Item response theory: how Mokken scaling can be used in clinical practice

Validity evidence for the coping strategy indicator-short version (CSI-S) among psychology students

The abbreviated measurement of coping strategies is useful for monitoring and identifying the effects of stress. The Coping strategy indicator-Short version (CSI-S, including the dimensions of seeking support, problem solving and avoidance strategies) is a new adaptation of the full version of this indicator, and additional evidence of its validity is needed. Psychology students (n = 125) from a public university in Lima, Peru, were recruited to help provide such evidence of validity in terms of internal structure, reliability and associations with other variables (perceived stress and general efficacy in cope with difficulties), which were evaluated using nonparametric item response theory procedures. Support-seeking and problem-solving items from the Mokken scale and the avoidance scale exhibited limitations. The correlations between the scales were moderate or low and exhibited theoretical consistency, and the relationship with perceived stress highlighted the predictive capacity of avoidance and problem-solving strategies. In general, the CSI-S exhibits suitable psychometric properties; however, the avoidance score requires further examination or reconstruction of its items.

A stepwise methodological approach to develop and validate the digital and technological self-efficacy scale for healthcare workers among nurses and nursing students

AIMS

To develop and validate the Digital and Technological Self-Efficacy Scale (Digitech-S) for healthcare workers among nurses and nursing students.

BACKGROUND

Digital and technological solutions (DTS) significantly impact working life in healthcare and educational settings. DTS-related self-efficacy might be defined the individual's confidence in proficiently performing digital and technological tasks, even when faced with challenges. Its assessment might guide educators in orienting focused interventions to enhance the self-efficacy of nurses and nursing students. Thus far, the assessment of DTS-related self-efficacy is currently undermined by the lack of valid and reliable measurements.

DESIGN

A stepwise methodological approach was employed in two main phases. Phase one focused on tasks guided by literature for generating items reflecting DTS. Phase two encompassed three steps: A content validity step, a first cross-sectional data collection for Mokken scaling analysis (MSA) performed to reduce the number of items toward a unidimensional structure and with a hierarchical approach, and a confirmatory factor analysis including the group (nurses vs. nursing students) as a covariate (MIMIC) to cross-validate the unidimensional structure and assess the measurement invariance using a second cross-sectional data collection round. A Multi-Group Confirmatory Factor Analysis (MG-CFA) was also conducted to test for configural, metric, scalar, and strict invariance across the two groups.

RESULTS

Phase one resulted in 36 items derived from a literature review, which was reduced to 33 after the content validity process. 660 responders (nurses = 388; nursing students = 272) were included in the sample analyzed with MSA, and 13 items were hierarchically selected for the subsequent data collection (Rho reliability = 0.95; Hs = 0.67; Hi ranging from 0.55 to 0.72). MIMIC models were performed on 421 responders (nurses = 268; nursing students = 153), and three items that caused non-invariance between nurses and nursing students were identified and removed from the final version (Cronbach's alpha = 0.928). The MG-CFA demonstrated configural and metric invariance, suggesting a consistent factor structure and factor loadings across both groups, but scalar and strict invariance were not fully achieved.

CONCLUSIONS

The Digitech-S is a 10-item scale showing a unidimensional and stable structure, which could be used for educational and research purposes.

Applicability And Efficiency of a Polytomous IRT-Based Computerized Adaptive Test for Measuring Psychological Traits

Currently, research on computerized adaptive testing (CAT) focuses mainly on dichotomous items and cognitive traits (achievement, aptitude, etc.). However, polytomous IRT-based CAT is a promising research area for measuring psychological traits that has attracted much attention. The main purpose of this study is to test the practicality of the polytomous IRT-based CAT and its equivalence with the paper-pencil version. Data were collected from 1449 high school students (45% female), using the paper-pencil version for IRT parameter estimates and CAT simulation studies. For the equivalence study, the research group consisted of 81 students (47% female) who participated in both the paper-pencil and live CAT application. The paper-pencil version of vocational interest inventory consists of 17 factors and 164 items. The simulation study showed that the EAP estimation method and the SE < .500 test termination strategy were superior compared to the other CAT designs. The Item selection did not help to reduce test duration or increase measurement accuracy. As a result, it was found that an area of interest can be assessed with about four items. The results of the live CAT application showed that the estimates of CAT were strongly positively correlated with its paper-pencil version. In addition, the live CAT application increased usability compared to the fixed-length test version by reducing test length by 50% and time by 77%. This study shows that the polytomous IRT-based CAT is applicable and efficient for measuring psychological traits.

Common perinatal mental disorders and post‐infancy child development in rural Ethiopia: a population‐based cohort study

Objective

To investigate whether maternal common mental disorders (CMD) in the postnatal period are prospectively associated with child development at 2.5 and 3.5 years in a rural low‐income African setting.

Methods

This study was nested within the C‐MaMiE (Child outcomes in relation to Maternal Mental health in Ethiopia) population‐based cohort in Butajira, Ethiopia, and conducted from 2005 to 2006. The sample comprised of 496 women who had recently given birth to living, singleton babies with recorded birth weight measurements, who were 15 to 44 years of age, and residing in six rural sub‐districts. Postnatal CMD measurements were ascertained 2 months after delivery. Language, cognitive, and motor development were obtained from the child 2.5 and 3.5 years after birth using a locally adapted version of the Bayley Scales of Infant Development (3rd Ed). Maternal CMD symptoms were measured using a locally validated WHO Self‐Reporting Questionnaire. A linear mixed‐effects regression model was used to analyze the relationship between postnatal CMD and child development.

Results

After adjusting for confounders, there was no evidence for an association between postnatal CMD and overall child development or the cognitive sub‐domain in the preschool period. There was no evidence of effect modification by levels of social support, socioeconomic status, stunting, or sex of the child.

Conclusions

Previous studies from predominantly urban and peri‐urban settings in middle‐income countries have established a relationship between maternal CMD and child development, which contrasts with the findings from this study. The risk and protective factors for child development may differ in areas characterized by high social adversity and food insecurity. More studies are needed to investigate maternal CMD’s impact on child development in low‐resource and rural areas.

Assessing medical mistrust in organ donation across countries using item response theory

Although medical mistrust (MM) may be an impediment to public health interventions, no MM scale has been validated across countries and the assessment of MM has not been explored using item response theory, which allows generalisation beyond the sampled data. We aimed to determine the dimensionality of a brief MM measure across four countries through Mokken analysis and Graded Response Modelling. Analysis of 1468 participants from UK (n = 1179), Ireland (n = 191), India (n = 49) and Malaysia (n = 49) demonstrated that MM items formed a hierarchical, unidimensional measure, which is very informative about high levels of MM. Possible item reduction and scoring changes were also demonstrated. This study demonstrates that this brief MM measure is suitable for international studies as it is unidimensional across countries, cross cultural, and shows that minor adjustments will not impact on the assessment of MM when using these items.

