Introduction
The proportion of the population age 65 and over is continuously increasing worldwide. Korea is also expected to take a step closer to becoming a super-aged society and reach 20.3% in 2025 [1]. Effective screening or diagnosis tests for chronic diseases in the growing elderly population are thus required. One of these diseases is dementia, which accounts for approximately 10% of the population age 65 and over [2]. Another clear aging disease is hearing loss (HL). According to the National Health Statistics, approximately 40% of the population age 65 and over suffer from HL in Korea (mild HL: 48.4%, moderate HL: 36.3%) [3].
Previous studies have also found that older adults with hearing loss are more likely to develop dementia [4-6]. When evaluating the brain age gap (BAG), defined as the difference between the chronological age and the estimated brain age in adults aged 20–79, the larger the BAG, the lower was the score on the Montreal Cognitive Assessment [7]. Thus, as BAG increases, cognitive function decreases, so the two relationships have significantly negative correlations. Nemati, et al. [7] suggested that there is a potential link between accelerated brain aging and auditory decline, as a higher BAG significantly increased hearing thresholds. Further, Ying, et al. [8] confirmed that people with hearing loss performed worse on cognitive assessments than did people with normal hearing (relative risk, 1.16–1.44).
Again, as the elderly population is steadily increasing in Korea, the number with chronic diseases, i.e., hearing loss and cognitive impairment, is also increasing. Because the social and economic burden of elderly care also continues to increase [1], it should be noted that early screening tools which can examine hearing and cognitive function are clearly needed. Currently, hearing screening tests are performed at a frequency of 1,000 Hz in general health checkups [9], and the translated versions of the Hearing Handicap Inventory for Adults [10] and the Hearing Handicap Inventory for the Elderly [11] are widely used. As a cognitive screening test, the Korean Mini-Mental State Examination (MMSE) [12] is mainly used in Korea. The Cognitive Impairment Screening Test (CIST), newly developed by the Central Dementia Center [13], has been added. These tools evaluate hearing and cognitive functions separately, but as mentioned above, hearing loss and cognitive impairment are strongly correlated, and the symptoms of the two diseases are often similar [7,8]. Thus, an integrated tool that can screen the aspects of both hearing and cognition in the elderly should be developed. Specifically, if we can identify their common (similar) or differential (unique) problems due to hearing loss and cognitive impairment, clinicians will gain greater insight into the auditory-cognitive domains of older adults and find potential solutions by treating them in comprehensive approach. Applying this perspective, we have developed a questionnaire that simultaneously screens for hearing and cognitive problems in older adults. As a first sub-objective, this study aimed to extract and select appropriate self-screening items (or questions) for the cognition part.
Subjects and Methods
Study selection
We used six electronic journal databases (i.e., the Cochrane Library, EBSCO, Embase, Ovid MEDLINE, PubMed, Web of Science) to search for questionnaires already developed to screen for cognitive impairment. Since the first attempt to assess cognitive function was made in 1956 [14], we investigated studies done from 1956 to the present using the keywords “Dementia” OR “Cognitive Impairment” OR “Cognitive Decline” OR “Cognitive Dysfunction” AND “Questionnaire” OR “Self-Report” OR “Examination” in November 2024.
This systematic search was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) criteria [15], which is evidence-based guidelines designed to improve the transparency and completeness of reporting in systematic reviews and meta-analyses. A total of 155,894 studies were initially identified in the journal databases that were reviewed. After excluding 47,694 duplicate studies, 108,201 titles and abstracts were screened. Of these, 108,090 were removed, and thus, 111 full texts were analyzed applying the criteria of participants, index test, control group, outcome, and study design (PICOS) (Table 1), and 14 articles were included. For example, participants were set as being 60 years of age or older based on a study that had reported that MMSE scores decline rapidly after 60 years of age [16]. Of the 14 articles, four used questions unsuitable for diagnostic and/or screening purposes [17-20], while one article was an adaptive questionnaire where the questions were changed according to the responses [21]. Therefore, 9 studies were finally selected for the current effort (Fig. 1).
