BackgroundBarth syndrome (BTHS, OMIM 302060) is a rare, life-threatening, x-linked genetic disorder that occurs almost exclusively in males and is characterized by cardiomyopathy, neutropenia, skeletal muscle myopathy primarily affecting larger muscles, and shorter stature in youth. A greater number of individuals with BTHS are now surviving into adulthood due to advancements in diagnosis and disease management. Given these improvements in life expectancy, understanding the disease experience over time has become increasingly important to individuals with the condition, treatment developers, and regulatory agencies. A study was conducted to explore the experience of BTHS from the perspective of adult males at least 35 years of age with the condition via in-depth qualitative interviews.ResultsFindings showed that adults with BTHS experienced a variety of signs/symptoms with variable onset and severity throughout their lives, the most frequently reported being the symptoms of tiredness, muscle weakness, and a fast and/or irregular heart rate, and the sign of short stature in youth. These signs/symptoms negatively impacted individuals’ emotional, physical, social, and role functioning. Tiredness and weakness impacted some individuals’ physical functioning from an early age and into adulthood. These symptoms generally worsened over time, increasingly interfering with individuals’ ability to fully participate in paid and unpaid labor and to partake in family and leisure activities.ConclusionsThis research complements recent studies characterizing the potentially degenerative and progressive nature of BTHS and can encourage future research into the natural history and progression of BTHS in untreated individuals. Participants’ interview responses revealed a range of symptoms and the potential for multiple impacts on individuals’ physical, social, emotional, and role functioning as a result of BTHS symptoms, yet also revealed variability in severity of experience as well as the possibility of resilience and adaptation to the condition.

Background Barth Syndrome (BTHS) is a rare genetic disorder that presents as a complex of debilitating symptoms and reduced life expectancy. Well-developed, BTHS-specific assessments measuring primary signs and symptoms of BTHS are not currently available, making it difficult to evaluate treatment effects in BTHS clinical studies. The objective of this research was to develop symptom-focused patient-reported outcome (PRO) measures for use in clinical studies with adolescents and adults with BTHS. Methods Concept elicitation interviews (CEIs) with pediatric (n = 18, age < 16 years) and adult (n = 15, age ≥ 16 years) individuals with BTHS and/or their caregivers were conducted to identify signs and symptoms relevant to BTHS and important to individuals with the condition. Based on CEI results, questionnaire construction activities were conducted to create unique adolescent and adult versions of the Barth Syndrome-Symptom Assessment (BTHS-SA). The questionnaires were evaluated in cognitive debriefing interviews (CDIs) with adolescents (n = 12; age 12- < 16 years) and adults (n = 12; age ≥ 16 years) with BTHS to assess relevance and readability of the tools. Results During the CEIs, a total of 48 and 40 signs and symptoms were reported by the pediatric and adult groups, respectively; 31 were reported by both age groups. Fatigue/tiredness and muscle weakness were the symptoms most frequently reported by both pediatric and adult patients with BTHS as important to improve with an effective treatment. The CEI results informed construction of a nine-item version of the BTHS-SA for adolescents and an eight-item version for adults. Developed for daily administration, each version asks respondents to rate symptom severity “at its worst” over the 24 h prior to administration. CDIs with both adolescents and adults with BTHS demonstrated that each BTHS-SA version was reflective of the disease experience and that respondents could interpret the questionnaire as intended and provide responses that accurately reflected their symptom experience. Conclusions The BTHS-SA adolescent and adult versions are content-valid PRO measures that can be used to evaluate severity of disease-specific symptoms in future clinical trials. Given the lack of available and well-developed assessments in this underserved therapeutic area, these tools fulfill a need for clinical researchers developing treatments for individuals with BTHS.

