OBJECTIVES: Current validated DAIs in SLE require disease expertise and/or involve complex scoring systems, and are often impractical for use in daily clinical practice. In an attempt to address this issue, several new simplified DAIs in SLE are in different stages of development, including SLE Activity Tracking Evaluation Tool (LAST), Physician Global Assessment (PhGA), Clinical LAST (C-LAST), Total Lupus Activity Score (TLAS), and Simple Disease Assessment for People with Lupus Erythematosus (SIMPLE). The objective of this analysis is to assess responsiveness and test-retest reliability of the DAIs between baseline and 3mo assessments. METHODS: This is a prospective real-world observational cohort study of SLE patients receiving standard care in two private and two academic sites in the US. Respective portions of DAIs are completed by physicians and patients at four time points: baseline/3mo/6mo/12mo. Responsiveness was assessed by analyzing within-person change in scale scores and effect size (mean change divided by standard deviation of baseline score) between baseline and 3mo in relation to change in clinical status, as measured by SLEDAI-2K scores, categorized as “improved”, “no change”, or “worsened”, and test-retest reliability was assessed by Pearson correlation coefficient (r) comparing baseline and 3mo scores among those with “no change” in SLEDAI-2K scores. RESULTS: Within person change/effect size among the Improved group(n=54): LAST=-6.4/-0.537; C-LAST=-5.6/-0.536); TLAS=-1.7/-0.234; SIMPLE=-4.1/-0.359; PhGA(scale:0-10)=-1.3/-0.655; PhGA(scale:0-3)=-0.7/-0.915. No change(n=55): LAST=-0.7/-0.055; C-LAST: -0.5 /-0.049; TLAS: 1.7/0.159; SIMPLE: -1.3/-0.114; PhGA(scale:0-10): -0.2/-0.080; PhGA(scale:0-3): -0.02/-0.025. Worsened(n=40): LAST=4.1/0.323; C-LAST=2.9/0.265; TLAS=4.8/0.449; SIMPLE=1.9/0.170; PhGA(scale:0-10)=1.0/0.495; PhGA(scale:0-3)=0.4/0.480. Test-retest reliability (r; all p<.0001): LAST=0.694; CLAST=0.659; TLAST=0.761; SIMPLE=0.621; PhGA(scale:0-10)=0.663, PhGA(scale:0-3)=0.515). CONCLUSIONS: Test-retest reliability showed moderate-to-strong correlations between baseline and 3mo assessments. For the “improved” and “worsened” groups (per SLEDAI-2K change), effect sizes indicated a small to medium effect, whereas the “no change” group had effect sizes indicative of no change; mean within-person change scores were directionally responsive to clinical change.