trees in MeSH products #5 chronic hepatitis b in All Fields in all products #6 (#4 OR #5) #7 (#3 AND #6)
MEDLINE (WinSPIRS 5.0)	1950 to the time when the review is performed.	#1 explode "Lamivudine"/ all subheadings #2 lamivudin* #3 #1 or #2 #4 explode "Hepatitis‐B‐Chronic"/ all subheadings #5 chronic hepatitis b #6 #4 or #5 #7 #3 and #6 #8 random* or blind* or placebo* or meta‐analysis #9 #7 and #8
EMBASE (WinSPIRS 5.0)	1980 to the time when the review is performed.	#1 explode "lamivudine"/ all subheadings #2 lamivudin* #3 #1 or #2 #4 explode "hepatitis‐B"/ all subheadings #5 explode "chronic‐hepatitis"/ all subheadings #6 chronic hepatitis b #7 #4 or #5 or #6 #8 #3 and #7 #9 random* or blind* or placebo* or meta‐analysis #10 #8 and #9
Science Citation Index EXPANDED (http://portal.isiknowledge.com/portal.cgi?DestApp=WOS&Func=Frame)	1945 to the time when the review is performed.	#1 TS=lamivudin* #2 TS=(chronic hepatitis b) #3 #2 AND #1 #4 TS=(random* or blind* or placebo* or meta‐analysis) #5 #4 AND #3