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.

Evaluating the quality of life impact of recurrent urinary tract infection: Validation and refinement of the Recurrent UTI Impact Questionnaire (RUTIIQ).

BACKGROUND AND AIMS: Recurrent urinary tract infection (rUTI) has significant negative consequences for a wide variety of quality of life (QoL) domains. Without adequate validation and assessment of the unique insights of people living with rUTI, clinical results cannot be fully understood. The Recurrent UTI Impact Questionnaire (RUTIIQ), a novel patient-reported outcome measure of rUTI psychosocial impact, has been robustly developed with extensive patient and clinician input to facilitate enhanced rUTI management and research. This study aimed to confirm the structural validity of the RUTIIQ, assessing its strength and bifactor model fit. METHODS: A sample of 389 adults experiencing rUTI (96.9% female, aged 18-87 years) completed an online cross-sectional survey comprising a demographic questionnaire and the RUTIIQ. A bifactor graded response model was fitted to the data, optimizing the questionnaire structure based on item fit, discrimination capability, local dependence, and differential item functioning. RESULTS: The final RUTIIQ demonstrated excellent bifactor model fit (RMSEA = 0.054, CFI = 0.99, SRMSR = 0.052), and mean-square fit indices indicated that all included items were productive for measurement (MNSQ = 0.52-1.41). The final questionnaire comprised an 18-item general "rUTI QoL impact" factor, and five subfactor domains measuring "personal wellbeing" (three items), "social wellbeing" (four items), "work and activity interference" (four items), "patient satisfaction" (four items), and "sexual wellbeing" (three items). Together, the general factor and five subfactors explained 81.6% of the common model variance. All factor loadings were greater than 0.30 and communalities greater than 0.60, indicating good model fit and structural validity. CONCLUSIONS: The 18-item RUTIIQ is a robust, patient-tested questionnaire with excellent psychometric properties, which capably assesses the patient experience of rUTI-related impact to QoL and healthcare satisfaction. Facilitating standardized patient monitoring and improved shared decision-making, the RUTIIQ delivers the unique opportunity to improve patient-centered care.

Perinatal and neonatal factors and mental disorders in children and adolescents: looking for the contributions of the early environment to common and dissociable aspects of psychopathology.

High rates of co-occurrence of mental disorders have been hypothesized to represent a result of common susceptibility to overall psychopathology. The purpose of this study is to test the hypothesis that commonalities among psychiatric disorders might be partially driven by sharable perinatal and neonatal environmental factors for mental disorders. Participants were 6-14 years of age children and their parents. Primary caregivers provided data on perinatal and neonatal information assessed retrospectively (n = 2231). Psychiatric disorders diagnoses were assessed using the Development and Well Being Behavior Assessment (DAWBA). We used bifactor models to disentangle common from dissociable aspects of psychopathology. These models allow modeling psychiatric disorders as the result of a common domain of psychopathology (p-factor) and three dissociable domains (fear, distress, and externalizing symptoms). Associations were tested using linear and tobit regression models. The p-factor was associated with male sex, low socioeconomic status, gestational smoking, gestational drinking, low levels of maternal education and presence of mental disorder in the mother. Associations with specific factors also emerged suggesting some risk factors might also have some role for fear, distress and externalizing factors. Our study supports the hypothesis that overall susceptibility to psychopathology might be partially driven by sharable perinatal and neonatal factors.

Comprehensive investigation of factor structure and gender equivalence of the Beck Depression Inventory-II among nonclinical adolescents.

The Beck Depression Inventory-II (BDI-II) is a widely used tool for rating the severity of depressive symptoms. Studies on the factor structure of the BDI-II in adolescents have yielded controversial findings. Most studies have reported an oblique two-factor model that describes the 'cognitive' and 'somatic-affective' dimensions. However, there is variation in the item composition of each factor across studies. Alternative factor structures have been proposed, including one-factor, three-factor, hierarchical, and bifactor models. Additionally, there is limited data on measurement invariance across genders. This study aimed to examine hypothetical factor structures and gender equivalence of the BDI-II in a sample of Brazilian nonclinical adolescents (N = 1,184, aged 13-18 years, 59.1% females). Cross-validation of the BDI-II was performed through exploratory (EFA) and confirmatory factor analysis (CFA). Measurement invariance was evaluated using multigroup-CFA (MG-CFA). EFA suggested an oblique two-factor model depicting "affective-cognitive" and "somatic" dimensions. CFA tested competing models for the structure of BDI-II, including the simple one- and two-factor models, a bifactor model, and the EFA model along with its corresponding bifactor model. All models demonstrated adequate and similar fitness, well-defined factors, and good reliability. Bifactor analyses indicated a robust general factor with low reliable variance in total scores attributed to multidimensionality caused by the group factors in bifactor models. MG-CFA supported invariance across gender, suggesting that the same BDI-II construct could be applied to both female and male adolescents. This study provides evidence that the BDI-II could be used as a unidimensional measure of depressive symptoms in adolescents by researchers and clinicians.

