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Background and Objective: Although comprehensive and widespread guidelines on how to conduct systematic reviews of outcome measurement instruments (OMIs) exist, for example from the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) initiative, key information is often missing in published reports. This article describes the development of an extension of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline: PRISMA-COSMIN for OMIs 2024., Methods: The development process followed the Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines and included a literature search, expert consultations, a Delphi study, a hybrid workgroup meeting, pilot testing, and an end-of-project meeting, with integrated patient/public involvement., Results: From the literature and expert consultation, 49 potentially relevant reporting items were identified. Round 1 of the Delphi study was completed by 103 panelists, whereas round 2 and 3 were completed by 78 panelists. After 3 rounds, agreement (≥67%) on inclusion and wording was reached for 44 items. Eleven items without consensus for inclusion and/or wording were discussed at a workgroup meeting attended by 24 participants. Agreement was reached for the inclusion and wording of 10 items, and the deletion of 1 item. Pilot testing with 65 authors of OMI systematic reviews further improved the guideline through minor changes in wording and structure, finalized during the end-of-project meeting. The final checklist to facilitate the reporting of full systematic review reports contains 54 (sub)items addressing the review's title, abstract, plain language summary, open science, introduction, methods, results, and discussion. Thirteen items pertaining to the title and abstract are also included in a separate abstract checklist, guiding authors in reporting for example conference abstracts., Conclusion: PRISMA-COSMIN for OMIs 2024 consists of two checklists (full reports; abstracts), their corresponding explanation and elaboration documents detailing the rationale and examples for each item, and a data flow diagram. PRISMA-COSMIN for OMIs 2024 can improve the reporting of systematic reviews of OMIs, fostering their reproducibility and allowing end-users to appraise the quality of OMIs and select the most appropriate OMI for a specific application. NOTE: This paper was jointly developed by Journal of Clinical Epidemiology, Quality of Life Research, Journal of Patient Reported Outcomes, Health and Quality of Life Outcomes and jointly published by Elsevier Inc, Springer Nature Switzerland AG, and BioMed Central Ltd., part of Springer Nature. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Either citation can be used when citing this article., Competing Interests: Declaration of competing interest Drs Terwee and Mokkink are the founders of COSMIN; Dr Moher is a member of the PRISMA executive; Dr Tricco is the co-editor in chief of the Journal of Clinical Epidemiology. The other authors have no conflicts of interest., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Post-COVID-19 condition (also known as long COVID) is a new, complex, and poorly understood disorder. A core outcome set (COS) for post-COVID-19 condition in adults has been developed and agreement is now required on the most appropriate measurement instruments for these core outcomes. We conducted an international consensus study involving multidisciplinary experts and people with lived experience of long COVID. The study comprised a literature review to identify measurement instruments for the core outcomes, a three-round online modified Delphi process, and an online consensus meeting to generate a core outcome measurement set (COMS). 594 individuals from 58 countries participated. The number of potential instruments for the 12 core outcomes was reduced from 319 to 19. Consensus was reached for inclusion of the modified Medical Research Council Dyspnoea Scale for respiratory outcomes. Measures for two relevant outcomes from a previously published COS for acute COVID-19 were also included: time until death, for survival, and the Recovery Scale for COVID-19, for recovery. Instruments were suggested for consideration for the remaining nine core outcomes: fatigue or exhaustion, pain, post-exertion symptoms, work or occupational and study changes, and cardiovascular, nervous system, cognitive, mental health, and physical outcomes; however, consensus was not achieved for instruments for these outcomes. The recommended COMS and instruments for consideration provide a foundation for the evaluation of post-COVID-19 condition in adults, which should help to optimise clinical care and accelerate research worldwide. Further assessment of this COMS is warranted as new data emerge on existing and novel measurement instruments., Competing Interests: Declaration of interests SLG is the project coordinator of the Core Outcome Measures in Effectiveness Trials (COMET) Initiative. NLH has received payment and honoraria for lectures and presentations from Lancaster University. PRW is chair of the COMET Management Group. DM is a co-chair of the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) Global Paediatric Long COVID working group and a member of the ISARIC working group on long-term follow-up in adults. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: Minimal important difference (MID), the smallest change or difference that patients perceive as important, aids interpretation of change in patient-reported outcome measure (PROM) scores. A credibility instrument that assesses the methodological rigor of an anchor-based MID includes one core item addressing the correlation between the PROM and the anchor. However, the majority of MID studies in the literature fail to report the correlation. To address this issue, we extended the anchor-based MID credibility instrument by adding an item addressing construct proximity as an alternative to the correlation item., Study Design and Setting: Informed by an MID methodological survey, we added an alternative item-a subjective assessment of similarity of the constructs (i.e., construct proximity) between PROM and anchor-to the correlation item and generated principles for the assessment. We sampled 101 MIDs and analyzed the assessments performed by each pair of raters. By calculating weighted Cohen's kappa, we assessed the reliability of the assessments., Results: Construct proximity assessment is based on the anticipated association between the anchor and PROM constructs: the closer the anticipated association, the higher the rating. Our detailed principles address the most frequently used anchors: transition ratings, measures of satisfaction, other PROMs, and clinical measures. The assessments showed acceptable agreement (weighted kappa 0.74, 95% CI 0.55-0.94) between raters., Conclusion: In the absence of a reported correlation coefficient, construct proximity assessment provides a useful alternative in the credibility assessment of anchor-based MID estimates., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objectives: The anchor-based minimal important change (MIC), based on the receiver operating characteristic (ROC) analysis or predictive modeling, is biased by the proportion of improved patients. The adjusted MIC, published in 2017, adjusts the predictive MIC for this bias but does not take the reliability of the transition ratings (i.e., the anchor) into account. The aim of this study was to examine whether the transition ratings reliability affects the accuracy of the adjusted MIC and, if so, whether the adjustment can be improved., Study Design and Setting: Multiple simulations of patient samples involved in anchor-based MIC studies with different characteristics of patient-reported outcome scores were used to determine the impact of reliability of the transition ratings on the MIC estimate. An improved adjustment formula was derived in an exploration set of simulated samples (number of samples = 19,440) and validated in a different set of simulated samples (number of samples = 12,960). The effect of sample size (100-1,000) was also evaluated in simulated datasets., Results: Reliability of the transition ratings biased the MIC estimate if the proportion improved was different from 0.5. The improved adjustment formula performed well, especially if the proportion improved was between 0.3 and 0.7. Smaller sample sizes were at the expense of the precision of the MIC estimates., Conclusion: We provide an improved formula for calculating the adjusted MIC, taking into account the proportion of improved patients and the reliability of the transition ratings., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Little is known about the impact of standardized imaging surveillance on anxiety levels and well-being of patients after endovascular aortic aneurysm repair (EVAR). We hypothesize that patient anxiety levels increase just before receiving the imaging results compared with standard anxiety levels., Methods: Prospective cohort study from November 2018 to May 2020 including post-EVAR patients visiting the outpatient clinics of 4 Dutch hospitals for imaging follow-up. The Patient-Reported Outcomes Measurement Information System (PROMIS) was used. Patients completed the PROMIS Anxiety v1.0 Short Form (SF) 4a, PROMIS-Global Health Scale v1.2, and PROMIS-Physical Function v1.2 SF8b at 2 time points: prior to the result of the imaging study (T1: pre-visit) and 6-8 months later (T2: reference measurement). Mean T-scores at T1 were compared to T2, and T2 to the general 65+ Dutch population., Results: Altogether 342 invited patients were eligible, 214 completed the first questionnaire, 189 returned 2 completed questionnaires and 128 patients did not participate. Out of 214 respondents, 195 were male (91.1%) and the mean (standard deviation) age was 75.2 (7.0) years. There were no significant differences between T1 and T2 in anxiety levels (0.48; 95% confidence interval[CI] -0.42-1.38), global mental health (0.27; 95% CI -0.79-0.84), global physical health (0.10; 95% CI -0.38-1.18) and physical function (0.53; 95% CI -0.26-1.32). Compared with the 65+ Dutch population, at T2 patients experienced more anxiety (3.8; 95% CI 2.96-5.54), had worse global physical health (-3.2; 95% CI -4.38 - -2.02) and physical function (-2.4; 95% CI -4.00 - -0.80). Global mental health was similar (-1.0; 95% CI -2.21 - 0.21)., Conclusions: Post-EVAR patients do not experience more anxiety just before receiving surveillance imaging results than outside this period, but do suffer from more anxiety and worse physical outcomes than the 65+ Dutch population., (Copyright © 2021. Published by Elsevier Inc.)

