Development and initial validation of a self-assessed lupus organ damage instrument

Karen H. Costenbader, Munther Khamashta, Silvia Ruiz-Garcia, Maria Teresa Perez-Rodriguez, Michelle Petri, Jennifer Elliott, Susan Manzi, Elizabeth W. Karlson, Tabitha Turner-Stokes, Bonnie Bermas, Jonathan Coblyn, Elena Massarotti, Peter Schur, Patricia Fraser, Iris Navarro, John G. Hanly, Timothy S. Shaver, Robert S. Katz, Eliza Chakravarty, Paul R. FortinMartha L. Sanchez, Jigna Liu, Kaleb Michaud, Graciela S. Alarcón, Frederick Wolfe

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

Objective. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) is a validated instrument for assessing organ damage in systemic lupus erythematosus (SLE). Trained physicians must complete it, thus limiting utility where this is impossible. Methods. We developed and pilot tested a self-assessed organ damage instrument, the Lupus Damage Index Questionnaire (LDIQ), in 37 SLE subjects and 7 physicians. After refinement, 569 English-speaking SLE subjects and 14 rheumatologists from 11 international SLE clinics participated in validation. Subjects and physicians completed the instruments separately. We calculated sensitivity, specificity, Spearman's correlations, and agreement using the SDI as the gold standard. Six hundred five SLE participants in the community-based National Data Bank for Rheumatic Diseases (NDB) study completed the LDIQ and we assessed correlations with outcome and disability measures. Results. The mean LDIQ score was 3.3 (range 0-16) and the mean SDI score was 1.5 (range 0-9). The LDIQ had a moderately high correlation with the SDI (Spearman's r = 0.50, P < 0.001). Specificities of individual LDIQ items were >80%, except for neuropathy. Sensitivities were variable and lowest for damage, with <1% prevalence. Agreement between the SDI and LDIQ was >85% for all but neuropathy, reduced renal function, deforming arthritis, and alopecia. In the NDB, the LDIQ correlated well with the comorbidity index (r = 0.45), the Short Form 36 physical component scale (r = 0.43), the Medical Research Council dyspnea scale (r = 0.40), disability (r = 0.37), and the Systemic Lupus Erythematosus Activity Questionnaire score (r = 0.37). Conclusion. The metric properties of the LDIQ are good compared with the SDI. It has construct validity and correlations with health assessments similar to the SDI. The LDIQ should allow expansion of SLE research. Its ultimate value will be determined in longitudinal studies.

Original languageEnglish (US)
Pages (from-to)559-568
Number of pages10
JournalArthritis Care and Research
Volume62
Issue number4
DOIs
StatePublished - Apr 2010

ASJC Scopus subject areas

  • Rheumatology

Fingerprint

Dive into the research topics of 'Development and initial validation of a self-assessed lupus organ damage instrument'. Together they form a unique fingerprint.

Cite this