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Internal consistency and item-total correlation of patient-reported outcome instruments and hemophilia joint health score v2.1 in US adult people with hemophilia: results from the Pain, Functional Impairment, and Quality of life (P-FiQ) study

Authors Wang M, Batt K, Kessler C, Neff A, Iyer NN, Cooper DL, Kempton CL

Received 9 May 2017

Accepted for publication 7 September 2017

Published 25 October 2017 Volume 2017:11 Pages 1831—1839


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Johnny Chen

Michael Wang,1 Katharine Batt,2 Craig Kessler,3 Anne Neff,4 Neeraj N Iyer,5 David L Cooper,5 Christine L Kempton6

1Hemophilia and Thrombosis Center, University of Colorado School of Medicine, Aurora, CO, 2Hematology and Oncology, Wake Forest School of Medicine, Winston-Salem, NC, 3Department of Medicine and Pathology, Division of Hematology/Oncology, Georgetown University Hospital, Washington, DC, 4Hematology and Medical Oncology, Cleveland Clinic, Cleveland, OH, 5Novo Nordisk Inc., Clinical, Medical, and Regulatory Affairs, Plainsboro, NJ, 6Departments of Pediatrics and Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA, USA

Background: The Pain, Functional Impairment, and Quality of Life study was an observational, cross-sectional assessment of the impact of pain on functional impairment and quality of life in adult people with hemophilia (PWH) of any severity in the USA who experience joint pain and/or bleeding.
Objective: To assess internal consistency (IC) and item-total correlation (ITC) of assessment tools used in the Pain, Functional Impairment, and Quality of Life study.
Methods: Participants completed 5 patient-reported outcome instruments (­EQ-5D-5L with visual analog scale, Brief Pain Inventory v2 Short Form [BPI], International Physical Activity Questionnaire [IPAQ], Short Form 36 Health Survey v2 [SF-36v2], and Hemophilia Activities List [HAL]) and underwent an optional physiotherapist-administered musculoskeletal exam (Hemophilia Joint Health Score v2.1) during routine visits. Reliability assessment included IC and ITC of each instrument.
Results: A total of 381 adult PWH (median age, 34 years) were enrolled. Participants were predominantly white/non-Hispanic (69.2%); 75% had congenital hemophilia A, and 70.5% had severe hemophilia. A total of 310 subjects reported bleeding within the past 6 months (mean [SD] number of bleeds, 7.1 [13.00]). IC was generally high across the instruments employed (Cronbach’s alpha 0.79–0.98) with the exception of HAL use of transportation (0.58) and IPAQ total physical activity (0.51). ITC was high (Pearson’s product-moment correlation coefficient >0.20) for all items except the “vigorous intensity activities” item of IPAQ, which was applicable to less than one-third of participants. The ITCs were generally highest in domains/scores that measured the functional consequences of hemophilic arthropathy on mobility and pain.
Conclusion: The demonstrated reliability (IC/ITC) of the patient-reported outcome instruments and Hemophilia Joint Health Score v2.1 support a role for these instruments in evaluating adult PWH in US clinical and research settings.

Keywords: hemophilia, pain, functional impairment, quality of life, patient-reported outcome, joint health

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