Julia G. Harris ^1,2* Catherine A. Bingham ^3,4 Sheetal S. Vora ^5,6 Cagri Yildirim-Toruner ^7,8 Michelle Batthish ⁹ Danielle R. Bullock ^10,11 Jon M. Burnham ¹² Danielle C. Fair ^13,14 Kerry Ferraro ¹² Suhas Ganguli ^15,16 Mileka Gilbert ¹⁷ Beth S. Gottlieb ^18,19 Olha Halyabar ²⁰ Melissa M. Hazen ²⁰ Ronald M. Laxer ^21,22,23 Tzielan C. Lee ^24,25 Alice Liu ²⁶ Daniel J. Lovell ²⁷ Melissa L. Mannion ²⁸ Edward J. Oberle ^29,30 Nancy Pan ^31,32 Michael Shishov ³³ Jennifer E. Weiss ^15,16 Esi M. Morgan ^34,35

• ¹ Children's Mercy Kansas City, Kansas City, United States
• ² School of Medicine, University of Missouri–Kansas City, Kansas City, Kansas, United States
• ³ College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania, United States
• ⁴ Penn State Hershey Children's Hospital, Hershey, Pennsylvania, United States
• ⁵ Levine Children's Hospital, Charlotte, North Carolina, United States
• ⁶ School of Medicine, Wake Forest University, Winston-Salem, North Carolina, United States
• ⁷ Texas Children's Hospital, Houston, Texas, United States
• ⁸ Baylor College of Medicine, Houston, Texas, United States
• ⁹ McMaster Children's Hospital, McMaster University, Hamilton, Ontario, Canada
• ¹⁰ University of Minnesota, Minneapolis, United States
• ¹¹ M Health Fairview Masonic Children’s Hospital, Minneapolis, Minnesota, United States
• ¹² Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
• ¹³ Medical College of Wisconsin, Milwaukee, Wisconsin, United States
• ¹⁴ Children's Hospital of Wisconsin, Milwaukee, Wisconsin, United States
• ¹⁵ Hackensack University Medical Center, Hackensack, New Jersey, United States
• ¹⁶ Hackensack Meridian Health, Montclair, California, United States
• ¹⁷ Medical University of South Carolina, Charleston, South Carolina, United States
• ¹⁸ Cohen Children's Medical Center, New Hyde Park, New York, United States
• ¹⁹ Northwell Health, New York, New York, United States
• ²⁰ Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
• ²¹ The Hospital for Sick Children, Toronto, Canada
• ²² St Michael's Hospital, Toronto, Ontario, Canada
• ²³ University of Toronto, Toronto, Ontario, Canada
• ²⁴ Stanford Medicine Children’s Health, Stanford, California, United States
• ²⁵ Stanford University, Stanford, California, United States
• ²⁶ Seattle Children's Research Institute, Seattle, Washington, United States
• ²⁷ Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
• ²⁸ University of Alabama at Birmingham, Birmingham, Alabama, United States
• ²⁹ Nationwide Children's Hospital, Columbus, Ohio, United States
• ³⁰ The Ohio State University, Columbus, Ohio, United States
• ³¹ Hospital for Special Surgery, New York, New York, United States
• ³² Weill Medical College of Cornell University, New York, United States
• ³³ Phoenix Children's Hospital, Phoenix, Arizona, United States
• ³⁴ Seattle Children's Hospital, Seattle, Washington, United States
• ³⁵ School of Medicine, University of Washington, Seattle, Washington, United States

Introduction The Pediatric Rheumatology Care and Outcomes Improvement Network (PR-COIN) is a North American learning health network focused on improving outcomes of children with juvenile idiopathic arthritis (JIA). JIA is a chronic autoimmune disease that can lead to morbidity related to persistent joint and ocular inflammation. PR-COIN has a shared patient registry that tracks twenty quality measures including ten outcome measures of which six are related to disease activity. The network’s global aim, set in 2021, was to increase the percent of patients with oligoarticular or polyarticular JIA that had an inactive or low disease activity state from 76% to 80% by the end of 2023. Methods Twenty-three hospitals participate in PR-COIN, with over 7200 active patients with JIA. The disease activity outcome measures include active joint count, physician global assessment of disease activity, and measures related to validated composite disease activity scoring systems including inactive or low disease activity by the 10-joint clinical Juvenile Arthritis Disease Activity Score (cJADAS10), inactive or low disease activity by cJADAS10 at 6 months post-diagnosis, mean cJADAS10 score, and the American College of Rheumatology (ACR) provisional criteria for clinical inactive disease. Data is collated to measure network performance, which is displayed on run and control charts. Network-wide interventions have included pre-visit planning, shared decision making, self-management support, population health management, and utilizing a Treat to Target approach to care. Results Five outcome measures related to disease activity have demonstrated significant improvement over time. The percent of patients with inactive or low disease activity by cJADAS10 surpassed our goal with current network performance at 81%. Clinical inactive disease by ACR provisional criteria improved from 46% to 60%. The mean cJADAS10 score decreased from 4.3 to 2.6, and the mean active joint count declined from 1.5 to 0.7. Mean physician global assessment of disease activity significantly improved from 1 to 0.6. Conclusions PR-COIN has shown significant improvement in disease activity metrics for patients with JIA. The network will continue to work on both site-specific and collaborative efforts to improve outcomes for children with JIA with attention to health equity, severity adjustment, and data quality.