Objective: Patient-reported transition ratings are supposed to reflect the change between a previous baseline health state and a present follow-up state, but may reflect the present state to a greater extent. This so-called "present state bias" (PSB) potentially threatens the validity of transition ratings. Several criteria have been proposed to assess PSB. We examined how well these criteria perform and to which extent confirmatory factor analysis (CFA) for categorical data provides an accurate assessment of the degree of PSB., Study Design and Setting: We simulated multiple samples with baseline and follow-up item responses to a hypothetical questionnaire, and transition ratings. The samples varied with respect to various distributional characteristics and the degree of PSB. The performance of criteria proposed in the literature, and a new CFA-based criterion, were evaluated by the proportion of explained variance in PSB. In addition, four real datasets were analyzed., Results: The known criteria explained 36-74% of the variance in PSB. A new CFA-based criterion, namely the ratio of the factor loadings of the transition ratings plus one, explained 81-98% of the variance in PSB across the samples., Conclusion: Present state bias in transition ratings can be estimated accurately using CFA., (Copyright © 2021. Published by Elsevier Inc.)

Objective: To systematically survey the literature addressing the reporting of studies estimating anchor-based minimal important differences (MIDs) and choice of optimal MIDs., Study Design and Setting: We searched Medline, Embase and PsycINFO from 1987 to March 2020. Teams of two reviewers independently identified eligible publications and extracted quotations addressing relevant issues for reporting and/or selecting anchor-based MIDs. Using a coding list, we assigned the same code to quotations capturing similar or related issues. For each code, we generated an 'item', i.e., a specific phrase or sentence capturing the underlying concept. When multiple concepts existed under a single code, the team created multiple items for that code. We clustered codes addressing a broader methodological issue into a 'category' and classified items as relevant for reporting, relevant for selecting an anchor-based MID, or both., Results: We identified 136 eligible publications that provided 6 categories (MID definition, anchors, patient-reported outcome measures, generalizability and statistics) and 24 codes. These codes contained 34 items related to reporting MID studies, of which 29 were also related to selecting MIDs., Conclusion: The systematic survey identified items related to reporting of anchor-based MID studies and selecting optimal MIDs. These provide a conceptual framework to inform the design of studies related to MIDs, and a basis for developing a reporting standard and a selection approach for MIDs., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: To examine current practices in late-phase trials published in major medical journals and examine trialists' views about core outcome set (COS) use., Study Design and Setting: A sequential multi-methods study was conducted. We examined late-phase trials published between October 2019 and March 2020 in JAMA, NEJM, The Lancet, BMJ, and Annals of Internal Medicine. The COMET database was searched for COS potentially relevant to trials not reporting using a COS; overlap of trial and COS outcomes was examined. An online survey examined awareness of, and decisions to search for and use a COS., Results: Ninety-five trials were examined; 93 (98%) did not report using a COS. Relevant COS were identified for 31 trials (33%). Core outcomes were measured in 9 (23%) studies; all trials measured at least one core outcome. Thirty-one trialists (33%) completed our survey. The most common barrier to COS use was trialist's own outcome preferences and choice (68%). The most common perceived facilitator was awareness and knowledge about COS (90%)., Conclusion: COS use in this cohort of trials was low, even when relevant COS were available. Increased use of COS in clinical trials can improve evaluation of intervention effects and evidence synthesis and reduce research waste., (Copyright © 2021. Published by Elsevier Inc.)

Background: The Patient-Reported Outcomes Measurement Information System (PROMIS) Profile-29 questionnaire is widely used worldwide, but it has not yet been validated in the Netherlands, nor in persons with hemophilia., Objective: To validate the Dutch-Flemish version of the PROMIS-29 Profile v2.01 in adults with hemophilia., Methods: Dutch males with hemophilia (all severities) completed questionnaires that contained sociodemographic and clinical characteristics, the PROMIS-29, RAND-36, and the Hemophilia Activities List (HAL). Structural validity of each subscale was assessed with confirmatory factor analysis (CFA). Internal consistency was calculated for each subscale with sufficient model fit in CFA. Construct validity was assessed by testing hypotheses about (1) correlations of each PROMIS-29 subscale with corresponding scales of RAND-36 and domains of HAL, and (2) mean differences in T-scores between subgroups with different hemophilia severities, self-reported joint impairment, and HIV infection status. We considered ≥75% of data in accordance with the hypotheses evidence for construct validity., Results: In total, 770 persons with hemophilia participated in this cross-sectional study. CFA revealed sufficient structural validity for five subscales: Physical Function, Depression, Sleep Disturbance, Ability to Participate in Social Roles and Activities, and Pain Interference. Internal consistency was high and Cronbach's alpha ranged from 0.79 for Sleep Disturbance to 0.96 for Pain Interference. Differences between clinical subgroups were in the expected direction. Construct validity was confirmed for Physical Function, Anxiety, Depression, Fatigue, Sleep Disturbance, and Pain Intensity., Conclusion: This study revealed sufficient evidence for structural validity, internal consistency, and construct validity for most PROMIS Profile-29 subscales among people with hemophilia in the Netherlands., (© 2021 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

