With low complication and mortality rates, live donor nephrectomy is a safe, low-risk surgical procedure. In contrast to patients, living donors are (generally) healthy individuals in whom a vital organ is removed for the benefit of others. It is of the utmost importance that any patient is correctly informed about the specific details, risks, and alternatives of a procedure, but the unique character of the live donor nephrectomy may warrant an extra vigilant approach to the informed consent process. Relevance further increases because extended criteria donors (e.g., overweight/obese donors, older donors, donors with hypertension, and/or vascular multiplicity/anomalies) are increasingly being accepted. These individuals could be more prone to complications, and potential donors must be well aware of the risks involved with their upcoming procedure (1).
Every physician, ethicist, or legalist will agree that a person giving consent should be “fully informed,” “free of coercion,” and “competent”(2), but there is no consensus on details to be provided during the process, nor the manner in which these should be delivered and documented. In 2011, the Advisory Committee on Organ Transplantation released a document with recommendations for the informed consent procedure in living organ donors in the United States. Although not legally binding, the committee recommended that each hospital involved in live organ donation should use a standardized informed consent form, adjusted to regional legislation. The document also provides a list of items that should be included in the educational process (3). These forms have not yet been implemented in all transplant centers, but at least a written and signed consent is mandatory in many (4). Unfortunately, the European situation differs from the American one. There are no European or nationwide guidelines nor are there legal documents providing structured details on the informed consent procedure. Although there are many different policies and guidelines outlining matters that should be disclosed to potential donors, details are often not specified (5, 6). The actual documentation of consent also differs regionally; Spanish law for example, dictates that consent for live donation has to be obtained, documented, and signed in the presence of a judge (7), whereas in Greece, at least two witnesses have to sign a declaration of consent (8).
These differences make it impossible for healthcare professionals to practice a uniform strategy, and it is challenging to determine which patient has received which information. Recent data from our group demonstrate that when tested on their knowledge, a large number of living kidney donors underestimate the complications and risks of live donor nephrectomy. Surman (9) published similar findings in renal and liver transplant patients, revealing significant conceptual limitations to their knowledge about their postoperative situation, underlining the importance of adequate preoperative education. Comparable results are demonstrated in other studies, where donors report varying degrees of (dis)satisfaction with and misunderstanding of provided information (10). The question is raised whether the necessary information has not been provided correctly, whether donors simply do not understand or remember it, or, as has been proposed by some, whether they selectively filter information and thus miss particular risks associated with donation. Standardizing the informed consent procedure will help us better understand and address this matter. In light of ever-growing demands for safety, transparency, and documentation within the healthcare system, it can be expected that a standardized procedure will be legally mandatory in the near future.
The aim of this systematic review is to make an assessment of the informed consent procedure as it is described in the available literature, with regards to disclosed information, timing, documentation and donor comprehension of, and satisfaction with provided information. We hereby hope to address shortcomings and create the basis for a standardized procedure. In addition, we will propose a concept to confirm the donors’ comprehension of the provided information.
Of the 1,009 articles identified in the initial search, 21 studies were included, consisting of 13 original articles and eight reviews. No additional studies were included after manually scrutinizing reference lists. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram for systematic reviews is presented in Figure 1. Unfortunately, the quality of the included articles ranges from very low to low which can be explained by the fact that our systematic review consists of observational studies, automatically downgrading the level of evidence. The detailed assessment of the quality of the available evidence using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) tool is presented in Figure 2.
Informed Consent Process
Table 1 summarizes the results of eight reviews published between 1971 and 2012 (10–17), including the country of origin and year of publication.
