title: Measuring financial toxicity as a clinically relevant patient-reported outcome: The validation of the COmprehensive Score for financial Toxicity (COST).
abstract: Cancer and its treatment lead to increased financial distress for patients. To the authors' knowledge, to date, no standardized patient-reported outcome measure has been validated to assess this distress.
  
  
  
  Patients with AJCC Stage IV solid tumors receiving chemotherapy for at least 2 months were recruited. Financial toxicity was measured by the COmprehensive Score for financial Toxicity (COST) measure. The authors collected data regarding patient characteristics, clinical trial participation, health care use, willingness to discuss costs, psychological distress (Brief Profile of Mood States [POMS]), and health-related quality of life (HRQOL) as measured by the Functional Assessment of Cancer Therapy: General (FACT-G) and the European Organization for Research and Treatment of Cancer (EORTC) QOL questionnaires. Test-retest reliability, internal consistency, and validity of the COST measure were assessed using standard-scale construction techniques. Associations between the resulting factors and other variables were assessed using multivariable analyses.
  
  
  
  A total of 375 patients with advanced cancer were approached, 233 of whom (62.1%) agreed to participate. The COST measure demonstrated high internal consistency and test-retest reliability. Factor analyses revealed a coherent, single, latent variable (financial toxicity). COST values were found to be correlated with income (correlation coefficient [r] = 0.28; P<.001), psychosocial distress (r = -0.26; P<.001), and HRQOL, as measured by the FACT-G (r = 0.42; P<.001) and by the EORTC QOL instruments (r = 0.33; P<.001). Independent factors found to be associated with financial toxicity were race (P = .04), employment status (P<.001), income (P = .003), number of inpatient admissions (P = .01), and psychological distress (P = .003). Willingness to discuss costs was not found to be associated with the degree of financial distress (P = .49).
  
  
  
  The COST measure demonstrated reliability and validity in measuring financial toxicity. Its correlation with HRQOL indicates that financial toxicity is a clinically relevant patient-centered outcome. Cancer 2017;123:476-484. © 2016 American Cancer Society.
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Jonas A
authors.initials: JA
authors.lastname: de Souza
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Bonnie J
authors.initials: BJ
authors.lastname: Yap
authors.affiliation: Department of Public Health Sciences, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Kristen
authors.initials: K
authors.lastname: Wroblewski
authors.affiliation: Center for Health Policy and Outcomes, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Victoria
authors.initials: V
authors.lastname: Blinder
authors.affiliation: Institute of Psychology, Illinois Institute of Technology, Chicago, IL.
authors.forename: Fabiana S
authors.initials: FS
authors.lastname: Araújo
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Fay J
authors.initials: FJ
authors.lastname: Hlubocky
authors.affiliation: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Lauren H
authors.initials: LH
authors.lastname: Nicholas
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: O'Connor
authors.affiliation: Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois.
authors.forename: Bruce
authors.initials: B
authors.lastname: Brockstein
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Ratain
authors.affiliation: Department of Medicine, The University of Chicago Medicine, Chicago, Illinois.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Daugherty
authors.affiliation: Department of Medical Social Sciences, Northwestern University, Chicago, Illinois.
authors.forename: David
authors.initials: D
authors.lastname: Cella
mesh_terms: D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D003362:Cost-Benefit Analysis; D004358:Drug Therapy / Q000191:economics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000191:economics* / Q000453:epidemiology*; D000071066:Patient Reported Outcome Measures; D011788:Quality of Life; D011795:Surveys and Questionnaires
keywords: cost of cancer; financial burden; financial toxicity; patient-reported outcome (PRO)