PT - JOURNAL ARTICLE AU - Henderson, Max AU - Page, Lisa TI - Appraising the evidence: what is selection bias? AID - 10.1136/ebmh.10.3.67 DP - 2007 Aug 01 TA - Evidence Based Mental Health PG - 67--68 VI - 10 IP - 3 4099 - http://ebmh.bmj.com/content/10/3/67.short 4100 - http://ebmh.bmj.com/content/10/3/67.full SO - Evid Based Ment Health2007 Aug 01; 10