INTRODUCTION: Sporadic inclusion body myositis (sIBM) is a progressive idiopathic inflammatory myopathy characterized by atrophy and weakness of proximal and distal muscle groups resulting in a loss of independence and the need for assistive devices and supportive care. To assess treatment benefit of new therapies, a patient-reported outcome measure of physical function was developed.
METHODS: The tool was rigorously developed in accordance with the U.S. Food and Drug Administration (FDA) Patient Report Outcomes (PRO) Guidance. A single-visit, observational study was conducted. Standard qualitative analytical methods were employed to analyze interview data and generate questionnaire items.
RESULTS: Twenty concept elicitation and 19 cognitive debriefing interviews were conducted, and 6 expert physicians were consulted. The tool consists of 11 items scored on a 0-10 numerical rating scale. Subjects completed the questionnaire utilizing either paper or electronic administration.
DISCUSSION: We have developed a PRO tool in alignment with FDA PRO Guidance for use in the functional assessment of treatment benefit in sIBM.
