Bifactor Structure Research Articles

Psychometric Properties of the Japanese Translation of the Parent Overprotection Measure for Mother and Father Reports.

The Parent Overprotection Measure (POM) is a promising scale to measure parent overprotection toward a child from the parent's perspective. However, no Japanese translation of the scale has been developed, and whether the POM can be applied to a Japanese population is unknown. This study translated the POM into Japanese and examined its psychometric properties. Parents of 380 children aged 4 to 7years (including 190 mothers and 190 fathers) completed online questionnaires. Exploratory and confirmatory factor analyses (CFA) indicated that the Japanese translation of the POM has a bi-factor structure, including one general factor (general overprotection) and two specific factors (care/attention and control/prevention). The measurement invariance of reports from mothers' and fathers' perspectives was confirmed by multiple group CFA. The McDonald's Omega was acceptable for all factors, but the general overprotection factor explained most scale variance. Pearson's correlation coefficients were more than .20 between the control/prevention factor and child anxiety symptoms in both mother and father reports. The correlation between the control/prevention factor and parent anxiety according to fathers' reports also exceeded .20. These results provided the factor structure and supported the reliability of the POM among a Japanese population; however, further investigation of the validity of the scale is needed.

Measuring general sense of agency: a Japanese adaptation and validation of the sense of agency scale (J-SoAS).

The Sense of Agency (SoA) refers to the individual's perception of control over actions and their subsequent impact on the external environment. SoA encompasses multiple dimensions, such as implicit/local and explicit/general, which can be quantitatively assessed through cognitive tasks and psychometric questionnaires, respectively. The explicit and general aspect of SoA is commonly evaluated using the Sense of Agency Scale (SoAS). This study's objective is to adapt and validate a Japanese version of the Tapal-SoAS. To achieve this, we distributed an online survey in three stages, gathering data from 8,237 Japanese participants aged between their 20s and 60s. Our analysis confirmed the bifactorial structure identified in the original study: the Sense of Positive Agency (SoPA) and the Sense of Negative Agency (SoNA). Metrics pertaining to test-retest reliability, internal consistency, and construct validity reached satisfactory thresholds. Furthermore, the two-factor models demonstrated suitable fit across various age cohorts. The Japanese version of the SoAS (J-SoAS) shows potential for cross-cultural comparisons of explicit and general SoA, particularly between Western and Eastern populations, and among distinct age groups, including young adults and the elderly.

Validation of the Valuing Questionnaire (VQ) to the Argentinian context

The aim of this study was to examine the psychometric properties of the Spanish version of the “Values Questionnaire” (VQ) in an Argentine sample. The VQ was administered to a total of 1596 participants. Measures of acceptance and action, cognitive fusion, life satisfaction, and sociodemographic variables were also included. The results confirmed the bifactor structure of the VQ. The scale showed adequate internal consistency and significant correlations with the former variables, which demonstrates adequate criterion validity. Furthermore, obstruction values emerged as a good predictor of low life satisfaction. In conclusion, the Argentine version of the VQ showed good psychometric properties to be used in the Argentinian context.

How should coronaphobia Be conceptualized? Evaluating competing models of the COVID-19 Phobia Scale using confirmatory factor analysis

Coronaphobia represents the fears and phobias attributed to the COVID-19 virus and pandemic. The COVID-19 Phobia Scale, previously validated as a four-factor structure, is a widely used multidimensional measure to assess coronaphobia. The current study scrutinized various competing factor structures of this instrument to identify the optimal psychometric representation of coronaphobia. Adults (N = 412) ranging in age from 19 to 84 years completed the COVID-19 Phobia Scale. Several theoretically plausible factor structures of coronaphobia were tested and compared using confirmatory factor analysis: four-factor structure, one-factor structure, higher-order factor structure, and five-factor bifactor structure. The one-factor structure showing an overarching factor of COVID-19 phobia revealed the poorest fit to the data. The five-factor bifactor structure that allowed every item to double-load on the COVID-19 general phobia factor alongside one of the COVID-19 specific phobia factors (psychological phobia, psycho-somatic phobia, economic phobia, or social phobia) produced the strongest fit indices and was superior to the widely accepted four-factor structure. The five-factor bifactor structure demonstrated multi-group measurement invariance across gender, race, age, and state urbanization. Furthermore, the general phobia factor and the psycho-somatic phobia factor from the five-factor bifactor structure uniquely predicted present moment state anxiety using structural equation modeling. This psychometric investigation underscores that coronaphobia is experienced as a general pandemic fear that is simultaneously experienced with specific domains of pandemic fears. Theoretical and methodological insights are offered for conceptualizing and measuring coronaphobia and understanding how pandemic phobias differ from traditional phobias.

