An introduction to the Rasch measurement model: an example using the Hospital Anxiety and Depression Scale (HADS)

Stress, anxiety, depression, and resilience in Canadian farmers

PURPOSE

To estimate the prevalence of stress, anxiety, depression, and resilience amongst Canadian farmers.

METHODS

An online cross-sectional survey using validated psychometric scales [Perceived Stress Scale (PSS), Hospital Anxiety and Depression Scale, Connor-Davidson Resilience Scale] conducted with farmers in Canada between September 2015 and February 2016.

RESULTS

1132 farmers participated in the study. The average PSS score was 18.9. Approximately 57% and 33% of participants were classified as possible and probable cases for anxiety, respectively; the respective proportions for depression were 34% and 15%. The average resilience score was 71.1. Scores for stress, anxiety, and depression were higher, and resilience lower, than reported normative data. Females scored less favorably on all mental health outcomes studied, highlighting important gender disparities.

CONCLUSIONS

These results highlight a significant public health concern amongst farmers, and illustrate a critical need for research and interventions related to farmer mental health. These findings are important for policymakers, physicians, and public and mental health service providers, and can help to inform decision-making, policy recommendations, resource allocation, and development and delivery of training programs for farmers.

Rasch Validation of the Arabic Version of the Chedoke-McMaster Attitudes Toward Children With Handicaps (CATCH-AR) Scale

Students' attitudes toward peers with disabilities are crucial for the social inclusion of the latter. Therefore, understanding such attitudes can help improve the social inclusion of students with disabilities. This study aimed to examine the psychometric properties of the Arabic version of the Chedoke-McMaster Attitudes toward Children with Handicaps scale. Data were collected from 415 elementary school students, including 232 (56%) girls and 183 (44%) boys, in grades three to six in Saudi Arabia. The psychometric properties of the scale were examined using the Rasch analysis procedures. The results did not support the unidimensionality of the 36-item scale. Dividing items based on whether they are negatively or positively phrased improved the scale fit. Both the 15-item (positive phrasing) and the 18-item (negative phrasing) scales were supported by the Rasch analysis as unidimensional scales.

The Fear Avoidance Beliefs Questionnaire (FABQ) Does it Really Measure Fear Beliefs?

STUDY DESIGN

A cohort study with 12 months of follow-up.

OBJECTIVE

To assess (1) the unidimensionality of the Fear-Avoidance Beliefs Questionnaire (FABQ) and (2) whether single questions in the FABQ predict future sickness absence as well as the whole scale.

SUMMARY OF BACKGROUND DATA

The fear-avoidance model is a leading model in describing the link between musculoskeletal pain and chronic disability. However, reported measurement properties have been inconsistent regarding the FABQ.

METHODS

Individuals (n = 722) sick listed due to musculoskeletal, unspecified or common mental health disorders undergoing rehabilitation was included. A Rasch analysis was applied to evaluate the measurement properties of FABQ and its two subscales (physical activity and work). Linear regression was used to assess how well single items predicted future sickness absence.

RESULTS

The Rasch analysis did not support the FABQ or its two subscales representing a unidimensional construct. The 7-point scoring of the items was far too fine meshed and in the present population the data only supported a yes or no or a 3-point response option. The items were invariant to age, whereas two of the items revealed sex differences. The item "I do not think that I will be back to my normal work within 3 months" was the best predictor of future sickness absence. Adding the item "I should not do my regular work with my present pain" improved the prediction model slightly.

CONCLUSION

The FABQ is not a good measure of fear-avoidance beliefs about work or physical activity, and the predictive property of the FABQ questionnaire is most likely related to expectations rather than fear. Based on these results we do not recommend using the FABQ to measure fear-avoidance beliefs.

LEVEL OF EVIDENCE

1.

New Perspectives in Computing the Point of Subjective Equality Using Rasch Models

In psychophysics, the point of subject equality (PSE) is any of the points along a stimulus dimension at which a variable stimulus (visual, tactile, auditory, and so on) is judged by an observer to be equal to a standard stimulus. Rasch models have been found to offer a valid solution for computing the PSE when the method of constant stimuli is applied in the version of the method of transitions. The present work provides an overview of the procedures for computing the PSE using Rasch models and proposes some new developments. An adaptive procedure is described that allows for estimating the PSE of an observer without presenting him/her with all stimuli pairs. This procedure can be particularly useful in those situations in which psychophysical conditions of the individuals require that the number of trials is limited. Moreover, it allows for saving time that can be used to scrutinize the results of the experiment or to run other experiments. Also, the possibility of using Rasch-based fit statistics for identifying observers who gave unexpected judgments is explored. They could be individuals who, instead of carefully evaluating the presented stimuli pairs, gave random, inattentive, or careless responses, or gave the same response to many consecutive stimuli pairs. Otherwise, they could be atypical and clinically relevant individuals who deserve further investigation. The aforementioned developments are implemented using procedures and statistics that are well established in the framework of Rasch models. In particular, computerized adaptive testing procedures are used for efficiently estimating the PSE of the observers, whereas infit and outfit mean-squares statistics are used for detecting observers who gave unexpected judgments. Results of the analyses carried out on simulated data sets suggest that the proposed developments can be used in psychophysical experiments.

Psychometric properties of the Danish Hospital Anxiety and Depression Scale in patients with cardiac disease: results from the DenHeart survey

BACKGROUND

Anxiety and depression symptoms are common among cardiac patients. The Hospital Anxiety and Depression Scale (HADS) is frequently used to measure symptoms of anxiety and depression; however, no study on the validity and reliability of the scale in Danish cardiac patients has been done. The aim, therefore, was to evaluate the psychometric properties of HADS in a large sample of Danish patients with the four most common cardiac diagnoses: ischemic heart disease, arrhythmias, heart failure and heart valve disease.

METHODS

The DenHeart study was designed as a national cross-sectional survey including the HADS, SF-12 and HeartQoL and combined with data from national registers. Psychometric evaluation included analyses of floor and ceiling effects, structural validity using both exploratory and confirmatory factor analysis and hypotheses testing of convergent and divergent validity by relating the HADS scores to the SF-12 and HeartQoL. Internal consistency reliability was evaluated by Cronbach's alpha, and differential item functioning by gender was examined using ordinal logistic regression.

RESULTS

A total of 12,806 patients (response rate 51%) answered the HADS. Exploratory factor analysis supported the original two-factor structure of the HADS, while confirmatory factor analysis supported a three-factor structure consisting of the original depression subscale and two anxiety subscales as suggested in a previous study. There were floor effects on all items and ceiling effect on item 8. The hypotheses regarding convergent validity were confirmed but those regarding divergent validity for HADS-D were not. Internal consistency was good with a Cronbach's alpha of 0.87 for HADS-A and 0.82 for HADS-D. There were no indications of noticeable differential item functioning by gender for any items.

CONCLUSIONS

The present study supported the evidence of convergent validity and high internal consistency for both HADS outcomes in a large sample of Danish patients with cardiac disease. There are, however, conflicting results regarding the factor structure of the scale consistent with previous research.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01926145.

Is Barthel Index Suitable for Assessing Activities of Daily Living in Patients With Dementia?

OBJECTIVES

To evaluate application of the Barthel Index (BI) in assessing basic activities of daily living (ADL) of patients with dementia using Rasch analysis.

DESIGN

A multi-country cross-sectional study.

SETTING AND PARTICIPANTS

Nineteen long-term care facilities located in China, Japan, South Korea, and Thailand. A total of 644 patients with dementia were included.

METHODS

Unidimensionality, global and item fit, local dependence, person-item targeting, threshold disordering, and differential item functioning (DIF) were examined. Negative correlations between scores for DIF items and Neuropsychiatric Inventory Nursing Home version (NPI-NH) were evaluated.

RESULTS

Item reliability (1.0) and person reliability (.88) were acceptable. The Rasch dimension explained 72.9% of the variance (Eigenvalue = 27), while the first contrast explained 6.6% (Eigenvalue = 2.4). The "mobility" was misfitting to the Rasch model (infit mean square = 1.86). The overall difficulty of the BI exceeded patients' ability (person location = -2.27 logits). The "stairs climbing" and "mobility" showed narrow category thresholds (< 1.4 logits). The location of "controlling bladder" and "toilet use" overlapped. Removing "stairs climbing", collapsing categories with narrow threshold widths in "mobility", and combining "controlling bowel" and "controlling bladder" into one item, improved unidimensionality, and item fit of the scale. Only three items ("grooming", "dressing", and "toilet use") were free from DIF across countries. The scores for "feeding" were negatively related to scores for "disinhibition" (r = -0.46, P < 0.01), and scores for "controlling bowel" were negatively related to scores for "disinhibition" (r = -0.44, P < 0.01), "agitation" (r = -0.32, P < 0.05), and "aggression" (r = -0.27, P < 0.01) in Japanese samples.

