Abstract
Objective. To assess factors associated with the ability to achieve and maintain target serum urate (SU) with allopurinol in patients with gout.
Methods. We used US Veterans Affairs (VA) databases from 2002–2012. Eligible patients had ≥ 1 inpatient or ≥ 2 outpatient visits with a diagnostic code for gout, filled a new index allopurinol prescription, had at least 1 posttreatment SU level measured, and met the 12-month observability rule. Treatment successes were defined as the achievement of postindex SU < 6 mg/dl (success 1) and postindex SU < 6 mg/dl that was sustained (success 2).
Results. Of the 198,839 unique patients with allopurinol use, 41,153 unique patients (with 47,072 episodes) and 17,402 unique patients (with 18,323 episodes) were eligible for analyses for success 1 and success 2; 42% each achieved (success 1) or achieved and maintained postindex SU < 6 mg/dl (success 2). In multivariable-adjusted models, factors associated with significantly higher odds of both outcomes were older age, normal body mass index, Deyo-Charlson index score of 0, rheumatologist as the main provider rather than non-rheumatologist, midwestern US location for the healthcare facility, a lower hospital bed size, military service connection for medical conditions of 50% or more (a measure of healthcare access priority), longer distance to the nearest VA facility, and lower preindex SU.
Conclusion. We identified novel factors associated with maintaining SU < 6 mg/dl based on a theoretical model. Several potentially modifiable factors can be targeted by individual/provider/systems interventions for improving successful achievement and maintenance of target SU in patients with gout.
Footnotes
This study was funded by the US National Institute of Arthritis, Musculoskeletal and Skin Diseases P50 AR060772 grant that also support efforts for Dr. Singh (Project PI) and Dr. Saag (main PI). The authors are ready to share the data with colleagues, after obtaining appropriate permissions from institutional review boards at the Birmingham VA Medical Center and the University of Alabama at Birmingham, related to their privacy and data-sharing policies. JAS has received consultant fees from Crealta/Horizon. JAS owns stock options in Amarin and Viking Pharmaceuticals Inc. JAS is a member of the Veterans Affairs Rheumatology Field Advisory Committee. JAS is the editor and the Director of the UAB Cochrane Musculoskeletal Group Satellite Center on Network Meta-analysis. JAS is a member of the executive of OMERACT, an organization that develops outcome measures in rheumatology and receives arms-length funding from 36 companies. He is also supported by the resources and the use of facilities at the VA Medical Center at Birmingham, Alabama, USA. KGS serves as a consultant for Amgen, Merck, and Radius and receives funding from Amgen and Merck.
- Accepted for publication August 2, 2019.