A steep growth in the number of people aged ≥60 years is expected by the end of the 21st century [1]. Age-related declines in physical and cognitive functioning and the associated adverse outcomes, such as restricted mobility, cognitive impairment, and falls, ultimately result in a decrease in the quality of life of older adults. Therefore, the term “active and healthy aging” (AHA) [2] is becoming increasingly important in policy frameworks worldwide.

A common strategy to promote healthy aging is to engage in physical activity. Previous research has shown that physical activity has a number of positive effects on physical and psychological health outcomes as well as on cognition in older adults [3-5]. Furthermore, it has been demonstrated that older adults benefit similarly from cognitive training programs targeting various cognitive functions such as memory, executive functions, attention, visuospatial skills, and information processing speed [6].

Given the comprehensive positive effects of physical activity and cognitive training, it has been suggested that a combination of both might be promising. Indeed, previous studies have revealed that simultaneous motor and cognitive training may be equally effective as, or even more effective than, separate or sequential training of both functions [7-13]. In fact, simultaneous motor-cognitive training can lead to improvements in physical functions such as balance [14-16], aspects of gait (eg, gait initiation) [17], and movement quality [18] as well as in cognitive functions such as executive control and processing speed [19,20], exercise enjoyment [21], decreased depressive symptoms, and an increased mental health–related quality of life [22].

However, several issues are limiting the success of such training programs; for instance, because most physical and cognitive training programs are provided face-to-face, accessibility is a major concern for older adults owing to potential mobility limitations, transportation issues, or a lack of facilities in their nearby community. Furthermore, demographic changes are increasing the need for long-term care and treatment [23] and pose financial, time, and personnel challenges to health care systems. As a result, training interventions can often not be provided for long enough durations, thus preventing patients classified as geriatric from reaching their full recovery potential and from leading an active and healthy lifestyle [24].

A solution to the aforementioned obstacles is offered by information and communication technologies, which can support the provision of care through telerehabilitation. Telerehabilitation is a broad term and can be defined as the remote provision of rehabilitation services [25]. Such a transfer of postacute rehabilitation to the home setting potentially offers a cost-effective solution to meet the increased demands on health care services, may solve the problem of accessibility, and can therefore play a key role in AHA. In addition, telerehabilitation is especially important during lockdown periods, such as those experienced during the recent COVID-19 pandemic.

Exergames are a promising option to provide telerehabilitation by means of simultaneous motor-cognitive training. They can be described as interactive whole-body movement game-based training approaches that efficiently connect motor and cognitive tasks [10]. This is the basic idea of the Cocare system (Dividat GmbH), a novel multicomponent exergame-based telerehabilitation system, including a stationary (Dividat Senso; Dividat GmbH) as well as a portable (Dividat Senso Flex; Dividat GmbH) exergame hardware device, an assessment system, and a digital training management system—the so-called rehabilitation cockpit. A more detailed description of the system can be found in the study by Seinsche et al [26].

Interventions with the Cocare system can be defined as complex interventions considering “the number of components involved; the range of behaviors targeted;...the number of groups, settings, or levels targeted; or the permitted level of flexibility of the intervention or its components” [27]. Implementation-based complex intervention research is primarily focusing on how to develop interventions that are implementable, cost-effective, and transferable to real-world settings and across different contexts [27,28]. Thereby, complex intervention research comprises four phases: (1) development of the intervention, (2) testing its feasibility, (3) evaluating the intervention, and (4) implementation of the intervention. In each phase, a major core element is the engagement of appropriate stakeholders, including those who will deliver and use the intervention [27,28]. Following this framework for the design and evaluation of complex interventions, the Cocare project was initiated to develop and validate the Cocare system applying an iterative user-centered design process to constantly refine the components of, and interventions with, the Cocare system. Previously, a focus group study was conducted to identify primary (older adults) and secondary (health care professionals) end-users’ needs and requirements regarding an exergame-based telerehabilitation system in general as well as the Cocare system specifically [26]. On the basis of the results, the Cocare system was adapted before being tested in a usability study that examined the perceived usefulness as well as the ease of use, acceptability, and enjoyment of the training approach [29]. In this usability study, the Cocare system received good acceptance by primary and secondary end users, with the primary end users indicating high enjoyment while playing the exergames. However, barriers such as difficulties in understanding certain assessment and game instructions were mentioned as well. After repeated adjustments, phases 2 and 3 of complex intervention research are now targeted (ie, testing the system’s feasibility and conducting a preliminary evaluation of its effectiveness).

The objectives of this study are (1) to test the feasibility of a personalized exergame-based motor-cognitive telerehabilitation training approach using the Cocare system in older adults with a prescription for rehabilitation (inpatient or outpatient) and (2) to obtain first insights into the effects of this training approach on cognitive and motor functions, balance confidence, and quality of life.

To be useful for decision makers, complex intervention research should take into consideration the complexity based on the intervention’s components as well as on its interaction with the context in which it is being implemented [27], which is why a pragmatic design approach was chosen. Thus, this study is conducted as an international pragmatic pilot randomized controlled trial (RCT) with 2 arms (parallel groups). The SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013 checklist was used for the reporting of this pragmatic RCT [30]; however, the item order has been modified slightly for good comprehensibility of our study procedures.

