Validation of a patient-reported outcome measure for giant cell arteritis.

OBJECTIVES: GCA is systemic vasculitis manifesting as cranial, ocular or large vessel vasculitis. A prior qualitative study developed 40 candidate items to assess the impact of GCA on health-related quality of life (HRQoL). This study aimed to determine final scale structure and measurement properties of the GCA patient reported outcome (GCA-PRO) measure. METHODS: Cross-sectional study included UK patients with clinician-confirmed GCA. They completed 40 candidate items for the GCA-PRO at times 1 and 2 (3 days apart), EQ-5D-5L, ICECAP-A, CAT-PROM5 and self-report of disease activity. Rasch and exploratory factor analyses informed item reduction and established structural validity, reliability and unidimensionality of the final GCA-PRO. Evidence of validity was also established with hypothesis testing (GCA-PRO vs other PRO scores, and between participants with 'active disease' vs those 'in remission') and test-retest reliability. RESULTS: The study population consisted of 428 patients: mean (s.d.) age 74.2 (7.2), 285 (67%) female; 327 (76%) cranial GCA, 114 (26.6%) large vessel vasculitis and 142 (33.2%) ocular involvement. Rasch analysis eliminated 10 candidate GCA items and informed restructuring of response categories into four-point Likert scales. Factor analysis confirmed four domains: acute symptoms (eight items), activities of daily living (seven items), psychological (seven items) and participation (eight items). The overall scale had adequate Rasch model fit (χ2 = 25.219, degrees of freedom = 24, P = 0.394). Convergent validity with EQ5D-5L, ICECAP-A and Cat-PROM5 was confirmed through hypothesis testing. Internal consistency and test-retest reliability were excellent. CONCLUSION: The final GCA-PRO is a 30-item, four-domain scale with robust evidence of validity and reliability in measuring HRQoL in people with GCA.

Development and validation of a patient reported experience measure for experimental cancer medicines (PREM-ECM) and their carers (PREM-ECM-Carer).

BACKGROUND: Our aim was to develop a validated Patient Reported Experience Measure (PREM) to capture patient and carer experience during participation in experimental cancer medicine trials (ECM): called PREM-ECM. METHODS: Mixed method design, consisting of four stages. Questionnaire items were produced for both patients and carers using interviews, focus groups, and cognitive interviews with patients and carers separately. For both patient and carer PREMs, a cross-sectional questionnaire study was conducted to identify final items for inclusion using hierarchical item reduction and Rasch analysis. Questionnaire validity and reliability were assessed, including administration feasibility. RESULTS: Initial interview participants suggested the need for three PREMs, two specific to patients: (i) a 'prior' questionnaire that captured experiences of trial introduction, screening, consenting, and early trial experience (< 6 weeks post consent); and (ii) 'on-trial' that captured experiences of ongoing consent and trial participation; and (iii) a PREM specific for carers. The draft 25-item 'prior' questionnaire was completed by 162 patients and 162 patients completed the draft 35-item 'on-trial' questionnaire. Hierarchical and Rasch analysis produced a 14-item 'prior' list and a 15-item list for 'on-trial'. Both patient PREM's demonstrated a good fit to the Rasch model following Bonferroni correction (X2p = 0.008). The carer 34-draft item questionnaire was completed by 102 participants. Hierarchical and Rasch analysis produced a 13-item list for PREM-ECM-Carer, with good fit to the Rasch model ( X2p = 0.62). The pilot testing demonstrated the feasibility of all the PREMs in capturing patient and caregiver experiences in routine clinical settings. CONCLUSIONS: The three PREM-ECM questionnaires will be the first validated experience measures for ECM trial patients and their carers. These questionnaires may be used to assess patients' and their carers' experiences of ECM and enable robust comparisons across cancer trial units highlighting areas for service improvement.

Rasch analysis of the modified Fatigue Severity Scale in neuromuscular disorders and comparison between sex, age and diagnoses.

