Globally, approximately 50 million people suffer from dementia, with a new case occurring every three seconds. By 2050, the number of people with dementia is expected to triple [1]. In Korea, dementia prevalence among individuals aged ≥ 65 years was 10.4% in 2020, affecting approximately 980,000 individuals. This number is projected to rise to 16.6%, or approximately 3.14 million individuals, by 2050, further increasing the societal and economic burden [2]. Dementia not only affects patients but also imposes significant caregiving and financial burdens on families and society. The global cost of dementia-related healthcare was estimated at United States dollar 1 trillion in 2010 and is expected to increase by 85% by 2030. In Korea, the annual cost of dementia management was estimated at 20.8 trillion Korean won (KRW) in 2022, representing 1% of the national gross domestic product, with projections reaching 138.1 trillion KRW by 2050 [3].

Dementia, which is characterized by acquired cognitive impairments that hinder daily and social functioning, has currently no available cure. Therefore, preventive management to delay its onset is essential. The World Health Organization has emphasized the importance of lifestyle changes, such as healthy eating, regular exercise, smoking cessation, and alcohol moderation, as well as the management of cardiovascular risk factors, such as obesity, hypertension, and diabetes. Furthermore, mental health care and early detection of dementia are critical [1]. In line with this, the Ministry of Health and Welfare of South Korea had established its 4th Comprehensive Dementia Management Plan (2021-2025), which focuses on expanding dementia screening to all ages and managing suspected cases through public health initiatives [4].

The health belief model (HBM), which had been developed to explain individuals’ preventive health behaviors, posits that perceived threats of illness (perceived susceptibility and perceived severity), expected outcomes of health behaviors (perceived benefits and barriers), and specific cues to action motivates individuals to engage in health-promoting actions [5]. Subsequently, the model was expanded to include the concept of health motivation to better explain patients’ role-related behaviors [5]. Additionally, as health behaviors began to focus on long-term lifestyle changes, the concept of self-efficacy was incorporated into the model to enhance the explanatory power of the model for preventive behaviors [6,7].

However, the HBM has been criticized for failing to include significant emotional factors, such as fear, which can play a crucial role in motivating behavioral changes and adopting preventive health behaviors [8]. Although previous studies have explored the relationship between dementia-related health beliefs and preventive behaviors, integration of emotional factors, such as fear, remains limited [9]. Additionally, only a handful of studies have incorporated knowledge of dementia into HBM [10]. Dementia knowledge refers to the extent of an individual’s understanding of various aspects related to dementia, including its causes, symptoms, treatment, and prevention [11]. Individuals with higher levels of dementia knowledge enables can accurately comprehend their condition, fostering appropriate perceptions and attitudes that positively influence dementia-preventive behaviors [11]. Conversely, a lack of dementia knowledge may promote unhealthy preventive actions and lifestyle choices, delaying the diagnosis of dementia and negatively affecting treatment outcomes [11]. Addressing this gap could provide new insights into promoting preventive behaviors among older adults, particularly in a super-aged society. This study aimed to expand the HBM by incorporating dementia knowledge and fear and evaluate their impact on dementia prevention behaviors among community-dwelling older adults.

This study was conducted to identify the expansion of the HBM by assessing the impact of dementia knowledge and fear on dementia prevention behaviors among community-dwelling older adults. Using the Korean version of the Dementia Knowledge Scale [14], this study found that community-dwelling older adults had an average dementia knowledge score of 18.03 out of 30. A similar study in China among adults aged 65 and older reported scores ranging from 17.2 to 17.5 [24]. Our participants exhibited higher dementia knowledge, possibly due to increased concern about aging and the impact of public dementia awareness and prevention programs, including the National Responsibility for Dementia System launched in 2017 [25]. Previous research has shown a significant positive correlation between dementia knowledge and preventive behaviors, with higher levels of knowledge having been associated with improved adherence to prevention practices [26,27]. Considering the positive relationship between dementia knowledge and preventive behaviors, developing and expanding ongoing educational programs that focus on dementia prevention is imperative.

Dementia fear is an important psychological factor influencing dementia prevention [28]. The current study assessed dementia fear using the K-FADS [16], with participants having an average dementia fear of 85.02 out of a maximum score of 150 points. Interestingly, the average score obtained in this study was notably higher than that 53.4 points reported in a study involving adults with an average age of 57.4 years [28]. These findings suggest that fear of dementia intensifies with age, a trend supported by research conducted by Cantegreil-Kallen and Pin [29], which revealed a similar correlation between advancing age and heightened fear of dementia. Excessive dementia fear, characterized by vague negative emotions, has been found to adversely affect preventive behaviors [30]. These results underscore the necessity of providing accurate information and psychological support to community-dwelling older adults in order to mitigate dementia fear and promote effective prevention practices.

