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Study Objectives: Sleep difficulties are common in CDKL5 deficiency disorder, a developmental and epileptic encephalopathy. This study evaluated the factor structure of the Disorders of Initiating and Maintaining Sleep (DIMS), Disorders of Excessive Somnolence (DOES), and Sleep Breathing Disorders domains of the Sleep Disturbance Scale for Children for CDKL5 deficiency disorder., Methods: A cross-sectional psychometric study design was used. Data were collected for 125 individuals aged 3 years or older who attended a United States Centers of Excellence clinic or registered with the International CDKL5 Disorder Database., Results: The median age was 10.3 years (range 3.2-40.7 years) and 105 (84%) were female. Two of the 3 Sleep Breathing Disorders items were not observed by most respondents and analysis was restricted to the DIMS and DOES domains. Using all items in the initial confirmatory factor analysis, 2 items in the DIMS domain and 1 item in the DOES domain loaded poorly. After deleting these items and repeating the analysis, item loading (.524-.814) and internal consistency (DIMS: .78, DOES: .76) statistics were good. The square of the interdomain correlation coefficient was .17, less than average variance extracted values for both domains and indicating good discriminant validity. The Tucker-Lewis and Comparative Fit indices were slightly lower than the threshold of > .9 for establishing goodness of fit., Conclusions: The modified DIMS and DOES domains from the Sleep Disturbance Scale for Children could be suitable clinical outcome assessments of insomnia and related impairments in CDKL5 deficiency disorder and potentially other developmental and epileptic encephalopathy conditions., Citation: Saldaris JM, Demarest S, Jacoby P, et al. Modification of a parent-report sleep scale for individuals with CDKL5 deficiency disorder: a psychometric study. J Clin Sleep Med . 2024;20 (12):1887-1893., (© 2024 American Academy of Sleep Medicine.)

Objective: The CDKL5 Clinical Severity Assessment (CCSA) is a comprehensive, content-validated measurement tool capturing the diverse challenges of cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD), a genetically caused developmental epileptic encephalopathy (DEE). The CCSA is divided into clinician-reported (CCSA-Clinician) and caregiver-reported (CCSA-Caregiver) assessments. The aim of this study was to evaluate the factor structure of these measures through confirmatory factor analysis (CFA) and evaluate their validity and reliability., Methods: Participants were recruited from the International CDKL5 Clinical Research Network to take part in an in-clinic CCSA-Clinician evaluation (n = 148) and/or complete the CCSA-Caregiver questionnaire (n = 198). CFA was used to determine domains, and factor loadings and validity were assessed. For the CCSA-Clinician, inter-rater reliability was assessed by nine CDD experienced clinicians via 14 pre-recorded evaluations. Eight clinicians re-viewed and re-scored the videos after 4 weeks to evaluate intra-rater reliability. The CCSA-Caregiver was completed on a second occasion by 34 caregivers after 2-4 weeks to assess test-retest reliability., Results: CFA resulted in three domains for the CCSA-Clinician (motor and movement, communication, vision) and four domains for the CCSA-Caregiver (seizures, behavior, alertness, feeding), with good item loadings across both measures. Structural statistics, internal consistency, discriminant validity, and reliability were satisfactory for both measures, and scores were consistent between known groups., Significance: This study provides strong evidence that the CCSA measures are suitable to assess the clinical severity of individuals with CDD, supporting their use in clinical trials. Further evaluation of responsiveness to change in a longitudinal assessment is planned. Use may also be appropriate in similar DEEs but would require validation in those populations., (© 2024 International League Against Epilepsy.)