INTRODUCTION/AIMS: Fatigue is a common and debilitating symptom encountered in the neuromuscular clinic. The 7-item Fatigue Severity Scale (FSS-7) is a Rasch-modified assessment validated in inflammatory neuropathies but not across a typical neuromuscular patient population. The aim of this study was to validate this measure in neuromuscular disorders and to compare between patient sex, age and diagnoses. METHODS: The modified FSS-7 was mailed to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis and descriptive statistics were performed on the Rasch converted data. RESULTS: The mFSS-7 met the Rasch model expectations with an overall Chi-square probability of 0.4918, a strict unidimensional scale free from differential item functioning (DIF) that satisfied the model with substantial test-retest reliability using Lin's concordance correlation coefficient 0.71 (95% CI 0.63-0.77). A 15.7% ceiling effect was observed in this patient cohort. Post hoc analysis did not show any significant difference in fatigue between sex, age or neuromuscular diagnoses. DISCUSSION: The self-completed Rasch mFSS-7 showed acceptable test-retest reliability across patients with varied disorders under follow-up in a specialist neuromuscular clinic. The ceiling effect constrains its use for those with the most severe fatigue. Future considerations could include assessment of the benefits of clinical interventions, particularly multidisciplinary team input or dedicated fatigue clinics.

Rasch analysis of the Unidimensional Self-Efficacy Scale in Neuromuscular Disorders and comparison between sex, age, and diagnoses.

INTRODUCTION/AIMS: Self-efficacy reflects a person's perceptions of their capabilities for specific tasks and influences motivation and performance. The Unidimensional Self-Efficacy in Neuromuscular Disorders (USE-NM) was modified from the Multiple Sclerosis (MS) USE-MS scale and administered to patients attending a specialist neuromuscular clinic. The aim was to investigate this measure in neuromuscular disorders and to compare between patient sex, age, and diagnosis. METHODS: The USE-NM was posted to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis using RUMM2030 software and descriptive statistics were performed using SPSS version 28. RESULTS: One hundred and ninety-eight patients (56.1% male) grouped by age (<50; 50-59; 60-69; and >69 years) and with varied NM disorders returned the USE-NM. It did not meet the Rasch model expectations due to disordered thresholds of items 6 and 8 ("Sometimes I feel inadequate as a person because of my neuromuscular disorder" and "I feel that my social life would be better if I did not have a neuromuscular disorder"). Following item re-scoring, the modified USE-NM satisfied the Rasch model with a unidimensional scale free from differential item functioning and an overall chi-square probability of 0.146 with good reliability and validity. Post hoc nonparametric testing showed no significant difference in fatigue between sex, age, and neuromuscular diagnoses. DISCUSSION: The Rasch-modified USE-NM offers a measure of self-efficacy for neuromuscular disorders encountered in a typical specialist clinic. Future considerations could be given to assessing any benefits of multidisciplinary team input, across a specialist neuromuscular service.

Improving outcome measures in late onset Pompe disease: Modified Rasch-Built Pompe-Specific Activity scale.

BACKGROUND AND PURPOSE: The Rasch-Built Pompe-Specific Activity (R-PAct) scale is a patient-reported outcome measure specifically designed to quantify the effects of Pompe disease on daily life activities, developed for use in Dutch- and English-speaking countries. This study aimed to validate the R-PAct for use in other countries. METHODS: Four other language versions (German, French, Italian, and Spanish) of the R-PAct were created and distributed among Pompe patients (≥16 years old) in Germany, France, Spain, Italy, and Switzerland and pooled with data of newly diagnosed patients from Australia, Belgium, Canada, the Netherlands, New Zealand, the USA, and the UK and the original validation cohort (n = 186). The psychometric properties of the scale were assessed by exploratory factor analysis and Rasch analysis. RESULTS: Data for 520 patients were eligible for analysis. Exploratory factor analysis suggested that the items separated into two domains: Activities of Daily Living and Mobility. Both domains independently displayed adequate Rasch model measurement properties, following the removal of one item ("Are you able to practice a sport?") from the Mobility domain, and can be added together to form a "higher order" factor as well. Differential item functioning (DIF)-by-language assessment indicated DIF for several items; however, the impact of accounting for DIF was negligible. We recalibrated the nomogram (raw score interval-level transformation) for the updated 17-item R-PAct scale. The minimal detectable change value was 13.85 for the overall R-PAct. CONCLUSIONS: After removing one item, the modified-R-PAct scale is a valid disease-specific patient-reported outcome measure for patients with Pompe disease across multiple countries.

