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.

Measuring disability in multiple sclerosis: the WHODAS 2.0.

INTRODUCTION: Reliable measurement of disability in multiple sclerosis (MS) using a comprehensive, patient self-reported scale, such as the World Health Organization Disability Assessment Schedule (WHODAS) 2.0, would be of clinical and research benefit. METHODS: In the Trajectories of Outcome in Neurological Conditions-MS study, WHODAS 2.0 (WHODAS-36 items for working, WHODAS-32 items if not working, WHODAS-12 items short-form) was examined using Rasch analysis in 5809 people with MS. RESULTS: The 36- and 32-item parallel forms, and the cognitive and physical domains, showed reliability consistent with individual or group use. The 12-item short-form is valid for group use only. Interval level measurement for parametric statistics can be derived from all three scales which showed medium to strong effect sizes for discrimination across characteristics such as age, subtype, and disease duration. Smallest detectable difference for each scale was < 6 on the standardised metric of 0-100 so < 6% of the total range. There was no substantial differential item functioning (DIF) by age, gender, education, working full/part-time, or disease duration; the finding of no DIF for time or sample supports the use of WHODAS 2.0 for longitudinal studies, with the 36- and 32-item versions and the physical and cognitive domains valid for individual patient follow-up. CONCLUSIONS: Disability in MS can be comprehensively measured at interval level by the WHODAS 2.0, and validly monitored over time. Routine use of this self-reported measure in clinical and research practice would give valuable information on the trajectories of disability of individuals and groups.

Measuring coping in multiple sclerosis: The Coping Index-MS.

BACKGROUND: Coping in multiple sclerosis (MS) refers to cognitive and behavioural efforts to manage stresses imposed by the illness. Existing generic and disease-specific coping scales do not meet modern guidelines for scale development and cannot produce interval-level metrics to allow for change scores. OBJECTIVE: The main aim of this study was to develop a brief patient-reported outcome measure for coping in MS, capable of interval-level measurement. METHODS: Qualitative work in 43 people with MS leads to a draft scale which was administered to 5747 participants, with longitudinal collection in 2290. A calibration sample of 1000 subjects split into development and validation sets was used to generate three scales consistent with Rasch model expectations. RESULTS: The total Coping Index-MS (CI-MS-T), CI-MS-Internal (CI-MS-I) and CI-MS-External (CI-MS-E) cover total, internal and externally focused coping. All three scales are capable of interval-level measurement. Trajectory analysis of 9000 questionnaires showed two trajectories in CI-MS-T: Group 1 showed a low level of coping with slight decline over 40 months, while Group 2 had a better and stable level of coping due to improving CI-MS-I which compensated for the deteriorating CI-MS-E over time. CI-MS-T < 30 identified group membership at baseline. CONCLUSION: The CI-MS-T, CI-MS-I and CI-MS-E, comprising 20 items, provide interval-level measurement and are free-for-use in not-for-profit settings.

Cross-cultural adaptation and psychometric testing of the Dutch and German versions of the Evaluation of Daily Activity Questionnaire in people with rheumatoid arthritis.

The Evaluation of Daily Activity Questionnaire (EDAQ) is a detailed patient-reported outcome measure of activity ability. The objective of this research was to assess the linguistic and cross-cultural validity and psychometric properties of the EDAQ in rheumatoid arthritis for Dutch and German speakers. The EDAQ was translated into Dutch and German using standard methods. A total of 415 participants (Dutch n = 252; German n = 163) completed two questionnaires about four weeks apart. The first included the EDAQ, Health Assessment Questionnaire (HAQ) and 36-item Short-Form v2 (SF-36v2) and the second, the EDAQ only. We examined construct validity using Rasch analysis for the two components (Self-Care and Mobility) of the Dutch and German EDAQ. Language invariance was also tested from the English version. We examined internal consistency, concurrent and discriminant validity and test-retest reliability in the 14 EDAQ domains. The Self-Care and Mobility components satisfied Rasch model requirements for fit, unidimensionality and invariance by language. Internal consistency for all 14 domains was mostly good to excellent (Cronbach's alpha ≥ 0.80). Concurrent validity was mostly strong: HAQ rs = 0.65-0.87; SF36v2 rs = - 0.61 to - 0.87. Test-retest reliability was excellent [ICC (2,1) = 0.77-0.97]. The EDAQ has good reliability and validity in both languages. The Dutch and German versions of the EDAQ can be used as a measure of daily activity in practice and research in the Netherlands and German- speaking countries.

