Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Development of a Limited Scleroderma Cutaneous Activity and Damage Index.
Chung1, Lorinda, Furst5, Daniel E., Maranian3, Paul, Arefiev2, Kait, Zwerner2, Jeffrey, Khanna4, Dinesh, Werth6, Victoria P.
Stanford Univ Medical Center, Palo Alto, CA
Stanford Univ Medical Center
UCLA Medical School
University of California Los Angeles, Los Angeles, CA
University of California Los Angeles Medical School, Los Angeles, CA
University of Pennsylvania, Philadelphia, PA
Most clinical trials for skin disease in systemic sclerosis patients have excluded patients with the limited cutaneous subtype (lcSSc) due to the lack of a robust measure of cutaneous disease in these patients. We sought to develop and partially validate a novel cutaneous index for patients with lcSSc.
We developed the Limited Scleroderma Cutaneous Activity and Damage Index (L-SCADI) based on an extensive literature review and input from 11 SSc experts (6 rheumatologists and 5 dermatologists) providing face and content validity. Following a 30 minute training session, 6 physicians (2 rheumatologists and 4 dermatologists) used the L-SCADI to score the severity of skin disease in 12 lcSSc patients. To assess construct validity, physicians completed visual analogue scales (VAS) to score global assessment of cutaneous activity and damage (PGA-a and PGA-d), and patients completed a VAS global assessment of skin disease (PtGA), the Health Assessment Questionnaire Disability Index, the Dermatology Life Quality Index, and the Short-Form-36 (SF-36). Inter-rater reliability was assessed using intraclass correlation coefficient (ICC) in a 2-way random model. After scoring every patient once, each physician scored at least one patient a second time to assess intra-rater reliability.
All 12 patients were female, 83% Caucasian, with mean disease duration from first non-Raynaud's symptom of 11.9±9.6 years (5 with <= 6 years, 7 with > 6 years). Mean time to complete the L-SCADI was 6.9±1.5 min. Mean activity (063), damage (053), and total (0116) scores were 10.7±6.3, 7.0±5.2, and 17.7±9.1, where 0=no disease. L-SCADI activity and damage scores were highly correlated with PGA-a and PGA-d (rho=0.77 (p=0.004) for activity, 0.8 (p=0.002) for damage). L-SCADI activity was moderately correlated with PtGA (rho=0.6, p=0.04), while L-SCADI damage was highly negatively correlated with the SF-36 Physical Component Summary score (rho=-0.92, p=0.0001). The inter-rater reliability for PGA-a and PGA-d was modest (ICC 0.34 and 0.43), while the consistency among raters for the L-SCADI activity, damage, and total scores was moderate (ICC 0.52, 0.58, 0.55). The ICC for L-SCADI total improved to 0.62 after excluding edema. Mean time between repeat assessments was 50.2±34.7 min. Intra-rater reliability for PGA-a was not significant, but was excellent for PGA-d (ICC 0.89). Intra-rater reliability for L-SCADI activity was moderate (ICC 0.57), while the damage and total scores had much higher correlations (ICC 0.86 and 0.69).
The L-SCADI is easy to perform and has reasonable construct validity. Inter- and intra-rater reliability for the L-SCADI activity score is moderate, but better than the PGA-a, with much greater intra-rater agreement for the assessment of disease damage. The variability in physician assessments suggests that more extensive training prior to use of the L-SCADI is essential, and further development of the scale is necessary.
To cite this abstract, please use the following information:
Chung, Lorinda, Furst, Daniel E., Maranian, Paul, Arefiev, Kait, Zwerner, Jeffrey, Khanna, Dinesh, et al; Development of a Limited Scleroderma Cutaneous Activity and Damage Index. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1213