title: Measuring the concerns of cancer patients with low platelet counts: the Functional Assessment of Cancer Therapy--thrombocytopenia (FACT-Th) questionnaire.
abstract: OBJECTIVE
  The specific concerns of people with low platelet counts (thrombocytopenia) have not been characterized well in the literature and as a result proper measurement of patient-reported concerns is lacking. We report on the development and validation of questions specifically targeted to patients with thrombocytopenia that can be added to the more general concerns in the Functional Assessment of Cancer Therapy-General.
  
  
  METHODS
  An 18-item FACT-Thrombocytopenia Subscale (ThS) was rated and evaluated by thrombocytopenic patients at baseline during a validation study of 40 thrombocytopenic and 43 nonthrombocytopenic cancer patients. To evaluate responsiveness, patients completed a battery of self-report measures including the FACT-Th and were followed up for change in platelet count over 2 weeks.
  
  
  RESULTS
  All subscales and aggregated scores showed high internal consistency at initial assessment and at retesting. Convergent and divergent validity were demonstrated by predicted relationships between FACT-Th subscales and mood, mental and physical component scores of the SF-36, and social desirability. The ThS differentiated patients with low platelets from those with normal platelet counts and good performance from poor performance status patients.
  
  
  CONCLUSIONS
  The FACT-Th is a reliable and valid measure for assessing the impact of thrombocytopenia on patients' lives. It can distinguish cancer patients with and without thrombocytopenia and is responsive to increase in platelet count over time. The FACT-Th may therefore prove useful as a measure of self-reported symptoms and concerns related to thrombocytopenia in clinical trials evaluating new pharmacologic agents and/or platelet transfusion practice.
authors.affiliation: Center on Outcomes, Research and Education, Evanston Northwestern Healthcare, Feinberg School of Medicine, Northwestern University, 1001 University Place, Suite 100, Evanston, IL 60201, USA. d-cella@northwestern.edu
authors.forename: David
authors.initials: D
authors.lastname: Cella
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Beaumont
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Webster
authors.forename: Jin-Shei
authors.initials: JS
authors.lastname: Lai
authors.forename: Linda
authors.initials: L
authors.lastname: Elting
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000523:psychology*; D010349:Patient Compliance; D010976:Platelet Count; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013921:Thrombocytopenia / Q000523:psychology*