Objectives: To study the test-retest reliability and measurement error, construct validity, responsiveness, interpretability, and floor/ceiling effects of a Patient-Reported Outcomes Measurement Information System (PROMIS) short form designed to measure physical function in geriatric rehabilitation patients (PROMIS-PF-GR)., Design: Prospective cohort., Setting and Participants: Inpatient geriatric rehabilitation patients., Methods: We evaluated the test-retest reliability by re-administering PROMIS-PF-GR 3 to 5 days after the admission measurement. The intraclass correlation coefficient (ICC) was calculated to determine test-retest reliability; an ICC of ≥0.70 was considered sufficient. Measurement error was established by calculating the standard error of measurement and smallest detectable change. Construct validity and responsiveness were determined by testing a priori formulated hypotheses (criterion: ≥75% hypothesis not rejected). Interpretability was evaluated by calculating the minimal important change using predictive modeling and a global rating as criterion for change. Floor/ceiling effects were established by calculating the percentage patients with the minimum/maximum raw score (criterion: ≤15%) at admission and discharge., Results: A total of 207 patients participated in the study [mean ± standard deviation age (80 ± 8.3 years), 58% female]. More than one-half of patients (56%) reported to be improved during rehabilitation. The ICC was 0.79 (95% confidence interval 0.70-0.84), the standardized error of measurement was 3.8, and the smallest detectable change 10.6. None of the 4 hypotheses for construct validity were rejected; 2 out of 5 hypotheses for responsiveness were rejected. The minimal important change was 8.0 (95% confidence interval 4.1-12.5). No floor/ceiling effects were found., Conclusions and Implications: The PROMIS-PG-GR showed sufficient test-retest reliability, measurement error, and construct validity. We did not find sufficient evidence for responsiveness, which may be due to the unexplained weak correlation between the PROMIS change score and the Global Rating Scale. We still recommend the use the PROMIS-PG-GR for measuring self-reported physical function in geriatric rehabilitation., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: PROMIS offers computerized adaptive tests (CAT) of patient-reported outcomes, using a single set of US-based IRT item parameters across populations and language-versions. The use of country-specific item parameters has local appeal, but also disadvantages. We illustrate the effects of choosing US or country-specific item parameters on PROMIS CAT T-scores., Study Design and Setting: Simulations were performed on response data from Dutch chronic pain patients (n = 1110) who completed the PROMIS Pain Behavior item bank. We compared CAT T-scores obtained with (1) US parameters; (2) Dutch item parameters; (3) US item parameters for DIF-free items and Dutch item parameters (rescaled to the US metric) for DIF items; (4) Dutch item parameters for all items (rescaled to the US metric)., Results: Without anchoring to a common metric, CAT T-scores cannot be compared. When scores were rescaled to the US metric, mean differences in CAT T-scores based on US vs. Dutch item parameters were negligible. However, 0.9%-4.3% of the T-score differences were larger than 5 points (0.5 SD)., Conclusion: The choice of item parameters can be consequential for individual patient scores. We recommend more studies of translated CATs to examine if strategies that allow for country-specific item parameters should be further investigated., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objectives: Once a core outcome set (COS) has been defined, it is important to achieve consensus on how these outcomes should be measured. The aims of this systematic review were to gain insight into the methods used to select outcome measurement instruments and to determine whether methods have improved following the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN)/Core Outcome Measures in Effectiveness Trials (COMET) guideline publication., Study Design and Setting: Eligible articles, which were identified from the annual COMET systematic review, concerned any COS development studies that provided a recommendation on how to measure the outcomes included in the COS. Data were extracted on the methods used to select outcome measurement instruments in accordance with the COSMIN/COMET guideline., Results: Of the 118 studies included in the review, 48% used more than one source of information when finding outcome measurement instruments, and 74% performed some form of quality assessment of the measurement instruments. Twenty-three studies recommended one single instrument for each core outcome included in the COS. Clinical experts and public representatives were involved in selecting instruments in 62% and 28% of studies, respectively., Conclusion: Methods used to select outcome measurement instruments have improved since the publication of the COSMIN/COMET guideline. Going forward, COS developers should ensure that recommended outcome measurement instruments have sufficient content validity. In addition, COS developers should recommend one instrument for each core outcome to contribute to the overarching goal of uniformity in outcome reporting., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: This study introduces a new method to establish clinical thresholds for multi-item tests, based on item response theory (IRT), as an alternative to receiver operating characteristic (ROC) analysis. The performance of IRT method was examined and compared with the ROC method across multiple simulated data sets and in a real data set., Study Design and Setting: Simulated data sets (sample size: 1,000) varied in means and variability of the test scores and the prevalence of disease. The true clinical threshold was defined as a predetermined location on the latent trait underlying the questionnaire, with its corresponding expected test score. The real data set (sample size: 295) comprised Hospital Anxiety Depression Scale (HADS) depression scores and Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition major depressive disorder (MDD) diagnoses., Results: The IRT method recovered the clinical thresholds without bias, whereas the ROC method identified thresholds that were biased by the prevalence of disease. Mild MDD was clinically diagnosed in 23%, moderate MDD in 12%, and severe MDD in 14% of the participants. The IRT method identified the following HADS depression score thresholds for mild, moderate, and severe MDD: 10.7, 13.2, and 15.1, respectively., Conclusion: The new IRT method identifies clinical thresholds that are unbiased by disease prevalence., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Huber et al. introduced a new concept 'positive health', defined as 'the ability to adapt and self-manage in the face of social, physical and emotional challenges' and suggested a conceptual model comprising six domains covering 32 aspects. Our aim was to generate items and pilot test an outcome measurement instrument for measuring 'positive health' in Dutch adult citizens., Study Design: A mixed-method study: a literature search, a qualitative study with interviews and a quantitative ranking study for the development phase, to be followed by a content validity study for the validation phase., Methods: We developed items based on the concept elicitation study of Huber et al. A ranking study with end users, Dutch citizens and members of an Expert Group was performed for item reduction. Content validity of the prefinal questionnaire was evaluated., Results: A prefinal 46-item questionnaire was developed. The results of the content validity study, however, showed major concerns with regard to relevance, comprehensiveness and comprehensibility of the questionnaire., Conclusions: Because of major concerns regarding the conceptual model of 'positive health', it was not possible to develop a valid questionnaire to measure 'positive health'. Future research should focus on the refinement of the conceptualization of 'positive health' before an adequate measurement instrument could be developed that can be used for outcome measurement purposes., (Copyright © 2019 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Objective: The Barthel index (BI) is a widely used observer-based instrument to measure physical function. Our objective is to assess the structural validity, reliability, and interpretability of the BI in the geriatric rehabilitation setting., Design: Two studies were performed. First, a prospective cohort study was performed in which the attending nurses completed the BI at admittance and discharge (n = 207). At discharge, patients rated their change in physical function on a 5-point Likert rating scale. To assess the internal structure of the BI, a confirmatory factor analysis was performed. Unidimensionality was defined by comparative fit index and Tucker-Lewis index of >0.95, and root mean square error of approximation of <0.06. To evaluate interpretability, floor/ceiling effects and the minimal important change (MIC) were assessed. Predictive modeling was used to calculate the MIC. The MIC was defined as going home and minimal patient-reported improvement defined as slightly or much improved physical function, which served as anchors to obtain a clinical- and patient-based MIC. A second group of 37 geriatric rehabilitation patients were repeatedly assessed by 2 attending nurses to assess reliability of the BI. The intraclass correlation coefficient, standard error of measurement, and smallest detectable change were calculated., Setting and Participants: Patients receiving inpatient geriatric rehabilitation admitted to 11 Dutch nursing homes (n = 244)., Results: Confirmatory factor analysis showed partly acceptable fit of a unidimensional model (comparative fit index 0.96, Tucker-Lewis index 0.95, and root mean square error of approximation 0.12). The clinical-based MIC was 3.1 [95% confidence interval (CI) 2.0-4.2] and the patient-based MIC was 3.6 (95% CI 2.8-4.3). The intraclass correlation coefficient was 0.96 (95% CI 0.93-0.98). The standard error of measurement and smallest detectable change were 1.1 and 3.0 points, respectively., Conclusions/implications: The structural validity, reliability, and interpretability of the BI are considered sufficient for measuring and interpreting changes in physical function of geriatric rehabilitation patients., (Copyright © 2018 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To synthesize the measurement properties of six health-related quality of life instruments (Short Form 36 [SF-36], Short Form 12 [SF-12], EuroQol 5D-3L [EQ-5D-3L], EuroQol 5D-5L [EQ-5D-5L], Nottingham Health Profile (NHP), and Patient-Reported Outcome Measurement Information System Global Health [PROMIS-GH-10]) in patients with low back pain (LBP)., Study Design and Setting: Six electronic databases (MEDLINE, EMBASE, CINAHL, PsycINFO, SportDiscus, and Google Scholar) were searched (July 2017). Studies assessing any measurement property in nonspecific LBP patients were included. Two reviewers independently screened the articles and assessed the risk of bias (COSMIN checklist). Consensus-based criteria were used to rate measurement properties results as sufficient, insufficient, or inconsistent; a modified GRADE approach was adopted for evidence synthesis., Results: High quality evidence was found for insufficient construct validity of SF-36 summary scores, and EQ-5D-3L utility and visual analogue scale scores. Moderate evidence was found for sufficient construct validity of SF-12 physical summary score and inconsistent responsiveness of EQ-5D-3L utility score. Very low quality evidence was found on each instrument's content validity; very low to low evidence underpinned the other assessed measurement properties. EQ-5D-5L, NHP and PROMIS Global Health-10 were not evaluated in LBP patients., Conclusion: Documentation of the measurement properties of health-related quality of life instruments in LBP is incomplete. Future clinimetric studies should prioritize content validity., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Instructing and guiding patients after surgery is essential for successful recovery. However, the time that health-care professionals can spend with their patients postoperatively has been reduced because of efficiency-driven, shortened hospital stays. We evaluated the effect of a personalised e-health-care programme on return to normal activities after surgery., Methods: A multicentre, single-blind, randomised controlled trial was done at seven teaching hospitals in the Netherlands. Patients aged 18-75 years who were scheduled for laparoscopic cholecystectomy, inguinal hernia surgery, or laparoscopic adnexal surgery for a benign indication were recruited. An independent researcher randomly allocated participants to either the intervention or control group using computer-based randomisation lists, with stratification by sex, type of surgery, and hospital. Participants in the intervention group had access to a perioperative, personalised, e-health-care programme, which managed recovery expectations and provided postoperative guidance tailored to the patient. The control group received usual care and access to a placebo website containing standard general recovery advice. Participants were unaware of the study hypothesis and were asked to complete questionnaires at five timepoints during the 6-month period after surgery. The primary outcome was time between surgery and return to normal activities, measured using personalised patient-reported outcome measures. Intention-to-treat and per-protocol analyses were done. This trial is registered in the Netherlands National Trial Register, number NTR4699., Findings: Between Aug 24, 2015, and Aug 12, 2016, 344 participants were enrolled and randomly allocated to either the intervention (n=173) or control (n=171) group. 