The Depression Anxiety Stress Scales for Youth (DASS-Y): evidence of validity and cross-national and gender measurement invariance.

The Depression Anxiety Stress Scales for Youth (DASS-Y) is a recently developed measure of unpleasant emotional experiences for children and adolescents; however, the evidence for its validity is still limited. The present study evaluated the evidence for the structural, convergent, and incremental validity of the DASS-Y on a sample of Serbian adolescents aged 15-19 years (N = 421; 48% female, mean age = 16.86). Measurement invariance across gender and two countries (Serbia and Australia) was also tested. The findings supported the bifactor exploratory structural equation modeling (bifactor-ESEM) representation of the DASS-Y, which includes the General factor of negative affect/emotional distress, and three specific factors of Depression, Anxiety, and Stress. The DASS-Y factors showed evidence of incremental validity in predicting global externalizing symptoms and demonstrated convergent validity in relation to measures of global internalizing and externalizing symptoms as well as subjective well-being. The bifactor-ESEM model of the DASS-Y was found to be invariant across gender and two countries. The present study findings highlight the importance of distinguishing between general and specific components of unpleasant emotional states.

Exploring the factor structure of a Chinese version of the CORE-OM: insights from network approach and bifactor modeling.

OBJECTIVE: The Clinical Outcomes in Routine Evaluation (CORE-OM) is a measure of clinical outcomes that has been widely used in mental health research. Nevertheless, the exploration of the factor structure of the CORE-OM yields diverse results. This study aims to explore the factor structure with an innovative method known as exploratory graph analysis (EGA) and supplemented with bifactor modeling. METHOD: A Chinese version of the CORE-OM was administrated to a total of 1361 clinical college students. We first examined the factor structure of the CORE-OM using EGA, and then compared the model derived by EGA with other models using CFA to find the most reasonable model. RESULTS: The result of EGA indicated a four-factor model of CORE-OM. The CFA further suggested a bifactor model with a four-factor structure combined with a general factor. The bifactor modeling suggested a significant proportion of shared variance among the variables was attributed to the general factor. The four-factor bifactor model exhibited a satisfactory fit to the data. CONCLUSION: The results confirm the robustness and parsimonious nature of a four-factor bifactor model for the Chinese version of CORE-OM. It is suitable for measuring intrapersonal psychological distress, positive emotions, interpersonal problems, and risk-related issues among the Chinese population.

Interpretational issues with the bifactor model: a commentary on 'Defining the p-Factor: An Empirical Test of Five Leading Theories' by Southward, Cheavens, and Coccaro.

Southward, Cheavens, and Coccaro (2022, Psychological Medicine) conducted an ambitious investigation aimed at determining the nature of the general p factor of psychopathology by considering the correlation between the p factor and five candidate constructs. Generally, in this area of research, the bifactor model is preferred to the second order common factor model. In this commentary, we identify several interpretational issues concerning the bifactor model, which are based on a realistic psychometric view of latent variables. These issues may hamper the study of the nature of p factor model using the bifactor model.

Applying multidimensional computerized adaptive testing to the MSQOL-54: a simulation study.