Hierarchy and Reliability of the Preschool Language Scales-Fifth Edition: Mokken Scale Analysis

Purpose This study examined the psychometric properties of the Preschool Language Scales-Fifth Edition (PLS-5 English) among preschool children from low-socioeconomic status (SES) families. Method The PLS-5 was administered individually to 169 3- to 4-year-old children enrolled in Head Start programs. We carried out a Mokken scale analysis (MSA), which is a nonparametric item response theory analysis, to examine the hierarchy among items and the reliability of test scores of the PLS-5 Auditory Comprehension (AC) and Expressive Communication (EC) scales. Results The PLS-5 EC items retained a moderate Mokken scale with the inclusion of all the items. On the other hand, the PLS-5 AC items formed a moderate Mokken scale only with the exclusion of five unscalable items. The latent class reliability coefficients for the AC and the EC scale scores were both above .90. Several items that violated the invariant item ordering assumption were found for both scales. Conclusions MSA can be used to examine the relationship between the latent language ability and the probability of passing an item with ordinal responses. Results indicate that for preschool children from low-SES families, it is appropriate to use the PLS-5 EC scale scores for comparing individuals' expressive language abilities; however, researchers and speech-language pathologists should be cautious when using the PLS-5 AC scale scores to evaluate individuals' receptive language abilities. Other implications of the MSA results are further discussed.

Psychometric properties of Addenbrooke's Cognitive Examination III (ACE-III): An item response theory approach

The Addenbrooke's Cognitive Examination III is one of the most widely used tests to assess cognitive impairment. Although previous studies have shown adequate levels of diagnostic utility to detect severe impairment, it has not shown sensitivity to detect mild decline. The aim of this study was to evaluate the psychometric properties of Addenbrooke's Cognitive Examination III in a large sample of elderly people through Item Response Theory, due to the lack of studies using this approach. A cross-sectional study was conducted with 1164 people from the age of 60 upwards, of which 63 had a prior diagnosis of Alzheimer dementia. The results showed that, globally, the Addenbrooke's Cognitive Examination III possesses adequate psychometrics properties. Furthermore, the information function test shows that the subscales have different sensitivity to different levels of impairment. These results can contribute to determining patterns of cognitive deterioration for the adequate detection of different levels of dementia. An optimized version is suggested which may be an economic alternative in the applied field.

Nurses' perceptions of caring activities in nursing

Aim

This study aimed to determine nurses' perceptions of caring activities in nursing.

Design

A descriptive study design.

Methods

A Turkish translation of the 25-item version of the Caring Dimensions Inventory was completed by 260 nurses working in one university hospital. Data were analysed using Mokken scaling.

Results

Technical aspects of nursing were highly endorsed items such as "observing the effects of a medication on a patient, measuring vital signs, being technically competent with a clinical procedure, consulting with the doctor" except for the item "providing privacy for a patient" which is a psychosocial item. The range of items included in the Mokken scale with "providing privacy for a patient" (mean = 4.31) as the most endorsed, and "exploring the patient's lifestyle" (mean = 2.60) being the least endorsed item. Listening to patients and involving them in their care are not considered as caring.

Measurement tools used to assess unfinished nursing care: A systematic review of psychometric properties

BACKGROUND

Different tools have been developed and validated to measure unfinished nursing care. However, no systematic review of the psychometric properties has been performed describing the quality of the methods used to estimate their validity.

AIMS

(a) To identify tools measuring unfinished nursing care that have undergone validation processes; (b) to evaluate critically the quality of the methods used in ascertaining their psychometric properties; and (c) to compare the estimated psychometric properties of these tools.

DESIGN

A systematic review of the psychometric properties also evaluating their methodological quality was performed by following the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) guideline for systematic reviews.

DATA SOURCES

The databases Medline, the Cumulative Index to Nursing and Allied Health Literature, PubMed, Google and Google Scholar were searched up to 30 June 2018.

REVIEW METHODS

Data extraction was performed following the predetermined eligibility criteria. Eight properties and their methodological quality were assessed using the COnsensus-based Standards for the selection of health Measurement INstruments criteria.

RESULTS

A total of 20 studies reported validation data regarding three family of tools: the Missed Care Survey (MISSCARE), the Basal Extent of Rationing of Nursing Care (BERNCA) and the Task Undone scale (TU-7). The most estimated psychometric properties across studies were internal consistency, followed by structural validity, content validity, and cross-cultural validity. The less evaluated psychometric properties were reliability, hypothesis testing and convergent and criterion validity.

CONCLUSION

The psychometric properties of the investigated tools showed a more than acceptable quality, as did the methodologies used to estimate these properties.

IMPACT

The MISSCARE survey is the most widely used tool validated across countries to date. Evaluating the concurrent reliability of the tools available is strongly recommended to assess their effectiveness in measuring the same phenomenon.

Spousal Violence: A Mokken Scaling Analysis of Attitudes of South Asian Men and Women

Attitudes toward intimate partner violence (IPV) are usually explored by asking participants to respond to some statements describing various instances or situations. Currently, we do not know if responses to such questions or statements are random, leading to a total score which is hard to compare between respondents, or in a hierarchical manner which makes such comparison much more meaningful. The study was conducted to explore the structure of an "attitudes to intimate partner" violence scale used in the Demographic and Health Surveys Program (DHS), for a hierarchy of items according to the criteria of Mokken scaling. Secondary analyses of the data related to attitudes to IPV of South Asian men and women, collected by the DHS from Pakistan, India, Bangladesh, Maldives, and Nepal between 2006 and 2014. A strong Mokken scale was apparent in the data with IPV by men being most justified in cases where the wife neglected the children and least endorsed in the case of refusing to have sex. Men and women endorsed the items in the same order, but some inter country differences were apparent.

Comparison of alternative full and brief versions of functional status scales among older adults in China

BACKGROUND

Brief assessments of functional status for community-dwelling older adults are needed given expanded interest in the measurement of functional decline.

METHODS

As part of a 2015 prospective cohort study of older adults aged 60-89 years in Jiangsu Province, China, 1506 participants were randomly assigned to two groups; each group was administered one of two alternative 20-item versions of a scale to assess activities of daily living (ADL) and instrumental activities of daily living (IADL) drawn from multiple commonly-used scales. One version asked if they required help to perform activities (ADL-IADL-HELP-20), while the other version provided additional response options if activities could be done alone but with difficulty (ADL-IADL-DIFFICULTY-20). Item responses to both versions were compared using the binomial test for differences in proportion (with Wald 95% confidence interval [CI]). A brief 9-item scale (ADL-IADL-DIFFICULTY-9) was developed favoring items identified as difficult or requiring help by ≥4%, with low redundancy and/or residual correlations, and with significant correlations with age and other health indicators. We repeated assessment of the measurement properties of the brief scale in two subsequent samples of older adults in Hong Kong in 2016 (aged 70-79 years; n = 404) and 2017 (aged 65-82 years; n = 1854).

RESULTS

Asking if an activity can be done alone but with difficulty increased the proportion of participants reporting restriction on 9 of 20 items, for which 95% CI for difference scores did not overlap with zero; the proportion with at least one limitation increased from 28.6% to 34.2% or an absolute increase of 5.6% (95% CI = 0.9-10.3%), which was a relative increase of 19.6%. The brief ADL-IADL-DIFFICULTY-9 maintained excellent internal consistency (α = 0.93) and had similar ceiling effect (68.1%), invariant item ordering (H trans = .41; medium), and correlations with age and other health measures compared with the 20-item version. The brief scale performed similarly when subsequently administered to older adults in Hong Kong.

