The Consolidated Criteria for Reporting Qualitative Studies (COREQ) guidelines were followed for the reporting of this study [29], with the COREQ checklist presented in Multimedia Appendix 1.

The CURATE.DTx platform is comprised of 4 tasks: Systems Monitoring, Communications, Tracking, and Resource Management, as depicted in Figure 1. Systems Monitoring requires the user to monitor the lights and gauges and respond as quickly as possible when they illuminate or change color. Communications requires the user to listen for the call sign “NGT504” and set the radio station and frequency according to the audio instructions, ignoring instructions for other call signs. Tracking requires the user to keep the ball as close to the center of the cross-hair as possible, dragging the ball back when it deviates away. Finally, Resource Management requires the user to maintain the two fuel tank levels within the score area by opening and closing the arrow valves, making appropriate adjustments when the valves occasionally turn off or fail. All 4 tasks can occur at the same time, and the user has to manage them simultaneously until the session ends.

This study was approved by the National University of Singapore’s institutional review board (reference NUS-IRB-2021-95). Participants were recruited through purposive sampling by age group from a community senior activity center in Singapore. The activity center coordinator identified potential participants, provided an overview of the study, and arranged for informed consent and study sessions. Participants were also told about the research team’s involvement in the study and the reasons for doing the research. The research team (SPK, VVL, SV, and AR) consisted of full-time researchers, 3 female postdoctoral fellows, and 1 male research assistant, and had previous training in qualitative data collection and analyses. They screened potential participants against the following inclusion criteria: (1) Singaporean older adults aged 60 years old and older and (2) fluent in English. Participants with significant hearing, visual, or cognitive impairment that would affect their ability to complete the study were excluded. No relationships with the participants were established before the interview sessions. Recruitment took place over a period of 4 months and ended when the target sample of 15 was obtained. No participants refused to participate or dropped out after consenting to the study.

This study used semistructured interview sessions to understand the participants’ experiences and attitudes toward CURATE.DTx. Each session was approximately 90 minutes and consisted of a 30-minute playtest where participants play-tested CURATE.DTx on a Samsung Galaxy Tab A7 (SM-T500) 10.4-inch tablet, followed by a 60-minute semistructured interview on their thoughts and experience. To reduce the risk of bias and enhance the credibility and robustness of the results, methods triangulation was used [30]. We compared the participants’ actions observed during their playtest with their verbal qualitative feedback provided in the subsequent interview to ensure consistency of findings across different mediums. All sessions were in-person at the senior activity center’s premises and were conducted in English with at least 2 members of the research team and no nonparticipants present.

Before the session commenced, the research team provided an overview of the study, and informed consent was obtained. All participants consented to the audio recording of the session for transcription purposes, while the participants’ demographic background details were also collected. While performance score data from the sessions were automatically collected, they were not accessed or analyzed as they did not relate to the purpose of this study. Open-ended questions were asked during the interview based on a semistructured interview guide, which was developed to include guiding topics that broadly cover the factors of the Technology Acceptance Model (TAM) framework [31]. The guiding topics used for the interview discussion are presented in Table 1. While the research team’s past familiarity with CURATE.DTx could have influenced them to engage with participants about it in a more positive manner, these guiding topics ensured that both positive and negative feedback were fully captured. Short field notes were also taken where necessary to ensure understanding and clarity of participants’ responses. At the end of the session, all participants were reimbursed for their time. All data collected, including signed consent forms, interview recordings, and demographic data, were stored in a secure database and deidentified for the purpose of this study.

The interview recordings were transcribed verbatim, and inductive thematic analysis was used to identify patterns and emerging or recurring themes [32]. Initial coding was conducted on Microsoft Word. Participants’ responses were descriptively labeled and summarized into codes independently by the 4 members of the research team. Any discrepancies in the codes were resolved through discussion. Codes were then organized into potential themes using Microsoft Excel and further reviewed and refined in relation to the entire data set. The final codes and broader themes were generated from multiple discussions and iterations by the research analysis team (SPK, VVL, SV, and AR). Data saturation was achieved when there were no new themes identified and confirmed through discussion within the research team. There were no repeat interviews, transcripts were not returned to participants for comments, and participants did not provide feedback on the findings.