CONCLUSIONS AND IMPLICATIONS

The performance of the BI for assessing patients with dementia might be compromised by misfit items, person-item mistargeting, measurement gaps, redundant items, narrow threshold width, and item bias. Mobility ability might not be helpful for determining capability of basic ADL in the patients. Comparisons of BI scores between countries should be undertaken with caution due to item bias. Neuropsychiatric symptoms might interact with basic ADL abilities of the patients. We will not suggest using the instrument in patients with dementia, without future refining to improve its performance.

A Rasch analysis of the Person-Centred Climate Questionnaire - staff version

Background

Person-centred care is the bedrock of modern dementia services, yet the evidence-base to support its implementation is not firmly established. Research is hindered by a need for more robust measurement instruments. The 14-item Person-Centred Climate Questionnaire - Staff version (PCQ-S) is one of the most established scales and has promising measurement properties. However, its construction under classical test theory methods leaves question marks over its rigour and the need for evaluation under more modern testing procedures.

Methods

The PCQ-S was self-completed by nurses and other care staff working across nursing homes in 35 Swedish municipalities in 2013/14. A Rasch analysis was undertaken in RUMM2030 using a partial credit model suited to the Likert-type items. Three subscales of the PCQ-S were evaluated against common thresholds for overall fit to the Rasch model; ordering of category thresholds; unidimensionality; local dependency; targeting; and Differential Item Functioning. Three subscales were evaluated separately as unidimensional models and then combined as subtests into a single measure. Due to large number of respondents (n = 4381), two random sub-samples were drawn, with a satisfactory model established in the first (‘evaluation’) and confirmed in the second (‘validation’). Final item locations and a table converting raw scores to Rasch-transformed values were created using the full sample.

Results

All three subscales had disordered thresholds for some items, which were resolved by collapsing categories. The three subscales fit the assumptions of the Rasch model after the removal of two items, except for subscale 3, where there was evidence of local dependence between two items. By forming subtests, the 3 subscales were combined into a single Rasch model which had satisfactory fit statistics. The Rasch form of the instrument (PCQ-S-R) had an adequate but modest Person Separation Index (< 0.80) and some evidence of mistargeting due to a low number of ‘difficult-to-endorse’ items.

Conclusions

The PCQ-S-R has 12 items and can be used as a unidimensional scale with interval level properties, using the nomogram presented within this paper. The scale is reliable but has some inefficiencies due to too few high-end thresholds inhibiting discrimination amongst populations who already perceive that person-centred care is very good in their environment.

Validation of the patient activation measure in patients at discharge from hospitals and at distance from hospital care in Sweden

BACKGROUND

The Patient Activation Measure (PAM) is a recognized measure of how active patients are in their care, and has been translated into several languages and cultural contexts. Patient activity, self-care, and health literacy have become increasingly important aspects of health care, and thus reliable measures of these are needed. However, a Swedish translation of PAM is currently lacking. The aim of the study was to translate and assess the validity and reliability of the Swedish PAM-13.

METHODS

A self-report questionnaire was handed out to 521 patients at ten medical, geriatric, and surgical wards, and one Virtual Health Room. The Rasch model was employed, using the partial credit model, to assess the functioning of the PAM scale, item fit, targeting, unidimensionality, local independence, differential item functioning (DIF), and person-separation index. Evidence of substantive, content, structural, and external validity was examined.

RESULTS

Of the 521 patients who were consecutively handed a questionnaire, 248 consented to participate, yielding a response rate of 47.6%. The average measure for each category advanced monotonically. The difficulty of the PAM items ranged from - 1.55 to 1.26. The infit and outfit values for the individual items were acceptable. Items 1, 2, and 4 showed disordered thresholds. The mean person location was 1.48 (SD = 1.66). The person-item map revealed that there were no item representations at the top of the scale. The evidence for unidimensionality was ambiguous and response dependency was seen in some items. DIF was found for age. The person separation index was 0.85.

CONCLUSION

The Swedish PAM-13 was reliable, but was not conclusively found to represent one underlying construct. It seems that the Swedish PAM-13 lacks strong evidence for substantive, content, and structural validity. Although valid and reliable measures of ability for activation in self-care among patients are highly warranted, we recommend further development of PAM-13 before application in everyday clinical care.

A Comparison of Classical and Modern Measures of Internal Consistency

Three measures of internal consistency - Kuder-Richardson Formula 20 (KR20), Cronbach's alpha (α), and person separation reliability (R) - are considered. KR20 and α are common measures in classical test theory, whereas R is developed in modern test theory and, more precisely, in Rasch measurement. These three measures specify the observed variance as the sum of true variance and error variance. However, they differ for the way in which these quantities are obtained. KR20 uses the error variance of an "average" respondent from the sample, which overestimates the error variance of respondents with high or low scores. Conversely, R uses the actual average error variance of the sample. KR20 and α use respondents' test scores in calculating the observed variance. This is potentially misleading because test scores are not linear representations of the underlying variable, whereas calculation of variance requires linearity. Contrariwise, if the data fit the Rasch model, the measures estimated for each respondent are on a linear scale, thus being numerically suitable for calculating the observed variance. Given these differences, R is expected to be a better index of internal consistency than KR20 and α. The present work compares the three measures on simulated data sets with dichotomous and polytomous items. It is shown that all the estimates of internal consistency decrease with the increasing of the skewness of the score distribution, with R decreasing to a larger extent. Thus, R is more conservative than KR20 and α, and prevents test users from believing a test has better measurement characteristics than it actually has. In addition, it is shown that Rasch-based infit and outfit person statistics can be used for handling data sets with random responses. Two options are described. The first one implies computing a more conservative estimate of internal consistency. The second one implies detecting individuals with random responses. When there are a few individuals with a consistent number of random responses, infit and outfit allow for correctly detecting almost all of them. Once these individuals are removed, a "cleaned" data set is obtained that can be used for computing a less biased estimate of internal consistency.

Development of the Melanoma Concerns Questionnaire (MCQ-28); refinement of the EORTC QLQ-MEL38 module

OBJECTIVE

Few patient-reported outcome measures (PROMs) have been developed that adequately measure the patient-experience following diagnosis and treatment of melanoma. Building on previous research, which developed the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Module (QLQ-MEL38), the aim of this study was to further test the hypothesised domain structure and psychometric properties of the phase 3 module, in a new larger sample of melanoma patients.

METHODS

Melanoma patients (n = 270) were recruited from four countries (Australia, England, Serbia, and Spain). Patients completed the EORTC core questionnaire (QLQ-C30), the QLQ-MEL38, and a sociodemographic survey. Using this new larger dataset, comparisons were made with the hypothesised domain structure of the EORTC phase 3 module using principal component analysis. Items which formed subscales in a revised domain structure were then tested for goodness of fit (GoF) to the Rasch model.

RESULTS

The original hypothesised and final domain structures were similar but not identical. Twenty-four items (83%) loaded onto the same distinct subscales previously generated by phase 3, and item-by-item comparison of the two pattern matrices indicated an extremely close match. Ten items were removed from the QLQ-MEL38 phase 3 module, and rescoring of some items was required. Four subscales, together with five individual items, comprised the final instrument.

CONCLUSION

The newly developed measure (named the Melanoma Concerns Questionnaire; MCQ-28) was found to tap into several important psychosocial domains of concern to melanoma patients, particularly those being managed in "usual" clinic settings.

A Scientometric Review of Rasch Measurement: The Rise and Progress of a Specialty

A recent review of the literature concluded that Rasch measurement is an influential approach in psychometric modeling. Despite the major contributions of Rasch measurement to the growth of scientific research across various fields, there is currently no research on the trends and evolution of Rasch measurement research. The present study used co-citation techniques and a multiple perspectives approach to investigate 5,365 publications on Rasch measurement between 01 January 1972 and 03 May 2019 and their 108,339 unique references downloaded from the Web of Science (WoS). Several methods of network development involving visualization and text-mining were used to analyze these data: author co-citation analysis (ACA), document co-citation analysis (DCA), journal author co-citation analysis (JCA), and keyword analysis. In addition, to investigate the inter-domain trends that link the Rasch measurement specialty to other specialties, we used a dual-map overlay to investigate specialty-to-specialty connections. Influential authors, publications, journals, and keywords were identified. Multiple research frontiers or sub-specialties were detected and the major ones were reviewed, including “visual function questionnaires”, “non-parametric item response theory”, “valid measures (validity)”, “latent class models”, and “many-facet Rasch model”. One of the outstanding patterns identified was the dominance and impact of publications written for general groups of practitioners and researchers. In personal communications, the authors of these publications stressed their mission as being “teachers” who aim to promote Rasch measurement as a conceptual model with real-world applications. Based on these findings, we propose that sociocultural and ethnographic factors have a huge capacity to influence fields of science and should be considered in future investigations of psychometrics and measurement. As the first scientometric review of the Rasch measurement specialty, this study will be of interest to researchers, graduate students, and professors seeking to identify research trends, topics, major publications, and influential scholars.

