Table 6. Voluntariness: knew could withdraw or refuse^*.

Developed country studies			Developing country studies
Author	Country	Knew could withdraw	Author	Country	Knew could withdraw
Joffe et al, 200149	USA	90%; 99% knew could refuse	Ellis et al, 201018	Mali	96% of adults 93% of parents
Ellis et al, 201018	USA	98%	Karim et al, 199834	South Africa	93% of evaluation study group, 88% of sensitisation control group†
Ravina et al, 201036	USA	98% felt ‘free to refuse to participate’	Pitisuttithum et al, 199735	Thailand	88% knew could refuse
Marshall et al, 200619	USA	97%	Moodley et al, 200527	South Africa	87%
Criscione et al, 200344	USA	96%	Pace et al, 200528	Thailand	71%
Benson et al, 198560	USA	Depression study: 95%; 75% knew could refuse.	Marshall et al, 200619	Nigeria	67%
		Schizophrenia study: 83%; 75% knew could refuse	Minnies et al, 200824	South Africa	65%
Bergenmar et al, 200837	Sweden	93%; 100% knew could refuse	Pace et al, 200529	Uganda	65%; 41% knew could refuse
Franck et al, 200740	UK	91%	Kaewpoonsri et al, 200625	Thailand	53.1%
Van Stuijvenberg et al, 199853	The Netherlands	91%	Lynöe et al, 200132	Bangladesh	48%: 65% knew could refuse
Lynöe et al, 200443	Sweden	90%	Sarkar et al, 200921	India	50%
Simon et al, 200348	USA	90% of majority English speakers	Ekouevi et al, 200430	Côte d'Ivoire	27%
		78% of minority English speakers	Joubert et al, 200331	South Africa	24% (but 92% said care would no longer be good if they quit)
		60% of minority non-English speakers	Oduro et al, 200822	Ghana	21%
Montgomery et al, 199852	UK	83%	Krosin et al, 200626	Mali	10%
Penman et al, 198461	USA	80%
Riecken et al, 198262	USA	80%; 95% knew could refuse
ACHRE, 199654	USA	78%
Bergler et al, 198064	USA	77% (at start), 61% (3 months later)
Harth et al, 199556	Australia	45% (but 32% said would not be allowed)
Schats et al, 200347	The Netherlands	25%; 59% knew could refuse‡

^*Arranged from highest to lowest %.

^†However, 98% of the evaluation study group and 100% of the sensitisation control group said hospital would not allow them.

^‡Knew participation was not obligatory.

ACHRE, Advisory Committee on Human Radiation Experiments.