Quality of study
A quality assessment of the studies was conducted using the Newcastle-Ottawa Scale (NOS) [22], which consists of three main domains—Selection, Comparability, and Exposure/Outcome—based on eight criteria. A total score ranged from 0 to 9; score of 0–3 was classified as “poor,” 4–6 as “fair,” and 7–9 as “good.” Among the nine studies examined [23-31], six were rated as “fair,” while three were seen as “good” (Supplementary Table 1 in the online-only Data Supplement).
Within the selected studies, the respondents were categorized into two groups: individuals who self-reported cognitive decline and the caregivers of those individuals experiencing or suspected of having a cognitive decline. Three out of the nine studies [23,27,29] were evaluated by two types of respondents. Except for these studies, four [25,26,28,31] were used for respondents who felt a subjective decline of their cognitive function, and the other two [24,30] were written by caregivers of people with cognitive decline. Regardless, since our goal was to develop a screening tool that could be administered by the suspects themselves, only seven questionnaires were analyzed in detail after excluding two [24,30] that were based on the observations of caregivers. These seven questionnaires and their characteristics are summarized in Supplementary Table 2 (in the online-only Data Supplement).
Selection of items
A total of 211 items (or questions) were extracted from the seven selected questionnaires. While these items were reviewed by two authors, similar questions from different questionnaires were re-classified into the same category. Sixty-eight items related to “memory,” the biggest of the other categories, and “personality changing” and “handling issue” categories were the next most asked questions at 33 and 16 items, respectively. Another 16 items were categorized as “Others” and they included difficulty with directions, change in driving habits, hard planning, difficulty remembering the story of movie, etc. These identified items were newly classified, and questions showing homogeneity were then merged into a single item. Two authors independently reviewed the re-classified items and compared their results to discuss and determine the appropriateness of the revised items. Finally, the 31 items were initially created into a questionnaire to use for screening cognitive impairment using a 5-point Likert scale (never: 0%, rarely: 25%, somewhat: 50%, sometimes: 75%, always: 100%). The authors revised 31 items (or sentences) where appropriate, and these revised meanings were scrutinized by one professor of community health nursing and one professor of geriatric audiology.
Subjects
Participants in this study were voluntarily recruited from the senior welfare facilities or clinics in Chuncheon, Korea. They included 40 older adults aged 60 years or older who wished to undergo hearing or cognitive evaluation [32,33]. These participants were then pseudo-randomly divided into four groups: normal hearing and normal cognition (NH+NC; from here on, this category is called Group 1 or G1), hearing loss and normal cognition (HL+NC; Group 2 or G2), normal hearing and cognitive decline (NH+CD; Group 3 or G3), and hearing loss and cognitive decline (HL+CD; Group 4 or G4). Each group consisted of 10 people, and group averages for age and hearing and cognitive tests are displayed in Table 2. Before beginning the experiment, individuals agreed to sign the consent form. All procedures were approved by the Institutional Review Board of Hallym University (HIRB-2024-097).
Assessment tools
To evaluate the participants’ hearing threshold, a pure tone audiometry was performed at 0.5 kHz to 4 kHz, and pure-tone averages (PTA) were then calculated. Per the criteria of ISO 7029 [34], participants with moderate-to-severe hearing loss (PTA >40 dB HL) were classified as a hearing loss group (G2 and G4), while those with hearing thresholds ≤40 dB HL were classified as having normal hearing (G1 and G3).
The CIST was used to measure cognitive status. It is a one-to-one interview-based test and includes 13 questions totaling 30 points. Based on these results, the group without any cognitive decline was defined as having a score of 19 or higher (G3 and G4), while the group with cognitive decline was defined as having a score of 17 or lower (G1 and G2) [35].
Testing procedures
First of all, the participants were tested with PTA and CIST. Using the results of the two tests, participants were assigned to four groups based on their cognitive and hearing ability: Groups 1, 2, 3, and 4. Then the participants were asked to respond to the Cognitive Impairment Screening for Elderly (CISE) while they were encouraged to read and complete the items by themselves. However, for those experiencing difficulties with vision impairment or comprehension issues, the questionnaire items were read by the examiner. Any inquiry about the item’s meaning was allowed. Through this process, it was verified whether the questionnaire was clinically applicable.
