**4. Discussion**

To our knowledge, this is the first study investigating the trend of search queries for kidney transplantation. We observed a global decrease in public interest regarding kidney transplant, in particular in the UNOS, the Eurotransplant areas, and the UK. There is a global increase in transplanted kidneys, however, an increase in waiting time and a shortage of kidney donors highlight the demand [8]. Kidney transplant is the optimal form of renal replacement therapy for patients with end stage renal disease, improving both quality and quantity of life. Whilst this is true for both live and deceased organ donation, recipients of a live donor kidney transplant demonstrate better outcomes at both, one and five-years post transplantation [9]. Thus, raising and maintaining awareness about kidney transplants is imperative. How can we achieve this essential goal? Along with strategies discussed below, supra-national alliances such as the European Kidney Health Alliance (EKHA) are essential.

Efforts should be made to increase the number of live kidney donor transplants which are performed [9]. To help overcome hurdles like lack of awareness, particularly in populations with lower rates of live donor kidney transplants, namely ethnic minority populations and in groups who suffer from socioeconomic deprivation [10,11], successful campaigns have been orchestrated using both traditional media as well as online media, and community-based venues. By using Google AnalyticsTM, the authors found an eight-fold increase in traffic to the Infórmate website, a website developed by the Northwestern University faculty in partnership with the National Kidney Foundation, compared to

the pre-campaign period [12]. Website exposure was associated with a significant knowledge score increase between pretest and posttest assessments, which was maintained at a follow-up assessment at three weeks [13]. Readability and accessibility of online living donor and deceased donor recipient material is essential. An analysis of the top ten websites for both revealed that the reading level for the living donor materials was 12.54, while it was 12.87 for the deceased donor materials, corresponding to a university level. Overall, the readability of online material remains too high for the corresponding health literacy rates among potential kidney transplant recipients [14]. Whilst the readability must be increased, Information Score (IS) assessment also revealed a poor quality of many websites and that more input from transplant physicians is needed. Information should be freely available in multiple languages, as well as in Braille format and as audio text. Generally, websites belonging to academic institutions have higher IS than professional, or commercial websites [15]. Among 46 Italian YouTube ® videos analyzed for usefulness to inform about live donor kidney transplantation, only a minority (15.2%) were categorized to contain useful information for the general population [16].

Kidney transplant knowledge should be improved in potential recipients. The Knowledge Assessment of Renal Transplantation (KART) contains 15 items including basic information about the procedure, prognosis, and insurance issues, and has an acceptable evidenced reliability. The KART distinguished patients who spent more or less than one hour receiving di fferent types of education, including communication between doctors and medical sta ff, reading brochures, browsing the Internet, and watching videos [17]. Limited knowledge is not only present among patients but is also evident amongs<sup>t</sup> medical students. In total, 96% were aware of the possibility of live donor kidney transplantation, but only 8% of the surveyed students were registered as potential donors in this South African study [18]. Similarly, a study from Leeds found that students had a basic understanding of organ donation and transplantation but lack detailed knowledge, such as understanding the criteria which are commonly used for brain death testing [19]. A study from India reporting on 200 interviews found that awareness will promote organ donation and there is a need for e ffective campaigns that educate people with relevant information, since a majority (59%) believed that donated organs might be misused, abused, or misappropriated [20].

Potential kidney transplant donors and recipients and those who have donated or received a transplant should be invited to share their experience online, in person, and on social media platforms. A survey involving 199 patients revealed that half use social media (52.3%, not further specified which channels were used) and most reported to be willing to post information about live kidney donation on their social networks (51%) [21]. Renal patients' organizations must also be supported and encouraged to provide information via social media.

Transplant physicians, surgeons, and nursing sta ff may also use social media to increase awareness of kidney transplantation. A survey among members of the American Society of Transplant Surgeons indicated that among 299 physicians who completed the survey, 59% use social media to communicate with surgeons, 57% with transplant professionals, 21% with transplant recipients, 16% with living donors, and 15% with waitlisted candidates. Younger age and fewer years of experience in transplantation were significantly associated with a stronger belief that social media may be influential in living organ donation [22].

Religious di fferences in mixed communities may play a role. In a Dutch study, the impact of religion on live donor kidney transplantation was assessed. The authors reported that religion is not perceived as an obstacle to live donation in the Netherlands. However, there is a necessity for increased clarity and awareness for di fferent religions with respect to live donation [23]. While most of the patients seemed to favor live donor kidney transplantation, a variety of potentially modifiable barriers were identified, including inadequate patient education, emotional factors, restrictive social influences, and suboptimal communication [24].

