[Psychometric Evaluation of the 'German Neurological Fatigue Index for Multiple Sclerosis (NFI-MS-G)' in a Sample of Rehabilitation Patients with Multiple Sclerosis]. / Psychometrische Prüfung des deutschsprachigen "Neurologischen Fragebogens zur Müdigkeit bei Multipler Sklerose (NFI-MS-G)" bei Rehabilitanden mit Multipler Sklerose.

PURPOSE: The purpose of this study was to provide a patient-reported outcome measure for people with multiple sclerosis (MS) comprehensively reflecting the construct of fatigue and developed upon the assumptions of the Rasch model. The Neurological Fatigue Index - Multiple Sclerosis (NFI-MS) is based on both a medical and patient-described symptom framework of fatigue and has been validated. Therefore, in this study the German version of the NFI-MS (NFI-MS-G) consisting of a physical and cognitive subscale and a summary scale was validated. METHOD: In this bi-centre-study, 309 people with MS undergoing outpatient rehabilitation or being≥2 months before or after their inpatient rehabilitation completed the German NFI-MS-G twice within 14-21 days together with other questionnaires. Correlation with established questionnaires and Rasch analysis were used for its validation. Additionally, psychometric properties of known-groups validity, internal consistency, test-retest reliability, measurement precision and readability were tested. Finally, the English NFI-MS and German NFI-MS-G were compared with each other to equate the language versions. RESULTS: The NFI-MS-G showed good internal construct validity, convergent and known-groups validity and internal consistency (Cronbach's alpha 0.84-0.93). The physical subscale showed minor local dependencies between items 1 and 7, 2 and 3 and 4 to 6, that could be treated by combining the respective items to testlets. Unidimensionality was found for the physical and cognitive subscales but not for the summary scale. Replacing the summary scale, a 2-domains subtest measuring the higher-order construct of fatigue was created. Good test-retest reliability (Lin's concordance correlation coefficient of 0.86-0.90) and low floor and ceiling effects were demonstrated. The NFI-MS-G was found easily readable and invariant across groups of gender, age, disease duration, timepoint and centre. CONCLUSION: The German version of the NFI-MS comprehensively represents the construct of fatigue and has adequate psychometric properties. The German version differs from the English original version with respect to a lack of unidimensionality of the summary scale and minor local dependencies of the physical subscale that could be canceled out using a testlet analysis.

Symptom burden and health-related quality of life in chronic kidney disease: A global systematic review and meta-analysis.

BACKGROUND: The importance of patient-reported outcome measurement in chronic kidney disease (CKD) populations has been established. However, there remains a lack of research that has synthesised data around CKD-specific symptom and health-related quality of life (HRQOL) burden globally, to inform focused measurement of the most relevant patient-important information in a way that minimises patient burden. The aim of this review was to synthesise symptom prevalence/severity and HRQOL data across the following CKD clinical groups globally: (1) stage 1-5 and not on renal replacement therapy (RRT), (2) receiving dialysis, or (3) in receipt of a kidney transplant. METHODS AND FINDINGS: MEDLINE, PsycINFO, and CINAHL were searched for English-language cross-sectional/longitudinal studies reporting prevalence and/or severity of symptoms and/or HRQOL in CKD, published between January 2000 and September 2021, including adult patients with CKD, and measuring symptom prevalence/severity and/or HRQOL using a patient-reported outcome measure (PROM). Random effects meta-analyses were used to pool data, stratified by CKD group: not on RRT, receiving dialysis, or in receipt of a kidney transplant. Methodological quality of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data, and an exploration of publication bias performed. The search identified 1,529 studies, of which 449, with 199,147 participants from 62 countries, were included in the analysis. Studies used 67 different symptom and HRQOL outcome measures, which provided data on 68 reported symptoms. Random effects meta-analyses highlighted the considerable symptom and HRQOL burden associated with CKD, with fatigue particularly prevalent, both in patients not on RRT (14 studies, 4,139 participants: 70%, 95% CI 60%-79%) and those receiving dialysis (21 studies, 2,943 participants: 70%, 95% CI 64%-76%). A number of symptoms were significantly (p < 0.05 after adjustment for multiple testing) less prevalent and/or less severe within the post-transplantation population, which may suggest attribution to CKD (fatigue, depression, itching, poor mobility, poor sleep, and dry mouth). Quality of life was commonly lower in patients on dialysis (36-Item Short Form Health Survey [SF-36] Mental Component Summary [MCS] 45.7 [95% CI 45.5-45.8]; SF-36 Physical Component Summary [PCS] 35.5 [95% CI 35.3-35.6]; 91 studies, 32,105 participants for MCS and PCS) than in other CKD populations (patients not on RRT: SF-36 MCS 66.6 [95% CI 66.5-66.6], p = 0.002; PCS 66.3 [95% CI 66.2-66.4], p = 0.002; 39 studies, 24,600 participants; transplant: MCS 50.0 [95% CI 49.9-50.1], p = 0.002; PCS 48.0 [95% CI 47.9-48.1], p = 0.002; 39 studies, 9,664 participants). Limitations of the analysis are the relatively few studies contributing to symptom severity estimates and inconsistent use of PROMs (different measures and time points) across the included literature, which hindered interpretation. CONCLUSIONS: The main findings highlight the considerable symptom and HRQOL burden associated with CKD. The synthesis provides a detailed overview of the symptom/HRQOL profile across clinical groups, which may support healthcare professionals when discussing, measuring, and managing the potential treatment burden associated with CKD. PROTOCOL REGISTRATION: PROSPERO CRD42020164737.