Purpose: To identify symptoms and their impacts on daily functioning and health-related quality of life (HRQoL) experienced by adult patients with ulcerative colitis (UC) and evaluate patient-reported outcome (PRO) measures for UC clinical studies., Methods: A conceptual model of symptoms and impacts of UC were developed from a literature review. PRO measures were identified from the literature, clinical trials databases, health technology assessment submissions, and regulatory label claims, and were selected for conceptual analysis based on disease specificity and use across information sources. PRO measures covering the most concepts when mapped against the conceptual model were assessed for gaps in psychometric properties using Food and Drug Administration (FDA) guidance and consensus-based standards for the selection of health measurement instruments (COSMIN) criteria., Results: The conceptual model grouped the 52 symptom concepts and 72 proximal and distal impacts into eight, two, and five dimensions, respectively. Of 65 PRO measures identified, eight underwent conceptual analysis. Measures covering the most concepts and assessed for psychometric properties were the Inflammatory Bowel Disease Questionnaire, Symptoms and Impacts Questionnaire for UC, UC-PRO symptoms modules, UC-PRO impact modules, and Crohn's and UC Questionnaire; all had good or excellent support for content validity. The UC-PRO Signs and Symptoms fully met FDA guidance and COSMIN criteria for content validity and most psychometric properties., Conclusion: Existing PRO measures assess concepts relevant to patients with UC, but all PRO measures reviewed require further psychometric evaluation to demonstrate they are fit for purpose., (© 2024. The Author(s).)

Objectives: To evaluate the psychometric properties of the Diary for Irritable Bowel Syndrome Symptoms-Constipation (DIBSS-C), which was developed to support primary and secondary endpoints in irritable bowel syndrome (IBS) with predominant constipation (IBS-C) clinical trials., Methods: Observational data were collected from 108 adults with IBS-C using a smartphone-type device for 17 days. DIBSS-C data regarding bowel movements (BMs) were collected for each event (along with the Bristol Stool Form Scale); abdominal symptoms were rated each evening. Global status items and the Gastrointestinal Symptom Rating Scale-IBS were completed on day 10 and day 17 and the IBS-Symptom Severity Scale on day 17. Item-level performance, internal consistency reliability, test-retest reliability, and construct validity were evaluated., Results: The Abdominal Symptoms Domain score demonstrated high internal consistency reliability (Cronbach's alpha week 1 = 0.98; week 2 = 0.96) and test-retest reliability (intraclass correlation coefficient [ICC] = 0.93). Test-retest reliability was stronger for abdominal symptoms (ICC = 0.91-0.94) than for the frequency-based BM-related outcomes (ICC = 0.54-0.66). Key construct validity hypotheses were supported by moderate to strong correlations with the corresponding Gastrointestinal Symptom Rating Scale-IBS, IBS-Symptom Severity Scale, and Bristol Stool Form Scale items. All known-groups comparisons were statistically significant for the abdominal symptom items and domain score; evidence for known-groups validity of BM-related outcomes was supportive when based on constipation severity., Conclusions: The results of this study provided key psychometric evidence for the DIBSS-C, ultimately contributing to its qualification by the US Food and Drug Administration for use in IBS-C clinical trials., Competing Interests: Author Disclosures Author disclosure forms can be accessed in the Supplemental Material section., (Copyright © 2024. Published by Elsevier Inc.)

The CMT-FOM is a 13-item clinical outcome assessment (COA) that measures physical ability in adults with Charcot-Marie-Tooth disease (CMT). Test-retest reliability, internal consistency and convergent validity have been established for the CMT-FOM. This current study sought to establish inter-rater reliability. Following an in-person training of six international clinical evaluators we recruited 10 participants with genetically diagnosed CMT1A, (aged 18-74 years, 6 female). Participants were evaluated using the CMT-FOM over 2 days. Participants were given at least a 3 hour rest between evaluations, and were assessed twice each day. Following the provision of training by master trainers, all 13 items of the CMT-FOM exhibited excellent inter-rater reliability for raw scores (ICC 1,1 0.825-0.989) and z-scores (ICC 1,1 0.762-0.969). Reliability of the CMT-FOM total score was excellent (ICC 1,1 0.983, 95% CI 0.958-0.995). The CMT-FOM is a reliable COA used by clinical evaluators internationally. The next steps are to establish further validation through psychometric evaluation of the CMT-FOM in the Accelerate Clinical Trials in CMT (ACT-CMT) study., (© 2020 Peripheral Nerve Society.)