Altruistic live donation will play an increasing role in the future. Social media is used to facilitate transplantation (i.e., through websites such as MatchingDonors.com), which was implemented as early as 1994. An organ registration fee is one of the ethical concerns of such strategies. Facebook and Twitter are freely available platforms to communicate with others within groups and via hashtags and offer the opportunity to connect with potential live donors [25]. Moorlock et al. critically assessed the so-called "identifiable victim e ffect" and proposed that institutionally organized personal case-based campaigns aimed at promoting specific recipients for directed donation, despite its ethical concerns, should be preferred to facilitate altruistic live donation [26]. Building a framework for social media and organ donation is necessary and recommendations for transplant hospitals have been issued [27]. Programs such as the Kidney Coach Program (KCP) need to be implemented in the clinical practice to equip individuals (candidates and advocates for candidates) with tools to identify potential donors, which enables individuals to discuss donation with people in their social network [28].

Amongst countries participating in the Eurotransplant program, di fferent legal strategies are employed; for instance, in Germany a potential donor needs to declare willingness to be registered as a deceased donor or 'opt in' [29]. This can increase the time it takes to ascertain suitability and thus delay transplant surgery. It also means that there are likely to be many willing donors, who simply do not register but if the system were 'opt out' would be very willing to be organ donors. Furthermore, 'opt in' systems for deceased donor donation lead to ongoing political debate which one might anticipate would help to raise awareness. When this was assessed via a Google TrendsTM search, the decrease in the Google TrendsTM index mirrored the changes observed in other Eurotransplant countries and thus this ongoing debate did not influence the public interest as assessed by Google TrendsTM. By the end of 2020, the organ donation laws in the UK will have moved from an 'opt in' system for deceased donor organ donation to an 'opt out' system (i.e., a deemed authorization system, applicable to the vast majority of the population with some notable exceptions). Northern Ireland is excepted from this change and the donation system there remains 'opt in' [30]. A significant factor in this change in legislation is the result of campaigning and lobbying from a nine-year old boy, Max Johnson, and his family. Max was awaiting a heart transplant which he ultimately received from Keira Ball, a nine-year old girl whose parents selflessly agreed to donate her organs. The legislation is to be commonly referred to as Max and Keira's Law [31].

Whilst this study shows a decreasing interest in web-based information over time in most areas, the number of live kidney donations increased in the ONT, the Eurotransplant areas, and the UK, while it was almost stable over time in the UNOS area (−3.1% from 2004 to 2018). This highlights that in most countries information from the treating physicians is more important than from the World Wide Web. A scoping review addressed strategies to increase live kidney donation and found that recipient-based education that reaches friends and family has the best evidence of being e ffective [32]. In contrast to the global trend, the Google TrendsTM search highlighted an increase in search queries in Spain. In the same time period, the number of live and deceased kidney transplantation increased by 480.3% and 46.3%. It is tempting to speculate that either a sharp increase in transplant numbers or the implementation of non-heart-beating donation increased public interest [33].

This study has a few limitations. While Google TrendsTM captures Google search queries and might act as a surrogate for public interest, Google is not the only available search engine next to other social media networks being used to search for information on the Internet. Previous work by others however indicates that Google TrendsTM is a very valid measure of public interest. Additionally, the results obtained from Google TrendsTM represent only relative numbers with no information on the absolute interest being available. We restricted our analysis to countries with an excellent documentation of transplant numbers and excluded countries from Asia and Africa, although they were included in the worldwide Google TrendsTM analysis.

In conclusion, our Google TrendsTM analysis found a decreasing public interest in renal transplantation. Strategies to inform the general population about unmet needs in the transplant setting (i.e., reduction of the waiting list time and live kidney donation) need to be utilized by all involved in the care of patients with kidney disease, by the patients themselves, and by national societies and academic institutions. Easily accessible information must be provided which is coherent and available in multiple languages including Braille and audio text. The message conveyed should be

consistent and the information should be made available on multiple platforms including webpages, social media, and paper format. This may help reduce barriers in accessing information for different groups and improve outcomes according to the principles of patient-centered care.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/9/4/1048/s1, Table S1: Search terms for the respective countries and languages are given, Table S2: The numbers of deceased donor and living donor kidney transplantations over time are given.

**Author Contributions:** Conceptualization, A.K., M.E., and P.P. Data curation, A.K., M.E., and P.P. Formal analysis, P.P. Investigation, P.P. Supervision, A.K., M.E., and P.P., Validation, A.K., M.E., J.I.S., C.K., S.D., M.R., H.N., M.J.S., K.S., A.B., H.T., G.M., and P.P. Visualization, P.P. Writing—original draft A.K., M.E., J.I.S., C.K., S.D., M.R., H.N., M.J.S., K.S., A.B., H.T., G.M., and P.P. Writing—review & editing, A.K., M.E., J.I.S., C.K., S.D., M.R., H.N., M.J.S., K.S., A.B., H.T., G.M., and P.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflicts of interest.