Selecting PedsQL items to derive the PedsUtil health state classification system to measure health utilities in children.

BACKGROUND: There is a lack of preference-based health-related quality of life (HRQoL) measures that consistently value health across a full range of child age groups. The PedsQL is a generic HRQoL instrument validated for children 2-18 years, but it is not preference-based. The objective of this study was to derive the PedsUtil health state classification system from the PedsQL as a basis for a preference-based HRQoL measure for children. METHODS: A two-step process was used to select PedsQL items to include in the health state classification system: 1) exclude poorly functioning items according to Rasch analysis in each of the previously established seven dimensions of the PedsUtil health state classification system and 2) select a single item to represent each dimension based on Rasch and psychometric analyses, as well as input from child health experts and parents. All secondary analyses were conducted using data from the Longitudinal Study of Australian Children (LSAC). Analyses were stratified by age group (i.e., 2-5 years, 6-13 years, and 14-17 years) to represent the different developmental stages of children and to reflect the study design of the LSAC. Rasch analyses were also performed on five random subsamples for each age group to enhance robustness of results. RESULTS: Twelve items were excluded from the PedsUtil health state classification system after the first step of the item selection process. An additional four items were excluded in the second step, resulting in seven items that were selected to represent the seven dimensions of the PedsUtil health state classification system: Physical Functioning ("participating in sports activity or exercise"), Pain ("having hurts or aches"), Fatigue ("low energy level"), Emotional Functioning ("worrying about what will happen to them"), Social Functioning ("other kids not wanting to be their friend"), School Functioning ("keeping up with schoolwork"), and School Absence ("missing school because of not feeling well"). CONCLUSIONS: The PedsUtil health state classification system was derived from the PedsQL based on several criteria and was constructed to be applicable to children two years and older. Research is ongoing to elicit preferences for the PedsUtil health state classification system to construct the PedsUtil scoring system.

A scoping review to create a framework for the steps in developing condition-specific preference-based instruments de novo or from an existing non-preference-based instrument: use of item response theory or Rasch analysis.

BACKGROUND: There is no widely accepted framework to guide the development of condition-specific preference-based instruments (CSPBIs) that includes both de novo and from existing non-preference-based instruments. The purpose of this study was to address this gap by reviewing the published literature on CSPBIs, with particular attention to the application of item response theory (IRT) and Rasch analysis in their development. METHODS: A scoping review of the literature covering the concepts of all phases of CSPBI development and evaluation was performed from MEDLINE, Embase, PsychInfo, CINAHL, and the Cochrane Library, from inception to December 30, 2022. RESULTS: The titles and abstracts of 1,967 unique references were reviewed. After retrieving and reviewing 154 full-text articles, data were extracted from 109 articles, representing 41 CSPBIs covering 21 diseases or conditions. The development of CSPBIs was conceptualized as a 15-step framework, covering four phases: 1) develop initial questionnaire items (when no suitable non-preference-based instrument exists), 2) establish the dimensional structure, 3) reduce items per dimension, 4) value and model health state utilities. Thirty-nine instruments used a type of Rasch model and two instruments used IRT models in phase 3. CONCLUSION: We present an expanded framework that outlines the development of CSPBIs, both from existing non-preference-based instruments and de novo when no suitable non-preference-based instrument exists, using IRT and Rasch analysis. For items that fit the Rasch model, developers selected one item per dimension and explored item response level reduction. This framework will guide researchers who are developing or assessing CSPBIs.

Psychometric evaluation of the WHOQOL-BREF and its shorter versions for general Thai population: confirmatory factor analysis and Rasch analysis.

