Date	Event	Description
22 June 2015	New citation required but conclusions have not changed	The additional 18 studies added to this review update did not alter the original conclusions as the majority were retrospective case note reviews with poorly validated outcome criteria.
22 June 2015	New search has been performed	This updated review was originally published in 2000. It now includes 18 new studies (Abbas 2007; Blair 2001; Chi 2009; Fiori 2012; Furuya 2012; Goto 2012; Kolomainen 2012; Mangili 2005; Mooney 2013; Parveen 2009; Perri 2014; Pothuri 2003; Pothuri 2004; Sartori 2009; Sartori 2010; Winner 2013; Wong 2009: Zhang 2012). This review update also identified 18 further studies to exclude (Amikura 2010; Badgwell 2009; Badgwell 2011; Chakraborty 2011; Dalal 2011; Davis 2001; Fitzgerald 2012; Kucukmetin 2010; Lee 2011; Legendre 2001; McCahill 2003; Miller 2000; Miner 2004; Miner 2005; Podnos 2007; Suarez 2010; Ubogagu 2010; Xinopoulos 2004). We also updated the 'Risk of bias' assessment and added 'Risk of bias' summary tables.
25 September 2008	New search has been performed	Converted to new review format.