Table 6.

Comparison of blood loss and transfusion requirements

Study	Study design	Number of patients	Interaction	Blood loss (mL)	% patients who had transfusions		Followup
Warwick et al. [30]	Thromboprophylaxis						Not described (14 days?)
	THA	78	Enoxaparin	1207	1.65 units
	RCT	78	Control	1231	1.47 units (% not available)
Francis. et al. [9]	Thromboprophylaxis
	THA	279	Warfarin 12 hours preoperative versus	1601	% patients who received transfusions not described		7 ± 2 days
	RCT	271	dalteparin 2 hours preoperative	1600
Colwell et al. [5]	Thromboprophylaxis
	THA	176	Aprotinin	709	17%		Not described (“analysed if at least one efficacy measurement”)
	RCT	177	Control	957	32%
Hull et al. [13]	Thromboprophylaxis	496	Dalteparin 2 hours preoperative	1512	Day 0	42%	Not described (“central adjudication of safety events in our trial included all events from the commencement of surgery up to postoperative day 8”)
					Days 1–8	43%
	THA	487	12–24 hours postoperative	1503	Day 0	41%
					Days 1–8	38%
	RCT	489	Warfarin postoperative	1471	Day 0	38%
					Days 1–8	28%
Walsh et al. [29]	Risk for transfusion Retrospective THA	1034	LMWH and Coumadin® versus aspirin and foot pump	502 (perioperative, no drain?)	50% (RR 2.8 and 1.54)		Reviewed retrospectively
Johansson et al. [15]	Tranexamic acid
	THA	47	Tranexamic acid	969	(8/47)	17%	6–8 weeks
	RCT	53	Control	1324	(23/53)	43%
Borgen et al. [3]	Timing of thromboprophylaxis		Fragmin
	THA	298	12 hours preoperative	1230	53%		6 months
	Retrospective	301	6 hours postoperative	1084	35%
Current study	Timing of thromboprophylaxis		Fragmin
	THA	40	12 hours preoperative versus	1081	30%		6 months
	RCT	40	6 hours after start	1023	12.5%