The main concern with informed consent in live organ donation is that hardly any research has been performed on the subject. Despite the importance of informed consent emphasized by all authors and the advice to implement standardized procedures documenting the donors’ understanding of all risks and benefits, most hospitals have not yet done so, nor are there mandatory statutes issued by governments to ensure that hospitals live up to certain standards. Various authors compare living organ donors to medical research subjects (15–18). Although they are essentially not that different in undergoing a medical procedure for the benefit of others, for the latter, strict rules and regulations apply and every research project is subject to extensive analysis by an independent institutional review board (15, 17). It can be assumed that no institutional review board would ever approve kidney removal as part of a research trial (18). Multiple authors state that donors, contrary to research subjects, may not make a decision by carefully weighing risks and benefits but rather by emotional or moral reasoning (11, 13, 19, 20). Fellner (11) describes that there seems to be a discrepancy between what the potential kidney donor experiences during the screening period and what the medical team generally assumes. Instead of a deliberate balancing of risks and benefits, a simple yes-or-no decision is followed by an extensive waiting period and a feeling of having to defend the decision. Some authors believe that donors do not actually perceive all the information given to them, but rather focus on positive aspects to reaffirm their decision (13). The question has been raised whether they actually understand all information provided to them, and it is argued that potential donors may not be fully informed at the time of consent (10, 12, 13, 15, 21). Although this theory is somewhat confirmed by donors retrospectively reporting that they did not feel adequately informed about (some) aspects of kidney donation (10, 15), it has to be taken into account that the concept of live kidney donation has changed drastically since the 1970s. The live donor nephrectomy itself has been fully implemented in the general practice, and much more information has become available regarding outcome and possible perioperative and postoperative complications. Because of these developments, live kidney donation has gained ground over the past decades, and numbers are increasing worldwide; this merits a revisited opinion on information disclosure and consent. Although the informed consent process has evolved alongside the surgical procedure in an attempt to incorporate the most up to date knowledge and transfer it to potential donors in an understandable fashion, it still has to be brought to perfection. In addition, authors worry that psychosocial and financial aspects are neglected in the informed consent procedure, which is often led by medical specialists (14, 15). More research is needed to gain insight in what information should be provided to potential donors, by whom and in which manner to ensure optimal support in the decision making process, thereby safeguarding their autonomy (10, 15).
Thirteen original articles were identified (1970–2013). Table 2 provides an overview of the main characteristics and results of these studies, as well as the country of origin. Only a few studies have been performed assessing the informed consent procedure in live kidney donation. Most are surveys (N=5) among either medical professionals (N=3) or donors (N=2), or material (i.e., educational information, consent forms) or procedure analysis (N=4). In accordance with the reviews, considerable variations were observed between transplant centers, and in some centers information provision was even deemed inadequate (22). In one survey, a little over half of the respondents reported mentioning a certain risk of developing kidney failure but another 42% told donors that this risk was nonexistent or left it out completely (23). Similar differences were encountered by other authors (24), highlighting once again the need for a standardized procedure. Although these differences can be at least partially attributed to lack of evidence regarding the medical risks donors are exposed to after donor nephrectomy, it is alarming that potential donors receive different information in different centers.
Gordon (18) showed that some donors did not feel accurately informed about the postoperative risks and possible complications by the transplant team. Fellner (20) however, reported that all donors felt the information-giving process was more than adequate. Valapour et al. (25) described that although some donors did report a lack of understanding of especially long-term (i.e. 48%), psychologic (31%), and financial risks (68%), this did not influence their theoretical willingness to donate again or negatively affect their experience, supporting Fellner’s earlier conclusion that the decision making process in donors may differ from that in patients (19, 20, 25), which was later confirmed by Simmons et al. (26).
Contents of Informed Consent
Authors agree that although medical aspects of donation are usually well covered, psychosocial and financial aspects are much less frequently discussed (22, 23, 27). Worsened familial relations associated with live kidney donation are reported in a small number of cases and up to 25% of donors deal with adverse financial effects (28). The possibility of positive psychological outcomes is mentioned in about three quarters of the centers, whereas negative aspects are often neglected (23). Parekh et al. (23) describe that informed consent in U.S. centers is mainly obtained by surgeons (74%). In non-U.S. centers surgeons are responsible for approximately 50% of the cases. Housawi et al. (24) presented similar rates with surgeons obtaining consent in 70% of donors. Table 3 demonstrates items that should, according to current literature and our own experience, be incorporated in a standardized informed consent procedure for live donor nephrectomy, and by whom they should be provided.
