PT - JOURNAL ARTICLE ED - , TI - Correction AID - 10.1503/cmaj.109-2053 DP - 2009 Dec 08 TA - Canadian Medical Association Journal PG - 929--929-c VI - 181 IP - 12 4099 - http://www.cmaj.ca/content/181/12/929.4.short 4100 - http://www.cmaj.ca/content/181/12/929.4.full SO - CMAJ2009 Dec 08; 181