Measuring physical and mental health during pregnancy and postpartum in an Australian childbearing population - validation of the PROMIS Global Short Form

Background

Health related quality of life is a critical concept during the perinatal period but remains under-researched. The International Consortium for Health Outcomes Measurement have included the Patient Reported Outcomes Measurement Information System (PROMIS®) Global Short Form (GSF) in their core outcome set for pregnancy and childbirth to measure health related quality of life. The PROMIS GSF has not been fully evaluated as a valid and reliable instrument in this population. This study assessed the psychometric properties of the PROMIS GSF during pregnancy and postpartum period.

Methods

PROMIS GSF was administered to a sample of 309 pregnant women at four time-points during pregnancy (≤ 27 and 36-weeks) and postpartum (6- and 26-weeks). The structural validity, internal consistency reliability, construct validity, and responsiveness of the PROMIS GSF were evaluated. The internal structure of the PROMIS GSF was explored using Rasch Measurement Theory. Response format, item fit, differential item functioning (item bias), dimensionality of the scale and its targeting were assessed.

Results

Two revised subscales (Mental Health: four items; and Physical Health: five items) showed good fit to the Rasch model. The revised mental health subscale demonstrated good internal consistency reliability during pregnancy and postpartum period (α = .88 and .87, respectively). The internal consistency reliability of the physical health subscale was adequate (α = .76 and .75, respectively). The revised mental health subscale was sensitive to group differences according to a history of mental health disorder, income, smoking status, drug use, stress levels and planned versus unplanned pregnancy. Differences in scores on the revised physical subscale were detected for groups based on obesity, income, drug use, smoking status, stress, and history of mental health disorders. Scores on both subscales recorded significant changes across the four time-points, spanning pregnancy and postpartum period.

Conclusions

The revised version of the PROMIS GSF was better able to measure mental and physical health during pregnancy and postpartum period compared to the original version. Findings support the clinical and research application of the PROMIS GSF within the International Consortium for Health Outcomes Measurement Standard Set of Outcome Measures for Pregnancy and Childbirth. Ongoing psychometric analysis of the PROMIS GSF is recommended in other maternity populations.

Rasch Validation of the Arabic Version of the Behavioral Intention to Interact With Peers With Intellectual Disability Scale

This study aimed to examine the construct validity of the Arabic version of the behavioral intention to interact with peers using an intellectual disability (ID) scale. Rasch analysis was used to examine the psychometric properties of the scale. The sample contained 290 elementary students in Saudi Arabia (56% were girls and 44% were boys). Several parameters were examined: overall fit, item fit, person fit, assumption of local independence, and the scale’s unidimensionality. Eight items were rescored, 22 misfit persons were removed, and no item with differential item functioning (DIF) was detected. Disordered thresholds were detected in eight items. The scale demonstrated good internal consistency [person separation index (PSI) 0.80] and fulfilled all the requirements of the Rasch model. After rescoring the eight items, Rasch analysis supported the scale’s unidimensionality to measure children’s behavioral intention to interact with peers with ID. The Arabic version of the scale, with the proposed scoring, could be a useful tool to measure children’s behavioral intention to interact with peers with ID. Further studies with different samples are warranted to confirm the study’s findings.

The Balance Intensity Scales for Therapists and Exercisers Measure Balance Exercise Intensity in Older Adults: Initial Validation Using Rasch Analysis

BACKGROUND

The Balance Intensity Scales (BIS) have been developed to measure the intensity of balance exercise in older adults.

OBJECTIVE

The objective was to determine whether the BIS for therapists (BIS-T) and for exercisers (BIS-E) are unidimensional measures of balance exercise intensity, able to be refined using the Rasch model into a hierarchical item order, and appropriately targeted for the older adult population with a variety of diagnoses in a range of exercise testing settings.

DESIGN

This was a scale development study using a pragmatic mixed-methods approach.

METHODS

Older adult exercisers (n = 108) and their therapists (n = 33) were recruited from a large metropolitan health service and rated balance exercise tasks on the BIS-T and BIS-E in a single session.

RESULTS

Scores on both the BIS items and global effort ratings for therapists and exercisers had good correlation and demonstrated unidimensionality. The BIS-T and BIS-E demonstrated a hierarchical distribution of items that fit the Rasch model. The Person Separation Index was moderate (0.62) for the BIS-T but poor (0.33) for the BIS-E.

LIMITATIONS

The limitations were that therapists in this study underprescribed high-intensity balance tasks.

CONCLUSIONS

Initial validation of the BIS-T and the BIS-E demonstrated that these scales can be used for the measurement of balance exercise intensity in older adult populations. The BIS-T items and global effort ratings are recommended for use by therapists, and the global effort ratings are recommended for use by exercisers. Ongoing validation of both scales using high-intensity balance task ratings and different populations of older adults is recommended.

Outcomes of expedited rotator cuff surgery in injured workers: Impact of pathology on readiness for return to work

OBJECTIVES

The objectives of this study were to (1) examine the overall recovery and satisfaction following an expedited rotator cuff (RC) decompression or repair at 3-6 months and (2) explore group differences (repair vs. decompression) in demographics, clinical, disability, and psychosocial factors.

METHODS

This was a prospective longitudinal study of injured workers whose surgery was expedited. The outcome measures were Quick disabilities of the arm, shoulder, and hand ( QuickDASH), the Hospital Anxiety and Depression Scale (HADS), the readiness for return to work (RRTW) scale, and satisfaction with surgery and overall recovery.

RESULTS

Of 118 patients participated in the study, 106 patients, age: 51 (9), 71 males (67%) completed the study. Sixty-four (60%) patients underwent a RC repair and 42 (40%) had RC decompression. Patients improved on average in QuickDASH ( p = 0.004), anxiety ( p = 0.003), and depression scores ( p = 0.004). The majority of patients (75%) were satisfied with surgery. In the decompression group, the pre-contemplation (PC) stage of the RRTW which documents the absence of desire or planning for return to work in the non-working sample ( r = 0.81, p = 0.008) and the uncertain maintenance (UM) stage of the RRTW which explores the worker's struggle to stay at work in the working sample correlated with physical disability as measured by the QuickDASH scores ( r = 0.62, p = 0.0001). In the repair group, the above domains correlated with the depression HADS scores (PC: r = 0.64, p = 0.001 and UM: r = 0.57, p < 0.0001).

CONCLUSION

Expedited RC surgery improved physical disability and mental well-being and was associated with a relatively high satisfaction at a maximum of 6 months. The poorer report of readiness for return to work was associated with higher physical disability in the decompression group and higher report of depression in the repair group. These differential associations may emphasize the importance of physical versus psychological management in patients with different levels of pathology.

Measuring Burnout in Pediatric Oncology Staff: Should We Be Using the Maslach Burnout Inventory?

Burnout in health service staff is a cause for concern since it has negative consequences for the individual affected, the wider organization, and patients. The Maslach Burnout Inventory-Human Services Survey (MBI-HSS) has been widely used to assess the prevalence of burnout within oncology services. The MBI-HSS is a self-report measure comprising three subscales-Emotional Exhaustion (EE), Depersonalization (DP), and Personal Accomplishment (PA). This article reports on the first study to investigate the psychometric properties of the MBI-HSS when administered to pediatric oncology staff. Two hundred and three pediatric oncology staff recruited through seven UK Principal Treatment Centers (PTCs) and a children's cancer charity completed the MBI-HSS. The factor structure of the instrument was tested using confirmatory and exploratory factor analysis, with Rasch analysis applied to assess whether the measure meets the requirements of an interval-level scale. Cronbach alpha was used to assess internal reliability. Factor analysis did not support the traditional three-factor structure of the MBI-HSS but instead suggested seven factors. Rasch analysis and alpha coefficients indicated that while the EE and the PA subscales fulfilled the requirements of an interval-level measure for group-level diagnosis, DP did not. Further investigation revealed a "floor effect" on many DP items. Whereas the EE and PA subscales of the MBI-HSS can be used in research with pediatric oncology staff working in PTCs, there are considerable problems with the DP subscale, and researchers should be cautious in interpreting data from this subscale.

