PT - JOURNAL ARTICLE ED - , TI - Purpose and procedure AID - 10.1136/ebm.15.4.e1 DP - 2010 Aug 01 TA - Evidence Based Medicine PG - 101--102 VI - 15 IP - 4 4099 - http://ebm.bmj.com/content/15/4/101.short 4100 - http://ebm.bmj.com/content/15/4/101.full SO - Evid Based Med2010 Aug 01; 15