PURPOSE: Rasch analysis was employed to validate the World Health Organization Quality of Life-BREF (WHOQOL-BREF) and its existing shorter versions in the general Thai population. METHODS: 1200 respondents were randomly selected to complete the questionnaire. Confirmatory factor analysis (CFA) was employed to test the structure of the WHOQOL-BREF and its shorter versions with the random sub-sample of 900 respondents, while Rasch analysis was performed with a random sub-sample of 300 respondents. RESULTS: The CFA confirmed the factor structure of WHOQOL-BREF and its shorter versions. The Rasch analysis revealed that the WHOQOL-BREF, when a four-domain structure was tested using a subtest approach, achieved acceptable model fit to the Rasch model and met the expectations of unidimensionality with high reliability (PSI = 0.87). Individual domain models were also unidimensional, but reliability of the 3-item social domain was inadequate. While the 8-item EUROHIS-QOL-8 and 5-item WHOQOL-5 achieved an overall acceptable fit and met the expectations of unidimensionality, the reliability of the WHOQOL-5 was below the acceptable threshold (PSI = 0.66). Reliability of the EUROHIS-QOL-8 was satisfactory (PSI = 0.79). CONCLUSIONS: The WHOQOL-BREF is a valid instrument for use in the Thai general population, both as a total score as well as individual subscales. Rasch analysis also supports the use of EUROHIS-QOL-8, but the WHOQOL-5 lacks good reliability. While the reliability of the EUROHIS-QOL-8 is sufficiently high for between-group analysis, the Thai WHOQOL-BREF total score can also be used for within-participant analyses. Rasch investigation with a more varied health conditions of general Thai samples or patient groups is encouraged for future studies.

Correlates and trajectories of relapses in relapsing-remitting multiple sclerosis.

BACKGROUND AND AIMS: In people with relapsing-remitting multiple sclerosis (pwRRMS), data from studies on non-pharmacological factors which may influence relapse risk, other than age, are inconsistent. There is a reduced risk of relapses with increasing age, but little is known about other trajectories in real-world MS care. METHODS: We studied longitudinal questionnaire data from 3885 pwRRMS, covering smoking, comorbidities, disease-modifying therapy (DMT), and patient-reported outcome measures, as well as relapses during the past year. We undertook Rasch analysis, group-based trajectory modelling, and multilevel negative binomial regression. RESULTS: The regression cohort of 6285 data sets from pwRRMS over time showed that being a current smoker was associated with 43.9% greater relapse risk; having 3 or more comorbidities increased risk and increasing age reduced risk. Those diagnosed within the last 2 years showed two distinct trajectories, both reducing in relapse frequency but 25.8% started with a higher rate and took 4 years to reduce to the rate of the second group. In the cohort with at least three data points completed, there were three groups: 73.7% followed a low stable relapse rate, 21.6% started from a higher rate and decreased, and 4.7% had an increasing then decreasing pattern. These different trajectory groups showed significant differences in fatigue, neuropathic pain, disability, health status, quality of life, self-efficacy, and DMT use. CONCLUSIONS: These results provide additional evidence for supporting pwRRMS to stop smoking and underline the importance of timely DMT decisions and treatment initiation soon after diagnosis with RRMS.

Measurement of visual functioning following first and second eye cataract surgery using Vision-Related Activity Limitation Item Bank.

PURPOSE: This study aims to compare visual functioning (VF) after first or second eye cataract surgery using the vision-related activity limitation (VRAL) item bank. METHODS: This prospective, interventional study included 787 patients (mean age, 58.2 years) with cataract undergoing cataract surgery (first eye surgery with/out ocular comorbidity, second eye surgery with/out ocular comorbidity) at a tertiary eye care center, South India, who were administered the item bank pre- and at 6 weeks postoperatively to assess change in VF. Rasch analysis was used to estimate VF at both time points, and responsiveness to cataract surgery was calculated as effect size (ES) which was interpreted as small (≤ 0.2), moderate (0.3-0.7), and large (≥ 0.8). RESULTS: Mean best-corrected logMAR VA in surgical eye improved significantly postoperatively compared to preoperative VA (0.20 ± 0.40 vs. 1.19 ± 0.96; P < 0.0001) across all groups. Patients reported significant and large improvements in VF postoperatively across all groups: largest ES for first eye surgery without comorbidity (1.87 [95% CI, 1.61, 2.13]) and smallest for second eye without ocular comorbidity (1.55 [95% CI, 1.22, 1.88]). Compared to patients undergoing second eye surgery, first eye surgery patients reported significantly lower VF preoperatively (-0.72 ± 2.39 vs. 0.17 ± 2.34 logits; P < 0.0001), and a larger change in VF postoperatively (3.71 ± 2.33 logits vs. 4.27 ± 2.83 vs.; P = 0.004). CONCLUSIONS: Cataract surgery resulted in large and significant improvements in VF, regardless of ocular comorbidity and first or second eye surgery. The VRAL item bank is a useful tool to measure responsiveness to cataract surgery.

