## 1 Introduction
Moreover, eHealth solutions enable real-time communication between transplant teams, allowing seamless collaboration among specialists regardless of location. During the post-transplantation process, remote monitoring tools aid in tracking patient progress, vital signs, and medication adherence, fostering timely interventions and reducing the need for frequent in-person visits, especially critical in the early stages of recovery [17]. Overall, eHealth innovations significantly improve transplant care by optimizing workflows, enhancing communication, and ensuring personalized, continuous care for transplant recipients. However, according to [PERSON] and colleagues [19], existing eHealth in transplantation studies are fragmented. [PERSON] and colleagues [19] reviewed eHealth innovations in transplantation, highlighting their potential to improve workflows, communication, and personalized care. However, their analysis revealed a fragmentation in the field--a lack of integration and consistency across studies. Transplant types and eHealth adoption vary significantly due to the unique needs and challenges associated with different organ transplants. For example, kidney transplant recipients often require long-term remote monitoring for renal function [20], while lung transplant patients may need continuous monitoring of frailty status and pulmonary function using wearable technology [21]. Unlike general chronic disease management, transplantation involves medication adherence, frequent follow-ups, and a heightened risk of complications, making tailored eHealth solutions crucial [22, 23]. Additionally, factors such as the level of digital health literacy, trust in technology, and concerns about data security impact adoption differently across transplant populations [22, 24]. Understanding these contextual differences ensures that eHealth interventions are designed to meet the specific needs of transplant recipients, leading to better engagement, adherence, and health outcomes. These studies employed diverse eHealth interventions, such as 'telehealth' for remote healthcare services and patient education [12, 25] and 'telemedicine' for virtual clinician-patient consultations and medication-related clinic visits [18, 26]. While providing valuable insights, the existing review falls short of offering a cohesive synthesis of findings or addressing contextual differences in eHealth adoption. For this reason, to develop a comprehensive understanding of the advantages and barriers posed by eHealth in transplantation, and to delineate future research paths, it is essential to analyze and synthesize the collective body of relevant studies [27]. Therefore, this study aims to systematically review prior studies to identify the factors that have been investigated for their impact on the utilization and incorporation of eHealth in transplant care. Furthermore, it seeks to formulate an integrated framework on the application of eHealth for transplantation purposes. Given the fragmentation in existing research, as highlighted by [19], this study aims to address the lack of cohesion and consistency by offering a more comprehensive and integrated analysis of eHealth applications across different transplant types. By doing so, it will help identify the key factors influencing the adoption of eHealth in transplantation and guide the development of more tailored and effective digital health strategies. To guide this systematic review and synthesize insights from the literature, we formulated the following research questions prior to data extraction and analysis:  
* What evidence exists regarding the effectiveness of specific eHealth tools (e.g., virtual health, health apps, wearables) in improving health outcomes for transplant patients? * Who are the primary user groups of eHealth devices in the transplantation context, and how do their needs and experiences differ? * What are the predominant barriers hindering the widespread adoption of digital health tools among different user groups (e.g., patients, healthcare providers)?