An exploratory, cross-sectional design was employed to descriptively examine the distribution of cognitive, attitudinal, and psychological responses observed after exposure to a narrative-based digital intervention for ACP. The purpose was to explore how a combined educational experience, consisting of an explanatory video and an interactive narrative game, might be associated with initial postintervention responses in the context of the structural challenge of difficulty in initiating ACP discussions.

The study was designed within the framework of feasibility and exploratory intervention research, with a specific focus on assessing acceptability and identifying patterns of postintervention responses. “Effects” were operationally defined not as causal changes based on pre-post comparisons but as the distribution of responses observed following exposure to the intervention.

For quantitative analysis, means and SDs were calculated for each of the 12 primary outcome items (Q7-Q18) to describe the distribution of postintervention responses. As a secondary exploratory component of the analysis, postintervention responses were also descriptively compared between participants with and without involvement in health care/long-term care to examine preliminary patterns associated with professional background.

Owing to unequal group sizes, Welch t tests were conducted to compare responses between participants involved in health care/long-term care and those who were not involved. This comparison was performed as an exploratory subgroup analysis based on the premise that prior experiential exposure to health care or caregiving contexts may influence the formation of psychological readiness for ACP engagement [10,11].

Statistical significance was set at a 2-tailed α level of .05. As this study was exploratory and hypothesis-generating in nature, no adjustment for multiple comparisons was applied; findings from between-group analyses should therefore be interpreted as descriptive patterns rather than confirmatory statistical evidence.

Open-ended responses (Q20) were treated as exploratory supplementary data to contextualize and illustrate the quantitative findings. Responses were reviewed in their entirety and organized into broad descriptive themes based on recurring content patterns; representative excerpts were then selected from each theme to illustrate the range of reactions observed following the intervention. Although this was not designed as a formal mixed methods study, the integration of quantitative results with qualitative excerpts is theoretically supported as a complementary analytic approach [30].

This study was determined to constitute educational practice research and therefore was considered outside the scope of the Ethical Guidelines for Medical and Biological Research Involving Human Subjects issued by the Ministry of Education, Culture, Sports, Science and Technology, the Ministry of Health, Labour and Welfare, and the Ministry of Economy, Trade and Industry of Japan [31].

The study did not constitute medical or biological research involving human subjects. Accordingly, formal review and approval by an institutional review board were not required.

In accordance with Article 6 of the Research Ethics Regulations of the Kobe Institute of Computing, the study was reviewed and approved by the Dean of the Graduate School (acting as the Compliance Officer) and the supervising faculty member prior to data collection. No formal institutional review board approval number was issued under this institutional review process.

Participation was entirely voluntary. Before accessing the intervention, individuals received clear information regarding the study’s purpose, procedures, and their right to withdraw at any time without disadvantage, which was presented on a dedicated instructional webpage. Completion of the postintervention questionnaire was regarded as the provision of informed consent, consistent with established ethical practice in anonymous web-based research [19,20].

Personally identifiable information, such as names, contact details, or institutional affiliations, was not collected at any point. Questionnaire responses were collected using an anonymous Google Form. All collected data were stored in password-protected storage managed solely by the investigator, analyzed in anonymized form, and used solely for research purposes. Data were not disclosed to third parties.

Participants recruited via the crowdsourcing platform (Lancers) received ¥300 (approximately US $2) each, which was determined in accordance with the platform’s standard remuneration policy and considered commensurate with the estimated task duration (17‐22 min). Individuals were recruited through the researcher’s professional network or via direct referral participated voluntarily without compensation.

A separate small-group session was conducted with 4 undergraduate and graduate nursing students for the purpose of content review and intervention feedback. These participants received a token honorarium; however, their responses were not included in the primary analysis.

The narrative game included a summary screen (“INITIAL DISCUSSION Summary”) displayed upon completion of gameplay. This screen aggregated participants’ in-game selections and was designed to be optionally captured as a personal screenshot. The summary screen was automatically cleared upon session termination, and no images or screenshots were collected by the research team. Choices recorded during gameplay were retained only temporarily to generate this summary and were not stored as identifiable behavioral data. No identifiable participant images, screenshots, or other visual materials were collected by the research team or included in the paper or supplementary materials. Any screenshots or illustrative images presented in this paper do not contain personally identifiable information and cannot be used to identify individual participants [20].

