PT - JOURNAL ARTICLE ED - , TI - Corrections AID - 10.1503/cmaj.090411 DP - 2009 Mar 31 TA - Canadian Medical Association Journal PG - 739--739-c VI - 180 IP - 7 4099 - http://www.cmaj.ca/content/180/7/739.4.short 4100 - http://www.cmaj.ca/content/180/7/739.4.full SO - CMAJ2009 Mar 31; 180