Our participants had an average dementia prevention behavior score of 58.78 out of a maximum score of 80 (equivalent to a score of 73.49 out of 100), which was higher than the average score of 69.4 out of 100 reported in a study involving high-risk older adults [9], but lower than the score of 74.11 out of 100 reported in other studies using the tools developed by Lee et al. [21] among community-dwelling older adults [31]. Such differences in scoring may be attributed to variations in the assessment tools. Indeed, Lee et al. [21] used a 3-point Likert scale to measure the subjective frequency of dementia prevention behaviors, whereas the tool used in the current study employed a 5-point Likert scale to assess behavior frequency on a weekly basis, providing a more objective measure [9].

The current study identified significant differences in dementia prevention behaviors among community-dwelling older adults according to age, religion, and dementia screening plans. Dementia prevention behaviors were highest among those aged 71~80 years, likely due to increased awareness and engagement in preventive activities with aging. Similar trends have been observed in prior studies [32,33], including research on hypertension, where older adults demonstrated more frequent health behaviors [34]. Given aging as a major dementia risk factor [35], older adults may prioritize prevention to maintain cognitive health [36]. Religious affiliation was also associated with higher dementia prevention behaviors, potentially due to social support and access to prevention information during religious gatherings. Religious engagement enhances social interaction, stress management, and knowledge-sharing, aligning with previous findings linking religion to increased dementia prevention behaviors [32,37,38]. Additionally, individuals with definite dementia screening plans exhibited higher prevention behaviors. Notably, those without screening plans also engaged in preventive behaviors, possibly due to confidence in their lifestyle choices or lower perceived benefits of screening. Raising awareness of the importance of regular dementia screenings and providing targeted support programs can further enhance prevention efforts.

After examining the relationships between dementia knowledge, fear, health beliefs, and dementia prevention behaviors in community-dwelling older adults, this study found that dementia fear, perceived susceptibility, and perceived barriers were significantly negatively correlated with dementia prevention behaviors. While perceived susceptibility is generally associated with increased health behaviors, our findings, along with previous studies [39,40], suggest the opposite trend. This may reflect optimistic thinking, where individuals engaging in active health behaviors perceive themselves at lower risk of developing dementia. Additionally, participants who already practice effective health behaviors may feel less vulnerable to dementia, leading to a weaker perceived need for additional prevention efforts. These findings highlight the complex relationship between risk perception and preventive behaviors, suggesting that tailored interventions are needed to balance awareness of susceptibility with motivation for proactive dementia prevention. Meanwhile, we found that perceived benefits, cues to action, and self-efficacy were positively correlated with dementia prevention behaviors. This finding suggests that individuals who perceive greater benefits from dementia prevention, had higher social influence encouraging preventive actions, and had greater confidence in their ability to adopt health-promoting behaviors were more likely to engage in dementia prevention behaviors. Perceived benefits, a critical motivational factor, can facilitate dementia prevention behaviors by emphasizing the improved quality of life and autonomy associated with prevention efforts [41]. The positive correlation between dementia prevention behaviors and a high level of cues to action also underscores the need to enhance social support networks for older adults, such as community-based initiatives aimed at dementia prevention and management. Based on Bandura’s self-efficacy theory, self-efficacy emphasizes an individual's belief in their ability to successfully perform a specific behavior, thereby playing a crucial role in behavior execution [42]. Thus, programs that support specific behavioral goals for dementia prevention and offer positive feedback on achievement may be effective.