An Age- and Stage-Appropriate Patient-Reported Outcome Measure of Vision-Related Quality of Life of Children and Young People with Visual Impairment

PURPOSE

Developmentally sensitive measures of vision-related quality of life (VQoL) are needed to capture age-specific concerns about the impact of living with visual impairment (VI) in children and young people. Our objective was to use our validated VQoL instrument for children and young people 10 to 15 years of age (the VQoL_CYP) as the foundation for development of age-specific extensions.

DESIGN

Questionnaire development.

PARTICIPANTS

A representative sample of children and young people 6 to 19 years of age with VI, defined as visual acuity worse than 0.50 logarithm of the minimum angle of resolution in the better eye. They were recruited from pediatric ophthalmology clinics at Great Ormond Street Hospital and Moorfields Eye Hospital and, in the final phase of the study, from 20 additional United Kingdom hospitals.

METHODS

Standard instrument development processes were followed across 4 phases. Twenty-nine semistructured interviews with children and young people permitted draft age-appropriate extensions. Twenty-eight cognitive interviews informed items and response options. Age-appropriate extensions were prepiloted with 49 participants to ensure feasibility and administered via a postal survey to a national sample of 160 participants for psychometric evaluation using Rasch analysis. Construct validity was evaluated through correlations with the Pediatric Quality of Life Inventory.

MAIN OUTCOME MEASURES

Psychometric indices of validity and reliability of the instrument versions.

RESULTS

Interviews confirmed that the existing VQoL_CYP content and format were relevant across a wider age range. Age-appropriate extensions were drafted for children (8-12 years) and young people (13-17 years). Psychometric item reduction produced 20-item child and 22-item young person versions, each with acceptable fit values, no notable differential item functioning, good measurement precision, ordered response categories and acceptable targeting, and no notable differential item functioning on items common to both. Construct validity was demonstrated through correlations with health-related quality of life (r = 0.698).

CONCLUSIONS

Using an efficient child- and young person-centered approach, we developed 2 robust, age-appropriate versions of an instrument capturing VQoL that can be used cross-sectionally or sequentially across the age range of 8 to 17 years in research and clinical practice. This approach may be applicable in other rare childhood ophthalmic disorders.

Measuring compassionate healthcare with the 12-item Schwartz Center Compassionate Care Scale

BACKGROUND

Patients and clinicians endorse the importance of compassionate healthcare but patients report gaps between its perceived importance and its demonstration. Empathy and compassion have been associated with quality of life and significant health outcomes but these characteristics are not optimally measured or used for performance and organizational improvement.

OBJECTIVE

To address these gaps, we conducted a study with the objective of evaluating the properties of the 12-item Schwartz Center Compassionate Care Scale® using psychometric analysis and cognitive debriefing.

METHODS

Non-hospitalized patients with multiple chronic conditions were sampled using an on-line platform. Classical test theory and Rasch measurement theory were used to evaluate psychometric properties of the scale. Structured questions elicited cognitive responses regarding clarity of each item.

RESULTS

Classical test theory analysis confirmed that the 12-item Schwartz Center Compassionate Care Scale is a unidimensional scale with excellent internal consistency and test-retest reliability. Patients' ratings of compassionate behaviors using the Schwartz Center Compassionate Care Scale correlated significantly with a related instrument designed to measure empathy, demonstrating convergent validity. Rasch measurement theory showed that reducing the number of response options on 3 items in the scale would improve respondents' discrimination between responses on these items. Although person-item threshold distribution analysis showed that patients may wish to rate compassionate care at levels both higher and lower than the scale permits, items could be ordered on an interval scale from low to high levels of compassionate care.

CONCLUSIONS

The current 12-item Schwartz Center Compassionate Care Scale demonstrates excellent psychometric properties by Classical Test Theory and Rasch measurement theory. The 12-item Schwartz Center Compassionate Care Scale adds questions related to understanding and discussing emotional, contextual issues and the needs of the patient and family. Easily completed on-line, it could be used for work-place based assessment and feedback to clinicians and performance or quality improvement.

What matters most to patients following percutaneous coronary interventions? A new patient-reported outcome measure developed using Rasch analysis

INTRODUCTION

Measuring patient reported outcomes can improve the quality and effectiveness of healthcare interventions. The aim of this study was to identify the final set of items that can be included in a patient-reported outcome measure to assess recovery of patients following percutaneous coronary interventions.

METHODS

A consecutive sample of 200 patients registered in the Victorian Cardiac Outcomes Registry participated in a telephone survey 30 days following their percutaneous cardiac procedure. Rasch analysis was used to select the best set of items to form a concise and psychometrically sound patient-reported outcome measure. Key measurement properties assessed included overall fit to the Rasch measurement model, unidimensionality, response formats (thresholds), targeting, internal consistency and measurement invariance.

RESULTS

Five items were identified as being reliable and valid measures of patient-reported outcomes: pain or discomfort, shortness of breath, confidence in performing usual activities, feeling unhappy and having trouble sleeping. Data showed overall fit to a Rasch model of expected item functioning (χ2 16.99; p = 0.07) and all items demonstrated unidimensionality (t-test less than 0.05 threshold value). Internal consistency was acceptable (equivalent Cronbach's α 0.65) given there are only five items, but there was a ceiling effect (mean logit score -1.24) with compromised score precision for patients with better recovery.

CONCLUSIONS

We identified a succinct set of items that can be used in a patient-reported outcome measure following percutaneous coronary interventions. This patient-report outcome measure has good structural validity and acceptable internal consistency. While further psychometric evaluations are recommended, the items identified capture the patient's perspective of their recovery following a percutaneous coronary intervention.

Robust maximum marginal likelihood (RMML) estimation for item response theory models

Self-report data are common in psychological and survey research. Unfortunately, many of these samples are plagued with careless responses, due to unmotivated participants. The purpose of this study was to propose and evaluate a robust estimation method to detect careless or unmotivated responders, while leveraging item response theory (IRT) person-fit statistics. First, we outlined a general framework for robust estimation specific for IRT models. Subsequently, we conducted a simulation study covering multiple conditions in order to evaluate the performance of the proposed method. Ultimately, we showed that robust maximum marginal likelihood (RMML) estimation significantly improves detection rates for careless responders and reduces bias in item parameters across conditions. Furthermore, we applied our method to a real data set, to illustrate the utility of the proposed method. Our findings suggest that robust estimation coupled with person-fit statistics offers a powerful procedure to identify careless respondents for further review and to provide more accurate item parameter estimates in the presence of careless responses.

Construct validity of a global scale for Workplace Social Capital based on COPSOQ III

BACKGROUND AND AIM

Workplace Social Capital has been suggested as a useful concept when addressing organizational and social factors of the work environment. The overall aim of the present study is to establish and evaluate the construct validity of a measure of Workplace Social Capital based on the operationalization suggested in the third version of the Copenhagen Psychosocial questionnaire.

METHODS

The present study is based on data collected as part of a validation and development project for the use of the Swedish version of COPSOQ at workplaces and includes responses from 1316 human service workers answering a workplace survey. Six items from scales for organizational justice, vertical trust and horizontal trust in COPSOQ III were included in the analyses. Rasch Analysis was used for scale validation.

RESULTS

The analyses showed that the psychometric properties of the suggested COPSOQ scale for Workplace Social Capital were satisfactory after accommodation for local dependency. Each individual item worked as intended, the scale was unidimensional and functioned invariantly for women and men, and for younger and older employees. The scale was furthermore found to be valid for use for distinguishing groups, not individuals.

CONCLUSION

We have established that the scale for Workplace Social Capital measured by COPSOQ III is valid for distinguishing groups, e.g. work teams. The scale exhibits good construct validity as it satisfies the measurement criteria defined by the Rasch model.

Comparison of Hospital Anxiety and Depression Scale (HADS) and Zung Self-Rating Anxiety/Depression Scale (SAS/SDS) in Evaluating Anxiety and Depression in Patients with Psoriatic Arthritis

BACKGROUND

This study aimed to compare the Hospital Anxiety and Depression Scale (HADS) and the Zung Self-Rating Anxiety/Depression Scale (SAS/SDS) in evaluating anxiety and depression in psoriatic arthritis (PsA) patients.

METHODS

A total of 70 PsA patients were enrolled. Demographic and clinical characteristics were collected after enrollment. HADS-A and SAS were used to evaluate the anxiety of PsA patients, while HADS-D and SDS were used to evaluate the depression of PsA patients.

