Databases were searched for both published and unpublished studies. The approach to searching for studies for a scoping review followed the standard 3-step method [8]. The first step involved an initial limited search of relevant databases, followed by an analysis of the text words in the title and abstract, as well as the index terms used to describe the article. The search for published studies included a 2-way search strategy. One way was to search the journal and reference databases, such as CINAHL, MEDLINE, JBI, and Web of Science. Another way was to search article-based (journal) databases, such as ACM Digital Library, IEEE Xplore, and BMJ Journals. The search for unpublished studies included Mednar, Trove, OCLC WorldCat, and Dissertations and Theses. A second search was undertaken across all included databases using all identified keywords and index terms. Additional search strategies, including citation searches for specific researchers or articles (eg, gold-standard articles) and chain searches (reviewing the reference lists of systematically selected articles), were included to complement the search for published and unpublished papers. Studies, such as reviews (systematic, scoping, and umbrella) and letters to editors, were excluded. Studies published in English were considered. While the precise origin of the specific phrase “digital health twin” is hard to pinpoint, the foundational concepts of digital twins began gaining significant traction in healthcare around 2016, driven by advancements in related fields like the internet of medical things and artificial intelligence [24].

This scoping review considered experimental and quasi-experimental study designs, including randomized controlled trials, nonrandomized controlled trials, before-and-after studies, and interrupted time-series studies. In addition, analytical observational studies, including prospective and retrospective cohort studies, case-control studies, and analytical cross-sectional studies, were also considered for inclusion. This review considered descriptive observational study designs, including case series, individual case reports, and descriptive cross-sectional studies for inclusion.

Qualitative studies were also considered, focusing on qualitative data, including, but not limited to, designs such as phenomenology, grounded theory, ethnography, qualitative description, and action research. Text and opinion papers regarding the benefits, challenges, and strategies to overcome the challenges posed by DHT were also considered, as the scoping review includes a broad scope of evidence.

Following the search, all identified citations were collated and uploaded into EndNote 20 (Clarivate Analytics), and duplicates were removed. Following a pilot test, titles and abstracts were then screened by 2 or more independent reviewers for assessment against the inclusion criteria for the review. Potentially relevant sources were retrieved in full, and their citation details were imported into a Microsoft Excel sheet instead of the JBI System for the Unified Management, Assessment, and Review of Information [35] due to a lack of resources. In addition, 2 independent reviewers assessed the full text of selected citations in detail against the inclusion criteria. Reasons for excluding sources of evidence in full text that did not meet the inclusion criteria were recorded and reported in the scoping review. Any disagreements that arose between the reviewers at each stage of the selection process were resolved through discussion or with the assistance of an additional reviewer (as an arbitrator). The search results and the study inclusion process were reported in full in the final scoping review and presented in the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) flow diagram [36,37].

A total of 2 independent reviewers used a data extraction tool they had developed to extract data from the papers included in the scoping review (see Table 1). The data extracted included specific details about the participants, concept, context, study methods, and key findings relevant to the review questions.

A draft charting table was developed as a data extraction tool. While extracting data from each included evidence source, the charting table was modified and revised as necessary. The modifications were detailed in the scoping review. Any reviewer disagreements were resolved either by the reviewer or with the assistance of an additional reviewer (as an arbitrator).

We extracted variables to ensure alignment with our research questions, while some variables may emerge during full-text screening; therefore, it was essential to predefine the key data extraction elements (as the protocol is structured). Clearly outlining these variables ensured consistency in data collection, enhanced transparency in the scoping review methodology, and strengthened the study’s replicability. We also followed the JBI Manual for Evidence Synthesis as a guide, which provided a basic data extraction table template to ensure completeness, methodological consistency, and adherence to best practices in data extraction [38].

The results are presented as a “map” of the data extracted from the included papers, in a tabular form (as necessary) and in a descriptive format that aligns with the review’s objective and scope. A clear explanation for each category is provided, accompanied by a narrative summary that describes how the results relate to the review’s objectives and questions. This scoping review synthesizes key findings from the literature on the application of DHTs in older adult care settings.

A result-based convergent synthesis design was used in which all types of studies, such as quantitative and qualitative, were analyzed and presented [39]. The findings were then integrated using convergent synthesis, which identified five key challenges. Those challenges included (1) data security and privacy concerns, (2) equity and accessibility of health care, (3) effectiveness concerning context, timing, and location, (4) ethical implications regarding autonomy, consent, and overdiagnosis, and (5) the impact of DHTs on health care workflows and provider workload.

Figure 1 shows the results of the search strategy and inclusion of studies as a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram. The total number of studies identified was 856, which included searching bibliographic databases (n=786 studies) and searching for gray literature and other sources, such as reference lists of included studies (n=70 studies). After removing 344 duplicates, a total of 512 records were screened. The titles and abstracts of each of the 512 studies were screened independently by 2 reviewers (the principal author as the first reviewer of all studies and the contributing authors as second reviewers on a similar number of studies each); 354 studies were excluded after screening because they were not relevant to the review question. A full-text review assessing the eligibility of the remaining 158 studies resulted in 20 studies being advanced to the final list of included studies, while 138 studies were excluded (see Figure 1).