Background The Primary Mitochondrial Myopathy Symptom Assessment (PMMSA) is a 10-item patient-reported outcome (PRO) measure designed to assess the severity of mitochondrial disease symptoms. Analyses of data from a clinical trial with PMM patients were conducted to evaluate the psychometric properties of the PMMSA and to provide score interpretation guidelines for the measure. Methods The PMMSA was completed as a daily diary for approximately 14 weeks by individuals in a Phase 2 randomized, placebo-controlled crossover trial evaluating the safety, tolerability, and efficacy of subcutaneous injections of elamipretide in patents with mitochondrial disease. In addition to the PMMSA, performance-based assessments, clinician ratings, and other PRO measures were also completed. Descriptive statistics, psychometric analyses, and score interpretation guidelines were evaluated for the PMMSA. Results Participants (N = 30) had a mean age of 45.3 years, with the majority of the sample being female (n = 25, 83.3%) and non-Hispanic white (n = 29, 96.6%). The 10 PMMSA items assessing a diverse symptomology were not found to form a single underlying construct. However, four items assessing tiredness and muscle weakness were grouped into a “general fatigue” domain score. The PMMSA Fatigue 4 summary score (4FS) demonstrated stable test–retest scores, internal consistency, correlations with the scores produced by reference measures, and the ability to differentiate between different global health levels. Changes on the PMMSA 4FS were also related to change scores produced by the reference measures. PMMSA severity scores were higher for the symptom rated as “most bothersome” by each subject relative to the remaining nine PMMSA items (most bothersome symptom mean = 2.88 vs. 2.18 for other items). Distribution- and anchor-based evaluations suggested that reduction in weekly scores between 0.79 and 2.14 (scale range: 4–16) may represent a meaningful change on the PMMSA 4FS and reduction in weekly scores between 0.03 and 0.61 may represent a responder for each of the remaining six non-fatigue items, scored independently. Conclusions Upon evaluation of its psychometric properties, the PMMSA, specifically the 4FS domain, demonstrated strong reliability and construct-related validity. The PMMSA can be used to evaluate treatment benefit in clinical trials with individuals with PMM. Trial registration ClinicalTrials.gov identifier, NCT02805790; registered June 20, 2016; https://clinicaltrials.gov/ct2/show/NCT02805790.

Objectives: Primary mitochondrial myopathy (PMM) is a genetic condition characterized by life-limiting symptoms such as muscle weakness, fatigue, and pain. Because these symptoms are best reported by individuals with PMM, the objective of this qualitative research study was to develop a PMM-specific patient-reported outcome (PRO) questionnaire. Method: Individuals with PMM were interviewed, identifying the most salient symptoms of PMM and assessing the resulting questionnaire's relevance and comprehensibility. Results: Developed based on patient interviews, the 10-item Primary Mitochondrial Myopathy Symptom Assessment assesses patients' symptom experiences at their worst in the last 24 hours. Individuals with PMM confirmed the concepts of the questionnaire as relevant and comprehensive to their symptom experiences and responded to the items consistently with developers' intentions. Conclusions: The Primary Mitochondrial Myopathy Symptom Assessment is a content-valid PRO questionnaire with qualitative and quantitative support as a valuable tool to evaluate and monitor the day-to-day experience of PMM symptoms from the patient perspective.

INTRODUCTION: Patients with eosinophilic gastritis and/or gastroenteritis (EG/EGE) experience significantly reduced health-related quality of life related to the symptoms and signs of their disease. There is a need to develop a PRO questionnaire for clinical research in EG/EGE. The objectives of this study were to develop a symptom questionnaire (drafted using literature and clinician input to determine preliminary measurement concepts) and then (1) identify, describe, and substantiate signs, symptoms, and impacts of EG/EGE from the perspective of adults with the condition via concept elicitation methods; and (2) evaluate the properties of the questionnaire and make modifications via cognitive debriefing methods. METHODS: Interviews were conducted, transcribed, coded, and analyzed. Eligible adults with EG/EGE first participated in a concept elicitation segment where they described their experiences with EG/EGE, continuing until saturation was achieved, adding symptoms to the draft symptom questionnaire as needed. This was followed by a cognitive debrief to assess the appropriateness of the draft symptom questionnaire, where patients assessed readability, comprehensibility, relevance, and comprehensiveness. The questionnaire was modified based on patient feedback, then re-evaluated to confirm its appropriateness. RESULTS: In total, 16 interviews were conducted and 24 signs and symptoms were reported during concept elicitation. The most frequently reported (Figure 1) were abdominal pain, nausea, diarrhea, vomiting, and abdominal cramping; while abdominal pain, nausea, and diarrhea were the most bothersome to patients. Saturation was achieved after 12 interviews. In the cognitive debriefing, revisions included the addition of a vomiting frequency item and revision of the early satiety item for clarity. Response options were modified to instruct the participants to assess each symptom “at its worst”. For the final version of the EG/EGE-SQ©, participants were able to read, comprehend, and provide appropriate responses, and reported that the resulting questionnaire was comprehensive for their condition. CONCLUSION: The results of this research support the content validity, including comprehensiveness and interpretability, of the EG/EGE-SQ© which offers the potential for use in clinical research to assess symptoms in patients with EG/EGE. Future research is needed to assess its psychometric properties including reliability and validity, responsiveness, and potential for use in pediatric populations.