Development and psychometric evaluation of the adjuvant endocrine therapy beliefs scale for breast cancer survivors.

PURPOSE: Adjuvant endocrine therapy has a vital role in reducing breast cancer mortality. The beliefs in adjuvant endocrine therapy is a very important factor in the medication adherence of breast cancer survivors. Therefore, it is necessary to develop a standardized scale for assessment of adjuvant endocrine therapy. The purpose of this study was to identify the attributes of adjuvant endocrine therapy beliefs, and to evaluate adjuvant endocrine therapy beliefs scale psychometric properties. METHODS: A hybrid model was applied to identify the concept of adjuvant endocrine therapy beliefs and measurement question were developed by the scale development process. Statistical analysis using validity analysis and Rasch analysis based on item response theory were performed. A total of 228 breast cancer survivors in South Korea participated in the study. RESULTS: The finally developed adjuvant endocrine therapy beliefs scale consisted of 22 items. The items extracted by 4 factors explained 59.72% of the total variance. The model fit showed an acceptable level. The adjuvant endocrine therapy beliefs scale was excellent in convergent and discriminant validity with reliability. CONCLUSION: This scale is expected to be practical and useful in identifying adjuvant endocrine therapy beliefs and developing intervention strategies to promote adjuvant endocrine therapy adherence. In addition, continuous education and support should be accompanied so that breast cancer survivors can maintain positive beliefs in adjuvant endocrine therapy adherence.

Exploring the use of Rasch modelling in "common content" items for multi-site and multi-year assessment.

Rasch modelling is a powerful tool for evaluating item performance, measuring drift in difficulty over time, and comparing students who sat assessments at different times or at different sites. Here, we use data from thirty UK medical schools to describe the benefits of Rasch modelling in quality assurance and the barriers to using it. Sixty "common content" multiple choice items were offered to all UK medical schools in 2016-17, and a further sixty in 2017-18, with five available in both years. Thirty medical schools participated, for sixty total datasets across two sessions, and 14,342 individual sittings. Schools selected items to embed in written assessment near the end of their programmes. We applied Rasch modelling to evaluate unidimensionality, model fit statistics and item quality, horizontal equating to compare performance across schools, and vertical equating to compare item performance across time. Of the sixty sittings, three provided non-unidimensional data, and eight violated goodness of fit measures. Item-level statistics identified potential improvements in item construction and provided quality assurance. Horizontal equating demonstrated large differences in scores across schools, while vertical equating showed item characteristics were stable across sessions. Rasch modelling provides significant advantages in model- and item- level reporting compared to classical approaches. However, the complexity of the analysis and the smaller number of educators familiar with Rasch must be addressed locally for a programme to benefit. Furthermore, due to the comparative novelty of Rasch modelling, there is greater ambiguity on how to proceed when a Rasch model identifies misfitting or problematic data.

Construction of a quality of life scale for older individuals with neuro-co-cardiological diseases.