Many brochures and informed consent forms appear to be quite difficult to read. Gordon et al. (29) assessed 332 informed consent forms demonstrating an average college freshman reading level. This stands in marked contrast to recommendations that patient education materials should be written at an average of 5th to 8th grade primary school reading levels. Seeing this in perspective of our own living donor population, this may seem a bit harsh. The median age of our population is currently 53 years, and a recent cohort demonstrates that 56% of our donors have received further education after primary school (Timmerman et al., unpublished data). Still, every donor needs to understand all provided information, and if nearly half of the population has only gone to primary school, college reading levels may be too difficult.
Timing of Information and Consent
Authors agree that information should be repetitive and provided at an early stage (10, 15).
Although most centers use presumed consent for the evaluation process, the Centers for Medicare and Medicaid Services require programs to have two separate informed consent processes; one for the screening period and one for the actual donor nephrectomy, the latter already being employed in most centers (23, 27). Many donors report that they decided to donate a kidney the first moment they heard about the option (19, 20), before receiving any information about the risks of the procedure. It is even more striking that none of them changed their mind after going through the extensive screening process. It is recommended that specific details of provided information are carefully documented on each donor contact. Although donor understanding is still not guaranteed, there will at least be more insight into the information-giving process.
The manner of providing information to (potential) donors and the method of acquiring informed consent is dependent on the local legal situation. Policies and laws vary enormously between different countries (30, 31), and in the United States even between different states (27). In some regions, the donor’s signed informed consent is sufficient (27), whereas others require witnesses or even a public authority to be present at the time of consent (7, 8, 31). Even though informed consent is a standard requirement for live organ donation in most countries, some require additional justification (31). In the Netherlands, the law on organ donation stems from May 1996 and is quite lenient on the matter of live organ donation. Consent has to be obtained in writing, signed and dated. This is further documented in the EU Directive (EU Directive 2010/53/EU for Living Organ Donation Practice) (32) which requires Member States to adhere to minimum standards in live organ donation (van Assche et al., submitted).
Few studies discuss donors’ experience with the informed consent procedure (18, 25, 28), and most are descriptive, retrospective studies or surveys. Fellner reports positive results in early studies dating back to the seventies, with all interviewed donors reporting the experience to be “the most meaningful of their lives” (19, 20). More recent studies demonstrate that donors generally feel well informed and most of them would be willing to donate again with the information at hand (25, 28). Nonetheless, some donors do report various degrees of dissatisfaction with and misunderstanding of provided information. Gordon et al. (18) published numerous living donor experiences. For some donors, it was the most meaningful experience of their lives; others look back on the ordeal with mixed feelings. Many donors felt, at least to some degree, unprepared for (adverse) postoperative events. Two donors reported a negative experience with donor education and informed consent: complication and mortality rates and long-term risks were inadequately described as were lifestyle adjustments and risks for the recipient. Another donor reports a similar experience, where she feels that “everything she learned about live kidney donation, she learned after her surgery” and regrets the blind trust she put in the transplant team. Yet another donor criticizes the media and medical industry for “only promoting the happily-ever-after stories,” failing to investigate or share negative donor experiences. Another recurring statement in the donors’ narratives was the postoperative realization that they were ‘blinded’ and thereby not quite informed at the time of giving consent: “I acknowledged my understanding, but never actually believed the rules applied to me”, or: “I thought my consent was informed, but I eagerly heard what I wanted to hear—that I was eligible to donate”.