This study was approved by the National University of Singapore’s institutional review board (NUS-IRB reference: NUS-IRB-2021-95). All participants provided informed consent and were informed of their right to withdraw from the study at any time. All data collected were deidentified for the purpose of this study. At the end of their sessions, participants were reimbursed SGD 45 (US $34) for their time and participation.

A total of 15 participants completed the study (10 males, 5 females; mean age 66.1, SD 3.5, range 62-73 years). Participants were from a range of education level backgrounds, with 5 O Levels (10+ years), 6 Diploma (13+ years), and 4 University (16+ years). All participants reported regular use of technology, such as mobile phones, computers, televisions, and tablets. Full participant demographics and characteristics are presented in Table 2.

From the participants’ responses, 3 main themes emerged—comprehension, acceptability, and facilitators to adoption. Comprehension describes the participants’ understanding of the CURATE.DTx platform, acceptability covers their thoughts and attitudes towards the CURATE.DTx platform and the tablet hardware, and facilitators to adoption encompass feedback on several recommendations discussed with the participants.

Under the theme of comprehension, 2 subthemes emerged from participants’ responses, namely instruction comprehension, which is the feedback specific to the “How To Play” instructions page on the web-based platform, and task comprehension, their feedback on the individual MATB tasks and overall gameplay.

Under the theme of acceptability, 3 subthemes emerged from participants’ responses. The subthemes included table usability, engagement, and enjoyment of CURATE.DTx, and their attitude and perceived benefits of the intervention.

Under the theme of facilitators to adoption, 3 subthemes emerged from participants’ responses. The subthemes include framing and aesthetics recommendations, motivation recommendations, and the role of medical professionals.

This study aimed to understand the acceptability and user experience of older Singaporean adults using CURATE.DTx, a digital cognitive training DTx platform. Overall, we found that participants faced some difficulties with understanding the CURATE.DTx platform. However, engagement with the platform was generally still strong, and participants were also enthusiastic about using it for cognitive training, especially if advised by medical professionals. In light of these findings, there is a need to address several key factors for the next iteration of the CURATE.DTx platform to ensure greater adoption and sustained usage among this older adult demographic group, with these considerations broadly applicable to the development of other similar DTx platforms in this space as well.

We identified the importance of considering the comprehension of the instructions on overall experience when developing a cognitive training DTx. Aging has been shown to be associated with declining cognitive abilities that could affect information processing, such as in visual attention [33] and working memory [34]. Specifically, older adults may have a harder time processing unfamiliar visual information and retaining it in memory [35]. We observed this in some of our participants, who struggled to fully understand the game instructions provided on CURATE.DTx and perceived them to be too long-winded and complicated. Some of this difficulty can be attributed to the complexity of several task explanations, as well as the continuous sequential presentation of the instructions. Therefore, older adults would benefit from having complex concepts broken down into smaller portions so that each step is within their capacity for processing, and this information should be summarized again for each task to ensure that it is adequately rehearsed and retained in their memory [36]. Providing accessible bite-sized chunks of information that are reiterated at various points of the instructions will ensure that they are clear and concise, which would prevent misunderstanding and improve their overall experience when using CURATE.DTx. In addition, participants may also benefit from the implementation of instructions explained as an interactive tutorial with the opportunity to practice all 4 tasks simultaneously at the end. This would provide them with the opportunity to familiarize themselves with the tasks and gain a better understanding of the mechanisms involved.