BACKGROUND: The Multiple Sclerosis Quality of Life-54 (MSQOL-54) is one of the most commonly-used MS-specific health-related quality of life (HRQOL) measures. It is a multidimensional, MS-specific HRQOL inventory, which includes the generic SF-36 core items, supplemented with 18 MS-targeted items. Availability of an adaptive short version providing immediate item scoring may improve instrument usability and validity. However, multidimensional computerized adaptive testing (MCAT) has not been previously applied to MSQOL-54 items. We thus aimed to apply MCAT to the MSQOL-54 and assess its performance. METHODS: Responses from a large international sample of 3669 MS patients were assessed. We calibrated 52 (of the 54) items using bifactor graded response model (10 group factors and one general HRQOL factor). Then, eight simulations were run with different termination criteria: standard errors (SE) for the general factor and group factors set to different values, and change in factor estimates from one item to the next set at < 0.01 for both the general and the group factors. Performance of the MCAT was assessed by the number of administered items, root mean square difference (RMSD), and correlation. RESULTS: Eight items were removed due to local dependency. The simulation with SE set to 0.32 (general factor), and no SE thresholds (group factors) provided satisfactory performance: the median number of administered items was 24, RMSD was 0.32, and correlation was 0.94. CONCLUSIONS: Compared to the full-length MSQOL-54, the simulated MCAT required fewer items without losing precision for the general HRQOL factor. Further work is needed to add/integrate/revise MSQOL-54 items in order to make the calibration and MCAT performance efficient also on group factors, so that the MCAT version may be used in clinical practice and research.

Factor structure of the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) in a clinical sample recruited from the community.

BACKGROUND: The Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) are widely used self-report questionnaires to assess symptoms of social anxiety. While SPS measures social performance anxiety, SIAS measures social interaction anxiety. They are mostly reported simultaneously, but there have not been consistent results of the joint factor structure and therefore no consistent recommendations on how to use and evaluate the questionnaires. This study aimed (1) to evaluate the underlying joint factor structure of the SPS and SIAS and (2) to test whether SPS and SIAS are reliable scales to assess two different aspects of social anxiety. METHODS: The one-factor, two-factor, and bifactor models were tested in a clinical sample recruited from the community and diagnosed with a social anxiety disorder. Exploratory and confirmatory factor analyses were conducted, bifactor-specific indices were calculated, and the content of the less fitting items was examined. RESULTS: Confirmatory factor analyses showed that the best-fitting model was the bifactor model with a reduced set of items. The bifactor-specific indices showed that the factor structure cannot be considered unidimensional and that SPS and SIAS are reliable subscales. A closer examination of the less fitting item content and implications for future studies are discussed. CONCLUSIONS: In conclusion, SPS and SIAS can be reported together as an overall score of social anxiety and are separately reliable measures to assess different aspects of social anxiety. TRIAL REGISTRATION: This is a secondary analysis of data from two trials registered under ISRCTN75894275 and ISRCTN10627379.

Applying a bifactor model to the functions of relational aggression: Associations with hostile attribution biases and difficulties with emotion regulation.

Previous research suggests that reactive and proactive aggression likely have distinct underlying mechanisms that uniquely contribute to the perpetration of each as a result of faulty cognitive and emotional processes. Still, very little work has examined the association of the functions of relational aggression with emotion dysregulation and hostile attribution biases. In addition, it is important to examine relational aggression in its pure and co-occurring functions given that past work finds reactive and proactive aggression to occur both jointly and distinctly. Thus, the current study employed a bifactor model to distinguish between pure reactive, pure proactive, and co-occurring relational aggression in emerging adulthood (N = 647, Mage = 19.92, SD = 2.83), a developmental time period for which relational aggression is particularly prominent. To further address gaps in the relational aggression literature, indirect pathway models revealed that relational hostile attribution biases emerged as a concurrent indirect path in the relationship between emotion dysregulation and pure reactive relational aggression. Furthermore, emotion dysregulation was directly positively associated with both pure functions as well as co-occurring relational aggression, and hostile attribution biases for relational provocations were directly associated with both pure functions of relational aggression, though the association was negative for pure proactive and positive for pure reactive relational aggression. Findings highlight the potential influence of emotion dysregulation and attributing hostile intent to social situations on engaging in the different functions of relational aggression.

New Directions in L2 Self-efficacy Research: Comparing Bifactor and Second-Order Models in the English Public Speaking Domain.

Reflecting an alternative model comparison framework and grounded in Bandura's self-efficacy theory and in western and Chinese English Public Speaking (EPS) competences literature, we examine the possibility of a hierarchical structure of the EPS self-efficacy construct. In particular, we contrast an established first-order model of the EPS self-efficacy with two higher-order rival models, testing for subordinate (second-order model) versus nested (bifactor model) relationships in a sample of 203 Chinese EFL college students. From a theoretical perspective, the results supported the bifactor model as a strong conceptual foundation for understanding the EPS self-efficacy construct as nested. From a practical perspective, this conceptualization would allow for gauging EPS self-efficacy development both holistically and by subdomains. From a research methodology perspective, this study is among the first to bring the bifactor model into the broader field of L2 research. Other implications are discussed.

