Presentation (CTI)

OBJECTIVES: This is the first study to assess the psychometric properties of the mucopolysaccharidosis Health Assessment Questionnaire (MPS-HAQ) for the mucopolysaccharidosis (MPS) IVA population.
METHODS: The data used for the analysis were derived from the MOR-004 study and the UK Managed Access Agreement (MAA). Psychometric analyses included calculation of floor and ceiling effects, inter-item correlations, corrected item-total correlations, internal consistency reliability, convergent and discriminant validity, and test-retest reliability.
RESULTS: At a 35% threshold, the Self-care and Caregiver assistance domains had ceiling effects for 44% and 53% of items, respectively. Floor effects were only seen in the Self-care domain (7% of items). Inter-item correlations were within the expected range for all domains, supporting the structure of the domains. Corrected item-total correlations indicated good discrimination between the different items of the MPS-HAQ. Cronbach’s alpha indicated good internal consistency for all domains. The convergent and discriminant validity analysis results indicated that the MPS-HAQ and EuroQol 5 dimensions, 5 levels (EQ-5D-5L) tools are conceptually similar. The MPS-HAQ also demonstrated excellent test-retest reliability.
CONCLUSIONS: The MPS-HAQ displays good validity and reliability in patients with MPS IVA, supporting its use as an outcome measure in clinical trials and real-world studies in this population.