Statistical analysis
All of the statistical analysis was done using R version 4.2.2 [36]. If normality was shown by the Shapiro-Wilk test, an analysis of variance (ANOVA) was used to confirm whether there were any differences in the tests (e.g., PTA and CIST) between the groups. The Tukey HSD test was used when ANOVA showed there were differences between the groups in tests.
Cronbach’s alpha was applied to analyze the internal consistency of the CISE. To determine which items are related to cognitive ability, factor analysis and principal component analysis were conducted, and each item was then assigned to a factor based on the highest factor loading. Before doing the factor analysis, Kaiser-Meyer-Olkin (KMO) test and Bartlett’s test of sphericity were done to test suitability of the data.
Results
The number of subjects participating in each group was 10. However, while groups 1 and 2 had roughly half male and half female participants, groups 3 and 4 had significantly more female than male participants (Table 2). Specifically, looking at the subjects’ ages, Group 1, consisting of participants with normal hearing and normal cognition, was the youngest (mean age 69 years), while Group 4, consisting of participants who experienced hearing loss and cognitive decline, was the oldest (mean age 82.40 years).
Group comparison of results for PTA and CIST
The PTA of groups 1 and 3 without hearing loss was 30.40 dB HL and 35.00 dB HL, respectively, and the PTA of groups 2 and 4 with hearing loss was 57.70 dB HL and 50.5 dB HL, respectively. Meanwhile, the CIST scores of groups 1 and 2 without cognitive decline were 24.10 and 23.40, respectively, and the CIST scores of groups 3 and 4 with cognitive decline were 12.40 and 11.00, which were low.
There was a significant difference between the groups for PTA [F(3, 35)=11.86, p<0.001]. Although the Tuckey post hoc test showed no difference between G1 and G3 (p>0.99) and G2 and G4 (p=0.89), significant differences were found in G1 to G2 (p<0.01) and G4 (p<0.001) and were also found in G2 and G3 (p<0.001), G3 and G4 (p<0.05) (Fig. 2A).
ANOVA showed significant differences between the groups for the CIST total score [F(3, 35)=40.42, p<0.001]. In the post hoc test, G1 with G3 (p<0.001) and G4 (p<0.001) showed such significant differences, and G2 with G3 (p<0.001) and G4 (p<0.001) showed significant differences. However, between G1 and G2 (p>0.99) and between G3 and G4 (p>0.99) did not show any significant differences (Fig. 2B).
Internal consistency of CISE
The Cronbach alpha of the CISE score was 0.94, although Item 16 ‘‘Have you ever avoided conversation or given unusually short answers?” showed a low correlation (r=0.20). The KMO test showed 0.61, and Bartlett’s test also confirmed the appropriateness of factor analysis (p<0.001). However, when evaluating the appropriateness of individual items, Items 3, 8, 16, and 28 showed a poor fit (Q3: 0.28, Q8: 0.27, Q16: 0.14, Q28: 0.23).
Before conducting the principal component analysis, Item 16 was thus excluded due to poor fit of both KMO and Bartlett. Since the cumulative ratio of 0.7 spread across six principal components (PC), the optimal number of factors was from 1 to 6 (PC 1: 0.375, PC 2: 0.469, PC 3: 0.541, PC 4: 0.600, PC 5: 0.652, PC 6: 0.702). Further still, the scree plot results determined that there were four principal components, which represented the elbow point where the eigenvalues were greater than 1 and the slopes were flat (Fig. 3).
Four factors were determined to be suitable for factor analysis. The highest score of factors loading for each item was then assigned to the corresponding factor. The first factor included items 7, 9, 10, 17, 18, 21, 24, 25, 26, and 27, which are related to “daily activities associated with memory loss.” The second factor included items 1, 2, 3, 4, 5, 6, 28, and 31 for “emotional changes or stress.” The third factor included items 8, 11, 12, 19, 23, 29, and 30, which might be explained to “decreased social interaction and cognitive confusion.” Items 13, 14, 15, 20, and 22 comprised the fourth factor which is “difficulty in using the language.” Details are shown in Table 3.