The Charcot-Marie-Tooth disease Pediatric Scale (CMTPedS) is a Rasch-built clinical outcome measure of disease severity. It is valid, reliable, and responsive to change for children and adolescents aged 3 to 20 years. The aim of this study was to translate and validate an Italian version of the CMTPedS using a validated framework of transcultural adaptation. The CMTPedS (Italian) was translated and culturally adapted from source into Italian by two experts in CMT with good English language proficiency. The two translations were reviewed by a panel of experts in CMT. The agreed provisional version was back translated into English by a professional translator. The definitive Italian version was developed during a consensus teleconference by the same panel. CMT patients were assessed with the final version of the outcome measure and a subset had a second assessment after 2 weeks to evaluate test-retest reliability. Seventeen patients with CMT aged 5 to 20 years (eight female) were evaluated with the CMTPedS (Italian), and test-retest was performed in three patients. The CMTPedS (Italian) showed a high test-retest reliability. No patient had difficulty in completing the scale. The instructions for the different items were clearly understood by clinicians and therefore the administration of the outcome measure was straight forward and easily understood by the children assessed. The CMTPedS (Italian) will be used for clinical follow-up and in clinical research studies in the Italian population. The data is fully comparable to that obtained from the English language version., (© 2020 Peripheral Nerve Society.)

Purpose: Clinical outcome assessments (COAs) require evidence not only of reliability, validity, and ability to detect change, but also a definition of what constitutes a meaningful change on the instrument. The responder definition specifies the amount of change on the COA that may be interpreted as a treatment benefit and is critical for interpreting what constitutes a meaningful change on the COA scores. However, the literature that describes methods for developing and applying responder definitions can be difficult to navigate. Clear and concise guidelines regarding which methods to apply under what circumstances and how to interpret the results are lacking. This article provides a guide to the variety of available methods and issues that should be considered when establishing responder definitions for interpreting meaningful changes in COA scores., Methods: An overview is provided for selecting anchors, developing study designs, planning psychometric analyses, using psychometric results to set responder thresholds, and applying responder thresholds in demonstrating treatment efficacy., Results: There are a variety of anchor-based methods for consideration, but they all rely on a preference for strongly related and easily interpretable anchors. The benefits of applying multiple anchors and multiple analytic methods are discussed. The process of triangulation can synthesize results across multiple sources to gain confidence in a proposed responder definition. Though a link to meaningfulness from the patient's perspective is absent, distribution-based methods provide lower bound estimates of score precision and have a role in triangulation. Responder definitions are typically required within regulatory review, but their application may differ across clinical trial programs., Conclusions: By careful planning of anchor selection, study design, and psychometric methods, COA researchers can establish defensible responder thresholds that ultimately aid patients and clinicians in making informed treatment decisions.

Introduction: There has been a notable increase in the advocacy of using small-sample designs as an initial quantitative assessment of item and scale performance during the scale development process. This is particularly true in the development of clinical outcome assessments (COAs), where Rasch analysis has been advanced as an appropriate statistical tool for evaluating the developing COAs using a small sample., Methods: We review the benefits such methods are purported to offer from both a practical and statistical standpoint and detail several problematic areas, including both practical and statistical theory concerns, with respect to the use of quantitative methods, including Rasch-consistent methods, with small samples., Conclusions: The feasibility of obtaining accurate information and the potential negative impacts of misusing large-sample statistical methods with small samples during COA development are discussed.