PURPOSE: This study aimed to develop a Quality of Life (QOL) assessment scale for older patients with Neuro-co-Cardiological Diseases (NCCD) and to evaluate the reliability and validity of the scale. METHOD: The study participants were derived from the Elderly Individuals with NCCD Registered Cohort Study (EINCCDRCS), a multicenter registry of patients with NCCD. The preliminary testing of the questionnaire was conducted among 10 older individuals aged 65 years and older who had NCCD and were recruited from the registry. Other patients who met the inclusion criteria participated in the field testing. After verifying the unidimensionality, local independence, and monotonicity assumptions of the scale, we employed the Rasch model within Item Response Theory framework to assess the quality of the scale through methods including internal consistency, criterion validity, Wright map, and item functioning differential. Subsequently, we assessed the construct validity of the scale by combining exploratory factor analysis with confirmatory factor analysis. RESULTS: Based on well-validated scales such as the short-form WHOQOL-OLD, HeartQOL, IQCODE, and SF-36, an original Neuro-co-Cardiological Diseases Quality of Life scale (NCCDQOL) was developed. 196 individuals from the EINCCDRCS were included in the study, with 10 participating in the preliminary testing and 186 in the field testing. Based on the results of the preliminary testing, the original questionnaire was refined through item deletion and adjustment, resulting in an 11-item NCCDQOL questionnaire. The Rasch analysis of the field testing data led to the removal of 21 misfitting individuals. The NCCDQOL demonstrated a four-category structure, achieved by combining two response categories. This structure aligned with the assumptions of unidimensionality, local independence, and monotonicity. The NCCDQOL also exhibited good validity and reliability. CONCLUSION: The revised NCCDQOL questionnaire demonstrated good reliability and validity in the Rasch model, indicating promising potential for clinical application.

Chinese version of the Physical Resilience Scale (PRS): reliability and validity test based on Rasch analysis.

BACKGROUND: Physical resilience is known to minimize the adverse outcomes of health stressors for older people. However, validated instruments that assess physical resilience in older adults are rare. Therefore, the purpose of this study was to translate the Physical Resilience Scale (PRS) into Chinese and to validate its psychometric properties in a population of community-dwelling older adults following SARS-CoV-2 infection. METHODS: This study used a cross-sectional design and translated the Physical Resilience Scale into Chinese. A total of 426 older adults who had recovered from SARS-CoV-2 infection were chosen for assessment through convenience sampling. The measurement data were analyzed using the Rasch analysis. RESULTS: Rasch analysis indicates that the Physical Resilience Scale demonstrates excellent reliability, validity, and unidimensionality. The Infit MNSQ and Outfit MNSQ of each entry were 0.77 ~ 1.19, and the degree of fit of each entry to the scale was good. Person and item separation reliability support the internal consistency of the studied samples and PRS items. CONCLUSIONS: The Physical Resilience Scale has good reliability and is suitable for the assessment of physical resilience tests in older people. However, the overall difficulty of the scale is not suitable for older adults of all ability ranges, and it is possible to add higher and lower difficulty items and adjust the difficulty spacing between items in a later study.

Cross-cultural adaptation and validation of the caregiver self-efficacy in contributing to patient self-care scale in China.

BACKGROUND: Caregiver self-efficacy is crucial in improving patient outcomes and caregiver well-being, but there is a lack of suitable scales to assess this concept within the context of Chinese culture. This study aimed to cross-culturally translate the Caregiver Self-Efficacy in Contributing to Patient Self-Care (CSE-CSC) Scale and evaluate its psychometric properties using classical test theory and item response theory. METHODS: The CSE-CSC scale was adapted using Brislin's translation model after obtaining authorization from the original author. A multicenter, cross-sectional study was conducted to assess the psychometric properties of this scale. Classical test theory was used to evaluate reliability (internal consistency, test-retest reliability), validity (content validity, structural validity, convergent validity), and floor and ceiling effects. Item response theory was employed to assess the fit of the rating scale model, reliability, item difficulties, and measurement invariance. RESULTS: The translation and cultural adaptation process was completed. Classical test theory demonstrated good internal consistency (Cronbach's α = 0.935) and test-retest reliability (ICC from 0.784 to 0.829, p<0.001). The I-CVI and K* of each item ranged from 0.875 to 1.00 and 0.871 to 1.00. The first-order 2-factor model fit well (χ2/df = 3.71, RMSEA = 0.082, SRMR = 0.032, CFI = 0.973, TLI = 0.60). Convergent validity showed that the CSE-CSC scores had a strong positive correlation with three separate scales of the CC-SC-CII. There was no floor and ceiling effect in this scale. Rasch analysis showed that the CSE-CSC scale demonstrated a good fit to the rating scale model and exhibited excellent reliability (person/item separation index>2, person/item reliability coefficients>0.8). The Wright map showed that item difficulty matched the respondents' measured abilities. The analysis of differential item functioning (DIF) showed that all items were comparable in gender. CONCLUSIONS: This study indicated that the CSE-CSC scale had good reliability, validity, difficulty degree, and measurement invariance. The CSE-CSC scale can be used to measure caregiver self-efficacy of Chinese patients with multiple chronic conditions.

