Background
Due to the decrease of postmortem donation and the ongoing organ shortage, living donation has begun to serve as the most crucial donor pool with increasing numbers in the western world [
1,
2]. A specific advantage of living kidney donation is the superiority of its outcome compared to deceased organ donation [
1]. Under these circumstances, transplant centers have a legitimate interest in expanding the pool of possible donors and first studies tailored to increase living donor transplantation have been published [
3,
4]. On the other hand, the apparent medical benefits for transplant recipients have to be balanced against possible harm to living donors. A psychosocial evaluation can identify eligible donors with resilient personality traits and help to exclude psychologically vulnerable donors and finally to prevent them from possible psychological harm in the aftermath of donation [
5]. There is no consensus about the scope of the psychosocial evaluation. Currently its scientific basis is insufficient and needs to be strengthened [
6]. Besides a minimal standardized psychosocial screening [
7] also a comprehensive evaluation of donor candidates has been recommended [
8]. Therefore priority must be given to developing standards for the pre-donation psychosocial evaluation of living donor candidates.
In our previous work we researched protective factors of mental health that have been shown to facilitate healthy adjustment to life stresses as possible predictors of donors` eligibility [
5,
9]. We demonstrated that resilience and social support are significant predictors of depression [
9] prior to living liver donation. In the present study, resilience was surveyed as a protective factor predicting donors’ ‘quality of life’ prior to and in the aftermath of kidney transplantation.
Resilience is defined as a personality trait and a resource in coping with stress and illness according to Antonovsky`s theory of salutogenesis [
10]. Rutter defined resilience as a buffering factor that protects individuals from mental distress [
11]. Resilient individuals possess self-esteem, believe in one`s self-efficacy, have a repertoire of problem-solving, and satisfying interpersonal relationships. Therefore, we expected the construct of resilience to fit with the personality requirements directed to donors.
‘Quality of life’ is an assessment of how the individual's well-being may be impaired by a disease or disability and makes a comparison of the reported actual life situation with the highest possible perceived well-being over the lifespan. Recent comprehensive reviews certify that kidney donors are of good mental health, without occurrence of depressive or anxiety symptoms in the majority. But these reports include also unfavorable psychological results such as depressive reactions and fatigue in a small proportion of donors [
12‐
14]. Altogether protective and situative factors fostering positive psychosocial outcome are not sufficiently surveyed.
The objective of the present study was to find out if the resilience questionnaire is an appropriate measure of the mental stability and hardiness of the donors. Therefore we compared eligible and excluded kidney donors in relation to resilience and quality of life. A representative German adult cohort served as the control group for each questionnaire. We assumed that donor candidates would express higher levels of resilience and health-related quality of life than the norm population, and that eligible donors would score higher on these parameters than the rejected donors. Furthermore a follow-up screening was made to analyze associations of pre-donation resilience with post-donation quality of life outcomes. A second objective was to standardize donor evaluation procedures and to optimize donor recruitment. Therefore, we present our evaluation protocol and analyze the causes of exclusion from donation.
Discussion
To our knowledge, this is the first study of living kidney donors to present results of the clinical psychosocial evaluation together with patient reported outcomes. A special objective was to characterize the differences between the groups of the eligible and excluded donor candidates and outline the sample of the rejected patients.
The primary strength of our study is a large sample with a 100 % response rate, with all donor candidates who fulfilled the inclusion criteria consenting to study participation. This high acceptance rate may be due to socially desired behavior in order to pass the donor evaluation prior to transplantation. On the other side, it shows the acceptance of the donors towards the psychosomatician as an advocate and interlocutor during the screening procedures. The whole sample consisted of 55.8 % women and therefore did not present a significant gender disparity. Some previous research has reported higher rates of female donors [
21]. In times when women contributed less to the family income, they might have been considered as an organ donor more often than the male members of the family. The proportions of gender may be equalizing due to changing perceptions of gender roles in society.
The donor selection process has been pointed out as an important limitation factor of living donor transplantation [
22]. In our survey, previous mental illness or ongoing signs of mental instability were the most frequent causes of exclusion, together with nonrelated donors whose personal relationship to the donor could not be ascertained.
Standardized procedures for the psychological evaluation of living kidney donors do not exist and reports about evaluation of donors’ eligibility in the literature are rare. It is therefore not surprising that exclusion rates for psychosocial reasons are varied. In a transplantation program in London [
23], voluntary withdrawal of 42 (27 %) of the prospective donors was the commonest reason for non-donation. In a US center analysis of donor evaluation [
24] 47 % of prospective donors were excluded, 22 (5 %) of these on the basis of psychosocial reasons. In our study only psychosocial eligibility was focused and 12 (8 %) of donors were excluded. This is comparable to the US center results. The respectively low exclusion rate can putatively be explained by the first nephrology information session which has the function of a pre-screening. Especially in cases when recipients are on dialysis, treating nephrologists are well informed about family and environmental conditions.
Concerning the socio-demographic characteristics of the donors, a relevant group in our survey was the nonrelated donors. Three nonrelated candidates were excluded on the basis that their personal closeness to the recipient was not substantiated; one was also deemed not to have sufficient mental stability. In contrast to the USA, where living donation is not limited to donor-recipient pairs with long-standing emotional relationships, the German transplantation law stipulates an “obvious individual relationship” between the recipient and the donor. Donors without a prolonged emotional relationship to the recipient are therefore excluded from donation. Reasons for this procedure are concerns about covertly accepted financial profit or secret coercion, which are difficult to clarify in unrelated donation.