The COVID-19 Yorkshire Rehabilitation Scale (C19-YRS): Application and psychometric analysis in a post-COVID-19 syndrome cohort.

As our understanding of the nature and prevalence of post-coronavirus disease 2019 (COVID-19) syndrome (PCS) is increasing, a measure of the impact of COVID-19 could provide valuable insights into patients' perceptions in clinical trials and epidemiological studies as well as routine clinical practice. To evaluate the clinical usefulness and psychometric properties of the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS) in patients with PCS, a prospective, observational study of 187 consecutive patients attending a post-COVID-19 rehabilitation clinic was conducted. The C19-YRS was used to record patients' symptoms, functioning, and disability. A global health question was used to measure the overall impact of PCS on health. Classical psychometric methods (data quality, scaling assumptions, targeting, reliability, and validity) were used to assess the C19-YRS. For the total group, missing data were low, scaling and targeting assumptions were satisfied, and internal consistency was high (Cronbach's α = 0.891). Relationships between the overall perception of health and patients' reports of symptoms, functioning, and disability demonstrated good concordance. This is the first study to examine the psychometric properties of an outcome measure in patients with PCS. In this sample of patients, the C19-YRS was clinically useful and satisfied standard psychometric criteria, providing preliminary evidence of its suitability as a measure of PCS.

The modified COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) patient-reported outcome measure for Long Covid or Post-COVID-19 syndrome.

BACKGROUND: The C19-YRS is the literature's first condition-specific, validated scale for patient assessment and monitoring in Post-COVID-19 syndrome (PCS). The 22-item scale's subscales (scores) are symptom severity (0-100), functional disability (0-50), additional symptoms (0-60), and overall health (0-10). OBJECTIVES: This study aimed to test the scale's psychometric properties using Rasch analysis and modify the scale based on analysis findings, emerging information on essential PCS symptoms, and feedback from a working group of patients and professionals. METHODS: Data from 370 PCS patients were assessed using a Rasch Measurement Theory framework to test model fit, local dependency, response category functioning, differential item functioning, targeting, reliability, and unidimensionality. The working group undertook iterative changes to the scale based on the psychometric results and including essential symptoms. RESULTS: Symptom severity and functional disability subscales showed good targeting and reliability. Post hoc rescoring suggested that a 4-point response category structure would be more appropriate than an 11-point response for both subscales. Symptoms with binary responses were placed in the other symptoms subscale. The overall health single-item subscale remained unchanged. CONCLUSION: A 17-item C19-YRSm was developed with subscales (scores): symptom severity (0-30), functional disability (0-15), other symptoms (0-25), and overall health (0-10).

Capturing the experiences of patients with inherited optic neuropathies: a systematic review of patient-reported outcome measures (PROMs) and qualitative studies.