CONCLUSIONS

Asking if tasks can be done alone but with difficulty can modestly reduce ceiling effects. It's possible that the length of commonly-used scales can be reduced by over half if researchers are primarily interested in a summed indicator rather than an inventory of specific types of deficits.

A hierarchical analysis of the latent trait of borderline personality disorder and its possible clinical implications

Borderline personality disorder (BPD) is a severe mental disorder which is accompanied by impaired functioning, complex psychosocial problems and incurs large costs. However, it rarely has been examined whether BPD symptoms form a hierarchical (Mokken) scale, which would imply that symptoms are ordered along a latent dimension of borderline severity. In this study the data from 1,198 inpatients of a psychosomatic clinic were examined. A non-parametric Mokken analysis was employed to investigate if the BPD symptoms measured by the impulsivity and emotion dysregulation scale (IES-27) formed a hierarchical scale. 16 of the 27 items, mainly regarding emotion dysregulation, formed a monotonous Mokken scale with a very strong hierarchy of BPD symptoms. These results imply that single BPD symptoms provide information about BPD severity, suggesting several important consequences regarding escalation of BPD, diagnosis and treatment, e.g. how to optimize treatment planning.

Measurement Invariance of the Prosocial Behavior Scale in Three Hispanic Countries (Argentina, Spain, and Peru)

In a growing context of multiculturalism, prosocial behavior is important to build effective social exchange and service orientation among university students. The present study investigates prosocial behavior from a psychometric approach, to obtain evidence of the internal structure of the prosocial behavior scale (PS), in 737 young people enrolled at universities in Argentina (207), Spain (310), and Peru (220). First, the clarity of the items was explored in the three countries; second, possible irrelevant patterns of response, such as the careless and extreme responses, were evaluated; third, the non-parametric Mokken methodology was applied to identify the basic properties of the scale score; fourth, the structural equation modeling (SEM) methodology was used to identify the properties of the internal structure (dimensionality, tau-equivalence) of the latent construct; fifth, the measurement invariance according to sex (intra-equivalence) and country (inter-equivalence) was examined with the SEM methodology and other complementary strategies. Finally, reliability and internal consistency were evaluated both at score level and at item level. Implications for use of the PS instrument are discussed.

Disability in bipolar I disorder: Application of Mokken scaling analysis and the graded response model to the World Health Organization Disability Assessment Schedule 2.0

BACKGROUND

The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) evaluates an individual's functioning and disability within the conceptual framework of the ICF. The present study examines the measurement properties of the WHODAS 2.0 in patients with bipolar disorder using Mokken scaling analysis (i.e., monotone homogeneity and double monotonicity models) and the graded response model. No previous studies applying these models to this instrument were found.

METHODS

A sample of 291 patients with bipolar disorder (42.6% males) was tested.

RESULTS

The WHODAS 2.0 domains showed strong unidimensionality, with no items being omitted. In addition, the analysis of invariant item ordering showed that the items of each domain formed a hierarchical scale, with the exception of the 'Life activities' items for employed persons or students and item D4.5 'Sexual activities' in the 'Getting along' domain. The WHODAS 2.0 domains and the whole scale also showed excellent reliability in bipolar disorder.

LIMITATIONS

Although the study was limited to patients in Spain, the use of non-sample dependent procedures minimizes this limitation since the results are independent of the sample used.

CONCLUSIONS

The WHODAS 2.0 contains six strong unidimensional domains that are hierarchical and reliable for detecting disability in bipolar disorder, although caution should be exercised with regard to some items.

Severe Agitation in Dementia: An Explorative Secondary Data Analysis on the Prevalence and Associated Factors in Nursing Home Residents

Background:

The phenomena of severe agitation is not well understood and often not adequately treated.

Objective:

This article determines the prevalence and associated factors of severe agitation in nursing home residents with dementia.

Methods:

Secondary data analysis within an observational study in German nursing homes with n = 1,967 participants. We assessed severity of agitation with the Neuropsychiatric Inventory Questionnaire (NPI-Q) and defined the construct of agitation as a composite score of the NPI-Q items agitation/aggression, disinhibition, and irritability/lability; the dependent variable of severe agitation was considered as being present in residents who scored ‘severe’ in at least one of these symptoms. A binary logistic regression model was calculated to estimate associations.

Results:

The prevalence of severe agitation was 6.3% (n = 124). The strongest associations were found for elation/euphoria (OR 7.6, CI 3.1–18.5), delusions (OR 7.3, CI 4.0–13.2), apathy/indifference (OR 2.8, CI 1.7–4.7), anxiety (OR 2.2, CI 1.2–3.8), nighttime behaviors (OR 2.4, CI 1.4–4.2), motor disturbances (OR 2.4, CI 1.4–4.1), and male sex (OR 2.4. CI 1.3–4.2).

Conclusion:

Severe agitation in nursing home residents with dementia is a relevant clinical issue as approximately 70% of residents have a dementia. Residents with elation/euphoria and delusions may have a stronger risk of showing severe agitation. We consider delusions as a possible cause of agitation and therefore a prelude to agitation. Although it might be possible that elation/euphoria follows from agitation, we hypothesize that the residents first experience elation/ euphoria and exhibit agitation afterwards.

Evaluating hierarchical items of the geriatric depression scale through factor analysis and item response theory

Background

Geriatric depression scale (GDS) is a common screening tool for measuring depression among older adults. It employs a multi-factor structure and some differential item functioning (DIF) allowing different versions of GDS across cultures. The present study aimed to identify the short version of the hierarchical scale of GDS in which all items comprised the invariant item ordering, and items without DIF.

Methods

Participants and Measurement: A total of 803 participants, 70% female, with a mean age of 69.24 years (SD = 6.88) were enrolled from three geriatric units of tertiary care hospitals. All completed the 15-item GDS. Three methods of confirmatory factor analysis (CFA) with multiple indicators, multiple cause model, Mokken analysis and Rasch analysis were applied.

Results

Item 9 (prefer to stay at home) showed poor discriminatory power among all three methods. After removing DIF items due to sex and age, nine items remained suitable for the shortened version by CFA. When Mokken and Rasch analysis were applied, only six items remained for the hierarchical scale. Compared with other related shortened version of GDS, the new GDS-6 proved to have a comparable ability to detect depression as did the original 15-item GDS.

Limitation

The new GDS-6 needs to be investigated for test-retest reliability to ensure temporal stability of the scale. This cross-sectional analysis needs replication.

Conclusion

The GDS-6 derived from IRT had measurement properties and met criteria related to unidimensionality and ability to separate levels of depression. It was shown to be equal to or better in predicting performance compared with the original 15-item GDS.

Development of grading scales of pedal sensory loss using Mokken scale analysis on the Rotterdam Diabetic Foot Study Test Battery data

INTRODUCTION

Loss of sensation due to diabetes-related neuropathy often leads to diabetic foot ulceration. Several test instruments are used to assess sensation, such as static and moving 2-point discrimination (S2PD, M2PD), monofilaments, and tuning forks.