14 participants (4%) were lost to follow-up, with 330 participants included in the primary outcome analysis. Median time until return to normal activities was 21 days (95% CI 17-25) in the intervention group and 26 days (20-32) in the control group (hazard ratio 1·38, 95% CI 1·09-1·73; p=0·007). Complications did not differ between groups., Interpretation: A personalised e-health intervention after abdominal surgery speeds up the return to normal activities compared with usual care. Implementation of this e-health programme is recommended in patients undergoing intermediate-grade abdominal, gynaecological, or general surgical procedures., Funding: ZonMw., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: To summarize the evidence on content and structural validity of 17 patient-reported outcome measures (PROMs) to measure physical functioning in patients with low back pain (LBP)., Study Design and Setting: MEDLINE, EMBASE, CINAHL, PsycINFO, SportDiscus, and Google Scholar were searched (February 2017). Records on development and studies assessing content validity or unidimensionality in patients with LBP were included. Two reviewers defined eligible studies and assessed their methodological quality with updated Consensus-based Standards for the Selection of Health Measurement Instruments standards. Evidence was synthesized for three separate aspects of content validity: relevance, comprehensiveness, and comprehensibility, and for unidimensionality, a modified GRADE approach was applied to evidence synthesis., Results: High-quality evidence showed that 24-item Roland Morris Disability Questionnaire (RMDQ-24) is a comprehensible but not comprehensive PROM. Low to very low quality evidence underpinned the content validity of the other PROMs. Unidimensionality was: sufficient for Brief Pain Inventory pain interference subscale (moderate quality evidence); inconsistent for RMDQ-23, Oswestry Disability Index 2.1a (ODI 2.1a), and Quebec Back Pain Disability Scale (moderate quality); insufficient for RMDQ-24, ODI 1.0, and RMDQ-18 (high quality) and Short Form 36 physical functioning subscale (SF36-PF, moderate quality)., Conclusion: The content validity of PROMs to measure physical functioning in patients with LBP is understudied. Structural validity of several widely used PROMs is problematic., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: Optimisation of the cosmetic outcome after breast-conserving therapy (BCT) is important. We aimed to determine the cosmetic outcome following BCT and factors influencing this cosmesis and identify the most favourable options for delayed breast reconstruction., Materials and Methods: Four reconstructive surgeons evaluated the cosmetic outcome of 109 patients after BCT. Additionally, the surgeons indicated which patients were amenable for delayed reconstruction and the preferred type of reconstruction. The inter- and intra-observer agreement of the surgeons was rated., Results: The mean overall cosmetic outcome was rated as fair (2.7/4.0, SD 0.9, 1.0-4.0). Risk factors for a poor cosmesis were larger breast size (OR 3.81, p = 0.040), larger tumour (OR 1.63, p = 0.028) and axillary lymph node dissection (ALND) (OR 3.09, p = 0.013). Reconstruction of the ipsilateral side was recommended in 55.6% and 94.5% and contralateral reconstruction in 16.7% and 73.3% of patients with good and poor cosmesis, respectively. Flap reconstruction and lipofilling were most commonly reported for the ipsilateral, and breast reduction for the contralateral breast, with reasonable improvement expected (2.2/4.0, SD 0.5, 1.08-3.3). The inter- (0.5-0.7) and intra-observer (0.63-0.79) agreement of the cosmesis was moderate to good, however, poor regarding the recommended reconstruction techniques (mainly < 0.50)., Conclusion: Cosmetic outcome after BCT is influenced by breast and tumour size and ALND. Although several reconstructive options are available, the optimal method for revision surgery has not yet been determined. Future studies are necessary to obtain evidence-based guidelines for reconstructive surgery after BCT., (Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: The objective of this study was to assess the psychometric properties of the Dutch-Flemish Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank in Dutch patients with chronic pain., Study Design and Setting: A bank of 121 items was administered to 1,247 Dutch patients with chronic pain. Unidimensionality was assessed by fitting a one-factor confirmatory factor analysis and evaluating resulting fit statistics. Items were calibrated with the graded response model and its fit was evaluated. Cross-cultural validity was assessed by testing items for differential item functioning (DIF) based on language (Dutch vs. English). Construct validity was evaluated by calculation correlations between scores on the Dutch-Flemish PROMIS Physical Function measure and scores on generic and disease-specific measures., Results: Results supported the Dutch-Flemish PROMIS Physical Function item bank's unidimensionality (Comparative Fit Index = 0.976, Tucker Lewis Index = 0.976) and model fit. Item thresholds targeted a wide range of physical function construct (threshold-parameters range: -4.2 to 5.6). Cross-cultural validity was good as four items only showed DIF for language and their impact on item scores was minimal. Physical Function scores were strongly associated with scores on all other measures (all correlations ≤ -0.60 as expected)., Conclusion: The Dutch-Flemish PROMIS Physical Function item bank exhibited good psychometric properties. Development of a computer adaptive test based on the large bank is warranted., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: This study aims to identify elements perceived by Dutch fertility specialists as barriers and facilitators for the introduction of genetic testing, and their attitudes towards the use of genetic information. The genetic test would be implemented in routine screening for tubal pathology and identifies SNPs relevant for the immune response causing tubal pathology., Methods: Experienced reproductive specialists working in Dutch Academic Hospitals were interviewed. Based on the results of four interviews a questionnaire was developed and used to survey medical doctors in six out of eight Dutch Academic hospitals., Results: 60.4% (n=91) stated that the addition of genetic markers to the Chlamydia trachomatis antibody test (CAT) in screening for tubal pathology would increase screening accuracy. 68.2% (n=90) agreed they would require additional training on clinical genetics. Clinical utility (91.2%, n=91) and cost-effectiveness (95.6%, n=91) were recognized by the respondents as important factors in gaining support for the new screening strategy., Conclusion: In summary, respondents showed a positive attitude towards the implementation of a genetic test combined with CAT for tubal factor infertility (TFI) screening. To gain their support the majority of respondents agreed that clinical utility, specifically cost-effectiveness, is an important factor. Comprehensive research about economic implications and utility regarding the introduction of genomic markers should be the next step in the implementation strategy. Furthermore, education and training would need to be developed and offered to fertility care professionals about genetic markers, their interpretation, and implications for clinical decision-making., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: There are similarities between the different forms of reliability, such as internal consistency (internal reliability) and interrater and intrarater reliability. Reliability coefficients that are based on classical test theory can be expressed as intraclass correlation coefficients (ICCs), such as Cronbach's alpha. The Spearman-Brown prophecy formula (SB formula) is used to calculate the reliability when the number of items in a questionnaire is changed. This paper aims to increase insight into reliability studies by pointing to the assumptions of reliability coefficients, similarities between various coefficients, and the subsequent new applications of reliability coefficients., Design, Settings and Results: The origin and assumptions of Cronbach's alpha and the SB formula are discussed. Cronbach's alpha is written as an ICC formula, using the well-known property that taking the average value of a number of ratings increases the reliability of a measurement. We illustrate with an example that the ICC formulas for average measurements of multiple raters and the SB formula give similar results. This implies that the SB formula can be used to decide on the number of measurements to be averaged and thus on the number of raters required, for obtaining measurements with acceptable reliability, even if the variance components of the ICC formula are not known. Using the same example, we illustrate the principle of "Cronbach's alpha if item deleted" to decide on the poorest performing raters in a set of raters., Conclusion: These applications have different assumptions: the principle of "Cronbach's alpha if item deleted" is based on the assumption of a fixed set of items/raters and the SB formula is based on the assumption of random raters. The example also emphasizes the need for more raters in the design of the reliability study to obtain a robust estimation of reliability., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: Patients have their individual minimal important changes (iMICs) as their personal benchmarks to determine whether a perceived health-related quality of life (HRQOL) change constitutes a (minimally) important change for them. We denote the mean iMIC in a group of patients as the "genuine MIC" (gMIC). The aims of this paper are (1) to examine the relationship between the gMIC and the anchor-based minimal important change (MIC), determined by receiver operating characteristic analysis or by predictive modeling; (2) to examine the impact of the proportion of improved patients on these MICs; and (3) to explore the possibility to adjust the MIC for the influence of the proportion of improved patients., Study Design and Setting: Multiple simulations of patient samples involved in anchor-based MIC studies with different characteristics of HRQOL (change) scores and distributions of iMICs. In addition, a real data set is analyzed for illustration., Results: The receiver operating characteristic-based and predictive modeling MICs equal the gMIC when the proportion of improved patients equals 0.5. The MIC is estimated higher than the gMIC when the proportion improved is greater than 0.5, and the MIC is estimated lower than the gMIC when the proportion improved is less than 0.5. Using an equation including the predictive modeling MIC, the log-odds of improvement, the standard deviation of the HRQOL change score, and the correlation between the HRQOL change score and the anchor results in an adjusted MIC reflecting the gMIC irrespective of the proportion of improved patients., Conclusion: Adjusting the predictive modeling MIC for the proportion of improved patients assures that the adjusted MIC reflects the gMIC., Limitations: We assumed normal distributions and global perceived change scores that were independent on the follow-up score. Additionally, floor and ceiling effects were not taken into account., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: Conduct a systematic review of pediatric randomized controlled trials (RCTs) published in high-impact journals to assess the reporting of primary outcomes and the psychometric properties of their measures., Study Design and Setting: Systematic review with screening and simultaneous data extraction conducted by two independent reviewers. Electronic searches of six general medicine and four pediatric journals were conducted in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. RCTs of a single phase/step in a single publication, published in English between 2000 and 2010 with participants less than 21 years of age were included., Results: A random sample of 20% (n = 445) of 2,229 initial references was screened and 206 (46%) met inclusion criteria. Half (48.5%) of included studies reported a singular primary outcome, 27% did not identify any primary outcome, and 24% identified multiple primary outcomes (range 2-20). Twenty-one trials used an instrument to measure their primary outcome, but only 7 (33%) reported its psychometric properties., Conclusion: Pediatric trials published in top medical journals have inadequate reporting of their primary outcomes and the psychometric properties of their outcome measures. Whether the issue is one of poor reporting and/or poor validation will be further investigated., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Choosing the most fit-for-purpose outcome measurement instruments is fundamental because using inappropriate instruments can lead to detection bias and measurement inconsistency. Recent recommendations, consensus procedures and systematic reviews on existing patient-reported outcome measures (PROMs) informed this manuscript, which provides suggestions on which outcome domains and measurement instruments to use in patients with low back pain (LBP). Six domains are identified as highly relevant: (1) physical functioning, (2) pain intensity, (3) health-related quality of life, (4) work, (5) psychological functioning and (6) pain interference. For each domain, one or more PROMs are suggested for clinical research and practice, selecting among those that are most frequently used and recommended, and that have satisfactory measurement properties in patients with LBP. Further research on the measurement properties of these suggested PROMs is needed while also considering other emerging instruments, such as the PROMIS computerised adaptive testing and short forms., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: To present a new method to estimate a "minimal important change" (MIC) of health-related quality of life (HRQOL) scales, based on predictive modeling, and to compare its performance with the MIC based on receiver operating characteristic (ROC) analysis. To illustrate how the new method deals with variables that modify the MIC across subgroups., Study Design and Setting: The new method uses logistic regression analysis and identifies the change score associated with a likelihood ratio of 1 as the MIC. Simulation studies were conducted to investigate under which distributional circumstances both methods produce concordant or discordant results and whether the methods differ in accuracy and precision., Results: The "predictive MIC" and the ROC-based MIC were identical when the variances of the change scores in the improved and not-improved groups were equal and the distributions were normal or oppositely skewed. The predictive MIC turned out to be more precise than the ROC-based MIC. The predictive MIC allowed for the testing and estimation of modifying factors such as baseline severity., Conclusion: In many situations, the newly described MIC based on predictive modeling yields the same value as the ROC-based MIC but with significantly greater precision. This advantage translates to increased statistical power in MIC studies., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: The Douleur Neuropathique 4 (DN4), ID Pain, Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), PainDETECT, and Neuropathic Pain Questionnaire have been recommended as screening questionnaires for neuropathic pain. This systematic review aimed to evaluate the measurement properties (eg, criterion validity and reliability) of these questionnaires., Study Design and Setting: Online database searches were conducted and two independent reviewers screened studies and extracted data. Methodological quality of included studies and the measurement properties were assessed against established criteria. A modified Grading of Recommendations Assessment, Development and Evaluation approach was used to summarize the level of evidence., Results: Thirty-seven studies were included. Most studies recruited participants from pain clinics. The original version of the DN4 (French) and Neuropathic Pain Questionnaire (English) had the most number of satisfactory measurement properties. The ID Pain (English) demonstrated satisfactory hypothesis testing and reliability, but all other properties tested were unsatisfactory. The LANSS (English) was unsatisfactory for all properties, except specificity. The PainDETECT (English) demonstrated satisfactory hypothesis testing and criterion validity. In general, the cross-cultural adaptations had less evidence than the original versions., Conclusion: Overall, the DN4 and Neuropathic Pain Questionnaire were most suitable for clinical use. These screening questionnaires should not replace a thorough clinical assessment., (Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.)