PURPOSE: To identify and comprehensively evaluate studies capturing the experience of individuals affected by an inherited optic neuropathy (ION), focusing on patient-reported outcome measures (PROMs) and qualitative studies where the health status and quality of life (QoL) of these individuals have been explored. METHODS: Systematic review of five databases using a search strategy combining four concepts: (1) ION; (2) QoL and health status; (3) PROMs; and (4) qualitative research. Studies assessing the impact of ION on any QoL domain using a PROM or qualitative methodology were included and appraised, using criteria based on the COSMIN checklist (for PROM studies) and the CASP checklist (for qualitative studies). RESULTS: Of 1326 unique articles identified, six studies were included. Five PROMs were identified: Visual Function Index (VF-14); Hospital Anxiety and Depression Scale (HADS); a novel graphical online assessment tool (NGOAT) for reporting emotional response to vision loss; a new PROM informed by the DSM-V Criteria for Major Depressive Disorder; and an interpersonal and career 'impact rating' PROM. The psychometric performance of included PROMs were poorly described. Qualitative studies found that vision loss resulted in psychosocial losses including loss of social and communication skills and loss of independence and freedom. Factors that modified the response to vision loss were also identified. CONCLUSION: The current PROMs used by individuals with ION have poor content coverage, primarily measuring activity limitation and emotional well-being, and insufficient reporting of psychometric performance. There is a need to develop a PROM for individuals ION to report their experiences of living with their condition.

Is it time to revisit the Boston Carpal Tunnel Questionnaire? New insights from a Rasch model analysis.

BACKGROUND: The Boston Carpal Tunnel Questionnaire (BCTQ) is a patient-reported outcome measure (PROM) used to measure symptom severity and function in carpal tunnel syndrome (CTS). Despite its wide use, investigation of its measurement properties using modern psychometric methodologies is limited. METHODS: Completed BCTQ data collected routinely in the Canterbury carpal tunnel clinic was used to investigate the structural validity and measurement properties of the BCTQ through application of a Rasch model analytic approach. RESULTS: A total of 600 patients with electrodiagnostically confirmed CTS in their right hand were randomly selected from the database and analyzed. Mean age was 48.8 y, and 73% were women. Initial analysis showed that the 19 items could not be reliably added up to form a single linear construct. All subsequent analyses were done by subscale only. The Symptom Severity Subscale (SSS) displayed a large amount of local dependence. This could be accommodated through the creation of four clinically derived testlets, allowing for the ordinal SSS raw score to be transformed to a linear measure. The Functional Status Subscale (FSS) displayed a number of issues regarding its psychometric integrity. These include scale and item fit, targeting, differential item functioning, and dimensionality. CONCLUSIONS: This study shows that a single total score generated across all BCTQ items is not psychometrically valid, and that the SSS and FSS subscales should be treated separately. We propose a modified scoring system for the SSS, resulting in a linear measure that can be used in the analysis of future and existing datasets.

UK General Population Utility Values for the SIDECAR-D Instrument Measuring the Impact of Caring for People With Dementia.

OBJECTIVES: Dementia affects many people, with numbers expected to grow as populations age. Many people with dementia receive informal/family/unpaid care, for example, from a spouse or child, which may affect carer quality of life. Measuring the effectiveness of health/social care interventions for carers requires a value measure of the quality-of-life impact of caring. This motivated development of the Scales Measuring the Impact of Dementia on Carers-D (SIDECAR-D) instrument. This study aimed to obtain general population values for SIDECAR-D to aid incorporating the impact of caring in economic evaluation. METHODS: Members of the UK general public completed a best-worst scaling object case survey, which included the 18 SIDECAR-D items and EQ-5D-3L descriptions. Responses were analyzed using scale-adjusted finite mixture models. Relative importance scores (RISs) for the 18 SIDECAR-D items formed the SIDECAR-D relative scale measuring the relative impact of caring. The SIDECAR-D tariff, on the full health = 1, dead = 0 scale, was derived by rescaling EQ-5D-3L and SIDECAR-D RISs so the EQ-5D-3L RISs equaled anchored valuations of the EQ-5D-3L pits state from a visual analog scale task. RESULTS: Five hundred ten respondents completed the survey. The model had 2 parameter and 3 scale classes. Additive utility decrements of SIDECAR-D items ranged from -0.05 to -0.162. Utility scores range from 0.95 for someone affirming 1 item to -0.297 for someone affirming all 18. CONCLUSION: SIDECAR-D is a needs-based scale of the impact on quality of life of caring for someone with dementia, with a valuation tariff to support its use in economic evaluation.