P factor in children with chronic physical illness

BackgroundThe p factor represents the overall liability for the development of mental illness. While evidence supporting the p factor in adults has been reported, studies in children are fewer, and none have examined the p factor in children with chronic physical illness (CPI). ObjectiveWe aimed to model the p factor in a longitudinal sample of children with CPI using a parent-reported checklist and examine its construct validity against a structured diagnostic interview. MethodsWe used data from 263 children aged 2–16 years diagnosed with a CPI who were enrolled in the Multimorbidity in Children and Youth across the Life-course (MY LIFE) study. The p factor was modelled using the Emotional Behavioural Scales over 24 months using confirmatory factor analysis. Validation of the p factor was set against the Mini International Neuropsychiatric Interview for Children and Adolescents. ResultsFactorial evidence supported the p factor, modelled using a bi-factor structure, compared to a standard correlated-factors (i.e., two-factor) structure [Δχ2 = 9.66(4), p = 0.047]. p factor scores were correlated with the number of different mental illness diagnoses (r = 0.71) and total number of diagnoses (r = 0.72). Dose-response relationships were shown for the number of different diagnoses (p < 0.001) and total number of diagnoses (p < 0.001). ConclusionIn this first study of the p factor in children with CPI, we showed evidence of its bi-factor structure and associations with mental illness diagnoses. Mental comorbidity in children with CPI is pervasive and warrants transdiagnostic approaches to integrated pediatric care.

Differential item functioning of the revised Multigroup Ethnic Identity Measure (MEIM-R) in racially and income diverse youth with type 1 diabetes.

Racially minoritized youth with T1D are made vulnerable to disproportionately adverse health outcomes compared to White peers due to enduring systems of oppression. Thus, understanding modifiable psychosocial factors associated with diabetes-related outcomes in racially minoritized youth may help to buffer deleterious effects of racism. One factor meriting exploration is racial-ethnic identity. There is currently limited research on measures fit to assess ethnic identity in youth with chronic illnesses. This study's purpose is to examine the factor structure, reliability, and validity of the revised Multigroup Ethnic Identity Measure (MEIM-R) in a racially- and income-diverse sample of youth with T1D across sociodemographic and illness-related proxies for one's positionality in oppressive systems. As part of a larger study examining resilience, 142 youth with T1D ages 12-18 (Mage = 14.66, SDage = 1.62, 55.6% Black/African-American, 44.4% White) completed the MEIM-R and various psychosocial measures. HbA1c levels and illness duration were extracted from medical records and caregivers reported income information. Confirmatory factor analyses compared the structural validity of competing MEIM-R models, and uniform and non-uniform differential item functioning (DIF) was explored across sociodemographic and illness-related factors. While a bifactor structure was supported, the MEIM-R was found to exhibit DIF by race and gender on multiple MEIM-R items and did not demonstrate linear bivariate relations with other psychosocial factors. Since different MEIM-R item response patterns were observed across racial/ethnic and gender groups, caution is warranted in using this measure in racially and gender diverse youth with T1D.

Validation of the Interpersonal Relationships in Eating Disorders (IR-ED) Scale in an Eating Disorder Sample.

Interpersonal problems have been identified as a plausible mechanism underlying the onset and maintenance of eating disorders. The Interpersonal Relationships in Eating Disorders (IR-ED) scale is the first eating disorders-specific measure of interpersonal problems, which was developed in a nonclinical sample. The aims of the current study were to (a) confirm the factor structure of the IR-ED within a large clinical sample, (b) investigate measurement invariance of the IR-ED across nonclinical and clinical samples, (c) examine the convergent validity of the IR-ED using a generic measure of interpersonal problems, and (d) investigate the incremental clinical utility of the IR-ED in uniquely predicting eating disorder symptomatology. Treatment-seeking individuals (N = 437) completed the IR-ED at their initial assessment appointment at a specialist eating disorder outpatient service. A multiple-group confirmatory factor analysis supported an invariant bifactor structure comprising a general interpersonal problems factor and two group factors-Avoidance of Body Evaluation and Food-Related Interpersonal Tension. Convergent validity was demonstrated by a large, statistically significant correlation with a generic measure of interpersonal problems (r = 0.62, p < 0.001). A series of structural equation models further revealed unique incremental predictive utility of the IR-ED for eating disorder symptomatology. The IR-ED has strong psychometric properties and may prove beneficial in the assessment, formulation, and treatment of eating-specific interpersonal problems among patients with eating disorders.