A search strategy using Boolean search strings in databases is provided in Table S2 in Multimedia Appendix 2, and the inclusion and exclusion criteria used during the review process are outlined in Table S3 in Multimedia Appendix 2.

The studies reviewed emphasize the integration of DHTs in health care, offering a wide range of applications, including virtual simulations, disease monitoring, and health care delivery.

This review identified a range of challenges based on the key characteristics of the included studies (see Table 1), which are briefly described hereinafter:

Equity in access to DHT technologies is another significant concern, especially in the context of older adult care. Although DHTs hold promise for personalized care, disparities in access to technology may exacerbate existing health inequities [16].

The location and timing of DHT implementation significantly influence its effectiveness in care settings for older adults. Liu et al [26] and Bruynseels [12] showed that the efficacy of DHTs could vary considerably across different care environments, including home care, nursing homes, and hospital settings.

Ethical concerns are central to implementing DHTs, particularly in terms of patient autonomy, informed consent, and the risk of overdiagnosis.

Introducing DHTs into care settings for older adults may significantly alter the care workflow, with both positive and negative implications.

Several studies propose strategies to mitigate these ethical challenges that prioritize inclusivity, transparency, and patient autonomy (see Multimedia Appendix 1). Governance frameworks were aimed at ensuring the data had openness and privacy [12]. On the other hand, Sahal et al [32] and Zhou et al [33] advocated for integrating blockchain technologies and decentralized models to enhance data security and user control. In addition, Vidal et al [28] and Wickramasinghe et al [31] highlighted the importance of multidisciplinary collaboration and integrated care models, such as integrated living models, which promoted coordinated care and supported the ethical implementation of DHTs in practice [28,31].

Collectively, these studies illustrated a shared understanding of both the opportunities and ethical responsibilities associated with the deployment of DHTs in older adult care settings. There has been a consistent call for robust ethical oversight, patient-centered governance, and policies that ensure equitable access to these technologies [12,21,23].

Several studies offer suggestions for improving DHT integration into health care. Most studies highlighted ethical and quality of care challenges in care settings for older adults and recommend developing clear guidelines for using DHT (see Multimedia Appendix 1). For instance, Venkatesh et al [9] suggested considering computation, implementation, and regulation challenges to ensure the proper functioning of health digital twins for precision medicine. These suggestions highlighted the importance of addressing technical and ethical hurdles for DHTs to integrate into health and care systems fully.

The implementation of DHTs in health and social care for older adults presents both significant opportunities and inherent risks. In this scoping review, 20 studies were included from a total of 856 identified through a systematic literature search. This review aims to gain insights into the best available evidence on the implementation of DHTs for older adults in health and social care. This discussion critically examines five key challenges that emerge from the literature. These challenges include (1) data security and privacy concerns; (2) equity and accessibility of health care; (3) effectiveness in relation to context, timing, and location; (4) ethical implications regarding autonomy, consent, and overdiagnosis; and (5) the impact of DHTs on health care workflows and provider workload. Overcoming such issues will ensure that DHTs contribute to the quality of care of older individuals and do not take away from it.

The increasing reliance on DHTs requires robust data protection, particularly for vulnerable populations, such as older individuals. DHTs are based on large multimodal datasets, including biometric data, health records, and real-time environmental sensing, which raise significant ethical and privacy concerns [26,30]. Several studies highlight the risks associated with unauthorized data access and potential misuse, particularly for older individuals who may lack familiarity with digital systems and, consequently, are more vulnerable to exploitation [5,12]. Although DHTs provide substantial benefits, such as continuous health monitoring [40] and predictive health care analytics [7], they also introduce risks, including data breaches and unwarranted surveillance [19]. The establishment of ethical guidelines that mandate transparency, accountability, and patient consent is essential in curbing these threats [20]. Blockchain technology, as proposed by Sahal et al [32], could potentially provide a safe manner of data management; nonetheless, empirical investigations are required to ascertain its usefulness in real-life health care settings.

While DHTs offer potential advancements in personalized health care, concerns remain regarding equitable access. The digital divide, particularly amongst older cohorts within lower socioeconomic segments, stands to exacerbate health care disparities [21]. Furthermore, digital twin-controlled drug therapies and individualized health interventions may inadvertently become privileged health care solutions, accessible predominantly to wealthy populations, thereby further aggravating existing disparities [11]. Equity must take precedence while deploying DHTs, with policy measures to curb accessibility barriers through government policies, ring-fenced finances, and digital literacy programs. Otherwise, integrating DHTs will likely widen health and care inequalities rather than bridge them.