Our findings also showed that providing in-game feedback can be a useful tool for helping older adult users understand the tasks. In line with Nielsen’s usability heuristics, which emphasizes recognition rather than recall [37], incorporating visual elements that provide small reminders of information can aid users in navigating the task without requiring them to remember specific task instructions. Our study participants themselves mentioned a preference for learning CURATE.DTx mechanics through gameplay, using in-game feedback to gauge their performance and adjust their strategies. This is in line with the literature, where feedback in educational games can provide players with schemas to help them learn from their misunderstandings [38]. Indeed, providing regular feedback about their performance enables users to engage in more critical learning [39], and clear and specific feedback—such as indicating correct and incorrect actions, highlighting areas for improvement, and offering suggestions or tips—can direct them to develop more effective game strategies. Furthermore, it is also important to present feedback in a way that is easily understandable to older adults, taking into account their cognitive abilities and visual acuity. Hence, designing a user-friendly interface with intuitive controls, clear visual cues, and accessible feedback would enhance their interaction and learning with CURATE.DTx, thus improving their overall experience.

Our findings showed that there was strong interest in using CURATE.DTx for cognitive training. Participants recognized the importance of cognitive training for maintaining cognitive functioning and believed that the CURATE.DTx platform would be useful and beneficial for this purpose. These stated views align with previous research showing that older adults in Singapore are open to adopting technology to achieve their health goals [40]. Furthermore, the intended and perceived benefits of the training platform emerged as the most common facilitators of its use. This finding aligns with the principles of the TAM framework, which suggests that the perceived usefulness of a technological tool strongly influences its acceptance as a learning and training resource [41]. Given the existing intrinsic motivation and expressed interest in CURATE.DTx, ensuring sustained engagement, would thus be key to its long-term adoption in older adults.

Engagement and enjoyment were also found to affect the acceptability of the CURATE.DTx platform. Specifically, participants expressed a preference for more challenging tasks, like Resource Management, which requires them to develop an optimal strategy for balancing resources over simpler tasks, like Systems Monitoring, which merely requires them to click on lights when they illuminate. As facing challenges in a game has previously been reported to directly enhance learning and increase engagement with the game [42], incorporating more challenging tasks can offer participants a sense of accomplishment and keep them motivated. However, we also found that some tasks were reported to be overly complex and difficult to understand for this age group. Thus, striking a “sweet spot” trade-off between challenge and ease of understanding can lead to flow—the sense of engagement and immersion in the interactive experience [43]. While the use of an adaptive training approach such as CURATE.AI can partially aid in this by adjusting the difficulty to an optimal level based on personal performance [19], improving the design of the task elements based on participant feedback would help to ensure a more cohesively enjoyable experience.

The source of the challenge is also an important consideration. While there can be a motivating in-game frustration that causes the player to want to persevere and overcome the challenge, lack of comprehension of CURATE.DTx’s tasks could instead lead to disheartening at-game frustration that causes them to disengage [44,45]. As these seemingly contradictory aspects are rated most highly in terms of importance for older adults [46], successfully finding this balance can make the platform highly appealing to this demographic group.

Finally, participants generally viewed using tablets as the physical medium for CURATE.DTx positively. However, the size and weight of the tablets were highlighted as important factors to consider, underscoring the need for a device that is easy to manage and handle. Despite some concerns about screen reflectivity, the overall design of the tablet was well-received. This is in line with existing literature reporting high satisfaction among older individuals using tablets in clinical settings [47] as well as their perceived benefit not just for cognitive training but also for enjoyment [48]. Given that the effective deployment of a tablet-based DTx in a remote setting use case requires addressing additional factors such as ensuring household internet access, it is important to note that in Singapore, where 99% of resident households, including 93% of senior-only households, have internet access [49], this is less of a concern compared with the digital divide at the global level [50], with disparities in internet access often linked poverty and unemployment [51]. Therefore, understanding the specific needs and circumstances of the target group is crucial for the successful adoption of the tablet-based platform.