Assessing vulnerability to risk of suicide and self-harm in prisoners: a Rasch analysis of the suicide concerns for offenders in the prison environment (SCOPE-2).

BACKGROUND: With increasing levels of suicide and self-harm behaviour in the criminal justice system professionals would benefit from a tool that can identify individuals who may be at risk of self-harm and/or suicidal behaviour. METHOD: The Suicide Concerns for Offenders in the Prison Environment (SCOPE) tool was originally devised and validated in six UK prisons between 2003 and 2004. The goal of this study is to re-evaluate the SCOPE using Rasch methodology to produce a psychometrically robust instrument. Data were presented from 1051 SCOPE assessments of male and female offenders. RESULTS: The analysis produced a revised SCOPE-2 tool reducing the tool from a 27 to a 19 items and simplifying the categorical six point scale to a four item scale. CONCLUSIONS: Further validation of the new SCOPE-2 tool is required in samples of male and female prisoners to assess different cut-off points for clinical and policy use.

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.

Urinary, bowel and sexual health in older men from Northern Ireland.

OBJECTIVES: To provide data on the prevalence of urinary, bowel and sexual dysfunction in Northern Ireland (NI), to act as a baseline for studies of prostate cancer outcomes and to aid service provision within the general population. SUBJECTS AND METHODS: A cross-sectional postal survey of 10 000 men aged ≥40 years in NI was conducted and age-matched to the distribution of men living with prostate cancer. The EuroQoL five Dimensions five Levels (EQ-5D-5L) and 26-item Expanded Prostate Cancer Composite (EPIC-26) instruments were used to enable comparisons with prostate cancer outcome studies. Whilst representative of the prostate cancer survivor population, the age-distribution of the sample differs from the general population, thus data were generalised to the NI population by excluding those aged 40-59 years and applying survey weights. Results are presented as proportions reporting problems along with mean composite scores, with differences by respondent characteristics assessed using chi-squared tests, analysis of variance, and multivariable log-linear regression. RESULTS: Amongst men aged ≥60 years, 32.8% reported sexual dysfunction, 9.3% urinary dysfunction, and 6.5% bowel dysfunction. In all, 38.1% reported at least one problem and 2.1% all three. Worse outcome was associated with increasing number of long-term conditions, low physical activity, and higher body mass index (BMI). Urinary incontinence, urinary irritation/obstruction, and sexual dysfunction increased with age; whilst urinary incontinence, bowel, and sexual dysfunction were more common among the unemployed. CONCLUSION: These data provide an insight into sensitive issues seldom reported by elderly men, which result in poor general health, but could be addressed given adequate service provision. The relationship between these problems, raised BMI and low physical activity offers the prospect of additional health gain by addressing public health issues such as obesity. The results provide essential contemporary population data against which outcomes for those living with prostate cancer can be compared. They will facilitate greater understanding of the true impact of specific treatments such as surgical interventions, pelvic radiation or androgen-deprivation therapy.

Developing the Polish Educational Needs Assessment Tool (Pol-ENAT) in rheumatoid arthritis and systemic sclerosis: a cross-cultural validation study using Rasch analysis.

OBJECTIVES: To undertake cross-cultural adaptation and validation of the educational needs assessment tool (ENAT) for use with people with rheumatoid arthritis (RA) and systemic sclerosis (SSc) in Poland. METHODS: The study involved two main phases: (1) cross-cultural adaptation of the ENAT from English into Polish and (2) Cross-cultural validation of Polish Educational Needs Assessment Tool (Pol-ENAT). The first phase followed an established process of cross-cultural adaptation of self-report measures. The second phase involved completion of the Pol-ENAT by patients and subjecting the data to Rasch analysis to assess the construct validity, unidimensionality, internal consistency and cross-cultural invariance. RESULTS: An adequate conceptual equivalence was achieved following the adaptation process. The dataset for validation comprised a total of 278 patients, 237 (85.3 %) of which were female. In each disease group (145, RA and 133, SSc), the 7 domains of the Pol-ENAT were found to fit the Rasch model, X (2)(df) = 16.953(14), p = 0.259 and 8.132(14), p = 0.882 for RA and SSc, respectively. Internal consistency of the Pol-ENAT was high (patient separation index = 0.85 and 0.89 for SSc and RA, respectively), and unidimensionality was confirmed. Cross-cultural differential item functioning (DIF) was detected in some subscales, and DIF-adjusted conversion tables were calibrated to enable cross-cultural comparison of data between Poland and the UK. CONCLUSION: Using a standard process in cross-cultural adaptation, conceptual equivalence was achieved between the original (UK) ENAT and the adapted Pol-ENAT. Fit to the Rasch model, confirmed that the construct validity, unidimensionality and internal consistency of the ENAT have been preserved.

