Evaluating the Properties of a Frailty Index and Its Association With Mortality Risk Among Patients With Systemic Lupus Erythematosus

• Type of Material: Article
• Authors: Alexandra Legge, Dalhousie University; Susan Kirkland, Dalhousie University; Kenneth Rockwood, Dalhousie University; Pantelis Andreou, Dalhousie University; Sang-Cheol Bae, Hanyang University Hospital for Rheumatic Diseases; Caroline Gordon, University of Birmingham; Juanita Romero-Diaz, Instituto Nacional de Ciencias Medicas y Nutrición; Jorge Sanchez-Guerrero, Instituto Nacional de Ciencias Medicas y Nutrición; Daniel J. Wallace, Cedars Sinai Medical Center; Sasha Bernatsky, McGill University; Ann E. Clarke, University of Calgary; Joan T. Merrill, Oklahoma Medical Research Foundation; Ellen M. Ginzler, SUNY Downstate Medical Center; Paul Fortin, CHU Quebec; Dafna D. Gladman, Toronto Western Hospital; Murray B. Urowitz, Toronto Western Hospital; Ian N. Bruce, University of Manchester; David A. Isenberg, University College London; Anisur Rahman, University College London; Graciela S. Alarcon, University of Alabama Birmingham; Michelle Petri, Johns Hopkins University; Munther A. Khamashta, Kings College London; M. A. Dooley, University of North Carolina; Rosalind Ramsey-Goldman, Northwestern University; Susan Manzi, Allegheny Health Network; Kristjan Steinsson, Landspitali University Hospital; Asad A. Zoma, Hairmyres Hospital; Cynthia Aranow, Feinstein Institute for Medical Research; Meggan Mackay, Feinstein Institute for Medical Research; Sung Lim, Emory University; Guillermo Ruiz-Irastorza, University of Basque Country; Murat Inanc, Istanbul University; Ronald F. van Vollenhoven, Karolinska Institutet; Andreas Jonsen, Lund University; Ola Nived, Lund University; Manuel Ramos-Casals, Hospital Clinic Barcelona; Diane L. Kamen, Medical University of South Carolina; Kenneth C. Kalunian, University of California San Diego; Soren Jacobsen, Copenhagen University Hospital; Christine A. Peschken, University of Manitoba; Anca Askanase, New York University; John G. Hanly, Dalhousie University
• Language: English
• Date: 2019-08-01
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2019 John Wiley & Sons, Inc. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1002/art.40859
• Title of Journal or Parent Work: Arthritis & Rheumatology
• Volume: 71
• Issue: 8
• Start Page: 1297
• End Page: 1307
• Grant/Funding Information: Dr. Caroline Gordon is supported by Lupus UK, Sandwell and West Birmingham Hospitals NHS Trust and the National Institute for Health Research (NIHR)/Wellcome Trust Birmingham Clinical Research Facility. The views expressed are those of the authors(s) and not necessarily those of the NHS, the NIHR or the Department of Health.; Dr. Soren Jacobsen is supported by the Danish Rheumatism Association (A3865) and the Novo Nordisk Foundation (A05990).; The Montreal General Hospital Lupus Clinic is partially supported by the Singer Family Fund for Lupus Research.; The Hopkins Lupus Cohort is supported by the NIH (grant AR43727 and 69572).; Dr. Paul R. Fortin presently holds a tier 1 Canada Research Chair on Systemic Autoimmune Rheumatic Diseases at Université Laval, and part of this work was done while he was still holding a Distinguished Senior Investigator of The Arthritis Society.; Dr. Sang-Cheol Bae’s work was supported in part by NRF-2017M3A9B4050335, Republic of Korea.; Dr. Mary Anne Dooley’s work was supported by the NIH grant RR00046.; Dr. John G. Hanly is supported by the Canadian Institutes of Health Research (grant MOP-88526).; Dr. Ramsey-Goldman’s work was supported by the NIH (grants 5UL1TR001422–02, formerly 8UL1TR000150 and UL-1RR-025741, K24-AR-02318, and P60AR064464 formerly P60-AR-48098).; Dr. Isenberg and Dr. Rahman are supported by the National Institute for Health Research, University College London Hospitals Biomedical Research Center.; Dr. Clarke holds The Arthritis Society Chair in Rheumatic Diseases at the University of Calgary.; Dr. Ruiz-Irastorza is supported by the Department of Education, Universities and Research of the Basque Government.; Dr. Bruce is a National Institute for Health Research (NIHR) Senior Investigator and is supported by Arthritis Research UK, the NIHR Manchester Biomedical Centre and the NIHR/Wellcome Trust Manchester Clinical Research Facility. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health.
• Keywords: Predictors; Quality of life; Damage index; Rheumatology; Deficit accumulation; People; Disease activity; Older adults; Science & Technology; Outcomes; Life Sciences & Biomedicine
• Research Categories: Health Sciences, Public Health; Health Sciences, Epidemiology; Health Sciences, Medicine and Surgery; Health Sciences, Immunology

Abstract

Objective: To evaluate the properties of a frailty index (FI), constructed using data from the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort, as a novel health measure in SLE. Methods: For this secondary analysis, the baseline visit was defined as the first study visit at which both organ damage (SLICC/ACR Damage Index [SDI]) and health-related quality of life (Short-Form 36 [SF-36]) were assessed. The SLICC-FI was constructed using baseline data. The SLICC-FI comprises 48 health deficits, including items related to organ damage, disease activity, comorbidities, and functional status. Content, construct, and criterion validity of the SLICC-FI were assessed. Multivariable Cox regression was used to estimate the association between baseline SLICC-FI values and mortality risk, adjusting for demographic and clinical factors. Results: The 1683 SLE patients in the baseline dataset were 89% female with mean (SD) age 35.7 (13.4) years and mean (SD) disease duration 18.8 (15.7) months. At baseline, the mean (SD) SLICC-FI score was 0.17 (0.08) with a range from 0 to 0.51. Baseline SLICC-FI values exhibited the expected measurement properties and were weakly correlated with baseline SDI scores (r=0.262; p<0.0001). Higher baseline SLICC-FI values (per 0.05 increment) were associated with increased mortality risk (Hazard Ratio 1.59; 95%CI 1.35–1.87), after adjusting for age, sex, steroid use, ethnicity/region, and baseline SDI scores. Conclusion: The SLICC-FI demonstrates internal validity as a health measure in SLE and predicts future mortality risk. The SLICC-FI is potentially valuable for quantifying vulnerability among patients with SLE, and adds to existing prognostic scores.