METHODS

Mokken scale analysis was applied to the Rotterdam Diabetic Foot Study data to select hierarchies of tests to construct measurement scales.

RESULTS

We developed 39-item and 31-item scales to measure loss of sensation for research purposes and a 13-item scale for clinical practice. All instruments were strongly scalable and reliable. The 39 items can be classified into 5 hierarchically ordered core clusters: S2PD, M2PD, vibration sense, monofilaments, and prior ulcer or amputation.

DISCUSSION

Guided by the presented scales, clinicians may better classify the grade of sensory loss in diabetic patients' feet. Thus, a more personalized approach concerning individual recommendations, intervention strategies, and patient information may be applied.

A Demonstration of Mokken Scale Analysis Methods Applied to Cognitive Test Validation Using the Egyptian WAIS-IV

The fourth edition of the Wechsler Adult Intelligence Scale (WAIS-IV) has been used extensively for assessing adult intelligence. This study uses Mokken scale analysis to investigate the psychometric proprieties of WAIS-IV subtests adapted for the Egyptian population in a sample of 250 adults between 18 and 25 years of age. The monotone homogeneity model and the double monotonicity model were consistent with the subtest data. The items of all subtests except Matrix Reasoning, Information, Similarities, and Vocabulary formed a unidimensional scale. The WAIS-IV subtests have discriminatory and invariantly ordered items, although some items violated the invariant item ordering and scalability criteria. Therefore, the WAIS-IV subtests—with the exception of some items—are hierarchical scales that allow items to be ordered according to difficulty and subjects to be ordered using the sum score. In conclusion, the current study provides evidence of the dimensionality and hierarchy of the WAIS-IV subtests in the framework of Mokken scaling, although care should be taken when interpreting or including certain items.

Comparing questionnaires across cultures: Using Mokken scaling to compare the Italian and English versions of the MOLES index

AIM

The aims of this study were (a) to translate the MOLES index from English to Italian and (ii) to compare the two versions using non-parametric item response theory.

DESIGN

An online survey was used to gather data.

METHODS

Forward and back translation was used to prepare the Italian version of the MOLES which was then analysed using the non-parametric item response theory of Mokken scaling.

RESULTS

Mokken scales were found in both the English and the Italian versions of the MOLES index. However, the two scales-while the total scale score was not significantly different-showed different properties, and Mokken scaling selected different items from each scale.

The brief Dimensional Apathy Scale: A short clinical assessment of apathy

Objective: Apathy is a prominent syndrome across neurodegenerative diseases. The Dimensional Apathy Scale (DAS) assesses three apathy subtypes-executive, emotional, and initiation-and is sensitive and valid in amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), and Parkinson's disease. This study describes the development of the brief DAS (b-DAS), which will enable apathy to be swiftly detected in the clinic.Method: 102 ALS and 102 AD patients' previously collected data were used. Mokken analyses were performed on item-level data of each informant/carer-rated DAS subscale (executive, emotional, and initiation) for the initial scale reduction. Item-total correlational analyses against standard apathy (convergent validity criteria) and depression (divergent validity criteria) measures and qualitative examination of items aided final item selection. Receiver operating curve analysis determined optimal cutoffs for the reduced subscales.Results: Mokken analyses suggested unidimensionality of each DAS subscale. Three items were removed that failed to satisfy monotone homogeneity model requirements, three items were removed due to validity criteria not being met, and six items were removed due to a combination of lower item scalability and item-total correlations. Item-theme examination further reduced the b-DAS to nine items, three per subscale, with a supplemental awareness deficit assessment being added. Sensitivity- and specificity-based optimal cutoffs were calculated for each b-DAS subscale.Conclusions: This study presents the b-DAS, an informant/carer-based robust yet short multidimensional apathy instrument with good convergent and divergent validity, with recommended clinical cutoffs. The b-DAS is appropriate for use in the clinic and for research to quickly and comprehensively screen for apathy subtype impairments.

Prevalence and relationship between burnout and depression in our future doctors: a cross-sectional study in a cohort of preclinical and clinical medical students in Ireland

OBJECTIVES

This cross-sectional study was designed to measure burnout and its impact on risk of depression in a medical student population, comparing the preclinical and clinical years.

DESIGN

We conducted a survey of 269 medical school students in both preclinical and clinical years at the Royal College of Surgeons in Ireland, using the Beck Depression Inventory-Fast Screen (BDI-FS), the Maslach Burnout Inventory-Student Survey and items assessing willingness to use mental health services. Burnout scores were calibrated to probability of depression caseness and classified as low risk (<25%), intermediate (25%-50%) and high risk (>50%) of depression.

RESULTS

There was a 39% (95% CI 33% to 45%) prevalence of depressive caseness based on a score of ≥6 on the BDI-FS. Prevalence did not vary significantly between clinical and preclinical years. The rate of burnout varied significantly between years (p=0.032), with 35% in the high-burnout category in clinical years compared with 26% in preclinical years. Those in the low burnout category had a 13% overall prevalence of depressive symptoms, those in the intermediate category had a 38% prevalence and those in the high category had a 66% prevalence of depressive symptoms. Increasing emotional exhaustion (OR for one-tertile increase in score 2.0, p=0.011) and decreasing academic efficacy (OR 2.1, p=0.007) increased the odds of being unwilling to seek help for mental health problems (11%).

CONCLUSION

While previous studies have reported significant levels of burnout and depression, our method of calibrating burnout against depression allows burnout scores to be interpreted in terms of their impact on mental health. The high prevalences, in line with previous research, point to an urgent need to rethink the psychological pressures of health professions education.

Item distribution, internal consistency, and structural validity of the German version of the DEMQOL and DEMQOL-proxy

Background

Accurate assessment of health-related quality of life as an endpoint in intervention studies is a major challenge in dementia research. The DEMQOL (29 items) and the proxy version (32 items), which is partly based on the DEMQOL, are internationally used instruments. To date, there is no information on the structural validity, item distribution, or internal consistency for the German language version of these questionnaires.

Methods

This psychometric study is based on a secondary data analysis of a sample of 201 outpatients with a mild form of Alzheimer’s disease (AD) and their informal caregivers. The informal caregivers who were interviewed were involved in the care of the person with AD several times per week. The analysis for the evaluation of the structural validity was performed using Mokken scale analysis. The internal consistency was calculated using the ρ of the Molenaar Sijtsma statistic and Cronbach’s α.

Results

For both versions, four subscales were identified: [A] “positive emotions”, [B] “negative emotions”, [C] “physical and cognitive functioning”, and [D] “daily activities and social relationships”. For both instruments, the internal consistency of all subscales was considered “good” (ρ = 0.71–0.88, α = 0.72–0.87).

Conclusions

The results are a first indication of good construct validity of the instruments used for the German setting. We recommend further investigations of the test-retest reliability and the inter-rater reliability of the proxy instrument.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0930-0) contains supplementary material, which is available to authorized users.

Investigating psychometric properties and dimensional structure of an educational environment measure (DREEM) using Mokken scale analysis - a pragmatic approach

BACKGROUND

Questionnaires and surveys are used throughout medical education. Nevertheless, measuring psychological attributes such as perceptions of a phenomenon among individuals may be difficult. The aim of this paper is to introduce the basic principles of Mokken scale analysis (MSA) as a method for the analysis of questionnaire data and to empirically apply MSA to a real-data example.

