Background:Different tools are commonly used to assess fatigue in RA including single items (visual analogue (VAS), numeric rating (NRS), and Likert scales), SF-36 Vitality, and PROMIS. Evidence is needed to identify scores that reflect meaningful change to patients to interpret fatigue results in trials and for clinical care.Objectives:To use symptom-specific and RA change anchors to estimate meaningful and detectable change scores from the patient perspective across several fatigue measures.Methods:Stable RA patients (ACR/EULAR 2010 criteria) were recruited from 3 academic clinical practices across the Southern, Mid-Atlantic, and Northeastern United States. Scales were administered at 2 consecutive visits to capture PROs including fatigue. We also asked a fatigue-specific change question (How would you rate your fatigue since the last visit?). Response options were a lot better, a little better, the same, a little worse, and a lot worse. An RA disease activity change question followed a similar format. We compared mean change between visits across fatigue and RA change categories for the Fatigue NRS, Fatigue 5-point Likert (none to very severe), SF36 Vitality, and PROMIS Fatigue 4a, 7a, and 8a.Results:The sample included 282 patients with stable RA who completed questionnaires 4.6 (SD 2.4) months apart. Patients were mostly white (78%) women (82%) with RA duration of 13 (11) years. At V1, most were in CDAI LDA (57%) or MDA (30%) with 5% in REM and 8% in HDA states. Using the Fatigue change anchor, 6% were a lot better, with mean change ranging from |1-11|points across scales (Table 1); among 13% a little better, smaller changes |0.4 to 5|were reported. Across all measures score changes for meaningful and minimal improvement were numerically larger for improvement than worsening.Fatigue Change CategoriesLot Better 6%Little Better 13%Same 49%Little Worse 22%Lot Worse 10%NMeanSDNMeanSDNMeanSDNMeanSDNMeanSDFatigue 11 point NRS19-2.22.437-0.72.3137-0.51.9610.41.9261.32.1Fatigue 5-point Likert19-0.81.236-0.41.21370.00.9600.20.9270.61.2SF36 Vitality (0-100)1911.216.1364.913.71370.310.659-3.215.326-11.416.6PROMIS Fatigue 7a19-5.98.537-2.67.51380.06.462-0.36.5274.38.3PROMIS Fatigue 8a19-6.110.237-2.77.1138-0.37.1621.36.9275.611.0PROMIS Fatigue 4a19-6.89.937-3.38.2138-0.47.4601.27.2275.211.5Using the RA change categories, more people rated their RA as at least a little better compared with fatigue (28% vs. 19%, respectively) at the second visit (Table 2). Similar patterns were evident across RA change categories, though score changes associated with improvement and worsening were about half those observed using fatigue change anchors.RA Disease Activity Change CategoriesLot Better13%Little Better15%Same42%Little Worse21%Lot Worse9%NMeanSDNMeanSDNMeanSDNMeanSDNMeanSDFatigue 11 point NRS36-0.82.343-0.62.7117-0.21.958-0.21.9260.72.2Fatigue 5-point Likert35-0.31.242-0.31.11180.11.0580.10.8260.31.3SF36 Vitality (0-100)356.417.4433.813.0117-0.612.957-3.711.325-6.017.0PROMIS Fatigue 7a37-1.69.543-1.57.4118-0.37.0590.55.6261.37.5PROMIS Fatigue 8a37-2.19.543-1.79.01180.17.6590.74.8263.011.4PROMIS Fatigue 4a36-2.79.643-2.39.01180.18.1590.45.6252.612.0Conclusion:The score change associated with meaningful improvement and worsening between visits on commonly used fatigue scales was much larger with fatigue vs. RA change categories. More people rated their RA improved as compared with fatigue at the 2nd visit. Symptom-specific anchors are likely to offer more relevant change scores associated with meaningful improvement and worsening than RA change anchors. These estimates offer new information about meaningful and detectable improvement and worsening on common measures for trialists, researchers, and clinicians monitoring fatigue in people with RA.Acknowledgements:The primary research data included within this report were acquired through funding in part from a PCORI Methods Award (SC14-1402-10818). This work was also supported by the NIH through the Rheumatic Diseases Resource-based Core Center (P30-AR053503 Core D, and P30-AR070254, Core B), the Camille Julia Morgan Arthritis Research and Education Fund, and the Rheumatoid Arthritis Discovery Fund.Disclosure of Interests:None declared