The performance of any digital health technology dramatically depends on the environment in which they are implemented [41,42]. Studies show that DHTs perform optimally in well-structured health care settings, such as hospitals and specialist clinics, with strong technological infrastructures that support real-time patient location and accurate data integration [26]. The usefulness of such technologies in home-care environments where technology and care capabilities are limited has not been adequately established [27]. On the other hand, the timing of DHT implementation is also a critical factor influencing its success. The rapid adoption of DHTs during the COVID-19 pandemic raised concerns regarding premature reliance on untested digital health solutions [20]. Similarly, DHT interventions conducted early in the course of dementia care are more beneficial than interventions done in later stages [19], and improve pain management and reduce patient outcome variability with the effect of physiological features on the achieved pain relief [18]. Therefore, strategies for implementing DHT must be customized according to individual health status, disease stages, and diverse care settings to optimize their impact.

The application of DHTs generates complex ethical questions, primarily about patient autonomy and informed consent. Older people with impaired cognition may be unable to fully grasp the implications of consenting to continuous digital health monitoring [29]. In addition, coercion, the compulsion that persons may feel in adopting DHTs by virtue of health care policy or social culture, is of interest to voluntary involvement [21]. The second ethical concern is overdiagnosis [43,44]. DHT predictive algorithms can lead to an overestimation of disease risk and, consequently, unnecessary medical procedures that increase patient anxiety and place additional pressures on health care systems (Lin et al [22]). While early diagnosis is one of the significant advantages of DHTs, careful calibration is necessary to distinguish between necessary interventions and overmedicalization. Ethical guidelines governing the use of DHT must prioritize informed patient choice over algorithmic assumptions, so that clinical decisions are made appropriately based on clinical need [28,45].

The presence of DHTs in geriatric care settings has conflicting effects on health care workers. On the one hand, DHTs can streamline care processes, reducing administrative workload through automated data collection and real-time patient monitoring, thereby enhancing clinical decision-making [7,20]. On the other hand, the transition to DHT-based care models necessitates significant changes to clinical workflows, potentially increasing short-term workload and requiring extensive training [31]. This necessitates that health care professionals be adequately trained to interpret and apply DHT-generated insights to patient care plans. Research by Alves et al [5] suggests that virtual reality (VR)-based training simulations facilitate the integration of digital twin technology before full-scale implementation. However, unless carefully managed, there is a risk of overreliance on automated decision-support systems, potentially undermining the clinical judgment of health care professionals [23]. Consequently, the integration of DHTs must be approached with caution, ensuring a balance between technological efficiency and the human expertise essential to high-quality patient care.

The study provides a strong ethical analysis, but it would benefit from more involvement of health care professionals and older adults, which could have enriched the findings with practical insights. The study highlights the importance of balancing technological innovation with ethical considerations to ensure DHTs enhance, rather than compromise, the quality of care for older adults. One of the key advantages is that this provides valuable insight into the benefits. A key strength is a systematic approach; the guidelines by JBI’s methodology for scoping reviews ensure methodological rigor. This study is comprehensive, as it consolidates evidence from various studies on the safety, equity, practicality, ethics, and impact on care workflow of these digital clinical points of care. This illustrates the potential of DHTs in early disease detection and dementia, particularly in highlighting their potential contribution to preventive health care [19]. However, concerns over overdiagnosed patients and unintended consequences, including heightened anxiety and unnecessary procedures, highlight the lack of empirical validation [22].

A significant limitation is the use of secondary data drawn mostly from the published literature, which may exhibit bias or an evidence gap, particularly in the context of mask implementation for DHTs in practice. Another drawback of the study is that the latest search was conducted in October 2023; no further search could have been performed due to lack of resources, including funding and the research team’s time commitment. For the same reason, that is, the lack of resources, we also did not follow the JBI Methodology strictly, but instead used it as a guide. Although the search identified 786 studies, some may have been missed. Due to the strict adherence to quality assurance in the gray literature search, including the credibility, objectivity, and accuracy of non–peer-reviewed sources, no unpublished articles could have been included in this review, except the study by Bui [21] (thesis) in 2023. Another limitation is that only studies published in English were included. However, the findings of 20 included studies relate to a range of 14 countries worldwide, with most studies emanating from the United Kingdom and Europe.

The following key considerations should guide future practice and policy:

To support the effective integration of DHTs into care for older adults, several key considerations for system adaptation can be identified:

The following key directions are proposed to guide future research and strengthen stakeholder engagement:

This scoping review was conducted to assess the available evidence on implementing DHTs for the care of older adults, highlighting both significant opportunities and inherent risks. A systematic search of the literature yielded 20 studies from an initial 856 records. The studies revealed several critical characteristics regarding the implementation and ethical considerations of DHT technologies, particularly in terms of safety, equity, timing, location, participant characteristics, and their impact on workflow. A total of 5 key challenges were identified through the integrated synthesis, which is crucial for understanding the potential and limitations of DHTs in enhancing care for older adults. The challenges included (1) data security and privacy concerns; (2) equity and accessibility of health care; (3) effectiveness concerning context, timing, and location; (4) ethical implications regarding autonomy, consent, and overdiagnosis; and (5) the impact of DHTs on health care workflows and provider workload. The implications of these challenges underscore the need for more practical ethical guidelines and policy frameworks to mitigate the potential risks associated with DHT application in older care, ensuring that patients remain the ultimate decision-makers. Further research should be conducted to examine other dimensions of the quality of care, such as timeliness, acceptability, and appropriateness.