With regulations in health care becoming even more strict, transplant teams are forced to reevaluate current practice concerning patient safety and informed consent, especially in living organ donors undergoing surgery for the benefit of others. Donor education, leading up to informed consent, needs to be carried out according to certain standards.
We performed a systematic review of the available literature to assess the existence and contents of these standards and whether transplant centers have actually implemented such procedures in their daily practice. We have included original articles and other reviews, thus creating a “meta-review” of the available literature. To the best of our knowledge, ours is the first article that actually bundles all available evidence on the informed consent procedure in live kidney donation. This is therefore the first overview article that can serve as a basis for creating a standardized procedure. Although many authors touch on the subject, most do not actually describe the contents of the informed consent procedure. Little research has been performed, and available data show a great deal of variation in practice between different hospitals (23, 24), and even between different team members within one organization. Similar results were encountered when information brochures and informed consent forms from different centers were analyzed. In addition, these forms proved to be of an average college freshman reading level, which is much higher than the recommended level of 5th to 8th grade primary school (29).
The most alarming finding however was the fact that, although a minority, some donors reported feeling misinformed, in some cases to such a degree that they felt the transplant team had lied to them regarding possible complications, long-term results and recipient outcome (18). These donor experiences are unacceptable and pose a threat to the success of a living donor transplant program. It is our responsibility to safeguard the informed consent procedure for live kidney donation by ensuring that potential donors are well educated and prepared for their upcoming procedure and postoperative course.
Although standardizing the informed consent procedure is a noble aim, there will inevitably be variations due to cultural, religious and educational differences between donors. Still, a standardized procedure will serve as a guideline, and alterations can be made according to the local population. Additional features can further support the educational system, and adjustments can be made according to local needs. Appointing independent donor advocates or involving a home-based educational team in the process could be of great value (33–35).
Another point of interest is the fact that we cannot change the way donors perceive the information laid on them. Fellner was the first to demonstrate that most donors made the decision to donate on the first moment of hearing of the option, and none of the interviewed donors had changed their mind after learning about all the risks associated with donating a kidney (19, 20). At the time these studies were conducted, live donation was performed only in family members. Donors may therefore have felt more pressure to donate because there were fewer options for their loved ones. Still, more recent studies confirm Fellner’s earlier findings, and although much more knowledge is available regarding the nephrectomy, its outcomes, and possible adverse events, it is again suggested that donors do not actually use the provided information to make a deliberate decision, carefully weighing risks and benefits in a process eventually leading up to consenting or declining, but rather to reassure them that they have indeed made the right call (13).
There are, unfortunately, few studies reporting on donor experience regarding education and consent in live kidney donation. In the field of live liver donation, a little more information is available, but results vary: some studies report donors’ knowledge of the risks and benefits to be “good to very good,” while some others report significant gaps in their knowledge (36). Available information on kidney donors is anecdotal, and no reliable conclusions can be drawn, but it does give some insight in their perception of the information process. Although most donors considered donating to be a positive and meaningful experience and the main proportion would repeat the procedure if given the chance, quite a large percentage of donors report not being fully informed about (certain aspects of) the procedure (18, 25). Some donors report being well informed but simply thinking that the mentioned risks would not apply to them (18). This not only further underlines the importance of adequate documentation to determine whether all donors have indeed received all the necessary information, it also warrants a new strategy to confirm donor comprehension. To assess whether the provided information has actually reached donors, a pop quiz could be administered to them at different moments in their screening process. A prospective trial using short questionnaires with open questions is currently being conducted in our center to assess whether this provides accurate information regarding donor comprehension. This will give us more insight in which items of the informed consent process are covered adequately, and which need more specific attention. This then will guide us in creating a standardized procedure.