Discussion
This pilot study sought to address a critical gap in geriatric assessment by developing and preliminarily validating a self-report instrument (CISE) for cognitive impairment, as the first step toward an integrated screening tool that simultaneously evaluates both hearing and cognitive functions in older adults. The need for such an integrated approach is underscored by the growing prevalence of hearing loss and cognitive decline among the elderly, and the accumulating evidence that these domains frequently co-occur and share overlapping symptomatology. Our results offer several meaningful insights and contributions to both the clinical and academic realms.
Interpretation of main findings
The CISE, comprising 30 items after item reduction, demonstrated excellent internal consistency (Cronbach’s α=0.94), indicating homogeneity and reliability in measuring aspects of cognitive function relevant to community-dwelling older adults. Exploratory factor analysis identified four distinct domains: 1) daily activities associated with memory loss, 2) emotional changes or stress, 3) decreased social interaction and cognitive confusion, and 4) difficulty in using language. Importantly, each factor aligns closely with symptom clusters frequently reported in the literature as early or prominent features of cognitive decline or dementia.
The subgroup analysis—considering hearing and cognitive status—revealed that participants with both hearing loss and cognitive impairment (Group 4) exhibited the highest levels of dysfunction across most CISE domains, particularly in language use and social interaction. This pattern supports prior findings indicating that sensory and cognitive impairments may interact synergistically, thereby compounding functional disability. Note, the process identified seven optimal items (factor loading >0.70) that may form the basis for a concise screening tool, enhancing feasibility for clinical and self-administered applications. This condensed format holds promise for deployment in primary care and community settings, where brief yet sensitive screening is vital for facilitating early intervention.
Comparison with previous studies
Our findings are consistent with earlier reports that deficits in memory-related daily activities and diminished ability to manage familiar tasks are sensitive indicators of early cognitive impairment [37]. Reasonably, items quantifying difficulties with routine technology or appliances robustly differentiated cognitively impaired groups, echoing the work of Ikeda, et al. [37] and Harada, et al. [38], who demonstrated that such deficits are typical even at early subjective cognitive decline stages. Moreover, the identification of emotional changes and stress as a principal component is aligned with observations that neuropsychiatric symptoms—including anxiety, irritability, and affective lability—are not only prevalent but may precede overt cognitive decline. The overlap in symptom domains among individuals with hearing loss, cognitive impairment, or both, as revealed in our factor analytic approach, reinforces the necessity of a holistic, multidisciplinary assessment paradigm, as advocated by recent consensus guidelines.
In order to examine the factors by item in more detail, items with factor loadings of 0.70 or higher in Fig. 3 were first considered to represent these factors. Representative questions that could define Factor 1 were selected as items 10 and 27. For example, “Q10. Are you having trouble handling equipment (appliances, electronic devices, etc.) due to memory loss?” and “Q27. Have you ever forgotten how to operate a familiar machine (rice cooker, vacuum cleaner, etc.)?” are related to forgetting the order or operation of frequently used home appliances due to memory loss. According to the latest study of Ikeda, et al. [37], elderly people begin to experience difficulties in daily life from the early stage of memory decline. This is related to cognitive decline, especially in the subjective memory impairment stage [37]. In addition, the study of Harada, et al. [38], which reported that older adults have difficulty using home appliances due to cognitive decline, is supported by similar results. Therefore, Q10 and Q27, which were higher scores in Groups 3 and 4 than the other groups, can be viewed as core items related to cognitive decline.
The second factor, “emotional changes or stress,” could be confirmed only through question 3: “Q3. Have you ever felt that your personality has changed recently? (anxiety, irritability, depression, coldness, frustration).” This item has also been confirmed in previous studies. In other words, symptoms commonly seen in dementia patients are anxiety, depression, irritability, and aggression [39]. These symptoms are related to the severity of dementia and occur more frequently as the severity increases. Dementia can also cause personality changes due to damage to specific areas of the brain [39]. For example, damage to the frontal lobe can lead to decreased planning and concentration, and impaired impulse control, which can lead to anxiety or irritability. However, because these personality changes in dementia patients are also related to age, and these symptoms may be more prominent in early-stage elderly patients [39], it is necessary to review these questions in the future to identify differences by age.
