Abstract
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.
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Abbreviations
- ANOVA:
-
Analysis of variance
- EXTEND:
-
Eltrombopag EXTENDed dosing study
- FACIT-F:
-
Fatigue subscale of the Functional Assessment of Chronic Illness Therapy
- FACT-Th:
-
Functional Assessment of Cancer Therapy-Thrombocytopenia
- HRQoL:
-
Health-related quality of life
- ICC:
-
Intraclass correlation coefficient
- ITP:
-
Immune thrombocytopenia
- LOTA:
-
Last on-treatment assessment
- MCS:
-
Mental component summary
- MEI-SF:
-
Motivation and Energy Inventory-Short Form
- MID:
-
Minimally important difference
- PCS:
-
Physical component summary
- RAISE:
-
RAndomized placebo-controlled ITP Study with Eltrombopag
- SD:
-
Standard deviation
- SF-36v2:
-
Medical Outcomes Study Short Form-36 version 2
- WHO:
-
World Health Organization
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Acknowledgments
Funding for this study was provided by GlaxoSmithKline. All listed authors meet the criteria for authorship set forth by the International Committee for Medical Journal Editors. The authors wish to acknowledge the following individuals for their contributions and critical review during the development of this manuscript: Lisa Breck, Steve Collins, and AOI Communications, L.P., for editorial assistance, and Kimberly Marino for critical review.
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Trial registration numbers: EXTEND NCT00351468, RAISE NCT00370331.
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Signorovitch, J., Brainsky, A. & Grotzinger, K.M. Validation of the FACIT-fatigue subscale, selected items from FACT-thrombocytopenia, and the SF-36v2 in patients with chronic immune thrombocytopenia. Qual Life Res 20, 1737–1744 (2011). https://doi.org/10.1007/s11136-011-9912-9
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DOI: https://doi.org/10.1007/s11136-011-9912-9