Validation of the FACIT-fatigue subscale, selected items from FACT-thrombocytopenia, and the SF-36v2 in patients with chronic immune thrombocytopenia

• Published in: Quality of life research 2011-12, Vol.20 (10), p.1737-1744
• Main Authors: Signorovitch, James, Brainsky, Andres, Grotzinger, Kelly M.
• Format: Article
• Language: English
• Subjects: Benzoates - administration & dosage; Benzoates - therapeutic use; Bleeding; Blood diseases; Blood platelets; Cancer; Cancer therapies; Chronic Disease; Chronic diseases; Chronic illnesses; Construct validity; Design; Disease; Dose-Response Relationship, Drug; Fatigue; Fatigue - drug therapy; Fatigue - etiology; Fatigue - psychology; Female; Focus groups; Hemorrhage - etiology; Hemorrhage - prevention & control; Hemorrhage - psychology; Humans; Hydrazines - administration & dosage; Hydrazines - therapeutic use; Idiopathic thrombocytopenic purpura; INSTRUMENT DEVELOPMENT; Male; Medicine; Medicine & Public Health; Patients; Platelets; Prospective Studies; Public Health; Pyrazoles - administration & dosage; Pyrazoles - therapeutic use; Quality of life; Quality of Life Research; Questionnaires; Receptors, Thrombopoietin - administration & dosage; Receptors, Thrombopoietin - agonists; Receptors, Thrombopoietin - therapeutic use; Reproducibility of Results; Sickness Impact Profile; Sociology; Thrombocytopenia; Thrombocytopenia - complications; Thrombocytopenia - drug therapy; Thrombocytopenia - psychology; Time; Transponders; Validity
• ISSN: 0962-9343; 1573-2649
• DOI: 10.1007/s11136-011-9912-9

Purpose To assess the validity and reliability of the fatigue subscale of the Functional Assessment of Chronic Illness Therapy (FACIT-F), a 6-item subset from the thrombocytopenia subscale of the Functional Assessment of Cancer Therapy (FACT-Th6) and the Short Form-36 Version 2 (SF-36v2) in 2 clinical trials of the thrombopoietin receptor agonist eltrombopag in chronic immune thrombocytopenia (ITP) patients. Methods In the 6-month, RAndomized placebo-controlled ITP Study with Eltrombopag (RAISE; n = 197), the FACIT-F, FACT-Th6, and SF-36v2 were administered at baseline, day 43, weeks 14 and 26, or early withdrawal. In the ongoing open-label extension study, Eltrombopag EXTENDed Dosing Study (EXTEND; n = 154), measures were administered at baseline, at the beginning of each stage, and at permanent discontinuation of study medication. Results FACIT-F, FACT-Th6, and SF-36v2 demonstrated acceptable internal consistency reliability (i.e., all Cronbach's alphas > 0.70) and test-retest reliability (all intraclass correlation coefficients > 0.70). Construct validity was supported by moderate (0.35 < r < 0.50) to strong (r > 0.50) inter-measure correlations for baseline and change scores. A small to medium magnitude of effect was captured by the FACIT-F and FACT-Th6 among patients who experienced sustained platelet responses. Conclusions Results provide support for the validity, reliability, and responsiveness of the FACIT-F, FACT-Th6, and SF-36v2 in chronic ITP patients.