Our findings revealed that enhancing the framing and aesthetics of the current CURATE.DTx platform would make it more appealing and engaging to the older Singaporean population. Specifically, incorporating visually appealing elements and features found in popular games in the current market, such as vibrant colors and attractive visuals, can help to enhance enjoyment. Adhering to design principles, such as judicious color use with no more than 2 or 3 fully saturated intense colors, can assist in accomplishing this [52]. Participants also expressed a preference for tasks framed to be more relatable and familiar to their daily lives, such as a car dashboard, rather than the current MATB flight deck simulator interface incorporated into CURATE.DTx. Again, DTx developers should consider Nielsen’s usability heuristics, specifically the principle of matching the system to the real world [37], to make the platform’s task more intuitive. Using familiar symbols, illustrations, or other analogies that resonate with older adults’ day-to-day lived experiences will ensure that they are able to understand the task requirements more easily. Such aesthetic changes can help to make the platform more appealing to older adults and increase their engagement with the platform [53].

Our findings also highlighted the importance of motivation in the DTx platform design. While participants already demonstrated intrinsic motivation in using the platform, they also welcomed extrinsic motivational factors to further strengthen their interest. Participants were particularly taken with the idea of gamification elements such as a scoring system, reporting that knowledge of their scores would drive them to improve. Enhancing scoring with a leaderboard may be an option to consider in a senior-friendly iteration of CURATE.DTx, as they have previously been shown to motivate players to strive for higher-difficulty goals [54]. Nevertheless, it is important to ensure that extrinsic motivation factors do not undermine participants’ existing intrinsic motivation to use the CURATE.DTx platform but rather enhance it [55].

Participants also supported the introduction of a greater variety of tasks for CURATE.DTx. This can be a means to prevent boredom and also promote meta-learning, a concept of applying knowledge from past experiences to new, related tasks [56]. While the concept is mainly applied in machine learning and artificial intelligence, recent research has proposed that this idea of drawing from past learned experience can be applied in cognitive training, in particular with cognitive control [57]. Promoting such learning could be beneficial to the older adults’ mental health while also increasing the appeal of the CURATE.DTx platform and improving its long-term engagement and adoption.

Finally, our findings revealed the role of medical professionals to be pivotal in the adoption process. In Singapore, health care providers are highly trusted sources for learning about health platforms [58,59], thus playing a critical role in influencing their patient’s decision to adopt new technologies. Participants also highlighted the importance of scientific evidence demonstrating the benefits of the DTx, likely reflecting this population’s trust in research [60]. They also viewed the DTx as a potential alternative to medication, indicating their willingness to explore nonpharmacological approaches to cognitive maintenance. Thus, collaborating with health care professionals and conducting further research studies to demonstrate the efficacy and cognitive benefits of the game could significantly increase trust and promote broader adoption among older Singaporean adults.

Several limitations should be considered when interpreting the findings of this study. First, the study was restricted to English-speaking older adults, which may not fully capture the experiences and perspectives of older adults from non–English-speaking backgrounds. Singapore is a multilingual country, and considering the diverse linguistic landscape, it is important to extend the research to include participants who speak languages other than English. This would provide a more comprehensive understanding of older adults’ acceptability and experiences with the cognitive training digital therapeutics platform.

In addition, it is worth highlighting that this study is focused solely on the particular DTx cognitive training platform used in this research. It’s important to acknowledge that this platform was not originally tailored for older adult users and that moving forward, it is recommended that future iterations be codesigned with the target demographic to develop a more bespoke solution. Future research should explore a wider range of cognitive training interventions and digital therapeutics platforms to gain a more comprehensive understanding of older adults’ acceptability and experiences across different interventions.

Overall, this study investigated the general acceptability and user experience of a cognitive training DTx in an older adult Singapore population. Despite facing some difficulties in instructional and task comprehension, participants were still highly engaged with the platform and found the challenge provided by the DTx to be enjoyable. Participants also expressed interest and recognized the importance of cognitive training for their population. We also found that certain aesthetics and motivational features and the incorporation of medical professionals into the onboarding process would facilitate greater adoption and long-term usage in this population. These findings highlight several important considerations that can serve as a useful reference to inform the design and implementation strategies of the future iteration of CURATE.DTx as well as other cognitive training interventions for this population.