One of the foreseen problems with the incorporation of a standardized information and consent process is the heterogeneity of the potential donor pool. Striving for a worldwide standard format will therefore be virtually impossible, in light of political, cultural, and religious differences between countries and even populations within one geographical area. A standardized format can serve as a basis, and alterations can be made according to the local situation. Another objection physicians may have to the implementation of a standardized procedure is the extra labor that mandatory documentation will add to their workload. However, 82% of surveyed transplant centers worldwide would be willing to adopt centralized consent templates, with U.S. centers being slightly more willing than non-U.S. centers (79% vs. 84%, P<0.001) (23).
A limitation and one of the major issues of this review is the fact that the available evidence is rather subjective and descriptive. Because donation procedures vary between regions, countries and centers (37), as do informed consent procedures, published data are subject to interpretation in light of local practice. The contents of the informed consent procedure, and the manner in which information is provided, is dependent on local legislation and opinions on for instance ethics and religion. These opinions vary over time and per country, or even per region within a country (37, 38). Because the included studies comprise a wide time range and geographical area, results must be seen in perspective of these differences. In addition, local statistics on live donation, especially live donor nephrectomy complication rates and success rates in recipients, may influence not only the way medical practitioners inform potential donors but also the way that donors perceive this information and how they experience the donation process in general.
For this systematic review, we have only included living kidney donors, as opposed to including all potential donors (i.e., liver, lung). Although the process of informed consent in live liver or lung donation is in many aspects similar to live kidney donation, complication rates in the former two are far greater than those in live kidney donation.
In addition, the geographical distribution of live liver and lung donation is different from live kidney donation. Although there are significant differences between countries regarding live kidney donation rates, this is still a much more common procedure. Live kidney donation was the first form of live donation to be performed, and informed consent procedures for the other organs may even be based on the procedures developed for kidney donation. Even so, the (also scarce) literature on informed consent in organ donation other than kidney similarly concludes that there are many variations in policy, opinions and donor comprehension, and consensus on best clinical practice is lacking (36).
There are obviously many more ethical issues that should be addressed regarding live kidney donation, and may deserve attention during donor education and the informed consent procedure, but which are not included in this systematic review. Medical practitioners should ascertain themselves that there are no signs of coercion, and that the decision to donate is indeed voluntary. There is also the matter of paid donation, a currently much debated issue, on which opinions differ greatly (39, 40). However, these issues do not quite fall within the scope of this review and are therefore not pursued any further.
Looking at the assessment of the quality of the included studies, using the GRADE tool, we conclude that the evidence of each included study ranges from very low to low. Because the GRADE tool is primarily useful for assessment of interventional studies, the evidence scale is automatically downgraded since the published literature consists only of observational studies. Creating a protocol for a randomized controlled trial regarding the informed consent procedure is difficult and at risk for bias, and this has to the best of our knowledge not yet been initiated. It would, however, drastically improve the quality of evidence regarding the consent procedure.
In conclusion, it is clear that a standardized informed consent procedure in the live donor nephrectomy is much needed to ensure donor safety and satisfaction. It is to be expected that this will become legally mandatory, thereby protecting donors and physicians. It will further aid the transplant community in systematically providing and documenting information that will optimally prepare potential donors for the procedure and postoperative course. Once implemented, it will serve as a basis in donor education and greatly benefit donors as well as medical practitioners.
The success of implementing a standardized procedure relies on input from transplant professionals from different centers and preferably different countries involved in live kidney donation. If an international working group were to be set up, local and regional protocols and guidelines could be combined to form a solid concept. The authors would like to invite those interested in participating in such a working group to contact us, preferably through e-mail correspondence.
MATERIALS AND METHODS
All aspects of the Cochrane Handbook for Interventional Systematic Reviews were followed, and the article was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (42). No review protocol was written in advance.