Death anxiety as general factor to fear of cancer recurrence.

OBJECTIVE: Fear of cancer recurrence or progress is strongly related to death anxiety (DA) in cancer patients, but due to lack of conceptualization and measurement methods, the relationship was not analyzed quantitatively before. The aim of the present study was to investigate the conceptual relationship of both constructs, with DA expected to be the general construct. METHODS: Cancer patients (N = 121) participated in an online study. They provided information on socio-demographical, medical and psychological measures including DA and fear of cancer recurrence or progression (FoP-Q-SF). Relation of constructs was assessed using a two-step process: Confirming individual construct structure with confirmatory factor analysis, including correlation of constructs and modification of measurement model, followed by structural equation modeling and comparison of structure models for best model fit. RESULTS: The measurement model was modified to include three residual correlations within and between constructs. Comparison of structure models supported a bifactor structure with DA as general factor and fear of recurrence or progression as group factor: SBχ2 (173) = 207.74 (p < 0.05), SB = 1.538, relative χ2  = 1.2, rRMSEA = 0.05 [0.01, 0.07] (p > 0.05), SRMR = 0.07, CFI = 0.94, AIC = 7543.60. CONCLUSIONS: DA can be interpreted as general factor to fear of cancer recurrence or progression. Psychological interventions to reduce emotional burden of cancer patients need to focus additionally on existential threat and individual fears regarding DA.

A bifactor model of personality organization in adolescence: the validity of a brief screening measure assessing severity and core domains of functioning.

BACKGROUND: Both the latest edition of the DSM-5 as well as the new ICD-11 have established a new focus in the diagnosis of personality disorders: the assessment of personality functioning. This recent shift in focus converges with long-standing psychodynamic conceptualizations of personality pathology, particularly Kernberg's object relations model. Although a significant amount of research supports these models in adults, much less is known about the validity of these frameworks in youth. Considering the paucity of brief measures of personality functioning in adolescents, the current study aimed to develop and investigate the validity of the Inventory of Personality Organization for Adolescents-Short Form, a theoretically-informed measure assessing severity and core domains of functioning in adolescents. METHODS: A total sample of N = 525 adolescents aged 13 to 19 years were recruited through a community University-Health Psychology Clinic as current patients (n = 94) or who responded to an online research call (n = 431). RESULTS: Results indicate that a bifactor model provided the best fit to the data and consisted of a general factor reflecting core self-other functioning and three specific factors, representing additional dimensions of personality organization. CONCLUSIONS: A brief 15-item version of the IPO-A was successfully derived for time-efficient screening of personality pathology in youth. Similarities with the ICD-11 framework are discussed.

Developmental cascade models linking contextual risks, parenting, and internalizing symptoms: A 17-year longitudinal study from early childhood to emerging adulthood.

Although internalizing problems are the most common forms of psychological distress among adolescents and young adults, they have precursors in multiple risk domains established during childhood. This study examined cascading risk pathways leading to depression and anxiety symptoms in emerging adulthood by integrating broad contextual (i.e., multiple contextual risks), parental (i.e., negative parenting), and child (i.e., internalizing behaviors) characteristics in early and middle childhood. We also compared common and differential pathways to depression and anxiety symptoms depending on the conceptualization of symptom outcomes (traditional symptom dimension vs. bifactor dimensional model). Participants were 235 children (109 girls) and their families. Data were collected at 3, 6, 10, and 19 years of child age, using multiple informants and contexts. Results from a symptom dimension approach indicated mediation pathways from early childhood risk factors to depression and anxiety symptoms in emerging adulthood, suggesting common and distinct risk processes between the two disorders. Results from a bifactor modeling approach indicated several indirect pathways leading to a general internalizing latent factor, but not to symptom-specific (i.e., depression, anxiety) latent factors. Our findings highlighted comparative analytic approaches to examining transactional processes associated with later internalizing symptoms and shed light on issues of early identification and prevention.

The Moral Injury Symptoms Scale-Military Version-Short Form: Further Scale Validation in a U.S. Veteran Sample.