Sexual Morbidity Assessment in Gyne-Oncology Follow-Up: Development of the Sexual Well-Being After Cervical or Endometrial Cancer (SWELL-CE) Patient-Reported Outcome Measure.

BACKGROUND: Clinical assessment and management of sexual difficulties after gynecological cancer remain a neglected aspect of women's rehabilitation. AIM: To develop and validate a patient-reported outcome measure of sexual well-being for women experiencing sexual consequences of cervical and endometrial cancer treatment for use in routine follow-up. METHODS: This is a sequential mixed method study comprising (i) in-depth qualitative interviews (n=21 of 118) to generate items regarding sexual consequences of cervical or endometrial cancer and treatment; (ii) questionnaire construction with 51 core items (all respondents) and 4 subsections (18-58 items), depending on the relationship status and whether or not participants were sexually active (SA/NSA); (iii) item refinement following cognitive debriefing (n=13 of 21); (iv) validation of resultant items via postal survey (n=788 women) and Rasch analysis; and (v) creation of brief (14-item) clinical screener. Women attending routine follow-up (3 months to 5 years) at 6 English cancer centers and members of 3 UK cancer patient websites, who met the study inclusion criteria, were invited to participate. OUTCOMES: The primary outcome of this study was the construction and initial psychometric testing of SWELL-CE short and long form versions. RESULTS: 21 women participated in interviews and 250 of 788 (32%) returned the postal survey (T1). 110 draft items were evaluated using cognitive testing (n=13) to refine instrument design and test face validity, comprehension, and acceptability. Exploratory factor analysis of survey data (n=250) produced an initial 6 domain structure as a guidance for the Rasch analysis. Subsequent Rasch analysis yielded a 3 domain structure: physical sexual function, sexual and relationship concerns, and sexual desire and sexual self-esteem, each satisfying Rasch model requirements within their respective SA (item pool =59) and NSA (item pool =53) categories, including the absence of local response dependency and all showing strict unidimensionality. The 3 subscales demonstrated good psychometric properties, external validity, and test-retest reliability. A valid Rasch short form of 14 items was created from the larger item pool. CLINICAL IMPLICATIONS: This PROM may assist clinicians to improve identification, discussion, and management of women who could benefit from sexual rehabilitation. STRENGTHS & LIMITATIONS: Initial evaluation supports psychometric validity and reliability in the assessment of physical sexual function, sexual interest and sexual self-esteem, and sexual and relationship concerns in this study sample. However, given this study's modest response rate (32%, n=250), findings should be interpreted with caution. This PROM identifies sexual concerns in women who are sexually active or sexually non-active due to illness or treatment-associated sexual difficulties. CONCLUSION: Sexual Well-being after Cervical or Endometrial Cancer is a novel and psychometrically valid sexual well-being measure for clinical assessment of female sexual difficulties after cervical or endometrial cancer treatment. White ID, Tennant A, Taylor C, Sexual Morbidity Assessment in Gyne-Oncology Follow-Up: Development of the Sexual Well-Being After Cervical or Endometrial Cancer (SWELL-CE) Patient-Reported Outcome Measure. J Sex Med 2020;17:2005-2015.

Investigating the patient acceptable symptom state cut-offs: longitudinal data from a community cohort using the shoulder pain and disability index.

