Table 2 Risk of bias assessment
From: A scoping review of the perceptions of death in the context of organ donation and transplantation
Study year location | Sample size | Representativeness of the sample Y/N or unclear. (Y if randomisation or stratified or systematic sampling technique was used or majority of population in question was targeted.) | Adequacy of response rate: excellent, good, average, poor or data not shared (> 75, > 50, > 25, > 0%) | Missing data | Conduct of pilot testing: Y/N (If no mention considered not done) | Established validity of survey instruments: Y/N (If no mention considered not done) | Overall risk of bias |
|---|---|---|---|---|---|---|---|
Alsaied 2012 Qatar [10] | 418 | Y | Good | Combined with non-responders so unclear (total 28.5%) | Y | Unclear | Low risk |
Burroughs 1998 USA [13] | 225 | Y | Excellent | No loss | Unclear (mentions questionnaire was refined) | Unclear (mentions questionnaire was refined) | Low risk |
Camut 2016 France [50] | 174 | Unclear how the participants were targeted | Good | No loss | Y | N | High risk |
Cohen 2008 Israel [25] | 2366 | Y | Good | Minimal overall less than 10% | Ya | Y | Very low risk |
DeJong 2013 Canada [43] | 189 | N (administered at a public festival and $5 incentive) | No data | Minimal | Y | Y | High risk |
Dhanani et al. 2012 Canada [40] | 245 | Y | Average | Minimal | Y | Y | Very low risk |
Dubois et al. 1999 USA [23] | 613 | Y | Average | Minimal | Y | Unclear | Low risk |
ElSafi et al. 2017 Saudi Arabia [26] | 434 | Y (single centre but good numbers) | Excellent | Minimal | Y | Y | Very low risk |
Floden 2011 Sweden [9] | 702 | Y | Good | Minimal | N | Partial validity | Low risk |
Goudet 2013 France [44] | 1057 | Y | Average | 11.60% | N | N | Low risk |
Hart et al. 2012 USA [45] | 1122 | Y | Average but non-response bias studied and excluded | Minimal as questionnaires with more than 80% of response were included | Y | Y | Very low risk |
Health professionals survey Canada 2006 [51] | 720 | N | Poor | < 15%b | N | Y | High risk |
Honarmand 2020 Canada [59] | 398 | Non- randomized (self-selection bias) | 21.2 | Incomplete surveys excluded | Y | Y | Low risk |
Hu 2015 China [51] | 373 | Adopted randomisation | Excellent | None | Y | Y | Very low risk |
Hyde et al. 2011 Australia [31] | 468 | N (possible snowballing of email, students enrolled in a particular subject were targeted, most likely for convenience) | Poor for public and average for uni students | Minimal | N | N | Very high risk |
Iriarte 2012 Spain [32] | 828 | Unclear (single university and demographics not shared) | Not shared | Not shared but apparently minimal | N | N | High risk |
Joffe et al. 2008 Canada [41] | 80 | N (single centre) | Good | Minimal | Y | Y | Very low risk |
Joffe et al. 2008 Canada [46] | 318 | N (medical Ethics and philosophy students only) | Excellent | Minimal | Y | Y | Very low risk |
Joffe et al. 2012 USA [22] | 192 | Y | Average | 12% (were excluded from the analysis) | Y | Maybe | Very low risk |
Keenan et al. 2002 Canada [56] | 128 | Y for public but not for healthcare workers | Not shared | Apparently minimal | Y | Y | Low risk |
Kubler et al. 2009 Poland [33] | 1128 | Y | Unclear | Minimal if any | N | N (translated but not validated in Polish) | Low risk |
Lee et al. 2018 Australia [57] | 161 | Non randomized (self selection bias) | Between 24 and 37% | Responses with missing data excluded | N | Y (content validity by expert panel) | Low risk |
Lewis et al. 2020 USA [60] | 92 | Non- randomized (self-selection bias) | 92/2460 | Appears minimal | N | N | High risk |
Lomero et al. 2015 Spain [24] | 236 | Single centre | Good | Minimal | Y | Y | Very low risk |
Mathur et al. 2008 USA [42] | 157 | Single centre | Excellent/good (pre and post) | < 10% | N | Y | Low risk |
Marck et al. 2012 Australia [30] | 811 | Y | Poor | Minimal | N | Y | High risk |
Marcum 2002 USA [14] | 229 | Y | Excellent | Minimal | N | Y | Very low risk |
Mikla et al. 2015 Poland [11] | 492 | Y (single university but attempts made to select from all levels of training) | Excellent | Minimal 93% completion rate | Y | Y | Very low risk |
Nair-Collins et al. 2015 USA [49] | 1096 | Y | Excellent | Minimal | Y | Y | Very low risk |
Nasrollahzadeh et al. 2003 Iran [27] | 130 | N (130 nurses from 10 ICUs is a small proportion without randomization) | Excellent | Minimal | Y | Y | Low risk |
Nowak et al. 2014 Poland [34] | 800 | Unclear (stratification medical vs non-medical, but non-medical demographics skewed towards female sex by a ratio of 3:1) | Seems 100% but unclear | Minimal | N | N | High risk |
Oo et al. 2020’ Malaysia [61] | 412 | HCW working in ED ICU and Neuro Sx | 98% | 6% | N | Y | Low risk |
Othman et al. 2020 International [38] | 1072 | Public (self selection bias) | – | Minimal | N | N | High risk |
Public survey Canada 2005 [37] | 1505 | Unclear | Not shared | Unclear | N | N | High risk |
Rodrigue et al. 2018 USA [48] | 112 | N (single transplant centre) | Good | Minimal | Y | Y | Low risk |
Rodriguez-Arias 2013 Spain France USA [47] | 587 | Y | Average | Minimal | Y | Y | Very low risk |
Roels et al. 2010 Multiple countries [20] | 19,537 | Yes | Good | Not mentioned | Y | Y | Very low risk |
Rozaidi et al. 2000 Malaysia [28] | 426 | Unclear | Unclear | Minimal | N | N | Very high risk |
Sarnaik et al. 2013 USA [39] | 264 | N (73.4% working in a transplant centre suggesting response bias) | Average | Minimal | Y | N | Low risk |
Schicktanz et al. 2017 Germany [35] | 648 | Unclear (some attempt at stratification) | Good | Minimal | N | Maybe (comprehensibility tested) | Low risk |
Siminoff et al. 2004 USA [36] | 1351 | Y | Good | Minimal | Y | Y | Very low risk |
Skwirczyńska et al. 2019 Poland [58] | 368 | Non- randomized (self-selection bias) | 73.6 | Unstated | Y | Y (previously validated and extensively used) | Low risk |
Teixeira et al. 2012 Brazil [12] | 136 | Single centre | Unclear | Minimal | N | N | High risk |
Yang et al. 2015 China [29] | 476 | N (convenience sampling) | Excellent | Some | N | Y | Low risk |
Youngner et al. 1989 USA [21] | 195 | Unclear (one group was randomized not the other) | Excellent | Minimal | Y | Y | Very low risk |