This study assessed the Moral Injury Symptoms Scale - Military Version - Short Form's (MISS-M-SF) factor structure and construct validity. Participants included 3650 combat-deployed U.S. veterans who answered all 10 MISS-M-SF items from the sixth wave of The Veterans Metric Initiative (TVMI). EFA results suggested a two-factor solution, based on item wording, fit best. CFA results indicated a bifactor model (one general factor and two method factors, based on item wording) fit best. Further investigation revealed that a one-factor model could be used despite the data's multidimensionality. Item-level analyses revealed four items represented the general factor exceptionally well, potentially simplifying assessment in research and clinical applications. Construct validity was also demonstrated through moderate to high correlations with conceptually related measures.

Viability of a MSQOL-54 general health-related quality of life score using bifactor model.

BACKGROUND: MSQOL-54 is a multidimensional, widely-used, health-related quality of life (HRQOL) instrument specific for multiple sclerosis (MS). Findings from the validation study suggested that the two MSQOL-54 composite scores are correlated. Given this correlation, it could be assumed that a unique total score of HRQOL may be calculated, with the advantage to provide key stakeholders with a single overall HRQOL score. We aimed to assess how well the bifactor model could account for the MSQOL-54 structure, in order to verify whether a total HRQOL score can be calculated. METHODS: A large international database (3669 MS patients) was used. By means of confirmatory factor analysis, we estimated a bifactor model in which every item loads onto both a general factor and a group factor. Fit of the bifactor model was compared to that of single and two second-order factor models by means of Akaike information and Bayesian information criteria reduction. Reliability of the total and subscale scores was evaluated with Mc Donald's coefficients (omega, and omega hierarchical). RESULTS: The bifactor model outperformed the two second-order factor models in all the statistics. All items loaded satisfactorily (≥ 0.40) on the general HRQOL factor, except the sexual function items. Omega coefficients for total score were very satisfactory (0.98 and 0.87). Omega hierarchical for subscales ranged between 0.22 to 0.57, except for the sexual function (0.70). CONCLUSIONS: The bifactor model is particularly useful when it is intended to acknowledge multidimensionality and at the same time take account of a single general construct, as the HRQOL related to MS. The total raw score can be used as an estimate of the general HRQOL latent score.

Associating Psychotic Symptoms with Altered Brain Anatomy in Psychotic Disorders Using Multidimensional Item Response Theory Models.

Reduced cortical thickness has been demonstrated in psychotic disorders, but its relationship to clinical symptoms has not been established. We aimed to identify the regions throughout neocortex where clinical psychosis manifestations correlate with cortical thickness. Rather than perform a traditional correlation analysis using total scores on psychiatric rating scales, we applied multidimensional item response theory to identify a profile of psychotic symptoms that was related to a region where cortical thickness was reduced. This analysis was performed using a large population of probands with psychotic disorders (N = 865), their family members (N = 678) and healthy volunteers (N = 347), from the 5-site Bipolar-Schizophrenia Network for Intermediate Phenotypes. Regional cortical thickness from structural magnetic resonance scans was measured using FreeSurfer; individual symptoms were rated using the Positive and Negative Syndrome Scale, Montgomery-Asberg Depression Rating Scale, and Young Mania Rating Scale. A cluster of cortical regions whose thickness was inversely related to severity of psychosis symptoms was identified. The regions turned out to be located contiguously in a large region of heteromodal association cortex including temporal, parietal and frontal lobe regions, suggesting a cluster of contiguous neocortical regions important to psychosis expression. When we tested the relationship between reduced cortical surface area and high psychotic symptoms we found no linked regions describing a related cortical set.

Parsing apart affective dimensions of withdrawal: Longitudinal relations with peer victimization.

The current study examined a bifactor model of affective dimensions of withdrawal. Specifically, a model which specified a general factor of anxious-avoidant withdrawal (i.e., withdrawal with negative affect), a specific factor of unsociability (i.e., withdrawal without negative affect), and a specific factor of negative affect without withdrawal was specified in the primary sample (n = 238, 56.3% boys, M age = 44.92 months, SD = 5.32 months) and a validation sample (n = 332, 52.6% boys, M age = 47.11 months, SD = 7.32 months). The model provided a good fit to the data in both samples. In the primary sample, longitudinal relations between the bifactor model and peer victimization were examined across three time points (Time 1 in the spring, Time 2 in the fall, and Time 3 in the spring). Results showed that negative affect without withdrawal was concurrently associated with higher levels of relational and physical victimization at T1, unsociability predicted reductions in relational victimization from T1 to T2 as children entered a new classroom, and anxious-avoidant withdrawal predicted reductions in relational and physical victimization from T2 to T3 as children acclimated to the new classroom. Developmental considerations and clinical implications are discussed.

