Serum Urate Monitoring amongst Older Adults with Gout Initiating Urate Lowering Therapy in Ontario, Canada.

OBJECTIVE: To assess the proportion of, and factors associated with older adults with gout receiving a serum urate (SUA) test after starting urate lowering therapy (ULT).

METHODS: We performed a population-based retrospective cohort study in Ontario, Canada in patients aged ≥66 years with gout newly dispensed ULT between 2010 and 2019. We characterized patients with SUA testing within 6- and 12-months after ULT dispensation. Multi-level logistic regression clustered by ULT prescriber evaluated factors associated with SUA monitoring within 6-months.

RESULTS: We included 44,438 patients with mean (SD) age of 76.0 (7.3) years and 64.4% males. Family physicians prescribed 79.1% of all ULTs. SUA testing was lowest in 2010 (56.4% at 6-months) and rose over time to 71.3% in 2019 (p <0.0001). Compared with rheumatologists, family physicians (OR 0.26, 95% CI: 0.23-0.29), internists (OR 0.34, 95% CI: 0.29-0.39), nephrologists (OR 0.37, 95% CI: 0.30-0.45), and other specialties (OR 0.25, 95% CI: 0.21-0.29) were less likely to test SUA, as were male physicians (OR 0.87, 95% CI: 0.83-0.91). Patient factors associated with lower odds of SUA monitoring included: rural residence (OR 0.81, 95% CI: 0.77-0.86), lower socioeconomic status (OR 0.91, 95% CI: 0.85-0.97), and patient comorbidities. Chronic kidney disease, hypertension, diabetes and co-prescription of colchicine/oral corticosteroids (OR 1.31, 95% CI: 1.23-1.40) were correlated with increased SUA testing.

CONCLUSION: SUA testing is suboptimal amongst older adults with gout initiating ULT but improving over time. ULT prescriber, patient, and prescription characteristics were correlated with SUA testing. This article is protected by copyright. All rights reserved.