Literature Search Strategy
A comprehensive search was performed on January 17th 2014 in Embase, Medline OvidSP, Web-of-Science, PubMed, CENTRAL (The Cochrane Library 2014, issue 1) and Google Scholar. No date limits were used, so that no potentially relevant articles would be missed. Detailed search strings for each database are provided in Appendix 1 (see SDC, http://links.lww.com/TP/B95), no other limits were applied. All references were screened by two independent reviewers (K.K., J.A.L.). If any discrepancies in inclusion or exclusion occurred, a senior investigator was consulted (F.J.M.F.D.). Study selection was accomplished through three phases of screening. During the first phase, the following types of studies were excluded: published conference abstracts and articles not presenting empirical research or reviews (e.g., personal commentary, letters to the editor). During the second phase, abstracts were reviewed for relevance, and the full-text articles were obtained. In the last phase, full-text articles were reviewed; requirements for inclusion were a description of the informed consent procedure in live donor nephrectomy. Manual reference checks were performed to search for potentially missing studies. No authors were contacted to provide full-text articles because all included articles were obtained in full-text. Articles not written in English were excluded to prevent translational bias.
Data Extraction and Critical Appraisal
Data extraction was performed by two authors (K.K., J.A.L.). Again, if any discrepancies occurred, consensus was reached after consulting a senior investigator (F.J.M.F.D.). The level of evidence of each article was established using the GRADE tool (43). The GRADE approach defines the quality of a body of evidence by consideration of risk of bias (methodological quality), directness of evidence, heterogeneity, precision of effect estimates and risk of publication bias.
The authors thank W.M. Bramer, biomedical information specialist, for his help in conducting the systematic literature search.
1. Ahmadi AR, Lafranca JA, Claessens LA, et al. Shifting paradigms in eligibility criteria for live kidney donation
: a systematic review. Kidney Int
2. Delmonico FL. Consensus statement on the live organ donor. J Am Med Assoc
2000; 284: 2919.
3. ACOT recommendations informed consent
. 2011 [Feb 13th 2014]; Available from: http://organdonor.gov/legislation/acotrecs118.html
4. Thiessen C, Kim Y, Formica R, et al. Living kidney donor consent: Compliance with CMS & OPTN requirements. Am J Transplant
2013; 13: 127.
5. Petrini C. Living organ donations: a comparison between the positions of national bioethics committees. Transplant Proc
2013; 45: 2594.
6. Andrews PA, Burnapp L, Manas D, et al. Summary of the British transplantation society/renal association UK guidelines for living donor kidney transplantation. Transplantation
2012; 93: 666.
Govantes MAG, Palomo PP. Assessing and selecting a living kidney donor. Nefrologia
2010; 30( SUPPL. 2): 47.
8. Canellopoulou-Bottis M. A new law on organ donation in Greece: one more effort to advance transplants. Eur J Health Law
2000; 7: 427.
9. Surman OS. Informed consent
: what the patient heard. Transplant Proc
2013; 45: 3155.
10. Gordon EJ. Informed consent
for living donation: a review of key empirical studies, ethical challenges and future research. Am J Transplant
2012; 12: 2273.
11. Fellner CH. Selection of living kidney donors and the problem of informed consent
. Semin Psychiatry
1971; 3: 79.
12. Mazaris E, Papalois VE. Ethical issues in living donor kidney transplantation. Exp Clin Transplant
2006; 4: 485.
13. Valapour M. The live organ donor’s consent: is it informed and voluntary? Transpl Rev
2008; 22: 196.
14. Ciszek M, Paczek L, Lukow P, et al. Effective optimization of living donor kidney transplantation activity ensuring adequate donor safety. Ann Transplant
2012; 17: 103.
15. Kallich JD, Merz JF. The transplant imperative: protecting living donors from the pressure to donate. J Corp Law
1994; 20: 139.
16. Adams RK. Live organ donors and informed consent
. A difficult minuet J Leg Med
. 1987; 8: 555.
17. Petrini C. Ethical issues with informed consent
from potential living kidney donors. Transplant Proc
2010; 42: 1040.