Objective: The aim was to critically appraise, compare, and summarize the quality of the measurement properties of all available disease specific patient reported outcome measures (PROMs) on health related quality of life and functional status validated in patients with intermittent claudication (IC)., Methods: A systematic search was carried out in Embase and Medline (last search November 18, 2013). The quality of the identified studies was assessed per measurement property according to the COnsensus-based Standards for the selection of health Measurements Instruments (COSMIN) checklist. Data on the measurement properties were extracted to determine a level of evidence per measurement property per instrument., Results: Forty three studies were found evaluating 10 health related quality of life and two functional status PROMs. Evidence for the existence of subscales (structural validity) and for internal consistency (interrelatedness of items within subscales) for PROMs was generally poor. Evidence for construct validity was limited. Accuracy and reproducibility of PROMs were often uncertain, since reliability studies were mostly performed in small patient samples. Responsiveness, or the ability of PROMs to detect change over time, was hardly ever studied., Conclusion: The quality of the validation of most disease specific PROMs for IC is alarming, hampering all conclusion based on these PROMs. Considering the results, the PAD quality of life questionnaire (PADQOL), Intermittent claudication questionnaire (ICQ) and the Vascular quality of life questionnaire (VascuQol) might be appropriate PROMs for health related quality of life, while the Walking impairment questionnaire (WIQ) and Estimate ambulation capacity by history questionnaire (EACH-Q) appear suitable PROMs for functional status. However, all PROMs require further validation studies to fill the gaps in their measurement properties. The shortcomings highlighted in this review should be taken into account when interpreting PROM results., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Some reports showed few but significant more axial femorotibial rotation in favor of mobile-bearing (MB) versus fixed-bearing (FB) total knee arthroplasty (TKA), mostly during knee bend fluoroscopic studies. The goal of the current study was to submit MB and FB groups of TKA patients to a turning activity, in which additional rotation was to be expected., Methods: Two consecutive cohorts of patients after TKA (10 FB and 11 MB knees in a total of 18 patients) were assessed using motion analysis five year postoperatively, while performing gait and sit-to-walk (STW) movements with and without turning steps., Results: Mean range of rotation in the FB group increased from 9.7° during gait, to 11.7° during STW straight, and to 14.3° during STW turning. Mean range of rotation in the MB group increased from 13.4° during gait to 21.0° during STW straight, and stayed at 21.1° during STW turning., Conclusions: Too many uncontrolled variables in the current study hinder a meaningful discrimination of MB from FB TKA rotation. However, the study does illustrate how more demanding task loads could be helpful in exploring the geometric constraints of TKA variants., Level of Evidence: Level III, therapeutic study., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: To determine the content, structural, and construct validity of the Dutch version of the Neck Disability Index (NDI)., Study Design and Setting: To assess content validity, 11 neck pain experts and 10 patients commented on the construct, comprehensiveness, and relevance of the NDI. Structural validity was assessed by item factor analysis (FA) and item response theory modeling using the generalized partial credit model. Differential item functioning (DIF) analysis for gender was examined. Pearson correlation coefficient with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was calculated to assess construct validity., Results: In addition to a suboptimal translation, we found a lack of consensus on the construct the NDI intends to measure. Experts and patients suggested that the NDI measures more than physical functioning. Unidimensionality of the NDI could not be confirmed. DIF analysis for gender showed DIF for the headache item. The goodness-of-fit statistics for FA with one factor were satisfactory when the item "concentration" was omitted. A correlation of 0.75 with the DASH was found supporting construct validity., Conclusion: It is questionable whether in research the NDI should be the instrument of choice for use as a primary outcome measure. Definition of the construct to be measured is a prerequisite for the assessment of validity., (Copyright © 2013 Elsevier Inc. All rights reserved.)