Based on the theoretical framework of the HBM, the current study evaluated the impact of adding dementia knowledge and fear to the independent variables of the HBM on its explanatory power of dementia prevention behaviors. Hierarchical polynomial regression analysis was conducted to account for the nonlinear effects of dementia knowledge. Notably, our results showed that adding health belief variables to Model 2, which initially only included the demographic characteristics of the participants in Model 1, promoted a significant 23.0% increase in the adjusted R² value. This finding suggests that the HBM provides a robust theoretical foundation for understanding behavioral changes related to dementia prevention, partially supporting the results of previous studies showing that perceived barriers, benefits, and severity influence dementia prevention behaviors [18,30,41]. In particular, perceived barriers and self-efficacy were identified as significant predictors of dementia prevention behaviors. One study found that perceived barriers negatively influenced behaviors, indicating that higher perceived difficulties in performing specific actions increased the likelihood of avoidance [43]. This finding highlights the need for strategies that identify and reduce the challenges older adults face in initiating and maintaining dementia prevention behaviors. Werner [44] emphasized that misconceptions about dementia and a lack of knowledge about prevention could act as barriers to behavioral change. Thus, providing accurate information about dementia prevention and management tailored to the functional status of older adults in accessible settings, such as senior centers or welfare facilities, is crucial. The current study reaffirmed self-efficacy as a key factor influencing dementia prevention behaviors, consistent with previous research [21]. Higher self-efficacy has been associated with increased engagement in dementia prevention behaviors [22], suggesting that enhancing self-efficacy in older adults, particularly community-dwelling seniors, could positively impact dementia prevention efforts. Evidence shows that self-efficacy is influenced by individual differences in performance capabilities and is crucial for adapting to and coping with diverse situations [45]. Previous studies have consistently identified self-efficacy as a primary factor in maintaining long-term dementia prevention behaviors [18,22,33]. Therefore, incorporating the strategies proposed by Bandura [46], such as mastery experiences, vicarious experiences, and verbal persuasion, into programs aiming to enhance self-efficacy in older adults is essential.

Model 4, which incorporated dementia health beliefs, knowledge, fear, and the quadratic term of dementia knowledge, significantly increased explanatory power by 35.5%. This study contributes to expanding the HBM by demonstrating that dementia knowledge and fear are critical variables in understanding dementia prevention behaviors. Unlike traditional HBM models that focus solely on perceived susceptibility, severity, benefits, and barriers, our findings highlight how cognitive and emotional factors—specifically dementia knowledge and fear—shape preventive behaviors. The inclusion of a quadratic term for dementia knowledge further refines the model by revealing its nonlinear relationship with dementia prevention behaviors. While increased dementia knowledge initially promotes preventive behaviors, excessive knowledge may heighten dementia fear, leading to avoidance behaviors or reduced motivation for prevention efforts. This underscores the need for tailored educational interventions that balance knowledge dissemination with psychological well-being to optimize dementia prevention strategies.

These findings align with previous research suggesting that excessive or inaccurate dementia knowledge can heighten dementia fear, delay diagnosis, and hinder treatment, ultimately negatively affecting prevention and management efforts [47,48]. Smith et al. [49] highlighted that mild dementia fear can motivate preventive behaviors, whereas extreme fear may obstruct them. Similarly, Bowen et al. [50] noted that dementia fear can either negatively impact dementia-related health behaviors or enhance sensitivity to dementia prevention through increased awareness. This study contributes to the growing body of research emphasizing that dementia prevention efforts must consider not only cognitive factors but also psychological and emotional influences. Future research should explore how dementia knowledge and fear interact to influence behavior, particularly within the HBM framework.

From a biological nursing science perspective, this study provides critical insights into dementia prevention behaviors among older adults. By integrating psychological and cognitive components into health behavior models, the findings support the development of holistic nursing interventions. Despite its contributions, this study has limitations. First, it was conducted in a single region, limiting the generalizability of the findings to other populations. Second, the cross-sectional design prevents causal inferences, and the self-reported nature of dementia prevention behaviors may introduce response biases. Third, while participants were screened for cognitive impairment through the CIST conducted by the Jeju Center for Dementia within the year prior to recruitment, cognitive status may change over time. This potential variation in cognitive function was not reassessed at the time of data collection, which may influence participants’ dementia-related perceptions and behaviors. Future studies should employ longitudinal designs, reassess cognitive function at multiple time points, and include diverse populations to further validate the expanded HBM framework incorporating dementia knowledge and fear.

Hierarchical polynomial regression analysis demonstrated significant results across all models: Model 1, including demographic variables; Model 2, with added health belief components; Model 3, with centered dementia knowledge and dementia fear; and Model 4, including a quadratic term for dementia knowledge. The explanatory power of the HBM ranged from 11.8% to 35.5. Significant improvements in adjusted R² values were observed for Models 2 and 4 but not for Model 3.

In Model 4, perceived barriers emerged as the most significant negative predictor of dementia prevention behaviors, indicating that lower perceived barriers increased engagement in dementia prevention behaviors. Meanwhile, self-efficacy and cues to action were identified as positive predictors of dementia prevention behaviors. The quadratic term for dementia knowledge suggested that dementia knowledge had a diminishing positive effect on prevention behaviors beyond a certain threshold. To develop more comprehensive models and better understand their combined effects on dementia prevention behaviors, future studies should investigate the interaction effects of dementia knowledge and dementia fear on prevention behaviors.