Serum Urate Monitoring Among 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 ages ≥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. Multilevel logistic regression clustered by ULT prescriber evaluated the factors associated with SUA monitoring within 6 months.

RESULTS

We included 44,438 patients with a mean ± SD age of 76.0 ± 7.3 years and 64.4% male. 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 (odds ratio [OR] 0.26 [95% confidence interval (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 mellitus, and coprescription of colchicine/oral corticosteroids (OR 1.31 [95% CI 1.23-1.40]) were correlated with increased SUA testing.

CONCLUSION

SUA testing is suboptimal among older adults with gout initiating ULT but is improving over time. ULT prescriber, patient, and prescription characteristics were correlated with SUA testing.