Furthermore, the characters depicted in the game interface (Figures 3 and 4), including “Nurse Lynn,” are fictional characters created solely for the educational intervention and do not represent the study investigator, research staff, or any study participants. The summary screen shown in Figure 4 displays only the player’s in-game selections and optional free-text comments. No participant names or other personally identifiable information are displayed or stored.

As described in the Methods section, 158 valid responses were included in the final analysis (46 with health care/long-term care experience and 112 without). All 12 primary outcome items (Q7-Q18) were administered as mandatory fields, and no missing data were observed for these variables. Demographic characteristics are summarized in Table 1.

This exploratory cross-sectional study evaluated the feasibility, acceptability, and postintervention response patterns of a fully web-based, narrative-based ACP educational intervention integrating an explanatory video and an interactive visual novel game. The intervention was successfully delivered in a fully asynchronous online format and was broadly acceptable to participants, consistent with the objectives of feasibility-oriented research [29]. Overall, participants reported positive responses regarding their understanding of ACP, the perceived importance of ACP, and its personal relevance. Responses related to imagining future ACP discussions and to perceived psychological barriers exhibited greater variability, suggesting differences in psychological readiness to engage with ACP. Exploratory subgroup analyses revealed only limited differences between participants with and without prior involvement in health care or long-term care. Because this study did not include baseline measurements or a control group, these findings should be interpreted as descriptive postintervention response patterns rather than evidence of causal effects or behavioral change [29].

ACP has increasingly been conceptualized as a continuing process of dialogue rather than a single decision-making event [1,26]. Nevertheless, previous studies have consistently reported that initiating ACP remains challenging because discussions are frequently delayed until medical crises occur and are influenced by emotional burden, uncertainty, and avoidance of future health deterioration [4,5,8,32]. The present findings align with this literature. Participants generally responded positively to the intervention, whereas responses related to psychological readiness demonstrated greater variability than those related to understanding of ACP or perceived importance of ACP. This pattern suggests that although participants readily understood the educational content, readiness to imagine engaging in future ACP discussions differed among individuals. Such variability aligns with previous descriptions of ACP as a highly individualized and emotionally sensitive process involving personal values and uncertainty regarding future health situations [1,8]. This observation also aligns with previous reviews suggesting that educational interventions improving knowledge and attitudes may be insufficient, on their own, to promote ACP engagement [6,7].

The intervention was intentionally designed to combine conceptual understanding through an explanatory video with emotionally engaging simulated experiences delivered through an interactive narrative [14]. This sequential structure reflects previous theoretical perspectives, suggesting that narrative experiences facilitate self-projection and personal meaning-making by transforming abstract health information into emotionally grounded reflection [12,13]. Rather than presenting ACP as a task requiring immediate decisions, the intervention encouraged participants to begin reflecting on their own values within a psychologically safe simulated environment, an approach consistent with narrative medicine and experiential learning frameworks [21,33,34].

Previous ACP educational interventions have largely relied on video decision aids or facilitator-led discussions [35,36]. Although such interventions have demonstrated improvements in ACP documentation and communication, participants have generally remained information recipients rather than active participants in simulated decision-making. In contrast, recent visual game-based ACP interventions have primarily been implemented in facilitated or synchronous formats and have focused on usability and immediate discussion outcomes [14,16-18].

The present intervention extends this growing body of research by evaluating a fully web-based, entirely asynchronous interactive educational program that integrates an explainer video with a branching narrative visual novel game and generates a personal “INITIAL DISCUSSION Summary” record designed to support ongoing ACP conversations without real-time facilitation. This design differs from previous game-based ACP interventions by positioning participants as decision-makers within emotionally engaging family-centered scenarios and by emphasizing psychological readiness as an educational outcome rather than immediate documentation or behavioral change [12-14,16-18,22].

Although these design features may partly explain the observed response patterns [12-14], the postintervention responses cannot be causally attributed to the intervention itself because no preintervention measurements or control group were included. Accordingly, it remains speculative whether the narrative design contributed to participants’ perceptions of personal relevance and psychological readiness or whether these responses reflected preexisting participant characteristics. Nevertheless, the observed response patterns align with the conceptualization of ACP as an ongoing reflective process rather than an intervention intended to produce immediate behavioral change.