Associations between digital health literacy and health system navigating abilities among Norwegian adolescents: validating the HLS19-DIGI scale using Rasch modeling.

BACKGROUND: Despite increasing global attention to health literacy and adolescents' digital health information seeking, no unidimensional instruments measuring digital health literacy (DHL) in adolescents have reportedly been validated using Rasch modeling. Moreover, the evidence of adolescents' abilities to navigate the health system (NAV-HL) in light of their DHL proficiency is still scarce. Therefore, our study aims to evaluate the psychometric properties of a DHL instrument (HLS19-DIGI scale) in order to investigate DHL in adolescents and young adults aged 16-25 and associations with abilities to navigate the health system. METHODS: A population-based cross-sectional survey among 890 Norwegian adolescents was conducted during April-October 2020 using computer-assisted telephone interviewing. Rasch modeling, independent samples t-test, chi-square test, and binary regression models were used to analyze the data. RESULTS: The HLS19-DIGI scale was sufficiently unidimensional, whereas no differential item functioning or disordered response categories were observed. However, relatively poor targeting was revealed indicating too many easy items for the target population. Yet, a high proportion (54%) of low DHL proficiency in adolescents was observed, as well as DHL was positively associated with the abilities to navigate the health system. CONCLUSIONS: The HLS19-DIGI scale is considered a sufficiently unidimensional and valid instrument for measuring DHL in adolescents, which may be a useful tool for health authorities, public health workers, and health service providers. While DHL affects adolescents' abilities to navigate the health system, future research should measure and examine their ability to utilize digital health services, separately.

Rasch Analysis of the Chinese Version of the Nociception Coma Scale-Revised in Patients with Prolonged Disorders of Consciousness.

OBJECTIVES: The aim of this study was to analyze the Chinese version of the Nociception Coma Scale-Revised in patients with prolonged disorders of consciousness within the framework of Rasch modeling, including investigating the invariance of total scores across different etiologies of disorders of consciousness. DESIGN: Prospective psychometric study. PARTICIPANTS: Patients with prolonged disorders of consciousness from the Rehabilitation and Neurology units in hospital. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The Nociception Coma Scale-Revised was undertaken by trained raters and the Coma Recovery Scale-Revised was used to assess patients' consciousness. The psychometric properties within the Rasch model including item-person targeting, reliability and separation, item fit, unidimensionality, and differential item functioning were assessed. RESULTS: 84 patients with prolonged disorders of consciousness (mean age 53 years; mean injury 5 months; 42 with Minimally Conscious State and 42 with Unresponsive Wakefulness Syndrome) of 252 observations were enrolled in the study. Through the procedure of repeated assessment and differential item function, a lower item bias Rasch set was purified. The Rasch model assumptions were examined and met, with item reliability and validity meeting the recommended threshold. CONCLUSIONS: The Chinese version of the Nociception Coma Scale-Revised demonstrated unidimensionality, good reliability and separation, and good item fit, but dissatisfied person fit and item-person targeting. The verbal subscale showed a notable discrepancy between person responses and the difficulty of the items, suggesting limited clinical significance.

The Fremantle Back Awareness Questionnaire: cross-cultural adaptation, reliability, and validity of the Italian version in people with chronic low back pain.

