Objective To assess the comparative effectiveness of allopurinol versus febuxostat for preventing incident renal disease in elderly.
Methods In a retrospective cohort study using 2006–2012 Medicare claims data, we included patients newly treated with allopurinol or febuxostat (baseline period of 183 days without either medication). We used 5:1 propensity-matched Cox regression analyses to compare the HR of incident renal disease with allopurinol use (and dose) versus febuxostat (reference). Sensitivity analyses included multivariable-adjusted regression models.
Results There were 31 465 new allopurinol or febuxostat treatment episodes in 26 443 patients; 8570 ended in incident renal disease. Crude rates of incident renal disease per 1000 person-years were 192 with allopurinol versus 338 with febuxostat. Crude rates of incident renal disease per 1000 person-years were lower with higher daily dose: allopurinol <200, 200–299 and ≥300 mg/day with 238, 176 and 155; and febuxostat 40 and 80 mg/day with 341 and 326, respectively. In propensity-matched analyses, compared with febuxostat, allopurinol use was associated with lower HR of incident renal disease, 0.61 (95% CI 0.49 to 0.77). Compared with febuxostat 40 mg/day, allopurinol doses <200, 200–299 and ≥300 mg/day were associated with lower HR of incident renal disease, 0.75 (95% CI 0.65 to 0.86), 0.61 (95% CI 0.52 to 0.73) and 0.48 (95% CI 0.41 to 0.55), respectively. Sensitivity analyses using multivariable-adjusted regression confirmed these findings.
Conclusions Allopurinol was associated with a lower risk of incident renal disease in elderly patients than febuxostat. Future studies need to examine the mechanism of this potential renal benefit of allopurinol.
- Outcomes research
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Contributors JAS developed the study protocol, reviewed all data analyses critically, wrote the first draft of the manuscript and revised the manuscript. DC performed all data programming, data analyses, reviewed data analyses critically and revised the manuscript. Both authors made the decision to submit the manuscript.
Funding This material is the result of work supported by research funds from UAB Division of Rheumatology and the resources and use of facilities at the Birmingham VA Medical Center.
Competing interests JAS has received research grants from Takeda and Savient and consultant fees from Savient, Takeda, Regeneron, Merz, Iroko, Bioiberica, Crealta/Horizon and Allergan pharmaceuticals, WebMD, UBM LLC and the American College of Rheumatology (ACR). JAS serves as the principal investigator for an investigator-initiated study funded by Horizon pharmaceuticals through a grant to DINORA, a 501 (c)(3) entity. JAS is a member of the executive of OMERACT, an organisation that develops outcome measures in rheumatology and receives arms-length funding from 36 companies; a member of the ACR's Annual Meeting Planning Committee (AMPC); chair of the ACR Meet-the-Professor, Workshop and Study Group Subcommittee; and a member of the Veterans Affairs Rheumatology Field Advisory Committee. JAS is the editor and Director of the UAB Cochrane Musculoskeletal Group Satellite Center on Network Meta-analysis. JAS is also supported by grant from the National Institute of Arthritis, Musculoskeletal, and Skin Diseases (NIAMS) P50 AR060772.
Patient consent The Ethics Committee waived the need for individual patient consent for this retrospective database study.
Ethics approval The University of Alabama at Birmingham’s Institutional Review Board approved this study and all investigations were conducted in conformity with ethical principles of research. The Ethics Committee waived the need for individual patient consent for this retrospective database study.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement The authors are ready to share the data after obtaining appropriate permissions from the Centers for Medicare and Medicaid Services (CMS) Chronic Condition Data Warehouse and the University of Alabama at Birmingham (UAB) Ethics Committee, related to HIPAA and Privacy policies.
Correction notice This article has been corrected since it published Online First. The section heading 'discussion' has now been added.