The study protocol was approved by all local ethical committees, including the Cantonal ethics committee in Zurich, Switzerland (2022-01746); the Don Carlo Gnocchi Foundation ethics committee in Italy (06_16/12/2022); and the Cyprus National Bioethics Committee (ΕΕΒΚ ΕΠ 2021 51). It has been registered at ClinicalTrials.gov (NCT05751551). Any amendments of the protocol are noted, and substantial changes will be reported to the ethics committees. All interested participants receive an information sheet and a consent form describing the study and providing sufficient information for the participant to make a decision regarding study participation. A team member (ie, the principal investigator or other investigators involved) arranges a personal meeting with the prospective participants and informs them again about all study procedures, benefits, risks, and their rights regarding study participation. Afterward, the consent form is signed by both—the participant and the investigator—before the participant undertakes any study procedure. The informed consent process is documented in REDCap (Research Electronic Data Capture; Vanderbilt University).

Assessments are performed in a standardized order at study entry (T1), before intervention period 2 (T2), and after the intervention (T3; Tables 1 and 2). Depending on group allocation, the T1 assessment takes 30 to 60 minutes and mainly serves to collect demographic data, randomize participants, and, in the case of IG participants, assess the functional status to subsequently create their training plan. The T2 and T3 assessments represent pre- and postintervention measurements for the evaluation of the home-based intervention’s effectiveness. Both measurements take approximately 90 minutes to complete.

An intended sample size of 180 is based on recommendations from Whitehead et al [53], who stated that, in pilot clinical trials, for an extra small standardized effect size (≤0.1) and 90% power, 75 participants per group are required. We are expecting a 20% dropout rate, which is why we aim to recruit 90 participants per group; thus, in total, 180 participants (n=60, 33% at each trial site).

In Switzerland, participants are recruited through VAMED Rehabilitation Centre Zürich Seefeld, through an advertisement in the University of the Third Age of the University of Zurich, through announcements to various senior centers and organizations, and through university newsletters. Furthermore, participants of previous studies on older adults are contacted. Participants in Italy are recruited via convenience sampling, and in Cyprus, older adults who are members of existing networks are contacted, and collaborations with multifunctional centers for older adults are used. Besides, an open invitation to the general public has been published.

The study results will be disseminated to academic groups and the public through publications, conference presentations, and social media.

This pragmatic RCT will provide new knowledge on the feasibility and effectiveness of an exergame-based telerehabilitation program in older adults.

Despite the promising results of previous studies investigating telerehabilitation and exergames in older adults, the feasibility and effectiveness of a combination of both have not yet been sufficiently demonstrated. Furthermore, the combined provision of both approaches (motor-cognitive training) performed in a home setting and independently by older adults is another novel, underexplored, and fertile research area tapped by this study. To the best of our knowledge, previous research has either investigated telerehabilitation approaches that rely on the consecutive conduction of motor and cognitive training [56], or, in the case of approaches that rely on exergames, these have often limited their focus to specific populations (eg, survivors of stroke [57-60]; patients with Parkinson disease [61,62]; and older adults with cognitive impairment [63], subsyndromal depression [22], or lower limb amputation [64]) or healthy older adults [65-67]. However, exergame-based telerehabilitation should be feasible and effective in a broader population of both healthy and recovering older adults. It should especially target those without long-term access to traditional rehabilitation interventions and should accompany them to full recovery.

For this reason, and given the nature of a pragmatic RCT, in this study, the inclusion and exclusion criteria are formulated in a rather broad way to analyze the feasibility of a motor-cognitive telerehabilitation intervention in a diverse population of older adults to mirror or reflect real-life conditions and usual clinical practice as best as possible. Therefore, only participants who are clearly unable to perform a step-based motor-cognitive training program owing to physical and cognitive limitations must be excluded (another reason for exclusion: they cannot be regarded as future targets of such intervention approaches).

Concerning the study design, pragmatic RCTs have a limited internal validity, but they provide real-world evidence as well as generalizability to many real-world settings and therefore high external validity. Thus, they are “becoming a major tool in the evaluation of complex interventions and services” [68].

The Cocare system is complex and innovative in terms of 4 aspects. First, it includes an assessment system comprising cognitive as well as physical assessments that are based on the validated TAP battery [40]. Second, it introduces in a home environment an exergame-based training approach that has previously been proven to be effective in inpatient rehabilitation of patients classified as geriatric [31]. This seems promising, given decreasing access to conventional supervised interventions owing to the demographic change. Third, the training program can constantly be monitored and managed by health care professionals who can also communicate with the participants directly through the system (eg, send them motivational or feedback messages). Finally, and most importantly, the system has been developed in an iterative user-centered design process, which previous system developers have failed to do [69,70]. Thus, after being adapted based on a focus group study and a usability study, the Cocare system is ready to enter phases 2 and 3 of complex intervention research, and an acceptable feasibility and effectiveness can be expected.