TY - JOUR
T1 - RETRACTED ARTICLE
T2 - Content validity and psychometric evaluation of Functional Assessment of Chronic Illness Therapy-Fatigue in patients with psoriatic arthritis
AU - Cella, David
AU - Wilson, Hilary
AU - Shalhoub, Huda
AU - Revicki, Dennis A.
AU - Cappelleri, Joseph C.
AU - Bushmakin, Andrew G.
AU - Kudlacz, Elizabeth
AU - Hsu, Ming Ann
N1 - Funding Information:
Editorial support under the guidance of the authors was provided by Paul Scutt, PhD, of CMC Connect, a division of Complete Medical Communications Ltd., Macclesfield, UK and was funded by Pfizer Inc., New York, NY, USA in accordance with Good Publication Practice (GPP3) guidelines (Ann Intern Med 2015;163:461–464). The authors would like to thank Dr. Vibeke Strand for her critical review of this manuscript.
Funding Information:
This study was funded by Pfizer Inc.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Background: To evaluate the measurement properties (e.g. content validity, reliability and ability to detect change) of the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale in patients with active psoriatic arthritis (PsA). Methods: One-on-one semi-structured qualitative interviews with adult patients with active PsA evaluated the content validity of FACIT-Fatigue. Quantitative measurement properties were evaluated using data from phase III tofacitinib randomized controlled trials (RCTs) in PsA: OPAL Broaden (NCT01877668) and OPAL Beyond (NCT01882439). Results: Of 12 patients included in the qualitative study, 2 (17%) had mild, 8 (67%) had moderate, and 2 (17%) had severe PsA disease activity; 7 (58%) attributed fatigue to PsA, and 7 (58%) rated fatigue as important or extremely important. Most patients considered the FACIT-Fatigue items relevant to their PsA experience and understood item content and response options as intended. In the psychometric analysis of RCT data, a second-order confirmatory factor model fit the data well (Bentler’s Comparative Fit Index ≥0.92). FACIT-Fatigue demonstrated good internal consistency (Cronbach’s coefficient α ≥ 0.90), test-retest reliability (Intraclass Correlation Coefficient ≥ 0.80) and a strong correlation with SF-36 Vitality (r > 0.80). A robust relationship between disease activity (based on Patient’s Global Assessment of Psoriasis and Arthritis) and FACIT-Fatigue was observed (effect sizes > 1.4), with clinically important difference for the FACIT-Fatigue total score estimated as 3.1 points, and the responder definition estimated as a 4-point improvement for FACIT-Fatigue total score. Conclusion: Fatigue was confirmed to be an important symptom to patients with PsA, and FACIT-Fatigue was found to be a reliable and valid measure in this population.
AB - Background: To evaluate the measurement properties (e.g. content validity, reliability and ability to detect change) of the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale in patients with active psoriatic arthritis (PsA). Methods: One-on-one semi-structured qualitative interviews with adult patients with active PsA evaluated the content validity of FACIT-Fatigue. Quantitative measurement properties were evaluated using data from phase III tofacitinib randomized controlled trials (RCTs) in PsA: OPAL Broaden (NCT01877668) and OPAL Beyond (NCT01882439). Results: Of 12 patients included in the qualitative study, 2 (17%) had mild, 8 (67%) had moderate, and 2 (17%) had severe PsA disease activity; 7 (58%) attributed fatigue to PsA, and 7 (58%) rated fatigue as important or extremely important. Most patients considered the FACIT-Fatigue items relevant to their PsA experience and understood item content and response options as intended. In the psychometric analysis of RCT data, a second-order confirmatory factor model fit the data well (Bentler’s Comparative Fit Index ≥0.92). FACIT-Fatigue demonstrated good internal consistency (Cronbach’s coefficient α ≥ 0.90), test-retest reliability (Intraclass Correlation Coefficient ≥ 0.80) and a strong correlation with SF-36 Vitality (r > 0.80). A robust relationship between disease activity (based on Patient’s Global Assessment of Psoriasis and Arthritis) and FACIT-Fatigue was observed (effect sizes > 1.4), with clinically important difference for the FACIT-Fatigue total score estimated as 3.1 points, and the responder definition estimated as a 4-point improvement for FACIT-Fatigue total score. Conclusion: Fatigue was confirmed to be an important symptom to patients with PsA, and FACIT-Fatigue was found to be a reliable and valid measure in this population.
KW - Content validity
KW - FACIT-fatigue
KW - Psoriatic arthritis
KW - Psychometric properties
KW - Tofacitinib
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U2 - 10.1186/s41687-019-0094-5
DO - 10.1186/s41687-019-0094-5
M3 - Article
C2 - 30680661
AN - SCOPUS:85078013447
VL - 3
JO - Journal of Patient-Reported Outcomes
JF - Journal of Patient-Reported Outcomes
SN - 2509-8020
IS - 1
M1 - 5
ER -