1. Assessment of patient-reported symptoms and distress in IgG4-related disease (IgG4-RD): Development, clinical validation, and content validation of the IgG4-RD Symptom Severity Index.
- Author
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Wallace ZS, McMahon GA, Hang B, Fu X, Harkness T, Donelan K, Fernandes A, Cook C, Katz G, Perugino C, and Stone JH
- Subjects
- Humans, Quality of Life, Patient Reported Outcome Measures, Immunoglobulin G4-Related Disease, Autoimmune Diseases diagnosis
- Abstract
Objective: IgG4-related disease (IgG4-RD), a multi-organ autoimmune disease, causes diverse manifestations that can lead to symptoms and distress. We developed and validated the Symptom Severity Index (SSI) to assess symptom burden., Methods: A pilot SSI was tested in n = 5; several gaps were identified. Twenty semi-structured qualitative interviews were performed to expand the item set and identify missing symptoms. Subsequent changes resulted in the current SSI; it was administered with quality of life (QOL) measures to n = 136. We assessed symptom burden and the construct validity of the SSI. A distress score for each symptom is calculated by multiplying symptom frequency ("Never" [0 points] to "Every Day" [3 points]) by associated distress ("None" [0 points] to "Very Much" [4 points]). Each distress score is summed to calculate a total SSI score., Results: The SSI assesses the frequency and distress of 24 symptoms. Among n = 136 with ≥ 1 SSI, 90% experienced ≥ 1 symptom and 88% had distress. The median SSI score was 6.5 (IQR 3.0, 18.0). Fear of more severe disease was observed in 49%. The SSI inversely correlated with the SF-36 (r= - 0.51, p<0.001), the feeling thermometer (r= - 0.28, p<0.001), and the EQ-5D (r= - 0.28, p<0.001). The median SSI score was higher during active vs non-active disease among n = 52 who completed >1 SSI (15 [6, 26] vs. 3 [2, 14], p = 0.008)., Conclusions: Symptoms and distress are common in IgG4-RD and associated with worse health-related QOL. The SSI has face, content, and construct validity; it corresponds with QOL measures., Competing Interests: Declaration of Competing Interest ZSW reports research support from Bristol-Myers Squibb and Principia/Sanofi and consulting fees or advisory board fees from Viela Bio, Zenas BioPharma, Horizon, Novartis, Visterra/Otsuka, Shionogi, and MedPace. ZSW and JHS receive royalties for use of the Symptom Severity Index., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
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