Background: The Near Visual Acuity Questionnaire Presbyopia (NAVQ-P) is a patient-reported outcome (PRO) measure that was developed in a phakic presbyopia population to assess near vision function impacts. The study refined and explored the psychometric properties and score interpretability of the NAVQ-P and additional PRO items assessing near vision correction independence (NVCI), near vision satisfaction (NVS), and near vision correction preference (NVCP). Methods: This was a psychometric validation study conducted using PRO data collected as part of a Phase IIb clinical trial (CUN8R44 A2202) consisting of 235 randomized adults with presbyopia from the US, Japan, Australia, and Canada. Data collected at baseline, week 2, and months 1, 2, and 3 during the 3-month trial treatment period were included in the analyses to assess item (question) properties, NAVQ-P dimensionality and scoring, reliability, validity, and score interpretation. Results: Item responses were distributed across the full response scale for most NAVQ-P and additional PRO items. Confirmatory factor analysis supported the pre-defined unidimensional structure and calculation of a NAVQ-P total score as a measure of near vision function. Item deletion informed by item response distributions, dimensionality analyses, item response theory, and previous qualitative findings, including clinical input, supported retention of 14 NAVQ-P items. The 14-item NAVQ-P total score had excellent internal consistency (α = 0.979) and high test-retest reliability (Intraclass Correlation Coefficients > = 0.898). There was good evidence of construct-related validity for all PROs supported by strong correlations with concurrent measures. Excellent results for known-groups validity and ability to detect change analyses were also demonstrated. Anchor-based and distribution-based methods supported interpretation of scores through generation of group-level and within-individual estimates of meaningful change thresholds. A meaningful within-patient change in the range of 8-15-point improvement on the NAVQ-P total score (score range 0–42) was recommended, including a more specific responder definition of 10-point improvement. Conclusions: The NAVQ-P, NVCI, and NVS are valid and reliable instruments which have the ability to detect change over time. Findings strongly support the use of these measures as outcome assessments in clinical/research studies and in clinical practice in the presbyopia population. [ABSTRACT FROM AUTHOR]

Background: Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra-rare, life-threatening hereditary disorder that causes patients to experience significant morbidity and decreased health-related quality of life (HRQoL). A cTTP disease-specific patient-reported outcome (PRO) instrument that is reflective of patients' experiences with the disorder does not currently exist. The objective of this study was to evaluate and validate the psychometric properties of the Congenital Thrombotic Thrombocytopenic Purpura–Patient Experience Questionnaire (cTTP-PEQ), developed using a literature review, interviews with expert clinicians, and qualitative concept elicitation and cognitive debriefing interviews. Methods: This prospective, observational study (NCT03519672) was conducted with patients diagnosed with cTTP currently receiving treatment. Patients were enrolled through investigator sites and direct-to-patient recruitment. Individuals completed electronic self-administered PRO measures, including the cTTP-PEQ, at baseline and Day 14 (+ up to 10 days). The cTTP-PEQ consisted of five multi-item domains (Pain/Bruising, Cognitive Impairment, Visual Impairment, Mood, Treatment Burden) and three single-item domains (Fatigue, Headache, Activity Limitation), and assessed symptoms and impact of cTTP in the previous 24 h, 7 days, and 2 weeks. Convergent and discriminant validity were evaluated using Spearman's rank correlation coefficients. Known-groups validity was assessed between patient groups separated by Patient Global Impression of Severity (PGI-S; normal vs. mild/moderate/severe). Internal reliability was assessed using Cronbach's alpha. Test–retest reliability was assessed using intraclass correlation coefficients (ICCs). Results: Thirty-six patients participated in this study. Convergent validity was confirmed with high-to-moderate correlations (r ≥ 0.4) for 12/15 hypothesized relationships between pairs of domains and/or total scores. Discriminant validity was confirmed with low correlations (r < 0.3) observed for 5/7 hypothesized relationships. Known-groups validity was confirmed with significant differences (p ≤ 0.05) in mean cTTP-PEQ scores between the two PGI-S groups for most domains and items at both timepoints. Cronbach's alpha was 0.88 at baseline and 0.91 at Day 14, confirming internal consistency of the instrument. Test–retest reliability was also confirmed with a high ICC (0.96). Conclusion: This study validates the psychometric properties of the novel cTTP-PEQ for use in research and clinical practice to assess HRQoL among patients with cTTP. This instrument will be particularly useful when assessing cTTP disease burden and the impact of new treatments. [ABSTRACT FROM AUTHOR]

