title: The king's foot of patient-reported outcomes: current practices and new developments for the measurement of change.
abstract: OBJECTIVE
  Assessing change remains a challenge in patient-reported outcomes. In June 2009, a group of psychometricians, biostatisticians, and behavioral researchers from other disciplines convened as a Longitudinal Analysis of Patient-Reported Outcomes Working group as part of the Statistical and Applied Mathematical Sciences Institute Summer Psychometric program to discuss the complex issues that arise when conceptualizing and operationalizing "change" in patient-reported outcome (PRO) measures and related constructs. This white paper summarizes these issues and provides recommendations and possible paths for dealing with the complexities of measuring change.
  
  
  RESULTS
  This article presents and discusses issues associated with: (1) conceptualizing and operationalizing change in PRO measures; (2) modeling change using state-of-the-art statistical methods; (3) impediments to detecting true change; (4) new developments to deal with these challenges; and (5) important gaps that are fertile ground for future research.
  
  
  CONCLUSIONS
  There was a consensus that important research still needs to be performed in order develop and refine high-quality PRO measures and statistical methods to analyze and model change in PRO constructs.
authors.affiliation: Jones Graduate School of Business, Rice University, Houston, TX, USA. rswartz@rice.edu
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Swartz
authors.forename: Carolyn
authors.initials: C
authors.lastname: Schwartz
authors.forename: Ethan
authors.initials: E
authors.lastname: Basch
authors.forename: Li
authors.initials: L
authors.lastname: Cai
authors.forename: Diane L
authors.initials: DL
authors.lastname: Fairclough
authors.forename: Lori
authors.initials: L
authors.lastname: McLeod
authors.forename: Tito R
authors.initials: TR
authors.lastname: Mendoza
authors.forename: Bruce
authors.initials: B
authors.lastname: Rapkin
mesh_terms: D006304:Health Status; D006801:Humans; D033183:Interdisciplinary Communication; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011594:Psychometrics; D011788:Quality of Life; D018434:Sickness Impact Profile; D016896:Treatment Outcome