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

Research output: Contribution to journalArticle

  • External authors:
  • Alexandra Legge
  • Susan Kirkland
  • Kenneth Rockwood
  • Pantelis Andreou
  • Sang Cheol Bae
  • Caroline Gordon
  • Juanita Romero-Diaz
  • Jorge Sanchez-Guerrero
  • Daniel J. Wallace
  • Sasha Bernatsky
  • Ann E. Clarke
  • Joan T Merrill
  • Ellen M. Ginzler
  • Paul Fortin
  • Dafna D. Gladman
  • Murray B. Urowitz
  • David A Isenberg
  • Anisur Rahman
  • Graciela S. Alarcón
  • Michelle Petri
  • Munther A. Khamashta
  • M. A. Dooley
  • Rosalind Ramsey-Goldman
  • Susan Manzi
  • Kristjan Steinsson
  • Asad A. Zoma
  • Cynthia Aranow
  • Meggan Mackay
  • Guillermo Ruiz-Irastorza
  • S. Sam Lim
  • Murat Inanc
  • Ronald F. van Vollenhoven
  • Andreas Jonsen
  • Ola Nived
  • Manuel Ramos-Casals
  • Diane L. Kamen
  • Kenneth C Kalunian
  • Soren Jacobsen
  • Christine A. Peschken
  • Anca Askanase
  • John G. Hanly

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 systemic lupus erythematosus (SLE). Methods: For this secondary analysis, the baseline visit was defined as the first study visit at which both organ damage (SLICC/American College of Rheumatology Damage Index [SDI]) and health-related quality of life (Short-Form 36 [SF-36] scores) 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: In the baseline data set of 1,683 patients with SLE, 89% were female, the mean ± SD age was 35.7 ± 13.4 years, and the mean ± SD disease duration was 18.8 ± 15.7 months. At baseline, the mean ± SD SLICC-FI score was 0.17 ± 0.08 (range 0–0.51). Baseline SLICC-FI values exhibited the expected measurement properties and were weakly correlated with baseline SDI scores (r = 0.26, P < 0.0001). Higher baseline SLICC-FI values (per 0.05 increment) were associated with increased mortality risk (hazard ratio 1.59, 95% confidence interval 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 might be used to predict future mortality risk. The SLICC-FI is potentially valuable for quantifying vulnerability among patients with SLE, and adds to existing prognostic scores.

Bibliographical metadata

Original languageEnglish
Pages (from-to)1297-1307
Number of pages11
JournalArthritis and Rheumatology
Volume71
Issue number8
Early online date20 Feb 2019
DOIs
Publication statusPublished - 1 Aug 2019