Validation of the educational needs assessment tool as a generic instrument for rheumatic diseases in seven European countries.

OBJECTIVES: To validate the educational needs assessment tool (ENAT) as a generic tool for assessing the educational needs of patients with rheumatic diseases in European Countries. METHODS: A convenience sample of patients from seven European countries was included comprising the following diagnostic groups: ankylosing spondylitis, psoriatic arthritis, systemic sclerosis, systemic lupus erythematosus, osteoarthritis (OA) and fibromyalgia syndrome. Translated versions of the ENAT were completed through surveys in each country. Rasch analysis was used to assess the construct validity of the adapted ENATs including differential item functioning by culture (cross-cultural DIF). Initially, the data from each country and diagnostic group were fitted to the Rasch model separately, and then the pooled data from each diagnostic group. RESULTS: The sample comprised 3015 patients; the majority, 1996 (66.2%), were women. Patient characteristics (stratified by diagnostic group) were comparable across countries except the educational background, which was variable. In most occasions, the 39-item ENAT deviated significantly from the Rasch model expectations (item-trait interaction χ(2) p<0.05). After correction for local dependency (grouping the items into seven domains and analysing them as 'testlets'), fit to the model was satisfied (item-trait interaction χ(2) p>0.18) in all pooled disease group datasets except OA (χ(2)=99.91; p=0.002). The internal consistency in each group was high (Person Separation Index above 0.90). There was no significant DIF by person characteristics. Cross-cultural DIF was found in some items, which required adjustments. Subsequently, interval-level scales were calibrated to enable transformation of ENAT scores when required. CONCLUSIONS: The adapted ENAT is a valid tool with high internal consistency providing accurate estimation of the educational needs of people with rheumatic diseases. Cross-cultural comparison of educational needs is now possible.

Psychometric analysis of the modified COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) in a prospective multicentre study.

BACKGROUND: Long COVID (LC) is a novel multisystem clinical syndrome affecting millions of individuals worldwide. The modified COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) is a condition-specific patient-reported outcome measure designed for assessment and monitoring of people with LC. OBJECTIVES: To evaluate the psychometric properties of the C19-YRSm in a prospective sample of people with LC. METHODS: 1314 patients attending 10 UK specialist LC clinics completed C19-YRSm and EuroQol 5D-5L (EQ-5D-5L) longitudinally. Scale characteristics were derived for C19-YRSm subscales (Symptom Severity (SS), Functional Disability (FD) and Overall Health (OH)) and internal consistency (Cronbach's alpha). Convergent validity was assessed using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue Scale. Known groups validity was assessed for the Other Symptoms subscale as tertiles, as well as by hospitalisation and intensive care admission. Responsiveness and test-retest reliability was evaluated for C19-YRSm subscales and EQ-5D-5L. The minimal important difference (MID) and minimal clinically important difference (MCID) were estimated. Confirmatory factor analysis was applied to determine the instrument's two-factor structure. RESULTS: C19-YRSm demonstrated good scale characteristic properties. Item-total correlations were between 0.37 and 0.65 (for SS and FD), with good internal reliability (Cronbach's alphas>0.8). Item correlations between subscales ranged between 0.46 and 0.72. Convergent validity with FACIT was good (-0.46 to -0.62). The three subscales discriminated between different levels of symptom burden (p<0.001) and between patients admitted to hospital and intensive care. There was moderate responsiveness for the three subscales ranging from 0.22 (OH) to 0.50 (SS) which was greater than for the EQ-5D-5L. Test-retest reliability was good for both SS 0.86 and FD 0.78. MID was 2 for SS, 2 for FD and 1 for OH; MCID was 4 for both the SS and FD. The factor analysis supported the two-factor SS and FD structure. CONCLUSIONS: The C19-YRSm is a condition-specific, reliable, valid and responsive patient-reported outcome measure for LC.

Development of a quality of life measure for left ventricular assist device recipients using a mixed methods approach.

