Table 3.

 Studies showing association between relatives’ understanding of brain stem death and consent rate for organ donation. Numbers are percentages of relatives consenting to organ donation when factor was present or not

Study	No studied	Type of study	Factors associated with consent	% consenting		P value
				With factor	Without factor
Siminoff et al,w1 2001, US	420	Retrospective data collection via chart reviews, and telephone interviews with healthcare practitioners or OPO staff, and face to face interviews with family for all donor eligible deaths	Family believed patient had died when brain stem death was confirmed	63	48*	0.001
DeJong et al,w3 1998, US	164	Structured telephone interview with immediate next of kin 4-6 months after death of relative	Family understood that people cannot recover when they are brain stem dead	80	48	<0.001
			Family understood someone is brain stem dead even though heart is still beating	80	60	<0.02
Rodrigue et al,w4 2006, US	285	Retrospective structured telephone interview with next of kin of donor eligible deceased individuals	Adequate knowledge of brain stem death	71	27*	<0.001
			Explanation of brain stem death given	74	43*	<0.001
Rosel et al,w5 1999, Spain	71	Postal survey sent to all families who had been approached for organ donation at single hospital within 12 month period	Understanding of brain stem death	NA	NA	<0.01
Jenkins et al,w6 1998, US	NA	Before and after study after implementation of rapid brain death protocol	After rapid brain stem death protocol with nuclear medicine scan to confirm brain death consent rate increased	71	44	<0.01
Frutos et al,w19 1998-2003, Spain	268	Family interview with families of possible donors accepted for transplant	Acceptance of brain stem death	67	51	0.044

OPO=organ procurement organisation; NA=not available (data not given).

*Calculated from published data.