Abstract Introduction Retinitis Pigmentosa (RP) and Leber Congenital Amaurosis (LCA) are rare inherited retinal degenerative disorders. The Visual Symptom and Impact Outcomes patient-reported outcome (ViSIO-PRO) and observer-reported outcome (ViSIO-ObsRO) instruments were developed in this population to assess visual function symptoms and impacts on vision-dependent activities of daily living (ADL) and distal health-related quality of life (HRQoL). This study aimed to explore the psychometric properties of the ViSIO-PRO and ViSIO-ObsRO in RP/LCA. Methods The 49-item ViSIO-PRO and 27-item ViSIO-ObsRO instruments were completed by 83 adult and adolescent patients and 22 caregivers of child patients aged 3–11 years with RP/LCA, respectively, at baseline and 12–16-day follow-up. Concurrent measures were also administered at baseline. Psychometric analyses assessed item (question) properties, dimensionality, scoring, reliability, validity, and score interpretation. Results Item responses were mainly evenly distributed across the response scale, and inter-item correlations were mostly moderate to strong (> 0.30) at baseline within hypothesized domains. Item deletion was informed by item properties, qualitative data, and clinical input and supported retention of 35 ViSIO-PRO items and 25 ViSIO-ObsRO items. Confirmatory factor analysis in line with pre-hypothesized domains supported a four-factor model assessing visual function symptoms, mobility, vision-dependent ADL, and distal HRQoL. A bifactor model supported calculation of total scores and four domain scores. Internal consistency was high for domain and total scores (Cronbach’s alpha > 0.70) and test–retest reliability for total scores was strong between baseline and 12–16-day follow-up (intraclass correlation coefficients 0.66–0.98). Convergent validity was supported by strong correlations in a logical pattern with concurrent measures. Mean baseline scores differed significantly between severity groups. Distribution-based methods provided initial insights to guide interpretation of scores. Conclusions Findings supported item reduction and established scoring of the instruments. Evidence of reliability and validity as outcome measures in RP/LCA was also reported. Further research is ongoing to explore responsiveness of the ViSIO-PRO and ViSIO-ObsRO instruments and interpretation of change scores.

Background: Angelman syndrome (AS) is a rare, heterogenous neurogenetic condition, which significantly impacts the lives of people with AS and their families. Valid and reliable measures reporting key symptoms and functional impairments of AS are required to support development of patient-centered therapies. We describe the development of clinician- and caregiver-reported, AS-specific Global Impression scales for incorporation into clinical trials. Best practice US Food and Drug Administration guidance for measure development was followed with input from expert clinicians, patient advocates, and caregivers during content generation and refinement. Results: Initial measurement domains for the Symptoms of AS—Clinician Global Impression (SAS-CGI) and the Caregiver-reported AS Scale (CASS) were identified from a conceptual disease model of AS symptoms and impacts, derived from interviews with caregivers and clinicians. Two rounds of cognitive debriefing (CD) interviews were performed; clinicians debriefed the SAS-CGI, with patient advocates and caregivers debriefing the CASS to ensure relevance and comprehension. Feedback was used to refine items and ensure wording was age-appropriate and captured AS-specific symptoms, as well as associated impacts and functional impairments. The SAS-CGI and CASS capture global assessments of seizures, sleep, maladaptive behaviors, expressive communication, fine and gross motor skills, cognition, and self-care, which were determined by clinicians, patient advocates, and caregivers to be the most challenging aspects of AS. Additionally, the measures include items for assessing overall AS symptoms and the meaningfulness of any change. In addition to ratings for severity, impact, and change, a notes field was included in the SAS-CGI to provide the rationale for the chosen rating. CD interviews confirmed the measures covered key concepts of AS from the perspective of clinicians and caregivers, and demonstrated that the measures' instructions, items, and response options were clear and appropriate. Interview feedback informed adjustments to the wording of the instructions and the items. Conclusions: The SAS-CGI and CASS were designed to capture multiple AS symptoms, reflecting the heterogeneity and complexity of AS in children 1 to 12 years old. These clinical outcome assessments have been incorporated into AS clinical studies, which will allow for the evaluation of their psychometric properties and inform further refinements if needed. [ABSTRACT FROM AUTHOR]

