SAT0070 Association of Improvement in Pain with Therapeutic Response as Determined by Individual Significant Improvement Criteria in Patients with Rheumatoid Arthritis
Authors: E. Scharbatke, F. Behrens, M. Schmalzing, M. Koehm, G. Greger, H. Gnann, H.-P. Tony, H. Burkhardt
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Patient-reported outcomes (PRO) provide an important perspective on patient9s perception of their clinical well-being. A better understanding of the association between improvements in PROs and rheumatoid arthritis (RA) disease measures could assist clinicians in managing symptoms and treatment expectations in patients with rheumatoid arthritis (RA). <h3>Methods</h3> We used methodology based on an analysis of variance model in patients with stable disease on stable therapy (Behrens et al., Arthritis Care Res 2013;65:1608) to establish critical differences (dcrit) defining the minimum change that constitutes a significant individual patient response in the PRO measures of pain (10cm visual analog scale [VAS]), fatigue (10cm VAS), and function (Funktionsfragebogen Hannover [FFbH] questionnaire; range of 0 to 100% remaining functional capacity). We then evaluated significant individual PRO responses in patients with an individual significant DAS28 response (DAS28-dcrit; decrease of ≥1.8 from baseline). <h3>Results</h3> In an exploratory cohort of approximately 600 patients with stable disease, the long-term retest reliability was 0.79 for pain, 0.79 for fatigue, and 0.94 for function; these values compared favorably with the retest reliability of 0.83 for DAS28. The critical difference defining the minimum change that exceeded random fluctuation was conservatively determined to be 3 points for pain, 4 points for fatigue, and 18 points for FFbH. These measures were then applied to a treatment cohort of 2788 patients. Of the 1483 patients with a significant individual DAS28-dcrit response (≥1.8 points) after 12 months of adalimumab treatment, 1130 (76.2%) achieved a significant response in at least 1 of the 3 PROs. Almost 70% achieved a significant improvement in pain while approximately 40% achieved a significant improvement in fatigue or function (Figure). Significant improvements in all 3 PROs occurred in 20.7% of patients; 23.8% did not have any significant PRO responses. In contrast, significant improvements in all 3 PROs occurred in only 3.3% of 1305 patients who did not achieve a DAS28-dcrit response at month 12, while 60.8% of these patients had no significant PRO responses at all. <h3>Conclusions</h3> Using a statistical method to calculate significant individual responses, we found that pain was the PRO most closely associated with a DAS28-dcrit response; almost 70% of patients with a DAS28-dcrit response had a pain response, but fewer than half the patients showed significant improvements in fatigue or function. The DAS28-dcrit criterion effectively identified therapeutic responses that are meaningful to patients, as 76.2% of patients with a DAS28-dcrit response achieved at least one significant PRO response while 60.8% of patients who did not have a DAS28-dcrit response failed to achieve any significant PRO responses. <h3>Disclosure of Interest</h3> E. Scharbatke Grant/research support from: Chugai, Consultant for: AbbVie, Roche, Chugai, F. Behrens Grant/research support from: Pfizer, Consultant for: AbbVie, M. Schmalzing Consultant for: AbbVie, Chuhgai, Actelion, UCB, Roche, Pfizer, M. Koehm Grant/research support from: Pfizer, Consultant for: AbbVie, Roche, Chugai, G. Greger Employee of: AbbVie Deutschland GmbH &amp; Co.KG, H. Gnann Grant/research support from: AbbVie Deutschland GmbH &amp; Co.KG, H.-P. Tony Consultant for: AbbVie, Roche, Chugai, MSD, Pfizer, UCB, Speakers bureau: AbbVie, H. Burkhardt Grant/research support from: Pfizer, Consultant for: AbbVie, Pfizer, BMS, UCB, Chugai