This prospective study aimed to determine the patient acceptable symptom state (PASS) cut-off for the patient reported outcome measure shoulder pain and disability index (SPADI), and evaluate predictors of PASS achievement following standard shoulder care. Patients with shoulder pain, referred for shoulder ultrasound were recruited from a community cohort. Patients completed both SPADI (scored 0-130) and a question on symptom state and followed-up at 6 months. PASS was calculated from Rasch-transformed scores using 2 methods: the 75th percentile of the cumulative response curve and the receiver operating characteristic curve (ROC). Logistic regression was used to identify factors associated with PASS. 304 participants (169 females, mean age 57.2 years) were included. At 6 months, 193 (63%) reported PASS. The association between SPADI at 6 months and PASS depended on baseline SPADI (interaction p = 0.036). Those with higher baseline scores had higher 6 months PASS cut-offs. Using the 75th percentile method, the 6 months total SPADI cut-off was 49.2 in those starting in the highest tertile at baseline compared to 39.4 in the lowest tertile: 46.4 vs. 36.7 for pain, 46.8 vs. 25.1 for disability. The ROC method yielded similar results. We have shown for the first time that the PASS cut-off for SPADI is dependent on baseline severity scores. Understanding the SPADI PASS threshold is important for clinical research to allow standardised reporting of shoulder intervention success at the patient level.

The influence and added value of a Standardized Assessment and Reporting System for functioning outcomes upon national rehabilitation quality reports.

OBJECTIVE: To demonstrate the influence and added value of a Standardized Assessment and Reporting System (StARS) upon the reporting of functioning outcomes for national rehabilitation quality reports. A StARS builds upon an ICF-based (International Classification of Functioning, Disability and Health) and interval-scaled common metric. DESIGN: Comparison of current ordinal-scaled Swiss national rehabilitation outcome reports including an expert-consensus-based transformation scale with StARS-based reports through descriptive statistical methods and content exploration of further development areas of the reports with relevant ICF Core Sets. SETTING: Swiss national public rehabilitation outcome quality reports on the clinic level. PARTICIPANTS: A total of 29 Swiss rehabilitation clinics provided their quality report datasets including 18 047 patients. INTERVENTIONS: Neurological or musculoskeletal rehabilitation. MAIN OUTCOME MEASURES: Functional Independence Measure™ or Extended Barthel Index. RESULTS: Outcomes reported with a StARS tended to be smaller but more precise than in the current ordinal-scaled reports, indicating an overestimation of achieved outcomes in the latter. The comparison of the common metric's content with ICF Core Sets suggests to include 'energy and drive functions' or 'maintaining a basic body position' to enhance the content of functioning as an indicator. CONCLUSIONS: A StARS supports the comparison of outcomes assessed with different measures on the same interval-scaled ICF-based common metric. Careful consideration is needed whether an ordinal-scaled or interval-scaled reporting system is applied as the magnitude and precision of reported outcomes is influenced. The StARS' ICF basis brings an added value by informing further development of functioning as a relevant indicator for national outcome quality reports in rehabilitation.

Psychological determinants of job retention in multiple sclerosis.

BACKGROUND: Maintaining paid work is a key issue for people with multiple sclerosis (PwMS). Different factors, including psychological attributes, can influence job retention. Understanding their role should inform potential interventions to help PwMS retain employment. OBJECTIVES: The aim of this study was to identify the key factors which improve job retention in an employed cohort of PwMS. METHODS: This three-year longitudinal study used validated self-completed measures of physical and psychological factors at four time points over 28 months. RESULTS: Of 208 employed PwMS, just over 1 in 10 was no longer working at the end of the study. Three variables were predictive of continuing employment; low 'work instability' at baseline increased the odds of job retention by a factor of 12.76; high levels of self-efficacy by a factor of 4.66 and being less than 50 years of age increased the odds of job retention by a factor of 3.90. Path analysis demonstrated the mediating role of self-efficacy between the physical impact of MS and the level of work instability at exit. CONCLUSION: Screening for work instability and self-efficacy in a clinical setting followed by appropriate interventions to increase self-efficacy and reduce work instability could aid job retention in MS.

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.

Test equating sleep scales: applying the Leunbach's model.