Introduction: Retinitis Pigmentosa (RP) and Leber Congenital Amaurosis (LCA) are rare inherited retinal degenerative disorders. The Visual Symptom and Impact Outcomes patient-reported outcome (ViSIO-PRO) and observer-reported outcome (ViSIO-ObsRO) instruments were developed in this population to assess visual function symptoms and impacts on vision-dependent activities of daily living (ADL) and distal health-related quality of life (HRQoL). This study aimed to explore the psychometric properties of the ViSIO-PRO and ViSIO-ObsRO in RP/LCA. Methods: The 49-item ViSIO-PRO and 27-item ViSIO-ObsRO instruments were completed by 83 adult and adolescent patients and 22 caregivers of child patients aged 3–11 years with RP/LCA, respectively, at baseline and 12–16-day follow-up. Concurrent measures were also administered at baseline. Psychometric analyses assessed item (question) properties, dimensionality, scoring, reliability, validity, and score interpretation. Results: Item responses were mainly evenly distributed across the response scale, and inter-item correlations were mostly moderate to strong (> 0.30) at baseline within hypothesized domains. Item deletion was informed by item properties, qualitative data, and clinical input and supported retention of 35 ViSIO-PRO items and 25 ViSIO-ObsRO items. Confirmatory factor analysis in line with pre-hypothesized domains supported a four-factor model assessing visual function symptoms, mobility, vision-dependent ADL, and distal HRQoL. A bifactor model supported calculation of total scores and four domain scores. Internal consistency was high for domain and total scores (Cronbach's alpha > 0.70) and test–retest reliability for total scores was strong between baseline and 12–16-day follow-up (intraclass correlation coefficients 0.66–0.98). Convergent validity was supported by strong correlations in a logical pattern with concurrent measures. Mean baseline scores differed significantly between severity groups. Distribution-based methods provided initial insights to guide interpretation of scores. Conclusions: Findings supported item reduction and established scoring of the instruments. Evidence of reliability and validity as outcome measures in RP/LCA was also reported. Further research is ongoing to explore responsiveness of the ViSIO-PRO and ViSIO-ObsRO instruments and interpretation of change scores. [ABSTRACT FROM AUTHOR]

Objective/background: This study evaluated psychometric properties of the Pediatric Narcolepsy Screening Questionnaire (PNSQ), developed in response to the difficulty of identifying pediatric narcolepsy.Patients/methods: The initial PNSQ was updated following debriefing interviews with parents of children with suspected/diagnosed narcolepsy. Subsequently, newly recruited caregivers were categorized into groups: clinician-confirmed narcolepsy, other sleep problems (OSP), and no sleep problems (controls). Caregivers completed the 11-item PNSQ assessing narcolepsy symptomatology. PNSQ psychometric properties were evaluated; mean PNSQ Total Score (TS) was compared inter-group using analysis of variance.Results: The analysis population (N = 158) included patients with narcolepsy (n = 49), OSP (n = 55), and controls (n = 54); mean ± SD age was 13.8 ± 2.8, 10.2 ± 4.3, and 10.0 ± 3.8 years, respectively. Inter-item Pearson correlations (range, 0.22-0.75) indicated good construct validity. Principal component analysis confirmed unidimensionality. Item discriminative power was high for narcolepsy vs control (range, 0.693-0.936) and lower for narcolepsy vs OSP (range, 0.584-0.729). The latent trait was well covered (separation index = 0.868). Item 7 (vivid dreams/nightmares), having low discriminative power and specificity, was removed. Cronbach's alpha (final PNSQ) indicated high internal consistency reliability (raw alpha = 0.88). Mean ± SD PNSQ TS (range, 0-50) in the narcolepsy, OSP, and control groups were 34.98 ± 7.98, 25.20 ± 9.43, and 9.54 ± 9.38, respectively (nominal P < 0.0001). Classification by PNSQ TS was defined: PNSQ+ (likely narcolepsy, TS ≥ 29), PNSQ 0 (likely OSP, TS 19-28), and PNSQ- (narcolepsy unlikely, TS ≤ 18); patients with narcolepsy were classified as PNSQ+ (79.6%), PNSQ 0 (18.4%), and PNSQ- (2.0%).Conclusions: The PNSQ demonstrated good psychometric properties and excellent performance discriminating narcolepsy, OSP, and control groups. [ABSTRACT FROM AUTHOR]

