Patient-Reported Outcome and Biomarkers in Asthma

• Activity Number: 122
• Type: Topic Contributed
• Date/Time: Monday, August 5, 2013 : 8:30 AM to 10:20 AM
• Sponsor: Biometrics Section
• Author(s): Wen-Hung Chen and Gary Globe and Ingela Wiklund and Seppi Lin and Michael Schatz and Maria Mattera and Yun Chon
• Companies: United BioSource Corporation and Amgen Inc. and United BioSource Corporation and Amgen Inc. and Kaiser Permanente Medical Center and United BioSource Corporation and Amgen Inc.
• Keywords: patient-reported outcome ; Rasch model ; chronic respiratory disease symptom measure ; PRO validation

Abstract

An electronic diary, administered on a daily basis via the AM3® device, has been developed as a patient-reported outcome (PRO) measure for evaluating the treatment effect on a chronic respiratory disease. This study describes the statistical methods used for item selection and measurement properties assessment for the diary. The study involved a prospective, observational study of 276 patients with the chronic condition from clinics in the United States. Participants completed the twice-daily diary at home for 28 days. They also completed related PRO measures at three study visits. Spirometry was performed using the AM3® at all visits. Factor analysis supported the diary items comprised a single scale. Rasch model was used to select items with correct ordering of response options, good discriminant ability, no differential item functioning, and align with patient population on the measurement scale. Evaluation of internal consistency, test-rest reliability, concurrent validity, known-group validity, and responsiveness supported that selected set of final item comprised a reliable and valid daily diary for use to explore the treatment effect on a chronic respiratory disease.