The third factor is items 12 and 23, which are described as “decreased social interaction and cognitive confusion.” “Q12. Have you noticed that your memory decline has made it harder for you to contact or meet friends and family? or “Q23. Have you ever had memory loss and found yourself confused about where you were?” are issues that occur in older adults who experience dementia or mild cognitive impairment (MCI). Specifically, in the middle stage of MCI, cognitive decline becomes more evident, and difficulties in daily life occur. These results may indirectly support this, as Items Q12 and Q23 scored highest in Group 4, which was 1.40 points lower than Group 3 based on the CIST results. Since the possibility of developing Alzheimer’s disease within 10 years is very high, with a 50% or higher probability, it is necessary to detect it early and manage it through a questionnaire such as CISE to delay its progression [40].
The last factor is related to Items 13 and 14, which are “difficulty in language use,” and representative items can be set as “Q13. Have you ever had trouble choosing the right words to use when having a conversation?” and “Q14. Have you ever had trouble saying a word?” In other words, hearing loss can cause problems related to language comprehension, which primarily arises from difficulties in auditory input [41]. However, since hearing loss and cognitive decline can interact to further impair the language processing ability of the elderly [42], it can be interpreted as both hearing and cognitive issues, common problems of two diseases. This can be proven by the fact that the score of Group 4 in factor 4 is more prominent than that of other factors.
Clinical and practical implications
This study underscores the necessity for integrated, practical screening instruments—such as CISE—that sensitize clinicians to the multidimensional interplay of sensory, cognitive, and affective deficits in older patients. A brief version incorporating the seven highest-loading items could facilitate widespread use in primary and community settings, enabling early triage and appropriate specialty referral. Moreover, the use of self-report enables rapid, patient-centered assessment but should be complemented in future by caregiver or proxy versions to enhance objectivity, especially in cases of low insight or advanced impairment.
Limitations
Several limitations of this pilot study merit consideration. First, the sample size was relatively small (n=40) and derived from a geographically limited population, which may restrict the generalizability of the psychometric findings. Second, there was an imbalance in age and gender distributions across participant groups; in particular, Group 4 (hearing and cognitive deficits) had a higher mean age, which could independently influence test scores. Although these characteristics are representative of clinical realities, future studies should employ larger, more diverse cohorts and apply statistical adjustments for potential confounders.
Additionally, the current iteration of the CISE focused solely on cognitive domains—the auditory portion of the integrated screener remains to be developed and validated. Test–retest reliability, predictive validity, and the responsiveness of CISE to clinical change over time also warrant further investigation.
Future directions
Going forward, expansion of the sample size, inclusion of participants from varied cultural and educational backgrounds, and multicenter validation are necessary to reinforce the psychometric robustness of the tool. The parallel development and integration of hearing-specific items using the same rigorous methodology will be essential to realizing the vision of a unified auditory-cognitive screening instrument.
It will also be important to compare the CISE with established brief cognitive and hearing screening measures, such as the Korean MMSE and the Hearing Handicap Inventory for the Elderly, to demonstrate added value and incremental validity. The use of digital administration platforms, potentially leveraging mobile health technology, could further increase accessibility and scalability, particularly for older adults in resource- limited or rural settings.
In parallel, future research should examine proxy/caregiver- reported versions of the CISE, to enhance objectivity and utility for individuals with limited insight or severe deficits. Finally, prospective longitudinal studies are required to evaluate the tool’s sensitivity to change, prognostic utility, and impact on health outcomes, such as delays in diagnosis or improved care coordination.
Conclusion
This preliminary validation of the cognitive domain of an integrated screening questionnaire lays the essential groundwork for comprehensive, multidimensional assessment of older adults. By systematically capturing the interrelated facets of daily cognition, emotion, social interaction, and communication, the CISE may ultimately facilitate earlier and more accurate identification of at-risk individuals and inform targeted interventions. With further development and validation—including integration of hearing-related items—this tool has the potential to significantly advance clinical practice and research at the intersection of audiology and cognitive aging.
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