Background: Familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized by high levels of circulating triglycerides, negatively impacts multiple organs, including the liver and pancreas. Objective: The objective of this study was to develop and support the content validity of a novel patient-reported outcome (PRO) measure addressing FCS symptoms and impacts. To facilitate use in clinical trials of new treatments, evidence supporting the new measure needed to be consistent with regulatory guidance and requirements. Methods: A pool of items addressing symptoms and impacts of FCS was initially developed based on data from a large burden-of-illness study with patients with FCS as well as a review of available literature and existing PRO measures. Two rounds of qualitative interviews were conducted with patients with FCS (N = 10) to refine the draft items and support the measure's content validity. Each interview began with concept elicitation followed by cognitive debriefing of the draft FCS measure. Results: Patient-reported symptoms and impacts of FCS were generally consistent with those identified by the burden-of-illness study; abdominal pain was particularly prevalent and salient for patients. Suggested changes to the draft item pool were generally minor. Comprehensibility and ease of completion for the final instrument were confirmed during the second set of interviews. Conclusion: The content validity of the final 17-item FCS Symptoms and Impacts Scale is strongly supported by patient input gathered through both a large burden-of-illness study and qualitative research. To further support use in clinical trials, psychometric evaluation of the measure is underway. [ABSTRACT FROM AUTHOR]

By bringing data collection closer to real time and minimizing recall bias, patient diaries or event-driven logs offer substantial benefits over retrospective questionnaires for many patient-reported disease concepts. Such assessments are increasingly used to support primary and secondary endpoints in randomized controlled trials. These diaries have the potential to provide more reliable and valid assessment of patients’ subjective experiences of symptoms and disease events. However, use of such diaries presents significant and unique challenges depending on the context of use. Of note, while symptom-related label claims are those most frequently granted by regulatory authorities, no guidance specific to support the development, psychometric evaluation, and interpretation of endpoints derived from patient diaries exists. This article provides an overview of key methodological, statistical, and clinical considerations for implementation of patient diaries with a regulatory perspective in mind. Approaches and solutions covered in this article include (1) techniques to establish content validity based on obtaining qualitative insights in naturalistic settings and real-life experience of diary completion, (2) demonstration of psychometric properties with respect to day-to-day variability, and (3) aggregation of data from multiple days/events to move from items to endpoints. The importance of the patients’ engagement is highlighted in order to help overcome these challenges throughout all stages of diary and endpoint development and evaluation. This article can inform researchers who are developing or implementing patient diaries as clinical trial endpoints to ensure that the nuances of this mode of data collection are considered in the development of endpoints and prior to regulatory interactions. [ABSTRACT FROM AUTHOR]

Historically, the assessment of longitudinal construct validity in the field of psychosocial measurement involved defining hypotheses and calculating correlation coefficients using scores based on 2 measures at 2 or more time points. In the context of patient-reported outcomes, this evolved into sensitivity to change and responsiveness, including the computation of effect size estimates of change, standardized response means, and indices such as Guyatt’s statistic. Cross-sectional analyses or analyses based on 2 time points have been the standard practice. Evolving conceptualizations have incorporated more than 2 time points and have included depictions of individual trajectories of change in multiple measures, structural equation models, and mixed modeling techniques. The focus of this article is on methods to evaluate longitudinal construct validity. We describe a sample of these methods and provide considerations and recommendations for designing a thoughtful longitudinal construct validity evaluation of clinical outcome assessments. [ABSTRACT FROM AUTHOR]