Development and content validity of the Glut1DS Movement Disorder Diary

To explore the experience of patients with glucose transporter type 1 deficiency syndrome (Glut1DS) and paroxysmal movement disorders (PMDs) and develop a novel movement disorder diary. A qualitative literature review, semi-structured concept elicitation interviews, and focus group were conducted to understand the experience of patients with PMDs. Pilot-testing and cognitive interviews evaluated the Glut1DS Movement Disorder Diary (Glut1DS-MDD). Nine types of PMDs were identified, including ataxia, dysarthria, dystonia, and oculomotor disorders. PMDs impacted physical functioning, sleep, daily activities, school/work, emotional wellbeing, and social life. Testing of the Glut1DS-MDD confirmed relevance and understanding. Evidence supports the content validity of the Glut1DS-MDD − the first assessment of Glut1DS PMDs developed in accordance with FDA Patient-Reported Outcome Guidance. ClinicalTrials.gov, NCT02960217; EudraCT, 2015-005536-17. The presentation and impact of paroxysmal movement disorders (PMDs) in Glut1DS was explored through a literature/online blog review, focus group, and qualitative interviews with clinicians, patients, and caregivers. Nine PMD types, heterogenous in presentation, were identified: ataxia, dysarthria, dystonia, oculomotor disorders, myoclonus, chorea, hypotonia, spasticity, and tremors. The presentation of PMDs varied both within and between patients and PMD events. PMDs impacted patient’s physical functioning, sleep, daily activities, school/work, emotional well-being, and social life.Findings informed the development of the Glut1DS Movement Disorder Diary (Glut1DS-MDD)–an electronic patient and caregiver-completed daily diary capturing the frequency and duration of PMD events considered disabling (i.e., those that affected or limited ability to perform daily activities, regardless of their severity) the type of PMDs involved in each event, and the specific impacts of each event on physical functioning and daily activities.Findings from pilot testing and cognitive interviews demonstrated that the Glut1DS-MDD was well understood by participants and that the concepts assessed were relevant to the experience of patients with PMDs in Glut1DS.This qualitative research provides novel and in-depth insights regarding the presentation of PMDs in Glut1DS and their impacts on patients’ physical functioning, daily activities, and broader domains of HRQoL. Findings support the content validity and usability of the Glut1DS-MDD, a novel assessment of Glut1DS PMDs and their functional impact, developed in accordance with the Food and Drug Administration’s Patient-Reported Outcome Guidance, as a clinical trial endpoint to establish treatment outcomes. The presentation and impact of paroxysmal movement disorders (PMDs) in Glut1DS was explored through a literature/online blog review, focus group, and qualitative interviews with clinicians, patients, and caregivers. Nine PMD types, heterogenous in presentation, were identified: ataxia, dysarthria, dystonia, oculomotor disorders, myoclonus, chorea, hypotonia, spasticity, and tremors. The presentation of PMDs varied both within and between patients and PMD events. PMDs impacted patient’s physical functioning, sleep, daily activities, school/work, emotional well-being, and social life. Findings informed the development of the Glut1DS Movement Disorder Diary (Glut1DS-MDD)–an electronic patient and caregiver-completed daily diary capturing the frequency and duration of PMD events considered disabling (i.e., those that affected or limited ability to perform daily activities, regardless of their severity) the type of PMDs involved in each event, and the specific impacts of each event on physical functioning and daily activities. Findings from pilot testing and cognitive interviews demonstrated that the Glut1DS-MDD was well understood by participants and that the concepts assessed were relevant to the experience of patients with PMDs in Glut1DS. This qualitative research provides novel and in-depth insights regarding the presentation of PMDs in Glut1DS and their impacts on patients’ physical functioning, daily activities, and broader domains of HRQoL. Findings support the content validity and usability of the Glut1DS-MDD, a novel assessment of Glut1DS PMDs and their functional impact, developed in accordance with the Food and Drug Administration’s Patient-Reported Outcome Guidance, as a clinical trial endpoint to establish treatment outcomes.