Development and initial validation of the contemporary Chinese Familism Scale.

Familism is a core ideology in Chinese society, yet it has been understudied in this cultural context, potentially attributed to the lack of quantifiable measures. This study sought to develop a reliable and valid scale, the Contemporary Chinese Familism Scale (CCFS), to assess Chinese familism and analyze its structural and psychological characteristics in contemporary China. The scale development and validation process comprised four studies: in Study 1, literature review, qualitative interviews, and item evaluations by experts were conducted to develop the initial item pool for the CCFS; in Studies 2 and 3, item analysis, exploratory and confirmatory factor analyses, competing model comparisons, and measurement invariance tests were conducted to examine the structure underlying familism (N₁ = 958, Mage = 25.4 years; N₂ = 570, Mage = 32.01 years); in Study 4, reliability and validity assessments were conducted to further explore the psychometric properties of the final 27-item CCFS using three samples (N₂ = 570, Mage = 32.01 years; N₃ = 710, Mage = 22.37 years; N₄ = 932, Mage = 40.98 years). A bifactor structure with one general factor and five specific factors (Connection and Closeness, Offspring and Lineage, Honor and Reference, Harmony and Sacrifice, and Care and Help) demonstrated the best fit for the data and supported the multidimensionality of familism in contemporary China. Subsequent psychometric analyses provided initial evidence for the optimal psychometric properties of the CCFS. This study contributes to our understanding of the multifaceted nature of familism in contemporary China by developing a culturally sensitive scale on Chinese familism. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Psychometric properties of the Chinese version of the Highly Sensitive Child Scale among Chinese adolescents

The present study aimed to develop the Chinese version of the Highly Sensitive Child (C-HSC) Scale and examine its psychometric properties in Chinese participants (grade 4 ∼ fourth year of college), and preliminarily explores what kinds of Environmental Sensitivity groups exist among Chinese adolescents. A total of 9091 data (46.65 % males, 9–23 years old) points were collected to examine the psychometric properties of the C-HSC scale, and half of the data were used to explore the types of Environmental Sensitivity groups. The results showed that the scale has good psychometric properties. First, the scale composed of three dimensions is consistent with the Highly Sensitive Child Scale, which is more consistent with the bifactor structure model than the three-factor structure model. In addition, the scale has good reliability, convergent validity and discriminant validity; and has full configural, full metric, and full scalar invariance (partial scalar invariance across developmental stages) across genders and developmental stages. Finally, three groups of Environmental Sensitivity were found among Chinese adolescents, namely, high (orchids), medium (tulips), and low (dandelions) Environmental Sensitivity. The proportions of low, medium and high environmental sensitivity were 24.09 %, 40.64 % and 35.27 %, respectively.

Development and validation of the Telepsychology Facilitators Scale: A national study.

This study developed and validated the Telepsychology Facilitators Scale (TFS), a novel measure that uses the theory of reasoned action and technology acceptance model as frameworks to assess factors that influence psychologists' openness to using telepsychology. At the beginning of the COVID-19 pandemic, an online sample of 2,619 psychologists completed initial items considered for the TFS, along with a measure assessing their actual use of telepsychology. The sample was split in half, with a preliminary exploratory factor analysis ultimately revealing a 13-item general scale with four distinct subscales (Positive Attitudes, Facilitating Infrastructure, Organizational Support, and External Policies). Higher scores on each subscale positively correlated with psychologists' percentage of patient treatment conducted with telepsychology. The exploratory factor analysis subscale structure was subsequently supported via confirmatory factory analyses of a four-factor structure and bifactor structure (tested separately) with the other half of the sample, revealing adequate model fit for both models and similar convergent validity. The TFS may help the field assess the potential barriers and drivers of telepsychology use among psychologists and be used to inform future organizational and policy efforts to increase telepsychology implementation and use across health service settings. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Impulsivity is a stable, measurable, and predictive psychological trait