METHODS

MSA provides a set of statistical tools for exploring the relationship between items and latent traits. MSA is a scaling method of item selection algorithms used to partition an array of items into scales. It employs various methods to probe the assumptions of two nonparametric item response theory models: the monotone homogeneity model and the double monotonicity model. The background and theoretical framework underlying MSA are outlined in the paper. MSA for polytomous items was applied to a real-life data example of 222 undergraduate students who had completed a 50-item self-administered inventory measuring the educational environment, the Dundee Ready Educational Measure (DREEM).

RESULTS

A pragmatic and parsimonious approach to exploring questionnaires and surveys from an item response theory (IRT) perspective is outlined. The use of MSA to explore the psychometric properties of the Swedish version of the DREEM failed to yield strong support for the scalability and dimensional structure of the instrument.

CONCLUSIONS

MSA, a class of simple nonparametric IRT models - for which estimates can be easily obtained and whose fit to data is relatively easily investigated - was introduced, presented, and tested. Our real-data example suggests that the psychometric properties of DREEM are not adequately supported. Thus, the empirical application depicted a potential and feasible approach whereby MSA could be used as a valuable method for exploring the behavior of scaled items in response to varying levels of a latent trait in medical education research.

The Edinburgh Feeding Evaluation in Dementia Scale: A Longitudinal Study in Nursing Home Residents

AIMS/BACKGROUND

The Edinburgh Feeding Evaluation in Dementia (EdFED) scale has been shown to have good psychometric properties using a range of methods including Mokken scaling. We aimed to study the Italian version of the EdFED using Mokken scaling.

METHODS

Data were gathered at 7 time points from 401 nursing home residents affected by dementia in the course of a 6-month intervention study using analysis of variance, Mokken scaling, and person-item fit statistics.

RESULTS

The properties of the EdFED-I scale were stable over the course of the study with 4 items showing invariant item ordering at all time points. Some items behaved differently at different levels of difficulty in the scale and also depending on the mean level of feeding difficulty. The test information function showed a dip in the mid-range of difficulty scores.

Item response theory evaluation of the biomedical scale of the Pain Attitudes and Beliefs Scale

OBJECTIVES

The assessment of health care professionals' attitudes and beliefs towards musculoskeletal pain is essential because they are key determinants of their clinical practice behaviour. The Pain Attitudes and Beliefs Scale (PABS) biomedical scale evaluates the degree of health professionals' biomedical orientation towards musculoskeletal pain and was never assessed using item response theory (IRT). This study aimed at assessing the psychometric performance of the 10-item biomedical scale of the PABS scale using IRT.

METHODS

Two cross-sectional samples (BeBack, n = 1016; DABS; n = 958) of health care professionals working in the UK were analysed. Mokken scale analysis (nonparametric IRT) and common factor analysis were used to assess dimensionality of the instrument. Parametric IRT was used to assess model fit, item parameters, and local reliability (measurement precision).

RESULTS

Results were largely similar in the two samples and the scale was found to be unidimensional. The graded response model showed adequate fit, covering a broad range of the measured construct in terms of item difficulty. Item 3 showed some misfit but only in the DABS sample. Some items (i.e. 7, 8 and 9) displayed remarkably higher discrimination parameters than others (4, 5 and 10). The scale showed satisfactory measurement precision (reliability > 0.70) between theta values -2 and +3.

DISCUSSION

The 10-item biomedical scale of the PABS displayed adequate psychometric performance in two large samples of health care professionals, and it is suggested to assess group-level professionals degree of biomedical orientation towards musculoskeletal pain.

What are the minimal sample size requirements for Mokken scaling? An empirical example with the Warwick- Edinburgh Mental Well-Being Scale

Purpose: Sample size in Mokken scales is mostly studied on simulated data, reflected in the lack of consideration of sample size in most Mokken scaling studies. Recently, [Straat, J. H., van der Ark, L. A., & Sijtsma, K. (2014). Minimum sample size requirements for Mokken scale analysis. Educational and Psychological Measurement, 74, 809-822] provided minimum sample size requirements for Mokken scale analysis based on simulation. Our study uses real data from the Warwick-Edinburgh Mental Well-Being Scale (N = 8463) to assess whether these hold. Methods: We use per element accuracy to evaluate the impact of sample size, with scaling coefficients and confidence intervals around scale, item and item pair scalability coefficients. Results: Per element accuracy, scalability coefficients, and confidence intervals around scalability coefficients are sensitive to sample size. The results from Straat et al. were not replicated; depending on the main goal of the research, sample sizes ranging from > 250 to > 1000 are needed. Conclusions: Using our pragmatic approach, some practical recommendations are made regarding sample sizes for studies of Mokken scaling.

Establishing dimensionality of sexual behaviours in patients with regional brain dysfunction

OBJECTIVE

To develop a validated, caregiver-based measurement scale to assess sexual changes across several domains in a sample of 86 patients with penetrating traumatic brain injury (TBI) and 65 patients with neurodegeneration due to frontotemporal dementia and corticobasal syndrome.

METHODS

A new measure, the Sexual Symptoms in Neurological Illness and Injury Questionnaire (SNIQ), was constructed. Dimensionality, monotonicity, item discrimination power, and scalability were evaluated using nonparametric Mokken item response theory (IRT) methodology.

RESULTS

Three primary domains were established. The domains presented with sufficient reliability (rho .70 to .80), while meeting the Mokken IRT criteria of medium scalability. The domains were labeled 'Prosocial sexual behaviour' (H = .42), 'Sexual interest' (H = .50), and 'Inappropriate sexual behaviour' (H = .41). A fourth dimension emerged, 'Detachment' (H = .47), but with very few items.

CONCLUSIONS

Construct validity was established for groups of items pertaining to three unique aspects of sexuality. These findings support further use of the SNIQ in assessing and researching sexual behaviours in patients with dementia and brain injury.

The value of measurement for development of nursing knowledge: Underlying philosophy, contributions and critiques

AIM

A philosophical discussion of constructive realism and measurement in the development of nursing knowledge is presented.

BACKGROUND

Through Carper's four patterns of knowing, nurses come to know a person holistically. However, measurement as a source for nursing knowledge has been criticized for underlying positivism and reductionist approach to exploring reality. Which seems mal-alignment with person-centred care.

DESIGN

Discussion paper.

DISCUSSION

Constructive realism bridges positivism and constructivism, facilitating the measurement of physical and psychological phenomena. Reduction of complex phenomena and theoretical constructs into measurable properties is essential to building nursing's empiric knowledge and facilitates (rather than inhibits) person-knowing.

IMPLICATIONS FOR NURSING

Nurses should consider constructive realism as a philosophy to underpin their practice. This philosophy supports measurement as a primary method of inquiry in nursing research and clinical practice. Nurses can carefully select, and purposefully integrate, measurement tools with other methods of inquiry (such as qualitative research methods) to demonstrate the usefulness of nursing interventions and highlight nursing as a science.