BACKGROUND: Left ventricular assist device (LVAD) recipients report symptom improvement but find adjusting to life with the LVAD challenging. These challenges are unique, and existing patient-reported outcome measures (PROMs) do not reflect their experiences. This study aimed to develop a culturally relevant quality of life PROM for use with LVAD recipients in future research, design evolutions and clinical practice. METHODS: A three-stage mixed-methods approach was used to develop a PROM: stage 1 included group concept mapping (GCM); stage 2 semi-structured qualitative interviews were conducted with 11 LVAD recipients and 10 clinicians, and a questionnaire was developed using a conceptual framework; and stage 3 used exploratory psychometric analysis of the PROM data using Rasch measurement theory. This paper presents stages 2 and 3. RESULTS: The conceptual framework consisted of four key concepts, including general health, life with the LVAD, equipment and clothing and emotional impact. Statements from interviews and GCM were used to create items for the LVAD quality of life (LVAD-QoL). Cognitive interviews tested face validity and participant comprehension. Forty-nine participants were recruited from three UK transplant centres. PROM data were collected and analysed using Rasch analysis. Four items displayed misfit; dependency between item sets was the biggest issue (57/485 pairwise differences). After restructuring and dealing with item misfit, the LVAD-QoL conformed to the Rasch model, supporting the psychometric properties and quality of the LVAD-QoL. CONCLUSIONS: Using a mixed-methods approach ensured the development of a robust and psychometrically sound tool for research, design evolution and clinical practice with LVAD recipients.

Development of a self-report scale of spasticity.

BACKGROUND: Although the Modified Ashworth Scale is the most common instrument used to grade spasticity, it is unsuitable for busy follow-up clinics, longer term follow-up, or community surveys. OBJECTIVES: To establish a simple questionnaire that would indicate the presence and extent of spasticity and would be suitable for use in everyday outpatient clinical practice and/or community follow-up. METHODS: Qualitative exploration of the experience and impact of spasticity among stroke patients led to the development of a short questionnaire. Rasch analysis was performed on the data and the scale items were externally validated by correlation with comparator measures. RESULTS: Forty-eight subjects were recruited for the qualitative interviews, half of whom were more than 2 years post stroke. Interviews generated items relating to spasticity that were categorized into pain, spasm, fatigue, restricted movement, loss of balance, and altered appearance. Eight items were chosen for the draft questionnaire. Five hundred questionnaires were sent, and 188 (38%) were returned. The mean age of the 188 responders was 72.6 years. In regard to health, 18.5% reported that they were in good or excellent health, and 49.7% reported only fair or poor health. Data from the 8-item scale were fitted to the Rasch measurement model. Initial fit of the 8 items was good, and all the assumptions of the model were satisfied. A strong and significant gradient was found between the summed 8-item scale and self-reported health. CONCLUSIONS: A short self-perceived scale for spasticity has been developed from grounded theory, which satisfies the most rigorous standards for measurement with fit to the Rasch model.

Development and Validation of Physical Activity-Specific Rumination Scale for Children Through UK Children's Voice.

Many physical activity (PA) interventions implemented to tackle the child obesity epidemic have shown limited effectiveness, possibly due to a lack of consideration of potential stress that accompanies behavior adaptation and the automatic perseverative cognition that exacerbates the stress (namely rumination). Purpose: The main aim of this paper is to develop and validate the PA-specific Rumination Scale for Children (PARSC) that assesses children's tendencies to engage in repeated negative thoughts about PA (Study 2). Items in the scale were derived from qualitative information about factors that inherently demotivates PA participation (intrinsic barriers) through the lived experience of UK children (Study 1). Methods: For Study 1, pedometry PA data were collected from 143 children (aged 6-10 years). Twenty-one focus groups were formed based on participants' year group, sex and PA level. For PARSC validation (Study 2), 382 children completed the questionnaire twice. Self-report PA, device-based PA, and avoidant coping were also assessed. Results: Study 1-Four overarching themes identified as intrinsic barriers were lack of competence, fear of negative experiences, external constraints and lacking a sense of purpose. Altogether, 10 higher order and lower order themes were used to construct PARSC items. Study 2-From Rasch analysis, PARSC possessed sound internal validity, internal consistency, and test-retest reliability. Self-report PA and avoidant coping were predictive of PA-specific rumination, but not device-based PA. Conclusion: PARSC is a useful tool to identify children ruminative about PA for whom interventions can be designed, with the intrinsic barriers considered, to promote PA behavior adaptation.