18. Gordon EJ. Living organ donors’ stories: (unmet) expectations about informed consent
, outcomes, and care. Narrat Inq Bioeth
2012; 2: 1.
19. Fellner CH, Marshall JR. Kidney donors: the myth of informed consent
. Am J Psychiatry1970
20. Fellner C. Renal transplantation and the living donor. Decision and consequences. Psychother Psychosom
1976; 27: 139.
21. Spital A. Ethical issues in living organ donation: donor autonomy and beyond. Am J Kidney Dis
2001; 38: 189.
22. Lennerling A, Nyberg G. Written information for potential living kidney donors. Transpl Int
2004; 17: 449.
23. Parekh AM, Gordon EJ, Garg AX, et al. Living kidney donor informed consent
practices vary between US and non-US centers. Nephrol Dial Transplant
2008; 23: 3316.
24. Housawi AA, Young A, Boudville N, et al. Transplant professionals vary in the long-term medical risks they communicate to potential living kidney donors: an international survey. Nephrol Dial Transplant
2007; 22: 3040.
25. Valapour M, Kahn JP, Bailey RF, et al. Assessing elements of informed consent
among living donors. Clin Transplant
2011; 25: 185.
26. RG S. Gift of Life: The Effect of Organ Transplantation on Individual, Family, and Societal Dynamics: Transaction Pub; 1987.
27. Rodrigue JR, Pavlakis M, Danovitch GM, et al. Evaluating living kidney donors: relationship types, psychosocial criteria, and consent processes at US transplant programs. Am J Transplant
2007; 7: 2326.
28. Cabrer C, Oppenhaimer F, Manyalich M, et al. The living kidney donation process: the donor perspective. Transplant Proc
2003; 35: 1631.
29. Gordon EJ, Bergeron A, McNatt G, et al. Are informed consent
forms for organ transplantation and donation too difficult to read? Clin Transplant
2012; 26: 275.
30. Midolo E, Minacori R, Panocchia N, et al. The legislation on living organ donation in Western Europe: Legal and ethical analysis and impact on clinical practice. Transplant Proc
2013; 45: 2576.
31. Lopp L. Informed Consent
. In: Ambagtsheer F, Weimar W, eds. The EULOD Project Living Organ Donation in Europe Results and Recommendations: Pabst
33. Rodrigue JR, Cornell DL, Kaplan B, et al. A randomized trial of a home-based educational approach to increase live donor kidney transplantation: effects in blacks and whites. Am J Kidney Dis
2008; 51: 663.
34. Sites AK, Freeman JR, Harper MR, et al. A multidisciplinary program to educate and advocate for living donors. Prog Transplant
2008; 18: 284.
35. Rudow DL. The living donor advocate: a team approach to educate, evaluate, and manage donors across the continuum. Prog Transplant
2009; 19: 64.
36. Gordon EJ, Daud A, Caicedo JC, et al. Informed consent
and decision-making about adult-to-adult living donor liver transplantation: A systematic review of empirical research. Transplantation
2011; 92: 1285.
37. Lennerling A, Loven C, Dor FJ, et al. Living organ donation practices in Europe—results from an online survey. Transpl Int
2013; 26: 145.
38. Lopp. Regulations Regarding Living Organ Donation in Europe: Possibilities of Harmonisation 2013. Report No.: 978-3-642-33799-4.
39. Working Group on Incentives for Living D Incentives for organ donation: proposed standards for an internationally acceptable system. Am J Transplant
2012; 12: 306.
40. Matas A. A regulated system of incentives for living kidney donation: it is time for opposing groups to have a meaningful dialogue! In: Am J Transplant
2014; 14: 1944.
41. Wright L, Faith K, Richardson R, et al. Ethical guidelines for the evaluation of living organ donors. Can J Surg
2004; 47: 408.
42. Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ
2009; 339: b2535.
43. Brozek JOA, Schünemann H. GRADEpro Computer Program 3.6 for Windows ed 2011.