Scale validation in applied health research: tutorial for a 6-step R-based psychometrics protocol

Background: Applied health science research commonly measures concepts via multiple-item tools (scales), such as self-reported questionnaires or observation checklists. They are usually validated in more detail in separate psychometric studies or very cursorily in substantive studies. However, methodologists advise that, as validity is a property of the inferences based on measurement in a context, psychometric analyses should be performed in substantive studies as well. Until recently, performing comprehensive psychometrics required expert knowledge of different, often proprietary, software. The increasing availability of statistical techniques in the R environment now makes it possible to integrate such analyses in applied research.

Methods: In this tutorial, I introduce a 6-step protocol which allows detailed diagnosis of core psychometric properties (e.g. structural validity, internal consistency) for scales with binary and ordinal response options aiming to measure differences in degree or quantity, the most common in applied research. The protocol includes investigations of (1) item distributions and summary statistics, item properties via (2) non-parametric and (3) parametric item response theory, (4) scale structure using factor analysis, (5) reliability via classical test theory, and (6) calculation and description of global scores. I illustrate the procedure on a measure of self-reported disability, the 24-item Sickness Impact Profile Roland Scale (RM-SIP), administered in a survey of 222 chronic pain sufferers. An R Markdown script is provided that generates reproducible reports.

Results: In this sample, 15 of 24 RM-SIP items formed a unidimensional ordinal scale with good homogeneity (H = 0.43) and reliability (α = .86[.84–.89]; ω = .87[.85–.88]). The two versions were highly correlated (r = .96), and regression models predicting RM-SIP disability produced comparable results.

Conclusions: The example analysis illustrates how psychometric properties may be assessed in substantive studies and identify avenues for measure improvement. Applied researchers can adapt this script to perform and communicate these analyses as part of questionnaire validation and substantive studies.

Psychometric properties of the Dutch version of the London Measure of Unplanned Pregnancy in women with pregnancies ending in birth

Objective

To evaluate the psychometric properties of the Dutch version of the London Measure of Unplanned Pregnancy in women with pregnancies ending in birth.

Methods

A two-phase psychometric evaluation design was set-up. Phase I comprised the translation from English into Dutch and pretesting with 6 women using cognitive interviews. In phase II, the reliability and validity of the Dutch version of the LMUP was assessed in 517 women giving birth recently. Reliability (internal consistency) was assessed using Cronbach’s alpha, inter-item correlations, and corrected item-total correlations. Construct validity was assessed using principal components analysis and hypothesis testing. Exploratory Mokken scale analysis was carried out.

Results

517 women aged 15–45 completed the Dutch version of the LMUP. Reliability testing showed acceptable internal consistency (alpha = 0.74, positive inter-item correlations between all items, all corrected item-total correlations >0.20). Validity testing confirmed the unidimensional structure of the scale and all hypotheses were confirmed. The overall Loevinger’s H coefficient was 0.57, representing a ‘strong’ scale.

Conclusion

The Dutch version of the LMUP is a reliable and valid measure that can be used in the Dutch-speaking population in Belgium to assess pregnancy planning. Future research is necessary to assess the stability of the Dutch version of the LMUP, and to evaluate its psychometric properties in women with abortions.

Factor analysis and Mokken scaling of the Organizational Commitment Questionnaire in nurses

AIMS

To generate an Arabic version of the Organizational Commitment Questionnaire that would be easily understood by Arabic speakers and would be sensitive to Arabic culture.

BACKGROUND

The nursing workforce in Saudi Arabia is undergoing a process of Saudization but there is a need to understand the factors that will help to retain this workforce.

INTRODUCTION

No organizational commitment tools exist in Arabic that are specifically designed for health organizations. An Arabic version of the organizational commitment tool could aid Arabic speaking employers to understand their employees' perceptions of their organizations.

METHODS

Translation and back-translation followed by factor analysis (principal components analysis and confirmatory factor analysis) to test the factorial validity and item response theory (Mokken scaling).

RESULTS

A two-factor structure was obtained for the Organizational Commitment Questionnaire comprising Factor 1: Value commitment; and Factor 2: Commitment to stay with acceptable reliability measured by internal consistency. A Mokken scale was obtained including items from both factors showing a hierarchy of items running from commitment to the organization and commitment to self.

DISCUSSION

This study shows that the Arabic version of the OCQ retained the established two-factor structure of the original English-language version. Although the two factors - 'value commitment' and 'commitment to stay' - repudiate the original developers' single factor claim.

CONCLUSION

A useful insight into the structure of the Organizational Commitment Questionnaire has been obtained with the novel addition of a hierarchical scale.

IMPLICATIONS FOR NURSING POLICY

The Organizational Commitment Questionnaire is now ready to be used with nurses in the Arab speaking world and could be used a tool to measure the contemporary commitment of nursing employees and in future interventions aimed at increasing commitment and retention of valuable nursing staff.

Validation of the Spanish version of the Edinburgh Feeding Evaluation in Dementia Scale for older people with dementia

AIMS

To adapt the Edinburgh Feeding Evaluation in Dementia Scale (EdFED) for use in a Spanish-speaking population and to assess its validity and reliability in patients with dementia.

METHOD

A cross-sectional study was carried out in two stages: 1. Cross-cultural adaptation (translation, back-translation, review by committee of experts, pilot test and weighting of results); 2. Clinimetric validation comprising interobserver reliability assessment, test-retest reliability and internal consistency. To determine construct validity, confirmatory factorial analysis and principal components analysis were performed by oblique rotations. Criteria validity was analysed using the Pearson correlation (p<0.05) with the BMI, MNA and analytical values of albumin, transferrin, cholesterol, absolute lymphocytes and total proteins. Data collection was carried out for six months in 2016 in nursing homes and Alzheimer's day centers in the province of Málaga (Spain), at nine centers, with 262 patients (aged over 60 years and presenting feeding difficulties), 20 nurses, 20 professional caregivers and 103 family caregivers.

RESULTS

A version of EdFED culturally adapted to Spanish was obtained. The sample presented the following characteristics: 76.3% women, mean age 82.3 years (SD: 7.9); MNA 18.73 (SD: 4.44); BMI 23.99 (SD: 4.72); serum albumin 3.79 mg/dl (SD: 0.36). A Cronbach's alpha of 0.88 was obtained, with an inter-item global correlation of 0.43 and a homogeneity index ranging from 0.42 to 0.73. The exploratory factor analysis reproduced the three-factor model identified by the original authors, explaining 62.32% of the total variance. The criterion validity showed a good inverse correlation with MNA and a moderate one with albumin, total proteins, transferrin and BMI.

DISCUSSION

The Spanish version of EdFED is reliable and valid for use in elderly people with dementia. The most appropriate for our environment is the three-factor model, which maintains the original factors, with a slight redistribution of the items.

