Table 1.

Prevalence of preoperative anaemia

Study	Cohort	Study population	Prevalence of anaemia (%)
Baron—BMJ 2014 [11]	Non-cardiac, non-neurological surgery	46,539	28.7
Sagger—Anesth Analg 2013 [12]	Non-cardiac surgery	574,860	25.3
Gupta Ann Surgery 2013 [13]	Patients over 65 elective vascular surgery	31,857	47
Musallam Lancet 2011 [14]	Non-cardiac surgery	227,425	30.44
Van Straten—Circulation 2009 [15]	Cardiac surgery	10,025	16
Beattie—Anaesthesiology 2009 [16]	Non-cardiac surgery	7759	39.5
Karkouti—Circulation 2008 [17]	Cardiac surgery	3500	26
Kulier—Circulation 2007 [18]	Cardiac surgery	4804	28.1 male 35.9 female
Wu JAMA 2007 [19]	Non-cardiac surgery	310,311	42.8

Broadly based on WHO definition of anaemia, <130 g/L for men and <120 g/L for non-pregnant women