Impulsivity is a personality construct frequently employed to explain and predict important human behaviors. Major inconsistencies in its definition and measurement, however, have led some researchers to call for an outright rejection of impulsivity as a psychological construct. We address this highly unsatisfactory state with a large-scale, preregistered study (N = 1,676) in which each participant completed 48 measures of impulsivity derived from 10 self-report scales and 10 behavioral tasks and reported frequencies of seven impulsivity-related behaviors (e.g., impulsive buying and social media usage); a subsample (N = 196) then completed a retest session 3 mo later. We found that correlations between self-report measures were substantially higher than those between behavioral tasks and between self-report measures and behavioral tasks. Bifactor analysis of these measures exacted one general factor of impulsivity I, akin to the general intelligence factor g, and six specific factors. Factor I was related mainly to self-report measures, had high test-retest reliability, and could predict impulsivity-related behaviors better than existing measures. We further developed a scale named the adjustable impulsivity scale (AIMS) to measure I. AIMS possesses excellent psychometric properties that are largely retained in shorter versions and could predict impulsivity-related behaviors equally well as I. These findings collectively support impulsivity as a stable, measurable, and predictive trait, indicating that it may be too early to reject it as a valid and useful psychological construct. The bifactorial structure of impulsivity and AIMS, meanwhile, significantly advance the conceptualization and measurement of construct impulsivity.

Spanish Adaptation of the D70 – The Dark Core of Personality in Spanish-Speaking Countries

Abstract: Socially aversive (“dark”) personality traits (e.g., Psychopathy, Narcissism, Machiavellianism, etc.) share many features which led Moshagen et al. (2018) to conceptualize D, the common core between them. This work aims to establish internal structure evidence for the validation of the Spanish version of its measure (D70) and to demonstrate measurement invariance across sex and country based on a total of 12,356 participants from six countries (Spain, Mexico, Argentina, Colombia, Chile, Peru). Item analysis, reliability, and confirmatory factor analysis following a bifactor structure were performed in each sample in order to assess the psychometric properties of the test, following tests of measurement invariance regarding sex and country. Results showed that the Spanish version of the D70 is an essentially unidimensional and reliable measure, and further supported invariance across sex and countries. This gives cross-cultural researchers a new tool for studying the common core of dark personality in Spanish-speaking countries, and the applied psychologist the possibility to assess socially aversive personalities from the dark factor model.

Design and validation of the perception of risk towards environmental unsustainability scale (PREUS)

AbstractNo validated scales are available to assess the perception of risk towards environmental unsustainability (PREU), which is a key construct for the adoption of sustainable behaviors. To fill this literature gap, the objective of this study was to develop and validate the PREU scale (PREUS). To this end, a total of 519 Spanish participants answered a survey composed of the PREUS and other psychosocial variables. The exploratory and confirmatory factor analyses ratify the bifactorial structure of the scale. The two factors refer to perceived risk to oneself and one’s own family (anthropocentric view of risk), and risk for the planet (ecocentric view), respectively. The structural equation modelling analyses confirmed (1) the expected relationships between both factors and other constructs of their nomological network, and (2) the mediating role of the ascription of responsibility in the relationship established between risk perception and sustainable behavior, offering empirical support for the external validity of the scale. Finally, both metric and scalar gender invariance were granted and, as expected, women showed higher PREU than men. The study provides a brief, easy-to-complete, reliable, valid, and sex-invariant instrument that can be useful for researchers and educators to assess the extent to which individuals perceive the risk that environmental unsustainability can pose.

Italian adaptation of the Multidimensional Iowa Suggestibility Scale (MISS).

Suggestibility is a personality trait that reflects a general tendency to accept messages. The Multidimensional Iowa Suggestibility Scale (MISS) is a self-report scale developed to measure the degree of individuals' perceptions of their suggestibility. This study aimed to adapt the MISS in an Italian sample. We conducted two studies. In the first study, 345 subjects (270 females (78%), mean age = 36.21 years ± 14.06 SD) completed the translated Italian version of the MISS, composed of five subscales (consumer suggestibility; persuadability; sensation contagion; physiological reactivity; peer conformity). We investigated the structural validity of the scale through confirmatory factor analysis (CFA) testing four measurement models (unidimensional, four-factor, hierarchical four factors, and bifactor) and explored reliability in terms of internal consistency through the McDonald's omega. In the second study, we cross-validated the MISS on a new independent sample. We enrolled 277 participants (196 females (71%), mean age 30.56, SD = 12.58) who underwent the new version of the scale. We performed factor analyses to test structural validity and compared four measurement models. Then, we investigated reliability and conducted a latent variable analysis to explore divergent validity. The CFA in the first study revealed a bifactor solution of the MISS. This structure was interpretable and provided an adequate fit for the data. The final version of the scale was reduced to forty-six items with globally good indices of adaptation. The scale also demonstrated acceptable reliability in terms of internal consistency through the McDonald's Hierarchical Omega. In the second study, we found that the bifactor structure was confirmed. Factor loadings inspection revealed that there was no justification to report only the separate scores for the subscales. We also found that the scale showed good internal consistency, but mixed evidence for divergent validity. In the end, the Italian version of the MISS demonstrated good psychometric properties which will be discussed in detail below.