BACKGROUND: In most cases, the total scores from different instruments assessing the same construct are not directly comparable, but must be equated. In this study we aimed to illustrate a novel test equating methodology applied to sleep functions, a domain in which few score comparability studies exist. METHODS: Eight scales from two cross-sectional self-report studies were considered, and one scale was common to both studies. The International Classification of Functioning, Disability and Health (ICF) was used to establish content comparability. Direct (common persons) and indirect (common item) equating was assessed by means of Leunbach's model, which equates the scores of two scales depending on the same person parameter, taking into account several tests of fit and the Standard Error of Equating (SEE). RESULTS: All items were linked to the body functions category b134 of the ICF, which corresponds to 'Sleep functions'. The scales were classified into three sleep aspects: four scales were assessing mainly sleep disturbance, one quality of sleep, and three impact of sleep on daily life. Of 16 direct equated pairs, 15 could be equated according to Leunbach's model, and of 12 indirect equated pairs, 8 could be equated. Raw score conversion tables between each of these 23 equated pairs are provided. The SEE was higher for indirect than for direct equating. Pairs measuring the same sleep aspect did not show better fit indices than pairs from different aspects. The instruments mapped to a higher order concept of sleep functions. CONCLUSION: Leunbach's equating model has been successfully applied to a functioning domain little explored in test equating. This novel methodology, together with the ICF, enables comparison of clinical outcomes and research results, and facilitates communication among clinicians.

Supporting construct validity of the Evaluation of Daily Activity Questionnaire using Linear Logistic Test Models.

PURPOSE: Construct validity is commonly assessed by applying statistical methods to data. However, purely empirical methods cannot explain what happens between the attribute and the instrument scores, which is the core of construct validity. Linear Logistic Test Models (LLTMs) can provide such explanation by decomposing item difficulties into a weighted sum of theoretical item properties. In this study, we aim to support construct validity of the Evaluation of Daily Activity Questionnaire (EDAQ) by using item properties accounting for item difficulties. METHODS: Dichotomized responses to the EDAQ were analyzed with (1) the Rasch model (to estimate item difficulties), and (2) LLTMs (to predict item difficulties). Seven properties of the items were identified and rated in ordinal scales by 39 Occupational Therapists worldwide. Aggregated metric estimates-the weights used to predict item difficulties in LLTMs-were derived from the ratings using seven cumulative link mixed models. Estimated and predicted item difficulties were compared. RESULTS: The Rasch model showed acceptable fit and unidimensionality for a sample of 42 locally independent EDAQ items. The LLTM plus error showed significantly better fit than the LLTM. In the former, three of the seven properties were not significant, and the corresponding model including only the significant properties was used to predict item difficulties; they explained 77.5% of the variance in estimated item difficulties. CONCLUSION: A satisfactory theoretical explanation of what makes an activity of daily living task more difficult than another has been provided by a LLTM plus error model, therefore supporting construct validity of the EDAQ.

Mitochondrial Bioenergetics in Brain Following Ozone Exposure in Rats Maintained on Coconut, Fish and Olive Oil-Rich Diets.

Dietary supplementation with omega-3 and omega-6 fatty acids offer cardioprotection against air pollution, but these protections have not been established in the brain. We tested whether diets rich in omega-3 or -6 fatty acids offered neuroprotective benefits, by measuring mitochondrial complex enzyme I, II and IV activities and oxidative stress measures in the frontal cortex, cerebellum, hypothalamus, and hippocampus of male rats that were fed either a normal diet, or a diet enriched with fish oil olive oil, or coconut oil followed by exposure to either filtered air or ozone (0.8 ppm) for 4 h/day for 2 days. Results show that mitochondrial complex I enzyme activity was significantly decreased in the cerebellum, hypothalamus and hippocampus by diets. Complex II enzyme activity was significantly lower in frontal cortex and cerebellum of rats maintained on all test diets. Complex IV enzyme activity was significantly lower in the frontal cortex, hypothalamus and hippocampus of animals maintained on fish oil. Ozone exposure decreased complex I and II activity in the cerebellum of rats maintained on the normal diet, an effect blocked by diet treatments. While diet and ozone have no apparent influence on endogenous reactive oxygen species production, they do affect antioxidant levels in the brain. Fish oil was the only diet that ozone exposure did not alter. Microglial morphology and GFAP immunoreactivity were assessed across diet groups; results indicated that fish oil consistently decreased reactive microglia in the hypothalamus and hippocampus. These results indicate that acute ozone exposure alters mitochondrial bioenergetics in brain and co-treatment with omega-6 and omega-3 fatty acids alleviate some adverse effects within the brain.

