title: The development of a survey to measure completeness of response to migraine therapy.
abstract: OBJECTIVE
  To assess the psychometric properties of a new patient-reported migraine instrument, the Completeness of Response Survey (CORS), which measures a comprehensive set of factors important to patients' decisions regarding the initiation and continuation of treatment.
  
  
  BACKGROUND
  Traditionally, migraine treatments and the instruments used to demonstrate their efficacy have focused on the relief of headache pain. As new treatments emerge with the potential for more complete and consistent migraine relief, more comprehensive tools are needed to demonstrate these benefits. The CORS includes 2 modules, the static CORS, which comprehensively evaluates one treatment at one time point, and the comparative CORS, which provides a more global comparison between 2 treatments at one time point. Together, the 2 modules can measure unmet treatment needs and improvements over the course of a clinical study.
  
  
  METHODS
  Data from an 8-site study comparing 147 patients' recent experiences with their current triptan therapy and 2 months of study treatment with a single-tablet formulation of sumatriptan/naproxen sodium were used to conduct a preliminary psychometric evaluation of the CORS. The study included both modules of the CORS, the Headache Impact Test, the revised Patient Perception of Migraine Questionnaire, and a migraine diary.
  
  
  RESULTS
  The CORS response categories in both the static and comparative modules demonstrated limited floor or ceiling effects and few missing values (<3%). Inter-item correlations, principal components analysis (component loading range: 0.62 to 0.95), and high estimates of internal consistency (alpha range: 0.88 to 0.94) for each composite score supported the structure and proposed scoring algorithm for the static module. The pattern of correlations between the CORS static and comparative items and composites with the revised Patient Perception of Migraine Questionnaire items and subscales, as well as the relationships between responses to selected static CORS items and the migraine diary, supported the construct validity of the CORS.
  
  
  CONCLUSIONS
  The CORS is capable of demonstrating advantages of more comprehensive migraine therapies over traditional therapies, which are primarily focused on the resolution of headache pain, by addressing the frequency and speed with which the most common migraine symptoms are resolved and patients' return to normal functioning. This research shows evidence for the value and utility for the CORS static and comparative items and components, and further evaluation is underway.
authors.affiliation: RTI Health Solutions, Research Triangle Park, NC 27709, USA. ccoon@rti.org
authors.forename: Cheryl D
authors.initials: CD
authors.lastname: Coon
authors.forename: Sheri E
authors.initials: SE
authors.lastname: Fehnel
authors.forename: Kimberly H
authors.initials: KH
authors.lastname: Davis
authors.forename: M Chris
authors.initials: MC
authors.lastname: Runken
authors.forename: M E
authors.initials: ME
authors.lastname: Beach
authors.forename: Roger K
authors.initials: RK
authors.lastname: Cady
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000628:therapy*; D010358:Patient Participation; D011594:Psychometrics / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult