Lupus disease measures such as the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the British Isles Lupus Assessment Group (BILAG) index are challenging to interpret. The Lupus Foundation of America-Rapid Evaluation of Activity in Lupus (LFA-REAL) is intended to provide an efficient application of anchored visual analog scores, each representing the individual severity of active symptoms, with the sum of individual scores deriving an overall disease activity assessment. Our objective was to compare the performance of LFA-REAL to systemic lupus erythematosus disease activity assessments and compare scores between trained lupus clinical investigators and clinicians.
Investigators scored the SLEDAI, BILAG, physician's global assessment (PGA), and LFA-REAL, while the clinicians scored the LFA-REAL. The level of agreement between physicians and instruments was determined.
The study included 99 patients (93% women, 31% white, mean ± SD ages 43.4 ± 13.2 years). At the first visit, the mean ± SD SLEDAI score was 5.5 ± 4.5, BILAG score 6.7 ± 7.8, and PGA score 33.6 ± 24.5. The mean ± SD investigator LFA-REAL score was 46.2 ± 42.9, and clinician LFA-REAL score 56.1 ± 53.6. At the second visit, the mean ± SD investigator LFA-REAL score was 41.3 ± 36.7, and clinician LFA-REAL score 48.3 ± 42.6. Total LFA-REAL scores correlated positively with PGA, SLEDAI, and BILAG (ρ = 0.58-0.88, P < 0.001). LFA-REAL scores produced correlation coefficients of ρ > 0.7 for musculoskeletal, mucocutaneous, and renal BILAG domains. The intraclass correlation coefficient between the LFA-REAL scores of investigators and clinicians was 0.79 for visit 1 (P < 0.001) and 0.86 for visit 2 (P < 0.001).
The LFA-REAL provides a reliable surrogate for more complicated disease activity measures when used by lupus clinical investigators or clinicians.