Measure of activity performance of the hand (MAP-Hand) questionnaire: linguistic validation, cultural adaptation and psychometric testing in people with rheumatoid arthritis in the UK.

BACKGROUND: Developed in the Norway, the Measure of Activity Performance of the Hand (MAP-Hand) assesses 18 activities performed using the hands. It was developed for people with rheumatoid arthritis (RA) using patient generated items, which are scored on a 0-3 scale and summarised into a total score range (0 to 54). This study reports the development and psychometric testing of the British English MAP-Hand in a UK population of people with RA. METHODS: Recruitment took place in the National Health Service (NHS) through 17 Rheumatology outpatient clinics. Phase 1 (cross-cultural adaptation) involved: forward translation to British English; synthesis; expert panel review and cognitive debriefing interviews with people with RA. Phase 2 (psychometric testing) involved postal completion of the MAP-Hand, Health Assessment Questionnaire (HAQ), Upper Limb HAQ (ULHAQ), Short-Form 36 (SF-36v2) and Disabilities of the Arm Shoulder Hand (DASH) to measure internal consistency (Cronbach's alpha); concurrent validity (Spearman's correlations) and Minimal Detectable Difference (MDC95). The MAP-Hand was repeated three-weeks later to assess test-retest reliability (linear weighted kappa and Intra-Class Correlations (ICC (2,1)). Unidimensionality (internal construct validity) was assessed using (i) Confirmatory Factor Analysis (CFA) (ii) Mokken scaling and (iii) Rasch model. The RUMM2030 software was used, applying the Rasch partial credit model. RESULTS: In Phase 1, 31 participants considered all items relevant. In Phase 2, 340 people completed Test-1 and 273 (80%) completed Test-2 questionnaires. Internal consistency was excellent (α = 0.96). Test-retest reliability was good (ICC (2,1) = 0.96 (95% CI 0.94, 0.97)). The MAP-Hand correlated strongly with HAQ20 (rs = .88), ULHAQ (rs = .91), SF-36v2 Physical Functioning (PF) Score (rs = -.80) and DASH (rs = .93), indicating strong concurrent validity. CFA failed to support unidimensionality (Chi-Square 236.0 (df 120; p < 0.001)). However, Mokken scaling suggested a probabilistic ordering. There was differential item functioning (DIF) for gender. Four testlets were formed, resulting in much improved fit and unidimensionality. Following this, testlets were further merged in pairs where opposite bias existed. This resulted in perfect fit to the model. CONCLUSIONS: The British English version of the MAP-Hand has good validity and reliability in people with RA and can be used in both research and clinical practice.

The Impact of Missing Values and Single Imputation upon Rasch Analysis Outcomes: A Simulation Study.

Imputation becomes common practice through availability of easy-to-use algorithms and software. This study aims to determine if different imputation strategies are robust to the extent and type of missingness, local item dependencies (LID), differential item functioning (DIF), and misfit when doing a Rasch analysis. Four samples were simulated and represented a sample with good metric properties, a sample with LID, a sample with DIF, and a sample with LID and DIF. Missing values were generated with increasing proportion and were either missing at random or completely at random. Four imputation techniques were applied before Rasch analysis and deviation of the results and the quality of fit compared. Imputation strategies showed good performance with less than 15% of missingness. The analysis with missing values performed best in recovering statistical estimates. The best strategy, when doing a Rasch analysis, is the analysis with missing values. If for some reason imputation is necessary, we recommend using the expectation-maximization algorithm.

Sexual functioning in multiple sclerosis: Relationships with depression, fatigue and physical function.

