**4. Discussion**

The majority of respondents indicated that they had not asked potential donors to donate, suggesting that transplant candidates may make assumptions as to why individuals may or may not be able to donate. Although 81.8% reported that one or more individuals had o ffered to donate, 14.4% of these participants did not have a potential donor that proceeded to donor assessment. Whilst some of these individuals may have received a DDKT before their potential donor started assessment, others may have been deemed unsuitable for donation by the transplant candidate. These findings highlight the importance of understanding patient-identified reasons as to why individuals are deemed unsuitable as living kidney donors.

Black, Asian and minority ethnic group participants were more likely than White participants to indicate that family members lived too far away to donate, and to report financial concerns in part linked to geographical distance. The qualitative data provided insight into these identified barriers, and as described they would appear to be surmountable. In the UK, NHS England allows potential donors from overseas to be reimbursed for travel, accommodation and visa costs after the event [33]. However these large "up-front" costs may be prohibitive to potential donors, and previous qualitative research has shown that many patients are unaware of the reimbursement policy [26]. Clarifying UK immigration policy and highlighting the reimbursement scheme may help potential Black, Asian and minority ethnic group recipients access their potential donor pool.

Previous research by the authors has suggested that Black, Asian and minority ethnic group ethnicity and non-Christian religious a ffiliation are associated with greater uncertainty in beliefs about living donation [34]. No respondents in our study reported perceiving a specific religion as forbidding living donation. This may reflect the success of work by faith leaders to clarify positions on living donation within the UK, including a new fatwa clarifying Islamic approval of organ donation and transplantation published in the UK in 2019 [35]. However, the participants' responses indicated that some of their potential donors did perceive religion as a barrier to donation. In particular there were several references to the distortion of religious beliefs being a barrier to donation. This highlights the need to better understand and consider the beliefs of potential donors who belong to non-mainstream religions, who may be outside the remit of denominational faith leaders.

A "culture of silence" about illness was an important theme identified in responses from Black, Asian and minority ethnic group participants. Although not directly comparable to the UK Black, Asian and minority ethnic group population, qualitative research in African-American LDKT recipients and donors has suggested that restricting disclosure and maintaining privacy of health status can protect against feelings of vulnerability [36], help to maintain self-perception and public identity, and is linked with rejection of the sick role which is sometimes associated with better coping skills in patients with kidney disease [37]. Potential African-American donors have also reported negative responses from family and friends regarding donation, and encouraging the recipient not to disclose their health status may be perceived as a protective act in that context [36]. We found that Black, Asian and minority ethnic group participants have larger potential donor pools than White participants, but this "culture of silence" may mean that Black, Asian and minority ethnic group individuals are less able to access their pool and therefore a LDKT. It may also mean that Black, Asian and minority ethnic group individuals are less able to access their social network during time of chronic illness: lack of social support and lack of an informed social network are associated with reduced access to transplantation [26,38–40], and worse transplant outcomes [41]. Interestingly, in White participants, lack of close relationships was identified as reason for non-donation, but this was not reported by Black, Asian and minority ethnic group participants, despite the geographical separation. Strategies to overcome this culture of silence could include interventions that engage with a patient's social network, such as the Dutch home-education model shown to be e ffective at increasing access to living-donor kidney transplantation for minority ethnic groups [42]. A focus on the potential benefits to family members from the education session (detection of undiagnosed kidney disease, how to optimise own health) could be emphasised. The use of "live donor champions" may also enable discussions to start: in this approach, a friend or family member is trained to undertake an advocate role, sharing information on the patient's behalf with the patient's wider social network [43]. Other approaches that may overcome "cultures of silence" include people with kidney disease, transplant recipients and donors sharing their experiences on an open web-platform such as healthtalk.org (http://healthtalk.org) and the living donation storytelling project (https://explorelivingdonation.org/) [44]. However, such approaches need to be formally evaluated for effectiveness.

Black, Asian and minority ethnic group respondents were more likely to report that potential donors were not the right blood group. Whether this represents true or perceived incompatibility requires further investigation. A single-centre study from the USA in 2002 found that more African-American donors than White donors were prevented from donating due to ABO incompatibility (9.7% vs. 5.6%, *p* < 0.01) [45]; however, to our knowledge this has not been examined in the UK. If found to be true, willingness to participate in the UK Living Kidney Sharing Scheme should be investigated, and participation encouraged.

This was a large, multicentre study utilising both quantitative and qualitative data. The questionnaire was evaluated in cognitive interviews prior to use and then piloted. The proportion of missing data was very small. However, the study has some limitations: (i) There is a risk of self-selection bias given our response rate, although this is comparable to other postal surveys in the UK [46,47] and the 47% response to a survey sent to Dutch and Swedish transplant recipients [48]. There is some evidence that Black, Asian and minority ethnic group individuals may have been under-represented but it is unclear whether the participants in the study would be different in respect to the reported reasons for non-donation. We suspect, if anything they would be more knowledgeable and engaged and so some of our results may underestimate the true associations. We did not have data on the ethnicity of non-responders and so we were unable to ascertain if there was a difference in response rate between the Black, Asian and minority ethnic group and White populations. (ii) Ethnicity can be described as a form of collective identity that draws on notions of ancestry, cultural commonality, geographical origins, and shared physical features. Ethnic identities are social constructs that are fluid across space and time [49]. In this study, ethnicity was coded using the UK's ONS 2011 census categories, but individuals may self-identify with several or none of the ethnic categories used in governmen<sup>t</sup> statistics [49]. Any ethnic identify categorisation fails to respect the heterogeneity within a group due to differing cultures, religions, languages, HLA-types, whether a person was born in their place of residence or migrated to it, and for migrants, time resident. We analysed all Black, Asian and minority ethnic group respondents as one group as our sample size prevented analysis by more specific ethnic groups (e.g., Asian-Indian, Black British, Chinese). Study findings should be considered an indicator of a signal that requires further detailed investigation. (iii) The questionnaire was only available in English, as several survey tools had only been validated in English. Findings may therefore not be applicable to patients who do not read English, who may be from White or Black, Asian and minority ethnic group groups. (iv) Participants had all received a kidney transplant and findings may not be generalisable to transplant eligible people active on the transplant waiting list. Qualitative responses were limited to hand-written free-text entries and were all in English, which may have restricted participants for whom this was not a first language. In-depth interviews would allow for further investigation of the issues raised. This study describes patient-reported and patient-identified reasons potential donors were not considered suitable for kidney donation. Patients are gatekeepers to the process, making personal judgements as to suitability: both who to approach and whose offers to accept or decline. However, surveying non-donors about their reasons for non-donation would provide a different and important perspective, although such a study would be ethically and practically challenging [50].