Psychometric Validity of the Visual Function Index in Leber Hereditary Optic Neuropathy.

Purpose: The purpose of this study was to determine the psychometric validity of the Visual Function Index (VF-14) for use by patients with Leber hereditary optic neuropathy (LHON). Methods: Rasch analysis was conducted in two stages using data for 196 individuals (74.5% male) carrying one of the three primary LHON mutations and affected by vision loss. In stage 1, scale unidimensionality, scale-to-sample targeting, response category threshold ordering, item fit statistics, local dependency, and reliability were assessed. In stage 2, iterative post-hoc revisions of the VF-14 structure (VF-14R) were applied and psychometrically re-evaluated. Results: Issues identified with the VF-14 included disordered response thresholds (12/14 items), local dependency (10/91 pairwise dependencies), and evidence of multidimensionality. However, the distribution of person estimates and item thresholds were fairly well matched, only one item showed misfit to the Rasch model, and there was good reliability (Person Separation Index 0.84). Rasch-informed VF-14 revisions included removing both driving items and the misfitting sports item, rescoring response options across all items by merging two response categories, and accounting for the dependency between two reading items. The VF-14R demonstrated improved psychometric validity. Conclusions: Clinicians and researchers using the VF-14 with LHON patients should be aware of its limitations. Compared to the original version, the proposed Rasch-based structure of the VF-14R appears to offer improved psychometric performance and interpretation of vision-related activity limitation. Translational Relevance: The original version of the VF-14 exhibits several limitations that undermines its psychometric validity as a patient-reported outcome measure for patients with LHON.

Screening for the risk of job loss in multiple sclerosis (MS): development of an MS-specific Work Instability Scale (MS-WIS).

BACKGROUND: Multiple sclerosis (MS) mainly presents amongst those of working age. Depending upon the type of MS, many people embark upon a long period of managing their day-to-day work-related needs in the face of intermittent and sometimes persistent disabling symptoms. The objective of this study was to explore the concept of work instability (WI) following the onset of MS and develop a Work Instability Scale (WIS) specific to this population. METHOD: WI amongst those with MS in work was explored through qualitative interviews which were then used to generate items for a WIS. Rasch analysis was used to refine the scaling properties of the MS-WIS, which was then validated against expert vocational assessment by occupational health physiotherapists and ergonomists. RESULTS: The resulting measure is a 22-item, self-administered scale which can be scored in three bands indicating low, medium and high risk of WI (job retention) problems. The scale meets modern psychometric requirements for measurement, indicated by adequate fit to the Rasch model with absence of local dependency and differential item functioning (DIF) by age, gender and hours worked. CONCLUSIONS: The scale presents an opportunity in routine clinical practice to take positive action to reduce sickness absence and prevent job loss.

A critique of Rasch analysis using the Dyspnoea-12 as an illustrative example.

AIM: This paper is a report of a study of the application and critique of Rasch analysis to the development of the Dyspnoea-12 questionnaire; an instrument that measures breathlessness severity. BACKGROUND: The development of questionnaires has traditionally involved application of classical test theory. Rasch analysis has gained international momentum as a robust application of 'modern' psychometric testing for the development of new instruments and the refinement of existing ones. METHOD: A total of 358 patients [mean age 62 (sd = 8); chronic obstructive pulmonary disease = 123, interstitial lung disease = 129, heart failure = 106], responded to an initial list of 81 items (between May 2006 and February 2008). Hierarchical modelling reduced the list to 34 items. Rasch analysis was used to inform decisions about further item removal and fit to the unidimensional model. Rasch analysis included tests of item response appropriateness, item residual, differential item functioning (including gender and diagnosis) and unidimensionality. RESULTS: Twenty-two items failed to reach the requirements of the Rasch model and were removed. Reasons included high residuals and item bias associated with gender and diagnosis. The 12-items conformed to the Rasch unidimensional parameters (number of statistically significant t-tests 6·7%; confidence interval: 4·4-9·0%). CONCLUSION: We have presented the steps involved in reducing and refining a large item-set by identifying those items which possessed the most reliable measurement properties. The Dyspnoea-12 is reliable and simple to use and should find utility in both practice and research settings. We recommend that nurses consider Rasch analysis in the development of health-related questionnaires.