BACKGROUND: Sexual dysfunction (SD) is common among people with multiple sclerosis, but there is limited information on its relationships. OBJECTIVE: This national study examines the relationships between sexual function with demographic factors, physical function, fatigue and depression. METHODS: Participants in the Trajectories of Outcomes in Neurological Conditions (TONiC) study completed the measures of fatigue, physical function and depression together with the Multiple Sclerosis Intimacy and Sexuality Questionnaire-15 (MSISQ-15), which covers sexual function (primary), symptoms that interfere with sexual function (secondary) and psychological issues (tertiary). All ordinal scores from the measures were converted to interval scale latent estimates via the Rasch model and used as single indicator latent variables in path analysis. RESULTS: From 722 patients, 538 were sexually active of whom 431 (80.1%) answered questions on sexual functioning. Of these, only 18.5% reported no impact on any aspect of sexual function. Dysfunction was linked to disease subtype and Expanded Disability Status Scale (EDSS). Subtype influenced the relationship between symptoms and sexual function, which was fully mediated by psychological factors in secondary progressive patients. Depression was not directly associated with sexual functioning, but appeared as a consequence of the psychological issues associated with SD. CONCLUSION: SD is common among participants in this UK-wide study, and psychological aspects of SD contributed to depression.

Rasch analysis of SF-Qualiveen in multiple sclerosis.

BACKGROUND: A 30-item Qualiveen questionnaire was developed to measure the impact of urinary problems on everyday living in spinal cord injury, and subsequently an 8-item SF-Qualiveen was developed for those with multiple sclerosis (MS). The validity of this short form has not been previously examined using modern psychometric techniques, such as the Rasch measurement model. OBJECTIVE: The aim of this study is to test if the short form meets the requirements of the Rasch model. METHODS: A total of 401 patients with clinically definite MS were given the questionnaire at three neuroscience centres in the UK. RESULTS: A total of 258 patients (64.3% response) completed the questionnaire. The original scale failed to meet the expectations of the Rasch model. A two-testlet solution was sought to account for local dependence, differential item functioning and disordered thresholds. After the modifications were made the scale fitted the model (χ2 = 5.93 P = 0.4305), had high internal consistency (α = 0.88) and was unidimensional. CONCLUSIONS: SF-Qualiveen is a simple and valid measure of the impact of urinary problems in multiple sclerosis, which meets the requirements of the Rasch measurement model. Summed ordinal scores can be converted to interval-level using the transformation table provided.

Adaptation of the osteoarthritis-specific quality of life scale (the OAQoL) for use in Germany, Hungary, Italy, Spain and Turkey.

The Osteoarthritis Quality of Life scale (OAQoL) is specific to individuals with osteoarthritis. The present study describes the adaptation of the OAQoL for use in the following five European languages: German, Hungarian, Italian, Spanish and Turkish. The study involved three stages in each language; translation, cognitive debriefing (face and content validity) and validation. The validation stage assessed internal consistency (Cronbach's alpha), reproducibility (test-retest reliability using Spearman's rank correlations), convergent and divergent validity (correlations with the Health Assessment Questionnaire, The Western Ontario and McMaster Universities Index of osteoarthritis and Nottingham Health Profile) and known group validity. The OAQoL was successfully translated into the target languages with minimal problems. Cognitive debriefing interviewees found the measures easy to complete and identified few problems with content. Internal consistency ranged from 0.94 to 0.97 and test-retest reliability (reproducibility) from 0.87 to 0.98. These values indicate that the new language versions produce very low levels of measurement error. Median OAQoL scores were higher for patients reporting a current flare of osteoarthritis in all countries. Scores were also related, as expected, to perceived severity of osteoarthritis. The OAQoL was successfully adapted for use in Germany, Hungary, Italy, Spain and Turkey. The addition of these new language versions will prove valuable to multinational clinical trials and to clinical practice in the respective countries.

Measurement properties of multidimensional patient-reported outcome measures in neurodisability: a systematic review of evaluation studies.

