1303 Physician global assessment of disease activity in childhood-onset systemic lupus erythematosus – Does the approach matter?

Background Physician Global Assessment of Disease Activity (PhGA) are commonly used outcome measures in pediatric rheumatology. For childhood-onset systemic lupus erythematosus (cSLE), the traditional visual analog scale (range: 0 – 10; 0=inactive; 10=very active; PhGA₀–₁₀) but also the SELENA-SLEDAI (range: 0–3; 0= none, 1=mild, 2=moderate, 3=severe; PhGA₀–₃) are used to measure treatment response, flare, and Lupus Low Disease Activity Status (LLDAS) with PhGA₀–₃ ≤1. Thus, the purpose of this study was to compare the measurement properties of the PhGA₀–₁₀ and the PhGA₀–₃ in cSLE and with scores of the SLEDAI-2k, and the SELENA-SLEDAI. Methods Secondary data analysis from a convenience sample of 100 cSLE followed every 3 months for up to 7 visits.¹ Ratings of PhGA₀–₁₀, PhGA₀–₃, parent assessment of patient well- being (ParGA; range: 0= very poorly, 10=very well), SLEDAI-2k and SELENA-SLEDAI were compared. After linear transformation of PhGA₀–₁₀ to a 0–3 range (tPhGA₀–₁₀) frequency of PhGA₀–₃≤1 were compared. Results In 601 visits, mean (SD)/median (range) of PhGA₀–₁₀, PhGA₀–₃, SLEDAI-2K and SELENA-SLEDAI were 2.13 (1.87)/2 (0–10), 0.79 (0.64)/1(0–3), 4.63 (4.14)/4 (0–28) and 4.51 (4.1)/4 (0–32) respectively. PhGA₀–₁₀ were moderately correlated with PhGA₀–₃ (r=0.73; p<0.0001; figure 1) with more variability for PhGA₀–₃ ≥2. ParGA was weakly correlated with PhGA₀–₁₀, PhGA₀–₃, SLEDAI-2k and SELENA-SLEDAI scores (r = -0.34, -0.30, -0.19 and -0.20). SELENA-SLEDAI and SLEDAI-2k scores were highly (r=0.98) correlated with each other. However, SLEDAI-2K/SELENA-SLEDAI scores were weakly correlated with PhGA₀–₃ (r=0.28/0.28; p <.001) and moderately correlated with PhGA₀–₁₀ (r= 0.56/0.54; p <.0001). There were 490/497 of 601 visits with PhGA₀–₃ ≤1/tPhGA₀–₁₀ ≤1 [Kappa (SE) =0.59 (0.04), McNemar p=0.4]. Conclusion Using the traditional PhGA₀–₁₀ in cSLE yields almost identical LLDAS rates compared to the PhGA₀–₃. Given its closer association with the scores of disease activity indices in cSLE, use of the PhGA₀–₁₀ may be preferable in pediatric populations. Reference Mina R, Klein-Gitelman MS, Nelson S, Eberhard BA, Higgins G, Singer NG, Onel K, Tucker L, O'Neil KM, Punaro M, Levy DM, Haines K, Martini A, Ruperto N, Lovell D, Brunner HI. Validation of the systemic lupus erythematosus responder index for use in juvenile- onset systemic lupus erythematosus. Ann Rheum Dis. 2014 Feb;73(2):401–6. PMID: 23345596.