title: Psychometric evaluation of the FACT Colorectal Cancer Symptom Index (FCSI-9): reliability, validity, responsiveness, and clinical meaningfulness.
abstract: BACKGROUND
  Patient-reported outcomes (PROs) are essential for evaluating treatment effects on health-related quality of life and symptoms from the patient's perspective. This study sought to evaluate the psychometric properties of the nine-item Functional Assessment of Cancer Therapy/National Comprehensive Cancer Network Colorectal Cancer Symptom Index (FCSI-9) in a metastatic colorectal cancer (mCRC) population.
  
  
  METHODS
  The FCSI-9 and EQ-5D were administered every 2-4 weeks to mCRC subjects in a phase III clinical trial. Three hundred ninety-one mCRC subjects completed the questionnaires at baseline and at least one follow-up assessment. Internal consistency reliability, test-retest reliability, construct validity, known groups validity, responsiveness, and the minimum important difference (MID) of the FCSI-9 were evaluated.
  
  
  RESULTS
  The internal consistency and test-retest reliability of the FCSI-9 were acceptable (0.81 and 0.76, respectively). Construct validity was supported based on moderate correlations with the EQ-5D. Known groups validity was evaluated by examining the FCSI-9 scores of subjects categorized by their Eastern Cooperative Oncology Group performance status (PS) score. Subjects with better PS scores reported significantly higher FCSI-9 scores than those with lower PS scores at both baseline and week 8. Responsiveness, as measured by Guyatt's statistic, was 0.77 from baseline to week 8 and 0.60 from week 4 to week 12. Considering all data together, the MID of the FCSI-9 is estimated to be in the range of 1.5-3.0 points.
  
  
  CONCLUSIONS
  Results provide preliminary evidence of the reliability, validity, and responsiveness of the FCSI-9.
authors.affiliation: ICON Clinical Research, Lifecycle Sciences Group, 188 Embarcadero, Suite 200, San Francisco, California 94105, USA. hilary.colwell@iconplc.com
authors.forename: Hilary H
authors.initials: HH
authors.lastname: Colwell
authors.forename: Susan D
authors.initials: SD
authors.lastname: Mathias
authors.forename: Michelle P
authors.initials: MP
authors.lastname: Turner
authors.forename: John
authors.initials: J
authors.lastname: Lu
authors.forename: Nicola
authors.initials: N
authors.lastname: Wright
authors.forename: Marc
authors.initials: M
authors.lastname: Peeters
authors.forename: David
authors.initials: D
authors.lastname: Cella
authors.forename: Giovanna
authors.initials: G
authors.lastname: Devercelli
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010166:Palliative Care; D000077544:Panitumumab; D010358:Patient Participation; D017060:Patient Satisfaction; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D000077544:Panitumumab