RESULTS

Similar results were observed in detecting the rate of anxiety by HADS-A and SAS (27.1 vs. 21.4%, p = 0.424), and there was no difference in classifying the severity of anxiety by HADS-A and SAS (p = 0.347). The Spearman test also disclosed that HADS-A score was positively associated with SAS score (p <0.001). The rates of depression were similar by HADS-D and SDS (27.1 vs. 40.0%; p = 0.108). However, different results were observed in grading the severity of anxiety by HADS-D and SDS (p = 0.009), and no correlation was observed between HADS-D and SDS scores (p = 0.138). The consumption of time for HADS assessment was shorter than that for SAS/SDS assessment (p < 0.001). In addition, a positive correlation of HADS-A score with patients' global assessment (PGA) (p = 0.022) and fatigue scores (p = 0.028) was discovered, and HADS-D score was positively associated with PGA score (p = 0.019). SAS or SDS score presented less correlation with clinical features of PsA patients, which illuminated that only SAS score was positively associated with duration of psoriasis (p = 0.030).

CONCLUSION

HADS seems to be a better option for anxiety and depression assessment than SAS/SDS in PsA patients.

Contributions of cardiovascular risk and smoking to chronic obstructive pulmonary disease (COPD)-related changes in brain structure and function

Background

Brain damage and cardiovascular disease are extra-pulmonary manifestations of chronic obstructive pulmonary disease (COPD). Cardiovascular risk factors and smoking are contributors to neurodegeneration. This study investigates whether there is a specific, COPD-related deterioration in brain structure and function independent of cardiovascular risk factors and smoking.

Materials and methods

Neuroimaging and clinical markers of brain structure (micro- and macro-) and function (cognitive function and mood) were compared between 27 stable COPD patients (age: 63.0±9.1 years, 59.3% male, forced expiratory volume in 1 second [FEV1]: 58.1±18.0% pred.) and 23 non-COPD controls with >10 pack years smoking (age: 66.6±7.5 years, 52.2% male, FEV1: 100.6±19.1% pred.). Clinical relationships and group interactions with brain structure were also tested. All statistical analyses included correction for cardiovascular risk factors, smoking, and aortic stiffness.

Results

COPD patients had significantly worse cognitive function (p=0.011), lower mood (p=0.046), and greater gray matter atrophy (p=0.020). In COPD patients, lower mood was associated with markers of white matter (WM) microstructural damage (p<0.001), and lower lung function (FEV1/forced vital capacity and FEV1) with markers of both WM macro (p=0.047) and microstructural damage (p=0.028).

Conclusion

COPD is associated with both structural (gray matter atrophy) and functional (worse cognitive function and mood) brain changes that cannot be explained by measures of cardiovascular risk, aortic stiffness, or smoking history alone. These results have important implications to guide the development of new interventions to prevent or delay progression of neuropsychiatric comorbidities in COPD. Relationships found between mood and microstructural abnormalities suggest that in COPD, anxiety, and depression may occur secondary to WM damage. This could be used to better understand disabling symptoms such as breathlessness, improve health status, and reduce hospital admissions.

Measurement Properties of the SF-MPQ-2 Neuropathic Qualities Subscale in Persons with CRPS: Validity, Responsiveness, and Rasch Analysis

OBJECTIVES

The purpose of this study was to conduct classical psychometric evaluation and Rasch analysis on the Neuropathic Qualities subscale of the Short-Form McGill Pain Questionnaire-2 utilizing scores from persons with complex regional pain syndrome to consider reliability and person separation, validity (including unidimensionality), and responsiveness in this population.

METHODS

Secondary analysis of longitudinal data from persons with acute complex regional pain syndrome was utilized for analysis of the psychometric properties and fit to the Rasch model of the Neuropathic Qualities subscale. We followed an iterative process of Rasch analysis to evaluate and address data fitting challenges.

RESULTS

Repeated measures from 59 persons meeting the Budapest criteria were used for analysis. Both item-total correlations and unidimensionality analyses supported theoretical construct validity; all convergent construct validity hypotheses were also supported. Responsiveness was demonstrated comparing baseline and one-year data at d = 0.92, with a standardized response mean of 0.97. Data were able to fit the Rasch model, but all Neuropathic Qualities items had disordered thresholds that required rescoring. Additionally, local dependency and differential item function were addressed by "bundling," suggesting that no further item reduction would be possible.

CONCLUSIONS

This study provided preliminary support for the validity and responsiveness of the Neuropathic Qualities subscale in persons with complex regional pain syndrome. Rasch analysis further endorses use of the Neuropathic Qualities subscale as a "stand-alone" measure for neuropathic features, but with substantial background data transformations. Replication with larger samples is recommended to increase confidence in these findings.

Identification of differential item functioning by race and ethnicity in the Childhood Trauma Questionnaire

BACKGROUND

The accurate assessment of childhood maltreatment (CM) is important in medical and mental health settings given its association to adverse psychological and physical outcomes. Reliable and valid assessment of CM is also of critical importance to research. Due to the potential of measurement bias when comparing CM across racial and ethnic groups, invariant measurement is an important psychometric property of such screening tools.

OBJECTIVE

In this study, differential item function (DIF) by race and ethnicity was tested. Uniform DIF refers to the influence of bias on scores across all levels of childhood maltreatment, and non-uniform DIF refers to bias in favor of one group.

METHOD

Participants were N=1,319 women and men (M_age=36.77, SD_age=10.37) who completed the Child Trauma Questionnaire-Short Form; 42.7% were women, 57.3% were male; 58.9% were White-American, 22.1% Black-American, and 8.0% as other; 26.3% were Hispanic.

RESULTS

Using empirical thresholds, non-uniform DIF was identified in five items by race, and no items by ethnicity.

CONCLUSIONS

Uniform DIF is less problematic given that mathematical corrections can be made to adjust scores for DIF. However, non-uniform DIF can usually only be corrected by removing the DIF items from the scale. Further methodological research is needed to minimize measurement bias to effectively assess racially diverse populations.

Psychometric performance of the PROMIS® depression item bank: a comparison of the 28- and 51-item versions using Rasch measurement theory

PURPOSE

The aim of this study is to illustrate an example application of Rach Measurement Theory (RMT) in the evaluation of patient-reported outcome (PRO) measures. RMT diagnostic methods were applied to evaluate the PROMIS® Depression items as part of a series of papers applying different psychometric paradigms in parallel to the same data.

METHODS

RMT was used to examine scale-to-sample targeting, scale performance and sample measurement of two PROMIS depression item pools including respectively 28 and 51- items.

RESULTS

Sub-optimal but improved targeting was displayed in the 51-item pool which covered 27% of the range of depression measured in the sample compared to only 15% in the 28-item bank, further reducing the sample percentage with lower depression not covered by the scale (28% Vs 34%). Satisfactory scale performance was observed by the 28-item bank with marginal item misfit. However, deviations from the RMT criteria in the 51-itempool were observed including: 9 reversed thresholds; 12 misfitting items and 12 item-pairs displaying dependency. Overall reliability was good for sets of items (Person Separation Index = 0.93 and 0.95), but sub-optimal sample measurement (17% Vs 19% fit residuals outside of the recommended range).

CONCLUSIONS

The RMT approach in this exercise provided evidence that compared to the 28-item bank, the extended 51-item version of the PROMIS depression, improved sample-to-scale targeting. However, targeting in the lower end of the concept of interest remained sub-optimal and scale performance deteriorated. There may be a need to improve the conceptual breadth of the construct under investigation to ensure the inclusion of items that capture the full range of the concept of interest for this context of use.

A Rasch analysis of the lumbar spine instability questionnaire

Purpose: A 2014 study found that the Lumbar Spine Instability questionnaire predicts response to two different types of exercise therapy. This is the first decision tool that has predicted response to exercise for chronic low back pain. The objective of this study was to evaluate the Lumbar Spine Instability questionnaire using Rasch analysis. Methods: Baseline data from patients included in a randomized controlled trial with chronic non-specific low back pain were included. Rasch Measurement Theory was used to assess the ordering of items along a common scale, data-to-model fit, Person Separation Index, unidimensionality and Differential Item Functioning. Results: Responses from 172 patients (102 females) underwent Rasch analysis. All Lumbar Spine Instability questionnaire items had fit residuals between ± 2.5 and Chi-Square values were non-significant with Bonferroni corrections. The Lumbar Spine Instability questionnaire demonstrated a Person Separation Index of 0.64, which is below the recommended cut-off of 0.7. Differential Item Functioning by different pain levels was identified for one item. Conclusion: The Lumbar Spine Instability questionnaire was found to be unidimensional, suggesting that the use of a summary score is appropriate. However, the low Person Separation Index value suggests that more items may be needed to increase the questionnaire's ability to discriminate among individuals with high and low clinical instability.

Beliefs about sharing illness experiences: Development of a scale and relationship with symptoms of fibromyalgia

OBJECTIVES

The aim of the current research was to evaluate, in people with fibromyalgia, the extent to which beliefs about sharing illness experiences are associated with functioning and distress, and to explore the mediating role of illness behaviours. A new scale was designed to address this.

