Adherence and Treat-to-Target Benchmarks in Older Adults With Gout Initiating Urate-Lowering Therapy in Ontario, Canada: A Population-Based Study

Abstract

Objective

We sought to evaluate urate-lowering therapy (ULT) adherence and treatment-to-target (T2T) serum uric acid (SUA) levels among older adults with gout starting ULT.

Methods

We performed a population-based retrospective cohort study in Ontario, Canada in patients with gout aged ≥66 years newly dispensed ULT between 2010 and 2019. We defined successful T2T as patients having SUA levels <360 μmol/L (6 mg/dL) within 12 months after ULT dispensation. We also assessed adherence to ULT. Multilevel logistic regression clustered by ULT prescriber evaluated patient, physician, and prescription factors associated with reaching target SUA levels.

Results

Among 44,438 patients (mean ± SD age 76.0 ± 7.3 years; 64.4% male), 30,057 (67.6%) patients had ≥1 SUA test completed. Overall, 52.3% patients reached SUA target within 12 months, improving from 45.2% in 2010 to 61.2% in 2019 (P < 0.0001). ULT adherence was 55.3% overall and improved annually. Key factors associated with achieving T2T included febuxostat treatment (odds ratio [OR] 11.40, 95% confidence interval [95% CI] 5.10–25.43) (was only dispensed in 88 patients), ULT adherence (OR 5.17, 95% CI 4.89–5.47), allopurinol starting doses >50 mg (OR 2.53, 95% CI 2.14–2.99), colchicine/oral glucocorticoids co-prescription (OR 1.24, 95% CI 1.14–1.34), and ULT prescription from a rheumatologist.

Conclusion

Only 52.3% of patients achieved an optimal SUA level within 1 year of ULT initiation. ULT adherence was suboptimal, although improving over time. ULT adherence and higher allopurinol starting doses had the strongest associations of achieving a target SUA level. This study highlights room for improvement in gout management and potential strategies to address care gaps.