BACKGROUND AND AIM: There is evidence to suggest that assessing back-specific altered self-perception may be useful when seeking to understand and manage low back pain (LBP). The Fremantle Back Awareness Questionnaire (FreBAQ) is a patient-reported measure of back-specific body perception that has never been adapted and psychometrically analysed in Italian. Hence, the objectives of this research were to cross-culturally adapt and validate the Italian version of this outcome measure (namely, the FreBAQ-I), to make it available for use with Italians suffering from chronic LBP. METHODS: The FreBAQ-I was developed by forward and backward translation, review by a committee skilled in patient-reported measures and test of the pre-final version to assess its clarity, acceptability, and relevance. The statistical analyses examined: structural validity based on Rasch analysis; hypotheses testing by investigating correlations of the FreBAQ-I with the Roland Morris Disability Questionnaire (RMDQ), a pain intensity numerical rating scale (PI-NRS), the Pain Catastrophising Scale (PCS), and the Tampa Scale of Kinesiophobia (TSK) (Pearson's correlations); reliability by internal consistency (Cronbach's alpha) and test-retest repeatability (intraclass correlation coefficient, ICC (2,1)); and measurement error by determining the minimum detectable change (MDC). After the development of a consensus-based translation of the FreBAQ-I, the new outcome measure was delivered to 100 people with chronic LBP. RESULTS: Rasch analysis confirmed the substantial unidimensionality and the structural validity of the FreBAQ-I. Hypothesis testing was considered good as at least 75% of the hypotheses were confirmed; correlations: RMDQ (r = 0.35), PI-NRS (r = 0.25), PCS (r = 0.41) and TSK (r = 0.38). Internal consistency was acceptable (alpha = 0.82) and test-retest repeatability was excellent (ICC (2,1) = 0.88, 95% CI: 0.83, 0.92). The MDC95 corresponded to 6.7 scale points. CONCLUSION: The FreBAQ-I was found to be a unidimensional, valid, and reliable outcome measure in Italians with chronic LBP. Its application is advised for clinical and research use within the Italian speaking community.

The Participation Assessment with Recombined Tools-Objective (PART-O): measurement properties of the Norwegian version after traumatic brain injury.

OBJECTIVE: To translate and evaluate the validity of the Participation Assessment with Recombined Tools-Objective (PART-O) in a Norwegian context. METHODS: One hundred and twenty persons with TBI with verified intracranial lesions and persistent symptoms lasting more than 2 years, included in a randomized controlled trial, rated their participation using the PART-O at baseline. The PART-O with its three subscales (Productivity, Out and About, and Social Relations) was translated to Norwegian. Descriptive statistics, Cronbach's alpha, Rasch analysis, and correlation analysis were applied. RESULTS: The Rasch analysis indicated a unidimensional construct of PART-O and its subscales (χ2 < 12.69, p > 0.28). The internal consistency was moderate (Cronbach's alpha 0.48-0.52) and there was a need to reduce scaling options for most of the items. The Out and About and Productivity subscales had considerable floor effects. PART-O showed moderate positive correlation to TBI-related quality of life and global functioning. CONCLUSIONS: PART-O and its subscales reflect unidimensional aspects of participation. In the present Norwegian TBI population the original scaling of PART-O was too detailed for all subscales. The floor effects and suboptimal targeting between items and subjects participation level of the Out and About subscale is a matter of concern.

Rasch analysis of the depression anxiety stress scales-21 (DASS-21) in a mild traumatic brain injury sample.

OBJECTIVE: In this study, we evaluated the psychometric properties of the Depression Anxiety Stress Scales 21 items (DASS-21) in a mild traumatic brain injury (mTBI) sample. METHOD: Treatment-seeking adults (n = 347) were recruited from outpatient rehabilitation services in New Zealand. Dimensionality, reliability, person separation index, and differential item functioning (DIF) of the DASS-21 were examined using Rasch analysis. RESULTS: Initial analysis of the complete 21-item DASS showed poor overall fit due to problems with individual items. Fit to the Rasch model was excellent when treated as three composite scores. The stress subscale demonstrated adequate model fit, dimensionality and good reliability. For anxiety, fit was not good, reliability was unsatisfactory and DIF was evident on one item. When this item was removed, fit to the model was still inadequate as was reliability. DIF was also evident for depression, but when this item was removed, fit to the model was adequate. CONCLUSION: The DASS-21 is a psychometrically sound measure of distress and stress for adults seeking treatment following mTBI. Ordinal to interval score conversion tables are provided to increase the precision of measurement. When assessing depression in a mTBI population, a 6-item depression subscale is recommended. Caution is advised in using the DASS-21 anxiety subscale alone.