High quality instruments are useful tools for clinical and research purposes. To determine whether an instrument has high quality, measurement properties such as reliability and validity need to be assessed, using standardised criteria. This paper discusses these quality domains and measurement properties using the standardised criteria that were recently published by the COSMIN group. Examples are given of studies evaluating the measurement properties of instruments frequently used in trauma. This paper presents a helpful tool for readers who want to evaluate or assess the quality of a measurement instrument on reliability and validity., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Objective: Lack of consensus on taxonomy, terminology, and definitions has led to confusion about which measurement properties are relevant and which concepts they represent. The aim was to clarify and standardize terminology and definitions of measurement properties by reaching consensus among a group of experts and to develop a taxonomy of measurement properties relevant for evaluating health instruments., Study Design and Setting: An international Delphi study with four written rounds was performed. Participating experts had a background in epidemiology, statistics, psychology, and clinical medicine. The panel was asked to rate their (dis)agreement about proposals on a five-point scale. Consensus was considered to be reached when at least 67% of the panel agreed., Results: Of 91 invited experts, 57 agreed to participate and 43 actually participated. Consensus was reached on positions of measurement properties in the taxonomy (68-84%), terminology (74-88%, except for structural validity [56%]), and definitions of measurement properties (68-88%). The panel extensively discussed the positions of internal consistency and responsiveness in the taxonomy, the terms "reliability" and "structural validity," and the definitions of internal consistency and reliability., Conclusions: Consensus on taxonomy, terminology, and definitions of measurement properties was reached. Hopefully, this will lead to a more uniform use of terms and definitions in the literature on measurement properties., (Copyright 2010 Elsevier Inc. All rights reserved.)