DESIGN

The Beliefs about Sharing Illness Experiences (BASIE) scale was developed, and initial tests of reliability and validity were conducted. A cross-sectional design was used to determine relationships, including mediation analyses.

METHODS

Individuals with fibromyalgia (n = 147) and a comparison group of individuals without fibromyalgia (n = 47) completed questionnaires online. Construct validity was assessed by comparing these two groups. Convergent validity was assessed through correlations with the BASIE and measures of support-seeking and self-sacrifice. Correlation analyses were used to determine relationships with illness behaviours and outcome measures (distress and global impact). Mediation analyses were used to test the indirect effects of illness behaviours.

RESULTS

The BASIE was correlated with expected convergent measures and had good internal consistency (Cronbach's alpha = .939). Individuals with fibromyalgia had significantly higher scores than the comparison group. There was a direct relationship between BASIE scores and outcomes, in terms of functioning and distress. The relationship between BASIE scores and functioning was partially mediated by personal/emotional support-seeking and all-or-nothing behaviours, and not by symptom-related support-seeking or limiting behaviours.

CONCLUSION

Beliefs about sharing illness experiences may be a key factor in maintaining cycles of distress and symptoms in people with fibromyalgia, together with all-or-nothing behaviours and personal/emotional support-seeking. Statement of contribution What is already known on this subject? Maintenance of fibromyalgia is likely to be a complex autopoietic relationship including symptoms, beliefs, behaviours, and emotions. Research suggests possible roles of beliefs about unacceptability of emotions and beliefs around interpersonal situations, and behaviours in social situations as well as limiting and all-or-nothing behaviours. People with fibromyalgia may experience stigma, sometimes resulting in secrecy around their condition and symptoms. What does this study add? The BASIE is a 21-item questionnaire that measures beliefs around sharing illness experiences. Individuals with fibromyalgia hold stronger beliefs around unacceptability of sharing illness experiences. These beliefs are related to functioning and distress, partially mediated by illness behaviours.

Cross-cultural adaptation and validation of the Ukrainian version of the ABILHAND-Kids questionnaire

PURPOSE

To develop and cross-culturally validate the Ukrainian version of the ABILHAND-Kids questionnaire by testing its psychometric properties in a sample of Ukrainian children with cerebral palsy.

METHODS

The ABILHAND-Kids questionnaire was translated into Ukrainian, cross-culturally adapted, and administered to 113 parents of children with cerebral palsy. The psychometric properties of the Ukrainian version and its cross-cultural validation were investigated through the Rasch rating scale model.

RESULTS

One major misfit has been found for the item "Rolling up a sleeve of a sweater" that further was removed. The item "Putting on a backpack/schoolbag" was split into gender-specific items, separately for girls and for boys, as it was systematically easier for Ukrainian girls. All remaining items contributed to the definition of a unidimensional measure of manual ability. The internal consistency reliability of the scale was high (R = 0.95). No significant floor (4%) and ceiling effects (5%) were observed. Three major differential item functioning items were found across Belgium and Ukraine, highlighting the need to use the Ukrainian calibration of ABILHAND-Kids in Ukraine.

CONCLUSION

The Ukrainian ABILHAND-Kids questionnaire has good psychometric properties for assessing manual ability in Ukrainian children with cerebral palsy, holding potential to be implemented in clinical practice nationwide.Implications for rehabilitationCerebral palsy impairs manual ability leading to decreased quality of life and participation.Professionals need valid and reliable tools to detect small changes of manual ability during rehabilitation.Metric properties and availability of the Ukrainian version of the ABILHAND-Kids questionnaire make it a useful tool in the assessment of children with cerebral palsy.

Meaningful and Measurable Health Domains in Huntington's Disease: Large-Scale Validation of the Huntington's Disease Health-Related Quality of Life Questionnaire Across Severity Stages

BACKGROUND

Although health-related quality of life is key for patients with long-term neurodegenerative conditions, measuring this is less straightforward and complex in Huntington's disease (HD).

OBJECTIVES

To refine and validate a fully patient-derived instrument, the Huntington's Disease health-related Quality of Life questionnaire (HDQoL), and to elucidate health domains that are meaningful to patients' lived experience.

METHODS

Five-hundred forty-one participants, from premanifest to end-stage disease, completed the HDQoL, together with generic quality-of-life measures and in-person motor, cognitive, and behavioral assessments. The psychometric properties of the HDQoL were examined using factor analysis and Rasch analysis.

RESULTS

Four HDQoL domains emerged, reflecting the classical triad of HD features; they were Physical-Functional, Cognitive, and 2 different behavioral aspects, that is, the Mood-Self domain and a distinct Worries domain. These domains clarify the behavioral sequelae as experienced by patients, and all showed good to excellent internal consistency. Known-groups analyses illustrated significant and graded changes in clinical assessments and corresponding HDQoL domains across disease severity levels. Convergent and discriminant validity was demonstrated by the expected pattern of correlations between specific HDQoL domains and corresponding domain-relevant clinical assessments as well as patient-reported measures. The data demonstrate robust support for the refined HDQoL across disease stages.

CONCLUSIONS

The HDQoL, with its 2 distinct behavioral domains of Mood-Self and Worries as well as the Physical-Functional and Cognitive domains, is a relevant, reliable, and valid patient-derived instrument to measure the impact of HD across all severity stages.

Rasch analysis of the Forgotten Joint Score in patients undergoing knee arthroplasty

PURPOSE

The purpose of this study was to test the hypothesis that the "Forgotten Joint Score" (FJS-12) is a unidimensional interval-level scale. Unidimensionality refers to measuring a single attribute, i.e., the single ability to forget the arthroplasty. If this property is not verified, the interpretation of the score can be confusing. Unidimensionality is an essential prerequisite of construct validity and required if FJS-12 response data are to be validly summated into a single score. Interval-level dimension is an essential prerequisite of the parametric statistics. Rasch analysis was used to test our study hypothesis.

METHODS

The FJS-12 questionnaire was validated in 248 unilateral knee arthroplasty patients. Successive analyses were used to select items with good psychometric qualities to constitute the new "FJS". The external validity was assessed with the KUJALA questionnaire.

RESULTS

Quantity of relevant items was greater than 50%. Of the 12 original items, nine showed disturbed thresholds, indicating that patients were unable to discriminate among the five levels for these items. The data set was reanalyzed using a four-level scale. The new analysis indicated that the internal consistency was good (r = 0.84). Three items did not fit with the model and they were removed. The nine items of the final scale defined a unidimensional and linear measure of the forgotten joint, and showed a continuous progression in their difficulty. The perception of difficulty was group-independent. The correlation coefficient was moderate between FJS and KUJALA score (r = 0.4).

CONCLUSIONS

This new and items reduced FJS can be used in clinical practice with good psychometric qualities. It provides a reliable tool to follow up patient's evolution and document changes related to knee arthroplasty. This valid FJS is needed in evaluating patients' assessment, one indicator of quality of care.

LEVEL OF EVIDENCE

III-Therapeutic.

Diagnosing depression in primary care: a Rasch analysis of the Major Depression Inventory

Objective: This study aimed to assess the measurement properties of the Major Depression Inventory (MDI) in a clinical sample of primary care patients. Design: General practitioners (GPs) handed out the MDI to patients aged 18-65 years on clinical suspicion of depression. Setting: Thirty-seven general practices in the Central Denmark Region participated in the study. Patients: Data for 363 patients (65% females, mean age: 49.8 years, SD: 17.7) consulting their GP were included in the analysis. Main outcome measures: The overall fit to the Rasch model, individual item and person fit, and adequacy of response categories were tested. Statistical tests for local dependency, unidimensionality, differential item functioning, and correct targeting of the scale were performed. The person separation reliability index was calculated. All analyses were performed using RUMM2030 software. Results: Items 9 and 10 demonstrated misfit to the Rasch model, and all items demonstrated disordered response categories. After modifying the original six-point to a five-point scoring system, ordered response categories were achieved for all 10 items. The MDI items seemed well targeted to the population approached. Model fit was also achieved for core symptoms of depression (items 1-3) and after dichotomization of items according to diagnostic procedure. Conclusion: Despite some minor problems with its measurement structure, the MDI seems to be a valid instrument for identification of depression among adults in primary care. The results support screening for depression based on core symptoms and dichotomization of items according to diagnostic procedure. Key points The Major Depression Inventory (MDI) is widely used for screening, diagnosis and monitoring of depression in general practice. This study demonstrates misfit of items 9 and 10 to the Rasch model and a need to modify the scoring system The findings support screening for depression based on core symptoms and dichotomization of items according to diagnostic procedure. Minor problems with measurement structure should be addressed in future revisions of the MDI.