Italian validation of the positive solitude scale

ABSTRACT Positive Solitude (PS) is the decision to use one’s time for a meaningful activity, with a choice made by and for oneself. The purpose of this study is to validate the Italian version of the Positive Solitude Scale (PSS) developed by Palgi et al. (2021a). Data were collected through the administration of a questionnaire to 1,120 Italian adults. Confirmatory factor analyses showed a bi-factor structure, indicating that the scale can be considered as unidimensional. Moreover, the Italian PSS demonstrated good internal consistency, supporting the scale’s good reliability. Then, PS was associated with improved psychological well-being, increased mindfulness, higher levels of positive effects and lower loneliness. However, we found no association between PS and depressive symptomatology. These results support a good convergent, discriminant, and divergent validity of the scale. Finally, this study enhances the understanding of PS in the Italian context providing a valuable tool for future research.

Bi-factor model of repetitive thinking: Replication and extension

Repetitive negative thinking, including worry and rumination, is considered a transdiagnostic process that contributes to the development and persistence of psychopathology. Recently, Castro et al. (2022) investigated how both repetitive negative thinking and more adaptive repetitive thinking may be related each other. They found evidence for a bi-factor structure of repetitive thinking with both shared variance in repetitive thinking and unique variance specific to each form of repetitive thinking, specifically worry, rumination, and reflection. The present study replicated this bi-factor structure of repetitive thinking in a younger sample from the Netherlands (N = 3906). Additionally, biological sex did not alter bi-factor structure fit. The present findings provide additional evidence of a bi-factor structure of repetitive thinking, and future work should continue to explore the clinical relevance of repetitive thinking and its distinct forms.

라이프스타일에 반영된 가치체계 평가도구(Yonsei Lifestyle Profile-Values)의 구성 타당성: 이중요인(Bifactor) 모델 접근

Objective: The construct validity and reliability of the Yonsei Lifestyle Profile-Values (YLP-V) were verified to measure the value system reflected in lifestyle behaviors. Methods: Data were collected from 300 community-dwelling older adults aged 55 years and older who were registered with an online research organization. The YLP-V was used to collect data, which underwent descriptive statistics, differential item functioning, and factor analysis. Exploratory factor analysis was conducted to estimate the factor structure, and confirmatory factor analysis was used to compare and confirm the validity of four competing models (single-factor, hierarchical factor, multidimensional factor, and bifactor). Results: Exploratory factor analysis using target rotation revealed that the dimensions of the YLP-V (activity, five items; interest, four items; opinion, nine items) showed factor loadings of 0.4 or higher, indicating good construct validity. Confirmatory factor analysis indicated that the bifactor model (χ2 = 164.58**, degree of freedom = 117, root mean square error of approximation = 0.05, standard root mean residual = 0.04, comparative fit index = 0.95, Turker Lewis index = 0.93) demonstrated the best fit among the tested models. Conclusion: We identified a factor structure consistent with evidence for developing the YLP-V, which allows for a micro-level lifestyle approach. The bifactor structure, with 18 items representing activity, interest, and opinion, demonstrated validity, and the YLP-V could be valuable for measuring and understanding the value systems reflected in behaviors within a healthy lifestyle.

Development of a rapid tool for screening financial toxicity based on the comprehensive score for financial toxicity

ObjectiveThis study aimed to use item response theory (IRT) to develop and validate a short version of the Chinese COmprehensive Score for financial Toxicity (COST-S-C) in patients with cancer. MethodsA total of 500 patients with cancer participated in the survey. Confirmatory factor analysis (CFA) was used to assess the factor structure of the COST-S-C. A two-parameter IRT model was used to examine the item fit of the COST-S-C. Item discrimination, item characteristic curves (ICCs), item information curves (IICs), and item fit were estimated. Differential item functioning (DIF) was assessed for participants’ gender and age. Reliability, convergent and discriminant validity was examined as well as estimating the optimal cut-off points of the COST-S-C. ResultsThe CFA results supported the bi-factor structure of the COST-S-C. The IRT analysis findings revealed that several items showed problems with the ICCs, providing little information in terms of IICs as well as poor discrimination. Item 5 showed a negligible DIF problem with age. A valid 3-item COST-S-C scale and its optimal cut-off point was developed. ConclusionsThe COST-S-C is a valid and quick screening tool used to distinguish patients with cancer who report significant financial toxicity in various medical settings.