A Psychometric Evaluation of the DSM-IV Criteria for Antisocial Personality Disorder: Dimensionality, Local Reliability, and Differential Item Functioning Across Gender

This study aims at evaluating the psychometric properties of the antisocial personality disorder (ASPD) criteria in a large sample of patients, most of whom had one or more personality disorders (PD). PD diagnoses were assessed by experienced clinicians using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Axis II PDs. Analyses were performed within an item response theory framework. Results of the analyses indicated that ASPD is a unidimensional construct that can be measured reliably at the upper range of the latent trait scale. Differential item functioning across gender was restricted to two criteria and had little impact on the latent ASPD trait level. Patients fulfilling both the adult ASPD criteria and the conduct disorder criteria had similar latent trait distributions as patients fulfilling only the adult ASPD criteria. Overall, the ASPD items fit the purpose of a diagnostic instrument well, that is, distinguishing patients with moderate from those with high antisocial personality scores.

Identifying longitudinal sustainable hierarchies in activities of daily living

Activities of daily living serve as an indicator of progression in disability and rehabilitation. It is know that some of the measurement scales used show hierarchical properties indicating that activities of daily living are lost and gained in a consistent pattern. Few studies have investigated the extent to which these patterns are sustained across time and across a range of disability. The study aimed to investigate the hierarchical properties of the activity of daily living items in the ValGraf functional ability scale, to establish if there is a hierarchy of items in the scale and to study the sustainability of the hierarchy over time. Secondary analysis of a retrospective database from 13,113 people over 65 years in 105 nursing homes in northern Italy, between 2008 and 2013 was conducted. Data were gathered 6-monthly and analysed using Mokken scaling to identify a hierarchy of items in the scale and if this was sustainable over time. A sustainable hierarchy of items was observed running in difficulty from urinary incontinence to feeding. The hierarchical structure of the activities of daily living observed in the present study is stable over time meaning that changes in total score for these items can be compared meaningfully across time.

Validation of the Spanish version of the Edinburgh feeding evaluation in dementia scale applied to institutionalized older persons with dementia: a study protocol

Aim

The aim of this study was to obtain a Spanish version of the Edinburgh Feeding Evaluation in Dementia Scale version, to assess its reliability for use by medical staff and caregivers at residential care homes, to evaluate by confirmatory methods its construct validity. A further aim was to determine the criterion validity with respect to biochemical markers of malnutrition such as serum albumin, transferrin, cholesterol and lymphocytes, the body mass index and the mini nutritional assessment.

Design

Clinimetric cross‐validation study.

Methods

Institutionalized subjects with dementia will be observed while consuming meals and evaluated with the instrument independently by nurses and caregivers.

Construct Validity of the Dutch Version of the 12-Item Partners in Health Scale: Measuring Patient Self-Management Behaviour and Knowledge in Patients with Chronic Obstructive Pulmonary Disease

Objective

The 12-item Partners in Health scale (PIH) was developed in Australia to measure self-management behaviour and knowledge in patients with chronic diseases, and has undergone several changes. Our aim was to assess the construct validity and reliability of the latest PIH version in Dutch COPD patients.

Methods

The 12 items of the PIH, scored on a self-rated 9-point Likert scale, are used to calculate total and subscale scores (knowledge; coping; recognition and management of symptoms; and adherence to treatment). We used forward-backward translation of the latest version of the Australian PIH to define a Dutch PIH (PIH(Du)). Mokken Scale Analysis and common Factor Analysis were performed on data from a Dutch COPD sample to investigate the psychometric properties of the Dutch PIH; and to determine whether the four-subscale solution previously found for the original Australian PIH could be replicated for the Dutch PIH.

Results

Two subscales were found for the Dutch PIH data (n = 118); 1) knowledge and coping; 2) recognition and management of symptoms, adherence to treatment. The correlation between the two Dutch subscales was 0.43. The lower-bound of the reliability of the total scale equalled 0.84. Factor analysis indicated that the first two factors explained a larger percentage of common variance (39.4% and 19.9%) than could be expected when using random data (17.5% and 15.1%).

Conclusion

We recommend using two PIH subscale scores when assessing self-management in Dutch COPD patients. Our results did not support the four-subscale structure as previously reported for the original Australian PIH.

Older adults with poor self-rated memory have less depressive symptoms and better memory performance when perceived self-efficacy is high

OBJECTIVE

To investigate whether self-efficacy moderates the association between self-rated memory and depressive symptoms in a large sample of older adults. The influence of self-efficacy and depressive symptoms on memory performance was also examined in a subsample of individuals who reported poor memory.

METHODS

Non-demented participants (n = 3766) were selected from the 2012 wave of the Health and Retirement Study. Depressive symptomatology was assessed with the 8-item Center for Epidemiologic Studies Depression Scale. A modified version of the Midlife Developmental Inventory Questionnaire was used as the measure of self-efficacy. Participants were asked to rate their memory presently on a five-point scale from Excellent (1) to Poor (5). Immediate memory and delayed memory (after a 5-min interval) were measured by the number of correct words recalled from a 10-item word list.

RESULTS

Multiple regression analyses revealed that negative ratings of memory were significantly associated with greater levels of depressive symptoms, with this effect being greatest in those with low levels of self-efficacy. Additionally, greater self-efficacy was associated with optimal objective memory performances but only when depressive symptoms were low in individuals who reported poor memory function (n = 1196).

CONCLUSION

Self-efficacy moderates the relationship between self-rated memory function and depressive symptoms. Higher self-efficacy may buffer against the impact of subjective memory difficulty on one's mood and thereby mitigating the effect of depressive symptoms on memory. Interventions should focus on increasing perceived self-efficacy in older adults reporting poor memory function to potentially minimize memory impairment.

The COPD-SIB: a newly developed disease-specific item bank to measure health-related quality of life in patients with chronic obstructive pulmonary disease

BACKGROUND

Health-related quality of life (HRQoL) is widely used as an outcome measure in the evaluation of treatment interventions in patients with chronic obstructive pulmonary disease (COPD). In order to address challenges associated with existing fixed-length measures (e.g., too long to be used routinely, too short to ensure both content validity and reliability), a COPD-specific item bank (COPD-SIB) was developed.

METHODS

Items were selected based on literature review and interviews with Dutch COPD patients, with a strong focus on both content validity and item comprehension. The psychometric quality of the item bank was evaluated using Mokken Scale Analysis and parametric Item Response Theory, using data of 666 COPD patients.

RESULTS

The final item bank contains 46 items that form a strong scale, tapping into eight important themes that were identified based on literature review and patient interviews: Coping with disease/symptoms, adaptability; Autonomy; Anxiety about the course/end-state of the disease, hopelessness; Positive psychological functioning; Situations triggering or enhancing breathing problems; Symptoms; Activity; Impact.

CONCLUSIONS

The 46-item COPD-SIB has good psychometric properties and content validity. Items are available in Dutch and English. The COPD-SIB can be used as a stand-alone instrument, or to inform computerised adaptive testing.