[Parkinson's disease and glutamate excitotoxicity]

AIM

To measure the concentration of glutamate in the serum of patients with Parkinson's disease (PD) and determine its association with clinical variants of disease course.

MATERIAL AND METHODS

One hundred and ten patients with PD and 90 healthy people were examined. Glutamate concentration in the blood serum was determined with a spectrophotometric method.

RESULTS AND CONCLUSION

Patients with Parkinson's disease had significantly higher levels of serum glutamate compared with healthy subjects (p<0,0001). Patients with a tremor-dominant subtype had significantly higher levels of serum glutamate compared to those in patients with akinetic-rigid and mixed subtypes. The results obtained allow us to expand our understanding of the pathogenesis of this disease. Changes in the concentration of glutamate may reflect neurodegenerative process in PD.

The relationships between symptoms, disability, perceived health and quality of life in amyotrophic lateral sclerosis/motor neuron disease

Objectives: Using the Wilson and Cleary model linking clinical variables to quality of life, we explored the associations between physical and psychological factors, disability, perceived health and quality of life in ALS/MND. Methods: The ongoing UK study of Trajectories of Outcomes in Neurological Conditions (TONiC) recruited participants with ALS/MND to complete a questionnaire pack including demographic factors and several patient reported outcome measures (PROMs); a clinician provided data on disease onset type and duration since diagnosis. All PROMs were transformed from ordinal raw scores to interval-scaled latent estimates via the Rasch measurement model. Results: Data from 636 patients were analyzed; mean age 65.1 years (SD 10.7), 61.3% male. Median duration since diagnosis was 11.2 months (IQR 4.6-29.9; range 0.4-295.9 months); 67.3% had limb and 27.3% bulbar onset disease. Symptoms such as breathlessness and fatigue, along with most domains of activity limitations, were shown to vary by onset type. A series of models illustrated the importance of physical functioning and anxiety upon quality of life, with breathlessness and fatigue having indirect effects. The models were invariant for gender and onset type. Conclusions: This large study highlights the importance of functional status and anxiety as key variables influencing quality of life in ALS/MND. The nature and diversity of factors, both physical and psychological, which have been shown to influence the quality of life of people with ALS/MND provide strong evidence in support of the widespread implementation of multidisciplinary care.

Children’s Psychological Representation of Earthquakes: Analysis of Written Definitions and Rasch Scaling

Natural disasters have a potential highly traumatic impact on psychological functioning. This is notably true for children, whose vulnerability depends on their level of cognitive and emotional development. Before formal schooling, children possess all the basic abilities to represent the phenomena of the world, including natural disasters. However, scarce attention has been paid to children’s representation of earthquakes, notwithstanding its relevance for risk awareness and for the efficacy of prevention programs. We examined children’s representation of earthquakes using different methodologies. One hundred and twenty-eight second- and fourth-graders completed a written definition task and an online recognition task, analyzed through the Rasch model. Findings from both tasks indicated that, in children’s representation, natural elements such as geological ones were the most salient, followed by man-made elements, and then by person-related elements. Older children revealed a more complex representation of earthquakes, and this was detected through the online recognition task. The results are discussed taking into account their theoretical and applied relevance. Beyond advancing knowledge of the development of the representation of earthquakes, they also inform on strengths and limitations of different methodologies. Both aspects are key resources to develop prevention programs for fostering preparedness to natural disasters and emotional prevention.

Cross-cultural adaptation and measurement properties of the Arabic version of the ABILHAND-Kids scale

Purpose: To cross-culturally adapt the ABILHAND-Kids into Arabic and to examine its measurement properties in children with cerebral palsy.Materials and methods: The Cross-cultural adaption of the ABILHAND-Kids into Arabic language included forward translation, backward translation, expert committee followed by preliminary testing. Structural validity using Rasch analysis, internal consistency, test-retest reliability, measurement error, and construct validity of the Arabic ABILHAND-Kids were examined in children with cerebral palsy (N = 154; 54% male, mean age 7.4 years).Results: Rasch analysis did not support the structural validity of the Arabic ABILHAND-Kids mainly due to response dependency. Removal of two items addressed the issue of the response dependency and resulted in a unidimensional scale meeting the requirement of the Rasch model. The scale had excellent internal consistency (Person Separation Index = 0.93) and excellent test-retest reliability (intraclass correlation coefficient = 0.98). The results supported 86% of the predefined hypotheses regarding correlation of the Arabic ABILHAND-Kids with the manual ability classification system, gross motor function classification system and the functional independence measure for children.Conclusion: The Arabic ABILHAND-Kids demonstrated adequate evidence supporting its structural validity as a unidimensional measure along with evidence supporting its internal consistency, test-retest reliability and construct validity as a measure of manual ability in children with cerebral palsy.Implications for rehabilitationThe Arabic ABILHAND-Kids is a reliable and valid measure of manual ability in children with cerebral palsy.The Arabic ABILHAND-Kids can be used to quantify manual ability in children with cerebral palsy in clinical practice and for research purposes.

Nursing student attitudes to people labelled with 'mental illness' and consumer participation: A survey-based analysis of findings and psychometric properties

BACKGROUND

Understanding student attitudes towards people diagnosed with mental illness is central to realising evidence-based nursing education and policy at an international level. Redressing stigmatised views can assist in preparing nursing students to work in mental health settings and support the active involvement of consumers in all aspects of mental health service delivery (known as: consumer participation) at individual and systemic levels. Accurate research on nursing student attitudes is dependent on the availability of valid and reliable measures.

OBJECTIVES

Using data from and international study, this research sought to: (1) evaluate two measures of nurse student attitudes, and (2) explore whether attitudes to people labelled with a diagnosis of mental illness and who use mental health services is associated with more positive attitudes to consumer participation in mental health services.

DESIGN

Self-report quantitative data gained via the Consumer Participation Questionnaire (CPQ) and Mental Health Nurse Education Survey (MHNES).

SETTING AND PARTICIPANTS

University nursing students in Australia and Western Europe.

DATA

Pooled CPQ and MHNES data from Australia, Ireland, Finland, Norway and the Netherlands.

METHODS

The MHNES and CPQ were evaluated via exploratory factor analysis and Rasch modelling. Hierarchical regression was applied to see whether attitudes to mental illness and mental health practice relate to attitudes to consumer participation after addressing demographic differences.

RESULTS

Refined MHNES scales demonstrated overall fit on Rasch models. Reliabilities for MHNES ranged from 0.82 to 0.73. Perceived value of mental health nursing to consumers and lower negative stereotypes were associated with positive attitudes to consumer participation independent of age, gender and country [F (9, 381) = 15.78, p < .001]. Students who considered mental health nursing made a valuable contribution represented the strongest association with a positive attitude towards consumer participation.

CONCLUSIONS

Differences in openness to consumer participation are partly attributable to views about people diagnosed with mental illness and the perception that mental health practice makes a positive difference to these people within health service contexts.

Assessing Beliefs Underlying Rumination About Pain: Development and Validation of the Pain Metacognitions Questionnaire

Metacognitions, which are beliefs about our own thinking processes, can modulate worry and rumination and thereby influence emotional distress. This study aimed to develop a self-report measure of unhelpful pain-related metacognitions which might serve as a clinical and research tool to better understand pain catastrophizing, a significant risk factor for adverse pain outcomes. Two phases of validation are presented. Phase 1 reports on how the Pain Metacognitions Questionnaire (PMQ) was empirically developed through a qualitative study of 20 people with chronic back (n = 15) or knee (n = 5) pain in secondary or tertiary care and then validated in a large internet sample of people experiencing pain (N = 864). Rasch analysis yielded a 21-item scale with two dimensions (positive and negative metacognition) assessing how useful and problematic people believe rumination about pain to be, respectively. In Phase 2, further validation using a new sample (N = 510) replicated initial findings. Both PMQ subscales have good retest reliability (r = 0.76, r = 0.72) and internal consistency (0.86, 0.87). They correlate negatively with mindfulness and positively with pain intensity, disability, anxiety, depression, catastrophizing, rumination, and metacognition. The PMQ also predicts unique variance in catastrophizing when other variables are controlled and predicts 'patient' status for pain catastrophizing. Sensitivity analysis yielded preliminary suggestions for clinically meaningful cut-offs. Unhelpful pain metacognitions can be validly and reliably measured using a self-report instrument. Future studies using the PMQ might shed new light on pain-related thinking processes to develop better interventions for people prone to worry and rumination about their pain.

