Table 1.

Citations of routine drainage studies

Preference	Ref.	Country	Study design	n	PD
Removed early	Kawai et al[60], 2006	Japan	Time cohort	104	104
Selective routine drainage	Jeekel et al[73], 1992	Netherlands	Prospective case report	22	22
	Heslin et al[74], 1998	United States	Retrospective	89	89
	Lim et al[72], 2013	France	Case-control analysis	54	54
	Mehta et al[93], 2013	United States	Retrospective	709	709
	Correa-Gallego et al[75], 2013	United States	Retrospective	1122	739
No routine drainage	Van Buren et al[79], 2013	United States	Randomized prospective	137	137