Objective: There is no consensus on the best method to determine the minimal important change (MIC) of patient-reported outcomes. Recent publications recommend the use of multiple methods. Our aim was to assess whether different methods lead to consistent values for the MIC., Study Design and Setting: We used two commonly used anchor-based methods and three commonly used distribution-based methods to determine the MIC of the subscales: pain and physical functioning of the Western Ontario and McMaster University Osteoarthritis Index questionnaire in five different studies involving patients with hip or knee complaints. We repeated the anchor-based methods using relative change scores, to adjust for baseline scores., Results: We found large variation in MIC values by the same method across studies and across different methods within studies. We consider it unlikely that this variation can be explained by differences between disease groups, disease severity, or lengths of follow-up. The variation persisted when using relative change scores. It was not possible to conclude whether this variation is because of true differences in MIC values between populations or to conceptual and methodological problems of the MIC methods., Conclusion: To better disentangle these two possible explanations, the MIC methodology should be improved and standardized. In the meantime, caution is needed when interpreting and using published MIC values.

Objective: Determining "minimally important change" (MIC) facilitates the interpretation of change scores on multi-item instruments. This article focuses on how MIC values should be interpreted when applied to individual patients., Study Design and Setting: The MIC value of a hypothetical questionnaire "Q" was determined in a sample of 400 patients who improved and 100 patients who did not improve, using the receiver operating characteristic (ROC) method, and three methods to quantify the uncertainty., Results: The MIC value on questionnaire Q was 10.5. Firstly, the 95% confidence interval (CI) of the MIC value (for questionnaire Q: 5.6-14.2) quantifies the uncertainty of the estimation of the MIC value. Secondly, "how sure we are that this MIC value holds for every patient" is quantified by the values for sensitivity (74%) and specificity (91%). Thirdly, the smallest detectable change (SDC) on questionnaire Q is calculated (16.0) to consider whether the MIC value (10.5) falls outside or within the measurement error., Conclusion: For application in clinical research and practice, MIC values are always considered at the individual level, but determined in groups of patients. The interpretation comes with different forms of uncertainty. To appreciate the uncertainty, knowledge of the underlying distributions of change scores is indispensable.

Objective: To provide a practical example showing how to relate measurement error to minimal important change (MIC) to estimate sample sizes required for detecting important changes in research, and to determine the usefulness of patient-reported outcomes (PROs) in daily clinical practice., Study Design and Setting: The standard error of measurement (SEM) can be calculated as a parameter of measurement error. MIC can be determined by taking the mean change in score on the questionnaire in the subgroup of patients that reported to be "a little better" or "better" on a global rating scale minus the mean change in score in the subgroup of patients that reported to be "not changed." Based on SEM and MIC, formulas are presented that can be used to estimate sample sizes and to determine whether the questionnaire can be used to monitor changes in individual patients in daily clinical practice., Results: A fully worked-out example is presented, using Western Ontario and McMaster University Osteoarthritis Index data from a cohort of patients undergoing hip or knee replacement., Conclusion: We strongly recommend investigators to present the SEM and MIC of PROs and use these to estimate sample sizes for research and to determine the usefulness of these outcomes in daily clinical practice.