Eligible and excluded donors presented high scores on resilience, with eligible donors even exceeding the normative values. This result is in agreement with previous research where donors had high levels of mental health-related quality of life, prior to and in the aftermath of donation [
12]. In a recent investigation by our study group, living liver donors demonstrated values of resilience comparable to the norm, and low levels of mental distress, measured as depression or anxiety [
9]. Rudow et al. [
25] established resilience levels similar to the general population in a mixed population of living liver and kidney donors, after donation, however the study results were limited due to poor response rates, which in our study could be overcome.
In analyzing the different domains of quality of life, high effect sizes in comparison to the norm were maintained in environmental factors, which include general living conditions. In many stages of organ donation, e.g. in the post-transplant period, families need good emotional and instrumental support and resources. Putatively good living conditions and resources are a necessary precondition for families to consider living organ donation. For the domain ‘physical health’, a medium effect size was observed. Small to medium effect sizes were established for the domains ‘social relationships’ and ‘psychological health’. These results show that differences in self-reported outcomes between the groups are small. However, eligible donors achieved significantly higher scores for physical and psychological quality of life than excluded donors, an outcome that strongly supports the soundness of our clinical evaluation interview.
Male gender predicted higher psychological quality of life. This is in line with the results of a recent follow-up survey 8 to 9 years after transplantation. The authors reported emotional summary score for quality of life was lower in female donors, caused by a reduced role functioning [
26]. The world-wide higher incidence of depressive disorders in women may explain the differences [
27,
28]. Women may be burdened by multiple familial role requirements in the context of donation, e.g. as donors and simultaneously as care giving marital partners. Nevertheless this finding requires further investigation and women should be regarded as a risk group.
Looking at the whole sample pre-donation health-related quality of life was higher than in the normative sample. This finding is in line with a recent study showing that kidney donors present high levels of emotional and physical functioning before transplantation [
29].
Only 46.7 % of donors responded our follow-up questionnaires. Incomplete follow-up information for donors has been recognized in many centers and in the United States one year post-donation information was eligible for only 66.8 % for living kidney donors in the period from 2008 to 2009 [
30]. Lacking motivation of donors who prefer to be treated by their own local physician rather than the transplant program was suggested as an explanation. In our center some donors reported they wanted to cope with the donation experience by themselves.
Three months after nephrectomy donors showed a significant decline in quality of life. This may be due to the early time point of our measurement. Similar results were shown by Lumsdaine et al. [
31] who proved quality of life of kidney donors reduces to UK normative levels 6 weeks after operation. In that cohort the scores improved again at 1 year. Other authors reported that, only a small proportion of kidney donors had adverse outcomes in psychosocial health after transplantation [
12]. A large-scale multi-center study [
13] established kidney donors’ quality of life outcomes to be equal to or exceeding normative values, with the mental component staying stable over time. In recent studies mental health outcome of donors have been compared to a matched population of healthy individuals. Also with this method outlined changes in mental health of donors after transplantation did not differ from the fluctuations found in the general population [
7]. Furthermore, the physical quality of life of the donors remained stable [
32]. Compared with healthy non-donors kidney donors had an increased risk of end stage renal disease, but the magnitude of the absolute risk increase was small. It must be noted, that post-nephrectomy quality of life was measured between 1 and 48 years after transplantation in those studies [
13,
29,
32]. Our results indicate donors may have higher distress levels in the early period after nephrectomy. Psychosocial support may be most necessary at this point in time. On the other hand donors report high quality of life comparable to the norm even in this moment. This excellent quality of life outcome after transplantation can be explained by the perfect health satisfaction prior to transplantation as measured in our survey.
In accordance with our expectations, resilience was significantly correlated with all dimensions of pre-donation health-related quality of life. The higher the resilience, the higher the domain scores of health-related quality of life. Regression analyses revealed resilience as a significant predictor of all domains of pre-donation health-related quality of life. These findings are in line with its psychological construction as a buffering or mediating factor between actual burden and the degree of distress symptoms expressed [
33]. Even though organ donation is a stressful life event, candidates possessing high resilience perceived themselves as having a high level of quality of life at the time-point of donor evaluation. For a perfect comparability of such reports the psychological assessment of donor candidates should be conducted in standardized steps as we suggest with our assessment procedure.
One important limitation of our study is that only 46.7 % of the donors responded to the post- donation screening. Secondly the tendency to report toward socially accepted behavior may lead to an understatement concerning mental distress and to exaggeration of personal strengths in donors. Furthermore, this was a single center study and the group of excluded donors could be too small to detect significant results. In future, efforts should be made to establish standardized evaluation criteria and procedures that would enable researchers to compare outcomes of donors from different transplant centers and countries.
Competing interests
The authors declare that they have no competing interests.
Authors’ contribution
YE designed and performed the research, collected and analyzed the data, and wrote the paper. YK analyzed the data and wrote the paper. FV collected the data. MB performed the research and collected the data. SK designed research. OW designed research, performed the research and collected the data. All authors approved the final version of the paper and had access to the primary clinical data.