Table 2:

Newcastle–Ottawa quality assessment of observational studies included in this meta-analysis on the impact of re-exploration for bleeding after cardiac surgery

Study	Representativeness	Selection	Ascertainment of exposure	Outcome not comparability present at start of study	Comparability	Assessment of outcome	Follow-up long enough	Adequacy of follow-up
Unsworth-White 1995	★	★	★	★		★	★	★
Moulton 1996	★	★	★	★		★	★	★
Sellman 1997	★	★	★	★		★	★	★
Dacey 1998	★	★	★	★		★	★	★
Karthik 2004	★	★	★	★	★★	★	★	★
Choong 2007	★	★	★	★		★	★	★
Ranucci 2008	★	★	★	★	★★	★	★	★
Mehta 2009	★	★	★	★		★	★	★