Psychometric Performance of the Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue Questionnaire Among Patients With Paroxysmal Nocturnal Hemoglobinuria

Speaker(s)

Cella D1, Vallow S2, Bermann G3, McDonald J4, Ngerano G5, Linton S4, Arenson E4, Maitra S6, Lamoureux R7, Dickie G4
1Northwestern University, Evanston, IL, USA, 2Novartis Pharmaceuticals Corporation, New Hope, PA, USA, 3Novartis Pharma AG, Basel, Switzerland, 4Adelphi Values, Boston, MA, USA, 5Adelphi Values, Raleigh, NC, USA, 6Novartis Healthcare Pvt. Ltd., Hyderabad, Rangareddy, India, 7Adelphi Values, North Chelmsford, MA, USA

Presentation Documents

OBJECTIVES: To evaluate the psychometric properties of the Functional Assessment of Chronic Illness Therapy—Fatigue (FACIT-Fatigue) in two Phase 3 trials: APPLY-PNH (randomized, active-controlled open-label) and APPOINT-PNH (single-arm, open-label) for patients with paroxysmal nocturnal hemoglobinuria (PNH), a rare hemolytic disorder characterized by hemolysis, bone marrow failure, and thrombosis. Fatigue is a frequently reported symptom.

METHODS: FACIT-Fatigue items were evaluated for item distribution and floor and ceiling effects. A bifactor model was conducted to test for essential unidimensionality and construct validity of a total score. Reliability analyses assessed both the internal consistency and stability over time of FACIT-Fatigue total score. Concurrent validity of the FACIT-Fatigue total score was assessed by examining correlations with a question on the patient’s global impression of fatigue severity (PGIS) and items from the EORTC-QLQ-C30 and EQ-5D-5L. Ability to distinguish between clinically distinct groups was assessed by PGIS level and hemoglobin change. Responsiveness to change was assessed by anchoring FACIT-F score to changes in EORTC-QLQ-C30 fatigue scores, PGIS level, and hemoglobin. Analyses were conducted separately by trial, except for the bi-factor model analysis, which used pooled data from APPOINT-PNH and APPLY-PNH to increase sample size.

RESULTS: Analysis population for APPLY-PNH (N=95) was 68% female, median age 53.0 years; for APPOINT-PNH (N=40) it was 57% male, median age 38.5 years. Participants endorsed the full range of FACIT-Fatigue response options. A bifactor model supported the essential unidimensionality of FACIT-Fatigue scores which were both internally consistent and stable across time. Mean FACIT-Fatigue total score decreased with increased fatigue severity. Strong correlations were found between changes in FACIT-Fatigue total score with changes in scores for the other PRO measures, and weak-to-moderate correlations with change in hemoglobin.

CONCLUSIONS: The FACIT-Fatigue was found to be reliable, construct-valid, and appropriate for use in measuring change in fatigue experienced by participants with PNH.

Code

PCR31

Topic

Clinical Outcomes, Patient-Centered Research

Topic Subcategory

Clinical Outcomes Assessment, Patient-reported Outcomes & Quality of Life Outcomes

Disease

Rare & Orphan Diseases, Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)