Chronic functional constipation is strongly linked to vitamin D deficiency

BACKGROUND

Few studies have examined intestinal motility disorders, which are disabling conditions associated with chronic functional constipation, whose pathogenesis is actually not well-defined.

AIM

To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation associated to intestinal motility disorders.

METHODS

We performed a prospective case-control study, from May-June to November 2017. Glucose/lactulose breath tests, radiopaque markers (multiple capsule techniques) and wireless motility capsule analysis were used to assess colonic and oro-cecal transit time, after excluding small-intestinal bacterial overgrowth condition. Then, we measured 25-hydroxyvitamin D levels in patients with intestinal motility disorders and we further evaluated the influence of intestinal motility disorders on psychological symptoms/quality of life using validated questionnaires, the Irritable Bowel Syndrome Quality of life (IBS-QOL), the Short Form Health Survey 12, and the Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D).

RESULTS

We enrolled 86 patients with chronic functional constipation associated to intestinal motility disorders and 86 matched healthy subjects. Patients with intestinal motility disorders had lower 25-hydroxyvitamin D levels (P < 0.001), and they showed a significant impairment of all health-related quality of life and psychological tests (IBS-QOL, Short Form Health Survey 12-Physical Component Summary, Short Form Health Survey 12-Mental Component Summary, HADS-14 A and HADS-14 D), as compared to the control group (P < 0.001), which significantly correlated with low vitamin D levels (r = - 0.57, P < 0.001; r = 0.21, P = 0.01; r = - 0.48, P < 0.001; r = - 0.57, P < 0.001; r = - 0.29, P < 0.001, respectively). At multivariate analysis vitamin D low levels remained a significant independent risk factor for the occurrence of intestinal motility disorder (odds ratio = 1.19; 95% confidence interval: 1.14-1.26, P < 0.001).

CONCLUSION

Vitamin D deficiency, anxiety and depression symptoms are commonly associated with chronic functional constipation induced by intestinal motility disorders. Vitamin D serum levels should be routinely measured in these patients.

Validation of the Indonesian version of the Safety Attitudes Questionnaire: A Rasch analysis

Introduction

Safety climate, which provides a snapshot of safety culture, is rarely measured in Indonesian healthcare organisations because there are no validated surveys that can be administered in its native language, Bahasa Indonesia. The objectives of this study were to translate and linguistically adapt the Safety Attitudes Questionnaire into Bahasa Indonesia, and investigate the internal construct validity and reliability of the translated survey.

Methods

The Safety Attitudes Questionnaire was translated into Indonesian language through forward and backward translation. The internal construct validity and reliability of the translated survey was assessed using Rasch analysis which examines overall model fit, unidimensionality, response format, targeting, internal consistency reliability and item bias.

Results

A total of 279 nurses (response rate 82%) completed the Indonesian version of the Safety Attitudes Questionnaire. Most respondents were Division 2 registered nurses (n = 209; 75%), female (n = 174; 62%), and aged less than 30 years (n = 187; 67%). All six domains of the Indonesian version of the Safety Attitudes Questionnaire demonstrated unidimensionality (t-test less than 0.05 threshold value). However, suboptimal targeting (ceiling effect) was observed in all domains, and had at least one misfitting item (item fit residual beyond ±2.5) Item bias was also evident in most domains.

Conclusion

This study has translated and validated an Indonesian version of the Safety Attitudes Questionnaire for the first time. Whilst there was general support to sum items to obtain domain scores, further work is required to refine the response options as well as the wording and number of items in this survey to improve its overall measurement properties.

Psychometric evaluation of an interview-administered version of the WHOQOL-BREF questionnaire for use in a cross-sectional study of a rural district in Bangladesh: an application of Rasch analysis

BACKGROUND

This study aimed to validate the psychometric properties of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF) questionnaire for use in a rural district of Bangladesh.

METHODS

This cross-sectional study recruited a multi-stage cluster random sample of 2425 participants from the rural district Narail of Bangladesh in May-July 2017. Rasch analysis was carried out using the sampled participants, as well as multiple validation random sub-samples of 300 participants, to validate four domains of the WHOQOL-BREF questionnaire: physical, psychological, social and environmental.

RESULTS

The original WHOQOL-BREF appeared to be a poor fit for both sampled and sub-sampled group of participants in Narail district in all underlying domains: physical, psychological, social and environmental. Two items (sleep and work capacity) from the physical domain, two items (personal belief and negative feelings) from the psychological domain and three items (home environment, health care and transport) from the environment domain were excluded for goodness of fit of the Rasch model. The social domain exhibited reasonably reliable fitness while fulfilling all the assumptions of the Rasch model. A modified version of the WHOQOL-BREF questionnaire using five-items for the physical ([Formula: see text] = 36.47, p = 0.013, Person Separation Index (PSI) = 0.773), four-items for the psychological ([Formula: see text] = 28.30, p = 0.029, PSI = 0.708) and five-items for the environmental ([Formula: see text] = 36.97, p = 0.011, PSI = 0.804) domain was applied, which showed adequate internal consistency, reliability, unidimensionality, and similar functioning for different age-sex distributions.

CONCLUSIONS

The modified WHOQOL-BREF questionnaire translated into Bengali language appeared to be a valid tool for measuring quality of life in a typical rural district in Bangladesh. Despite some limitations of the modified WHOQOL-BREF questionnaire, further application of Rasch analysis using this version or an improved one in other representative rural areas of Bangladesh is recommended to assess the external validity of the outcomes of this study and to determine the efficacy of this tool to measure the quality of life at the national rural level.

International multiphase mixed methods study protocol to develop a cross-cultural patient-reported outcome and experience measure for hand conditions (HAND-Q)

INTRODUCTION

patient-reported outcome measures (PROMs) are instruments used to measure outcomes and experiences of healthcare from the patient perspective. The specific methodology used to develop a PROM should be communicated to establish the quality of the instrument. This mixed methods protocol describes the development of a cross-cultural, internationally applicable PROM for hand conditions, the HAND-Q.

METHODS AND ANALYSIS

The multiphase approach used for this study has been previously used with the development of other PROMs by our team (eg, BODY-Q, BREAST-Q, CLEFT-Q, FACE-Q). In Phase I, we establish what important concepts matter to patients with hand conditions. A conceptual framework is developed from a systematic review of existing PROMs in the field and an extensive international qualitative study. Interpretive description is the qualitative approach used. Item generation is based on the qualitative data. The preliminary scales will be created for each theme identified in the conceptual framework. These scales will be refined by cognitive debriefing interviews with participants and expert input. Phase II involves a large international sample of patients with varied hand conditions completing the field-test version of the HAND-Q. The scales will be refined using the modern psychometric approach of Rasch Measurement Theory. Analysis will result in a shortened set of clinically meaningful and scientifically robust HAND-Q scales.

ETHICS AND DISSEMINATION

This study is coordinated at Flinders University (Adelaide, Australia) where it has ethics board approval for phase I and phase II. Findings will be published in peer-reviewed journals and presented at local, national and international conferences.

Diagnosing depression in primary care: a Rasch analysis of the major depression inventory

OBJECTIVE

This study aims to assess the measurement properties of the Major Depression Inventory (MDI) in a clinical sample of primary care patients.

DESIGN

General practitioners (GPs) handed out the MDI to patients aged 18-65 years on clinical suspicion of depression.

SETTING

Thirty-seven general practices in the Central Denmark Region participated in the study.

PATIENTS

Data for 363 patients (65% females, mean age: 49.8 years, SD: 17.7) consulting their GP were included in the analysis.

MAIN OUTCOME MEASURES

The overall fit to the Rasch model, individual item and person fit, and adequacy of response categories were tested. Statistical tests for local dependency, unidimensionality, differential item functioning, and correct targeting of the scale were performed. The person separation reliability index was calculated. All analyses were performed using RUMM2030 software.

RESULTS

Items 9 and 10 demonstrated misfit to the Rasch model, and all items demonstrated disordered response categories. After modifying the original six-point to a five-point scoring system, ordered response categories were achieved for all 10 items. The MDI items seemed well targeted to the population approached. Model fit was also achieved for core symptoms of depression (items 1-3) and after dichotomization of items according to diagnostic procedure.

CONCLUSION

Despite some minor problems with its measurement structure, the MDI seems to be a valid instrument for identification of depression among adults in primary care. The results support screening for depression based on core symptoms and dichotomization of items according to diagnostic procedure. Key points The Major Depression Inventory (MDI) is widely used for screening, diagnosis and monitoring of depression in general practice. This study demonstrates misfit of items 9 and 10 to the Rasch model and a need to modify the scoring system The findings support screening for depression based on core symptoms and dichotomization of items according to diagnostic procedure. Minor problems with measurement structure should be addressed in future revisions of the MDI.