## 4 Discussion
### Limitations and Future Research  
This study has a few limitations which should be considered. Firstly, this research draws upon data gathered from prior studies investigating the use of eHealth in transplantation. Since this study does not involve primary data collection, it is susceptible to inheriting the limitations and validity issues of the studies used as sources. However, to address this limitation, as a part of the exclusion criteria, only empirical studies were included in the literature review process. Secondly, this study relied on preceding journal articles and restricted data sources. This decision was made to ensure the reliability and academic rigor of the findings, as peer-reviewed studies are subject to stringent evaluation processes. However, with advancements in technology, eHealth is constantly changing and improving, meaning there is a considerable body of literature on the subject that may exist outside of traditional academic journals and databases, including online materials and commercial publications. Although this review presents a variety of eHealth tools and implementation strategies, we recognize the need to evaluate which approaches are more effective in specific transplantation contexts. Telehealth and mHealth solutions emerged as the most frequently used and widely studied, often showing consistent benefits in improving medication adherence, accessibility, and patient engagement, particularly during post-transplant recovery [14; 40; 56]. In contrast, AI-based tools and wearables, while promising, are still in early-stage development with limited empirical evidence supporting their effectiveness. Moreover, mHealth tools that integrated personalized feedback and in-app support features were more effective in promoting self-management than those providing static information. These observations suggest that while a range of approaches exist, those that support real-time interaction, tailored content, and seamless integration into clinical workflows offer greater promise for adoption and long-term use in transplant care. Despite excluding such sources, the findings presented within this study are still relevant as it utilizes studies from peer-reviewed, well-established journals and databases commonly used for previous systematic reviews. Future research could address these gaps by integrating insights from grey literature, industry publications, and non-English studies, providing a more comprehensive perspective on eHealth adoption and advancements in transplantation care. One notable limitation of this study is the potential age bias inherent in the reviewed literature. Most of the selected studies (\(n=22\)) focused on mHealth, a domain that is more accessible and appealing to younger users who tend to use mobile devices more frequently than older individuals. Consequently, the findings may not accurately reflect the digital health engagement of older transplant recipients, who might rely more on other forms of digital technology, such as desktop computers, or may be less inclined to adopt emerging mobile applications. This age bias suggests that the observed trends in eHealth usage may be disproportionately influenced by the habits of younger patients. Future research should investigate digital health interventions across a broader age spectrum to ensure that the diverse needs and preferences of all transplant recipients are adequately captured. Such studies could help develop more inclusive eHealth strategies that promote patient empowerment and self-management for both younger and older populations. Another gap identified was the lack of studies in countries that had high rates of transplantation. Countries that have high rates of transplantation could hold a wealth of information that can be used globally to improve patient care and outcomes for transplantation. Therefore, future research should further expand to different countries. Moreover, studies within this review involved different samples of studies from different countries.