Furthermore, the limited differences observed between participants with and without health or long-term care experience may suggest that narrative-based experiential learning operates beyond professional knowledge alone [37]. Previous qualitative studies have emphasized that ACP engagement is strongly influenced by personal relationships, caregiving experiences, and psychosocial contexts rather than professional expertise itself [38]. Accordingly, the present findings may indicate that experiential narrative interventions have the potential to function as introductory educational resources across diverse populations [16-18,21]. Although these interpretations remain exploratory because the study was not designed to test explanatory mechanisms directly, they provide preliminary support for future investigations into psychological readiness as a target of ACP education.

Several limitations should be considered when interpreting these findings. First, because this study was designed as an exploratory feasibility and acceptability study [29], no baseline measurements were obtained, rendering it impossible to determine whether the observed responses represented changes from participants’ preexisting attitudes. Second, the absence of a control group precludes causal interpretation of the observed response patterns [29]. Third, because the intervention combined an explanatory video with an interactive narrative game, each component’s contribution could not be evaluated separately. Fourth, the study was conducted exclusively in Japan, and cultural attitudes toward family decision-making and end-of-life communication may limit generalizability to other settings [39]. Finally, recruitment through online platforms may have introduced sampling bias owing to the nonrepresentative nature of internet samples and the self-selection of participants [19], and the grouping variable did not distinguish between different types or durations of health care or caregiving experience. Furthermore, the exploratory subgroup analyses should be interpreted cautiously because the observed between-group differences were descriptive rather than confirmatory. The variability in responses related to psychological readiness and the generally similar response patterns observed across professional backgrounds cannot be interpreted as evidence that prior health care experience does not influence ACP engagement. These findings should, instead, be regarded as preliminary observations that warrant confirmation in adequately powered controlled studies [29]. Consequently, the present findings should be interpreted as preliminary exploratory evidence requiring confirmation in controlled longitudinal studies.

The findings suggest that ACP education may be better conceptualized not solely as a strategy for producing immediate behavioral change, but as an educational process that supports the gradual development of psychological readiness for future ACP engagement [1,40]. Drawing on frameworks of nonformal and experiential learning, narrative-based educational interventions may provide opportunities to begin reflecting on personal values in advance of future health care situations, rather than requiring participants to make immediate decisions [12,13,21,33,34].

The limited differences between participants with and without health care experience further suggest that such interventions may be suitable for diverse populations, including members of the general public and students as well as health care professionals. Accordingly, fully web-based narrative interventions may complement existing ACP educational programs by functioning as accessible, entry-level experiences that initiate a reflective process and encourage subsequent dialogue with family members and health care professionals. Future work could adapt culturally contextualized videos and games for other populations and examine long-term changes in individuals’ perspectives on ACP as they age [1,21,37].

This exploratory study suggests that a fully web-based, narrative-based ACP educational intervention may serve as an accessible entry-level educational strategy for supporting reflection on ACP. Rather than promoting immediate behavioral change, the intervention may contribute to developing the psychological readiness necessary for future ACP discussions through experiential narrative engagement. These findings provide preliminary evidence supporting further investigation of narrative-based digital education within ACP implementation research. Future controlled longitudinal studies are warranted to examine sustained educational and behavioral outcomes.

Building on previous ACP educational interventions that have relied on video decision aids and facilitator-led discussions, this study evaluated a fully web-based, entirely asynchronous program integrating an explainer video, a branching narrative visual novel game and a personal “INITIAL DISCUSSION Summary” record. By positioning participants as active decision-makers within emotionally engaging family-centered scenarios, the intervention was designed to foster experiential reflection on values rather than presenting ACP solely as informational content.

These design features may help expand ACP education beyond clinical settings by providing a scalable, self-directed, entry-level resource that is applicable to both members of the general public and health care students. In addition, conceptualizing psychological readiness as an educational outcome distinct from immediate behavioral change may inform future intervention design and implementation research aimed at supporting earlier engagement with ACP across the life course.