Validation of the electronic Holistic Needs Assessment

Macmillan Cancer Support UK have developed an electronic Holistic Needs Assessment (eHNA) to: (1) help people living with cancer express all their needs, (2) help those helping them better target support. eHNA consists of 48 items each ranked from zero (no problem) to 10. There has been no psychometric analysis of this tool and so its validity and reliability are untested. The aim of this study was to evaluate the psychometric properties of the eHNA by examining its construct validity. Objectives were to (a) test whether the eHNA measured holistic concerns and (b) analyse the factor structure of the eHNA. Objectives were achieved through a secondary analysis of 5421 responses to eHNA using concurrent application of Rasch analysis and principal component analysis. All the items bar one fit with the Rasch rating model and were equivalently important to people. Differential item functioning was evident according to whether people were described as curative or not. A 12-factor solution explained 46 % variance. Of this the emotional/spiritual factor explained the most variance accounting for 15 %. The eHNA was internally consistent and conceptually coherent with the construct of holistic needs assessment. Clinical focus is best directed to the individual items highlighted by the patient except where patients check too many problems for the clinician to accurately prioritise. In these cases only, the emotional/spiritual factor may help identify appropriate clinical action. Strengths and weaknesses of the analyses are discussed, particularly in relation to ‘at risk’ subsamples such as those classified as non-curative.

From "aisle" to "labile": A hierarchical National Adult Reading Test scale revealed by Mokken scaling

Decline in cognitive ability is a core diagnostic criterion for dementia. Knowing the extent of decline requires a baseline score from which change can be reckoned. In the absence of prior cognitive ability scores, vocabulary-based cognitive tests are used to estimate premorbid cognitive ability. It is important that such tests are short yet informative, to maximize information and practicability. The National Adult Reading Test (NART) is commonly used to estimate premorbid intelligence. People are asked to pronounce 50 words ranging from easy to difficult but whether its words conform to a hierarchy is unknown. Five hundred eighty-seven healthy community-dwelling older people with known age 11 IQ scores completed the NART as part of the Lothian Birth Cohort 1936 study. Mokken analysis was used to explore item responses for unidimensional, ordinal, and hierarchical scales. A strong hierarchical scale (“mini-NART”) of 23 of the 50 items was identified. These items are invariantly ordered across all ability levels. The validity of the interpretation of this briefer scale’s score as an estimate of premorbid ability was examined using the actual age 11 IQ score. The mini-NART accounted for a similar amount of the variance in age 11 IQ as the full NART (NART = 46.5%, mini-NART = 44.8%). The mini-NART is proposed as a useful short clinical tool to estimate prior cognitive ability. The mini-NART has clinical relevance, comprising highly discriminatory, invariantly ordered items allowing for sensitive measurement, and adaptive testing, reducing test administration time, and patient stress.

International students' experience of a western medical school: a mixed methods study exploring the early years in the context of cultural and social adjustment compared to students from the host country

BACKGROUND

Few studies have addressed the challenges associated with international students as they adapt to studying medicine in a new host country. Higher level institutions have increasing numbers of international students commencing programmes. This paper explores the experiences of a cohort of students in the early years of medical school in Ireland, where a considerable cohort are from an international background.

METHODS

A mixed exploratory sequential study design was carried out with medical students in the preclinical component of a five year undergraduate programme. Data for the qualitative phase was collected through 29 semi-structured interviews using the peer interview method. Thematic analysis from this phase was incorporated to develop an online questionnaire combined with components of the Student Adaptation to College Questionnaire and Student Integration Questionnaire. First year students were anonymously surveyed online. The Mokken Scaling procedure was used to investigate the students' experiences, both positive and negative.

RESULTS

Three main themes are identified; social adjustment, social alienation and cultural alienation. The response rate for the survey was 49% (467 Respondents). The Mokken Scaling method identified the following scales (i) Positive experience of student life; (ii) Social alienation, which comprised of negative items about feeling lonely, not fitting in, being homesick and (iii) Cultural alienation, which included the items of being uncomfortable around cultural norms of dress and contact between the sexes. With the threshold set to H = 0.4. Subscales of the positive experiences of student life scale are explored further.

CONCLUSIONS

Overall student adjustment to a western third level college was good. Students from regions where cultural distance is greatest reported more difficulties in adjusting. Students from these regions also demonstrate very good adaptation. Some students from the host country and more similar cultural backgrounds were also struggling. Acculturation is more complex than being associated with cultural distance and worthy of further exploration.

Does the Order of Item Difficulty of the Addenbrooke's Cognitive Examination Add Anything to Subdomain Scores in the Clinical Assessment of Dementia?

Background

The Addenbrooke's Cognitive Examination (ACE) is used to measure cognition across a range of domains in dementia. Identifying the order in which cognitive decline occurs across items, and whether this varies between dementia aetiologies could add more information to subdomain scores.

Method

ACE-Revised data from 350 patients were split into three groups: Alzheimer's type (n = 131), predominantly frontal (n = 119) and other frontotemporal lobe degenerative disorders (n = 100). Results of factor analysis and Mokken scaling analysis were compared.

Results

Principal component analysis revealed one factor for each group. Confirmatory factor analysis found that the one-factor model fit two samples poorly. Mokken analyses revealed different item ordering in terms of difficulty for each group.

Conclusion

The different patterns for each diagnostic group could aid in the separation of these different types of dementia.

Modeling the World Health Organization Disability Assessment Schedule II using non-parametric item response models

The World Health Organization Disability Assessment Schedule II (WHO-DAS II) is a multidimensional instrument developed for measuring disability. It comprises six domains (getting around, self-care, getting along with others, life activities and participation in society). The main purpose of this paper is the evaluation of the psychometric properties for each domain of the WHO-DAS II with parametric and non-parametric Item Response Theory (IRT) models. A secondary objective is to assess whether the WHO-DAS II items within each domain form a hierarchy of invariantly ordered severity indicators of disability. A sample of 352 patients with a schizophrenia spectrum disorder is used in this study. The 36 items WHO-DAS II was administered during the consultation. Partial Credit and Mokken scale models are used to study the psychometric properties of the questionnaire. The psychometric properties of the WHO-DAS II scale are satisfactory for all the domains. However, we identify a few items that do not discriminate satisfactorily between different levels of disability and cannot be invariantly ordered in the scale. In conclusion the WHO-DAS II can be used to assess overall disability in patients with schizophrenia, but some domains are too general to assess functionality in these patients because they contain items that are not applicable to this pathology.

The Mini-Addenbrooke's Cognitive Examination: a new assessment tool for dementia

BACKGROUND/AIMS

We developed and validated the Mini-Addenbrooke's Cognitive Examination (M-ACE) in dementia patients. Comparisons were also made with the Mini Mental State Examination (MMSE).

METHOD

The M-ACE was developed using Mokken scaling analysis in 117 dementia patients [behavioural variant frontotemporal dementia (bvFTD), n = 25; primary progressive aphasia (PPA), n = 49; Alzheimer's disease (AD), n = 34; corticobasal syndrome (CBS), n = 9] and validated in an independent sample of 164 dementia patients (bvFTD, n = 23; PPA, n = 82; AD, n = 38; CBS, n = 21) and 78 controls, who also completed the MMSE.

RESULTS

The M-ACE consists of 5 items with a maximum score of 30. Two cut-offs were identified: (1) ≤25/30 has both high sensitivity and specificity, and (2) ≤21/30 is almost certainly a score to have come from a dementia patient regardless of the clinical setting. The M-ACE is more sensitive than the MMSE and is less likely to have ceiling effects.

CONCLUSION

The M-ACE is a brief and sensitive cognitive screening tool for dementia. Two cut-offs (25 or 21) are recommended.