AIM: To identify and appraise the quality of studies that primarily assessed the measurement properties of English language versions of multidimensional patient-reported outcome measures (PROMs) when evaluated with children with neurodisability, and to summarize this evidence. METHOD: MEDLINE, Embase, PsycINFO, CINAHL, AMED, and the National Health Service Economic Evaluation Database were searched. The methodological quality of the papers was assessed using the COnsensus-based Standards for selection of health Measurement INstruments checklist. Evidence of content validity, construct validity, internal consistency, test-retest reliability, proxy reliability, responsiveness, and precision was extracted and judged against standardized reference criteria. RESULTS: We identified 48 studies of mostly fair to good methodological quality: 37 papers for seven generic PROMs (CHIP, CHQ, CQoL, KIDSCREEN, PedsQL, SLSS, and YQOL), seven papers for two chronic-generic PROMs (DISABKIDS and Neuro-QOL), and four papers for three preference-based measures (HUI, EQ-5D-Y, and CHSCS-PS). INTERPRETATION: On the basis of this appraisal, the DISABKIDS appears to have more supportive evidence in samples of children with neurodisability. The overall lack of evidence for responsiveness and measurement error is a concern when using these instruments to measure change, or to interpret the findings of studies in which these PROMs have been used to assess change.

The reliability and validity of the English version of the Evaluation of Daily Activity Questionnaire for people with rheumatoid arthritis.

OBJECTIVES: The Evaluation of Daily Activity Questionnaire (EDAQ) includes 138 items in 14 domains identified as important by people with RA. The aim of this study was to test the validity and reliability of the English EDAQ. METHODS: A total of 502 participants completed two questionnaires 3 weeks apart. The first consisted of the EDAQ, HAQ, RA Quality of Life (RAQoL) and the Medical Outcomes Scale (MOS) 36-item Short-Form Health Survey (SF-36v2), and the second consisted of the EDAQ only. The 14 EDAQ domains were tested for: unidimensionality-using confirmatory factor analysis; fit, response dependency, invariance across groups (differential item functioning)-using Rasch analysis; internal consistency [Person Separation Index (PSI)]; concurrent validity-by correlations with the HAQ, SF-36v2 and RAQoL; and test-retest reliability (Spearman's correlations). RESULTS: Confirmatory factor analysis of the 14 EDAQ domains indicated unidimensionality, after adjustment for local dependency in each domain. All domains achieved a root mean square error of approximation <0.10 and satisfied Rasch model expectations for local dependency. DIF by age, gender and employment status was largely absent. The PSI was consistent with individual use (PSI = 0.94 for all 14 domains). For all domains, except Caring, concurrent validity was good: HAQ (rs = 0.72-0.91), RAQoL (rs = 0.67-0.82) and SF36v2 Physical Function scale (rs = -0.60 to -0.84) and test-retest reliability was good (rs = 0.70-0.89). CONCLUSION: Analysis supported a 14-domain, two-component structure (Self care and Mobility) of the EDAQ, where each domain, and both components, satisfied Rasch model requirements, and have robust reliability and validity.

A systematic review of generic multidimensional patient-reported outcome measures for children, part I: descriptive characteristics.

OBJECTIVES: To identify generic, multidimensional patient-reported outcome measures (PROMs) for children up to 18 years old and describe their characteristics and content assessed using the International Classification of Functioning, Disability and Health Children and Youth version (ICF-CY). METHODS: The search strategy, developed by an information specialist, included four groups of terms related to "measure," "health," "children and young people," and "psychometric performance." The search was limited to publications from 1992. Five electronic databases and two online-specific PROM databases were searched. Two groups of reviewers independently screened all abstracts for eligible PROMs. Descriptive characteristics of the eligible PROMs were collected, and items and domains of each questionnaire were mapped onto the ICF-CY chapters. RESULTS: We identified 35 PROMs, of which 29 were generic PROMs and 6 were preference-based measures. Many PROMs cover a range of aspects of health; however, social functioning is represented most often. Content covered differs both in which aspects of health are assessed and whether individual questions focus on functioning (what the subject can or does do) and/or well-being (how the subject feels about a certain aspect of his or her health). CONCLUSIONS: A broad variety of PROMs is available to assess children's health. Nevertheless, only a few PROMs can be used across all age ranges to 18 years. When mapping their content on the ICF-CY, it seems that most PROMs exclude at least one major domain, and all conflate aspects of functioning and well-being in the scales.