Objective: The aim of the study was to determine the cross-sectional and longitudinal validity of a performance-based assessment of knee function, DynaPort KneeTest (DPKT), in first-time consulters with nontraumatic knee complaints in general practice., Methods: Patients consulting for nontraumatic knee pain in general practice aged >18 years were enrolled in the study. At baseline and 6-months follow-up knee function was assessed by questionnaires and the DPKT; a physical examination was also performed at baseline. Hypothesis testing assessed the cross-sectional and longitudinal validity of the DPKT., Results: Eighty-seven patients were included for the DPKT, 86 were available for analysis. The studied population included 44 women (51.2%), the median age was 54 (range 18-81) years. At follow up, 77 patients (89.5%) were available for the DPKT. Only 3 out of 11 (27%) predetermined hypotheses concerning the cross-sectional and longitudinal validity were confirmed. Comparison of the general practice and secondary care population showed a major difference in baseline characteristics, DynaPort Knee Score, internal consistency, and hypotheses confirmation concerning the construct validity., Conclusion: The validity of the DPKT could not be demonstrated for first-time consulters with nontraumatic knee complaints in general practice. Measurement instruments developed and validated in secondary care are therefore not automatically also valid in primary care setting.

Objective: (1) To translate and validate the COOP/WONCA charts in Turkish, Moroccan-Arabic, and Tarifit for use among ethnic minority cancer patients in the Netherlands, and (2) to determine the patient-proxy agreement for Dutch speaking proxies., Study Design and Setting: Ninety Turkish patients (with 36 proxies) and 79 Moroccan patients (with 21 proxies) participated in the study. Psychometric evaluation included analysis of feasibility, construct validity, known-groups validity, and responsiveness. Patient-proxy agreement was analyzed at the group and individual level., Results: Few missing items were observed. Evidence of construct validity based on comparisons with the SF-36 was relatively strong. Known-groups validity was observed using performance status, comorbidity, and gender as grouping variables, but not using disease stage or treatment status. Moderate responsiveness was observed in the Turkish sample, but not in the Moroccan group. Proxy-patient agreement at the group level was relatively high for all domains, except pain. Agreement at the individual level was poor., Conclusion: The results provide relatively strong support for the use of the translated COOP/WONCA charts. However, further work is required to examine responsiveness in the Moroccan patient population. Proxy COOP/WONCA chart ratings may be appropriate at the group level, but not at the individual patient level.

Objectives: Recently, an increasing number of systematic reviews have been published in which the measurement properties of health status questionnaires are compared. For a meaningful comparison, quality criteria for measurement properties are needed. Our aim was to develop quality criteria for design, methods, and outcomes of studies on the development and evaluation of health status questionnaires., Study Design and Setting: Quality criteria for content validity, internal consistency, criterion validity, construct validity, reproducibility, longitudinal validity, responsiveness, floor and ceiling effects, and interpretability were derived from existing guidelines and consensus within our research group., Results: For each measurement property a criterion was defined for a positive, negative, or indeterminate rating, depending on the design, methods, and outcomes of the validation study., Conclusion: Our criteria make a substantial contribution toward defining explicit quality criteria for measurement properties of health status questionnaires. Our criteria can be used in systematic reviews of health status questionnaires, to detect shortcomings and gaps in knowledge of measurement properties, and to design validation studies. The future challenge will be to refine and complete the criteria and to reach broad consensus, especially on quality criteria for good measurement properties.

Background: Reproducibility concerns the degree to which repeated measurements provide similar results. Agreement parameters assess how close the results of the repeated measurements are, by estimating the measurement error in repeated measurements. Reliability parameters assess whether study objects, often persons, can be distinguished from each other, despite measurement errors. In that case, the measurement error is related to the variability between persons. Consequently, reliability parameters are highly dependent on the heterogeneity of the study sample, while the agreement parameters, based on measurement error, are more a pure characteristic of the measurement instrument., Methods and Results: Using an example of an interrater study, in which different physical therapists measure the range of motion of the arm in patients with shoulder complaints, the differences and relationships between reliability and agreement parameters for continuous variables are illustrated., Conclusion: If the research question concerns the distinction of persons, reliability parameters are the most appropriate. But if the aim is to measure change in health status, which is often the case in clinical practice, parameters of agreement are preferred.

Background and Objectives: To test the hypothesis that self-reported physical functioning is more influenced by pain than performance-based physical functioning., Methods: 163 knee-osteoarthritis patients completed the performance-based DynaPort KneeTest (DPKT), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and SF-36 (self-report measures of pain and physical functioning) before, 3, 6, and 12 months after knee replacement., Results: Correlations between (two) self-reported measures of functioning and (two) pain measures were higher (0.57-0.74) than correlations between the performance-based measure of functioning and the two pain measures (0.20 and 0.26). In factor analysis, WOMAC and SF-36 pain and physical functioning subscores loaded on the first factor (eigenvalue 3.2), while DPKT KneeScore2 loaded on the second factor (eigenvalue 0.92). Before surgery, correlations between performance-based and self-reported physical functioning were higher in patients with less pain (0.43) compared to patients with more pain (0.17), for the WOMAC (as expected), but not for the SF-36. After surgery, when the pain had diminished, the correlations between performance-based and self-reported physical functioning were higher, especially for the WOMAC., Conclusions: Our hypothesis was convincingly supported by the results of the WOMAC, and somewhat less by the results of the SF-36. We consider this as evidence for a lack of content validity of the WOMAC.

Background and Objective: Psychometrically sound questionnaires for the assessment of vision-related quality of life (QOL) are scarce. Therefore, the objective was to further validate two vision-related QOL questionnaires in a Dutch population of visually impaired elderly., Methods: A total of 329 visually impaired older persons referred to low vision services completed the low vision QOL (LVQOL) and Vision-Related Quality of Life Core Measure (VCM1) questionnaires at baseline, after 1-4 weeks (retest), and after 5 months. Confirmatory factor analyses were performed on baseline data. The smallest detectable change (SDC) was assessed, based on the standard error of measurement (SEM). Change scores between the baseline and 5 months follow-up data were related to a general transition question to assess the minimal important change (MIC). Furthermore, the MIC was related to the SDC, to examine whether the MICs were detectable beyond measurement error., Results: The original factor structures could not be confirmed. After omitting items and remodeling, adequate fits were obtained. SDCs comprised at least one quarter of the scale for all scales and subscales on the individual level and exceeded the MICs on every occasion., Conclusion: We propose MICs of 5-10 points for the scales and subscales of the LVQOL and VCM1. The questionnaires are not useful in the follow-up of individual patients.