Development and validation of an intrinsic capacity score in the UK Biobank study

BackgroundIn 2015, the World Health Organization introduced the concept of intrinsic capacity (IC) to define the individual-level characteristics that enable an older person to be and do the things they value. This study developed an intrinsic capacity score for UK Biobank study participants and validated its use as a tool for health outcome prediction, understanding healthy aging trajectories, and genetic research. MethodsOur analysis included data from 45,208 UK biobank participants who had a complete record of the ten variables included in the analysis. Factor adequacy was tested using Kaiser–Meyer–Olkin, Barthelt's, and the determinant of matrix tests, and the number of factors was determined by the parallel analysis method. Exploratory and confirmatory factor analyses were employed to determine the structure and dimensionality of indicators. Finally, the intrinsic capacity score was generated, and its construct and predictive validities as well as reliability were assessed. ResultsThe factor analysis identified a multidimensional construct comprising one general factor (intrinsic capacity) and five specific factors (locomotor, vitality, cognitive, psychological, and sensory). The bifactor structure showed a better fit (comparative fit index = 0.995, Tucker Lewis index = 0.976, root mean square error of approximation = 0.025, root mean square residual = 0.009) than the conventional five-factor structure. The intrinsic capacity score generated using the bifactor confirmatory factor analysis has good construct validity, as demonstrated by an inverse association with age (lower intrinsic capacity in older age; (β) =−0.035 (95%CI: −0.036, −0.034)), frailty (lower intrinsic capacity score in prefrail participants, β = −0.104 (95%CI: (−0.114, −0.094)) and frail participants, β = −0.227 (95%CI: −0.267, −0.186) than robust participants), and comorbidity (a lower intrinsic capacity score associated with increased Charlson's comorbidity index, β =−0.019 (95%CI: −0.022, −0.015)). The intrinsic capacity score also predicted comorbidity (a one-unit increase in baseline intrinsic capacity score led to a lower Charlson's comorbidity index, β = 0.147 (95%CI: −0.173, −0.121)) and mortality (a one-unit increase in baseline intrinsic capacity score led to 25 % lower risk of death, odds ratio = 0.75(95%CI: 0.663, 0.848)). ConclusionThe bifactor structure showed a better fit in all goodness of fit tests. The intrinsic capacity construct has strong structural, construct, and predictive validities and is a promising tool for monitoring aging trajectories.

Longitudinal change of intrinsic capacity and associated factors in older Chinese adults: China Health and Retirement Longitudinal Study

BackgroundAlthough intrinsic capacity (IC) has been constructed in older populations, whether IC retains the same structure over time has not been formally examined, nor have the factors associated with the changes in IC over time been thoroughly investigated. This study aimed to establish that the structure of IC remains unchanged over time by testing its longitudinal measurement invariance and to investigate factors that influence the longitudinal change of IC over time. MethodsData came from 7,271 participants aged 60 and older from the China Health and Retirement Longitudinal Study in 2011 (Wave 1) and 2015 (Wave 3). Bifactor confirmatory factor analysis (CFA) was used to construct IC with its domains, and the longitudinal measurement invariance of IC between Waves was tested. ResultsBifactor CFA fitted the data well at both Waves and showed good construct validity. Partial scalar invariance was supported with non-invariant intercepts for delayed word recall, math, and close vision. Decreases in IC were associated with increasing age, being female (−0.030, 95% CI: −0.045, −0.016), living in rural areas (−0.019, 95% CI: −0.030, −0.009), BMI < 18.5 (−0.019, 95% CI: −0.035, −0.003), and hypertension (−0.012, 95% CI: −0.022, −0.001). Increases in IC were associated with higher education (primary school: 0.012, 95% CI: 0.001, 0.024; lower secondary school: 0.023, 95% CI: 0.005, 0.041) and drinking ≥4/week (0.019, 95% CI: 0.003, 0.034). Stratifying the sample by gender, the protective effect of education was observed only in women. ConclusionsThe bifactor structure of the IC construct was valid and retained its meaning over time. Longitudinal changes in IC were associated with various sociodemographic factors, lifestyle, and health conditions, confirming the need to monitor IC for timely intervention, particularly in those with risk factors for IC decline.