Confirmatory factor analysis of the Evidence-Based Practice Attitude Scale (EBPAS) in a large and representative Swedish sample: is the use of the total scale and subscale scores justified?

BACKGROUND: There is a call for valid and reliable instruments to evaluate implementation of evidence-based practices (EBP). The 15-item Evidence-Based Practice Attitude Scale (EBPAS) measures attitude toward EBP, incorporating four lower-order factor subscales (Appeal, Requirements, Openness, and Divergence) and a Total scale (General Attitudes). It is one of a few measures of EBP attitudes evaluated for its psychometric properties. The reliability of the Total scale has been repeatedly supported, but also the multidimensionality of the inventory. However, whether all of the items contribute to the EBPAS Total beyond their subscales has yet to be demonstrated. In addition, the Divergence subscale has been questioned because of its low correlation with the other subscales and low inter-item correlations. The EBPAS is widely used to tailor and evaluate implementation efforts, but a Swedish version has not yet been validated. This study aimed to contribute to the development and cross-validation of the EBPAS by examining the factor structure of t a Swedish-language version in a large sample of mental health professionals. METHODS: The EBPAS was translated into Swedish and completed by 570 mental health professionals working in child and adolescent psychiatry settings spread across Sweden. The factor structure was examined using first-order, second-order and bifactor confirmatory factor analytic (CFA) models. RESULTS: Results suggested adequate fit for all CFA models. The EBPAS Total was strongly supported in the Swedish version. Support for the hierarchical second-order model was also strong, while the bifactor model gave mixed support for the subscales. The Openness and Requirements subscales came out best, while there were problems with both the Appeal (e.g. not different from the General Attitudes factor) and the Divergence subscales (e.g. low reliability). CONCLUSIONS: Overall, the psychometric properties were on par with the English version and the total score appears to be a valid measure of general attitudes towards EBP. This is the first study supporting this General Attitudes factor based on a bifactor model. Although comparatively better supported in this Swedish sample, we conclude that the use of the EBPAS subscale scores may result in misleading conclusions. Practical implications and future directions are discussed.

Electronic Health Literacy in Swiss-German Parents: Cross-Sectional Study of eHealth Literacy Scale Unidimensionality.

BACKGROUND: Parents often use digital media to search for information related to their children's health. As the quantity and quality of digital sources meant specifically for parents expand, parents' digital health literacy is increasingly important to process the information they retrieve. One of the earliest developed and widely used instruments to assess digital health literacy is the self-reported eHealth Literacy Scale (eHEALS). However, the eHEALS has not been psychometrically validated in a sample of parents. Given the inconsistency of the eHEALS underlying factor structure across previous reports, it is particularly important for validation to occur. OBJECTIVE: This study aimed to determine the factor structure of the German eHEALS measure in a sample of parents by adopting classic and modern psychometric approaches. In particular, this study sought to identify the eHEALS validity as a unidimensional index as well as the viability for potential subscales. METHODS: A cross-sectional design was used across two purposive sampling frames: online and paper administrations. Responses were collected between January 2018 and May 2018 from 703 Swiss-German parents. In addition to determining the sampling characteristics, we conducted exploratory factor analysis of the eHEALS by considering its ordinal structure using polychoric correlations. This analysis was performed separately for online-based and paper-based responses to examine the general factor strength of the eHEALS as a unidimensional index. Furthermore, item response theory (IRT) analyses were conducted by fitting eHEALS to a bifactor model to further inspect its unidimensionality and subscale viability. RESULTS: Parents in both samples were predominantly mothers (622/703, 88.5%), highly educated (538/703, 76.9%), of Swiss nationality (489/703, 71.8%), and living with a partner (692/703, 98.4%). Factor analyses of the eHEALS indicated the presence of a strong general factor across both paper and online samples, and the Wilcoxon rank-sum test indicated that the eHEALS total sum score was not significantly different between the paper and online samples (P=.12). Finally, the IRT analyses indicated negligible multidimensionality, insufficient subscale reliability after accounting for the eHEALS general factor, and a reduced subset of items that could serve as a unidimensional index of the eHEALS across the paper and online samples. CONCLUSIONS: The German eHEALS evidenced good psychometric properties in a parent-specific study sample. Factor analyses indicated a strong general factor across purposively distinct sample frames (online and paper). IRT analyses validated the eHEALS as a unidimensional index while failing to find support for subscale usage.