PT - JOURNAL ARTICLE ED - , TI - PURPOSE AND PROCEDURE AID - 10.1136/ebm.6.6.162 DP - 2001 Nov 01 TA - Evidence Based Medicine PG - 162--162 VI - 6 IP - 6 4099 - http://ebm.bmj.com/content/6/6/162.short 4100 - http://ebm.bmj.com/content/6/6/162.full SO - Evid Based Med2001 Nov 01; 6