Among older adults with gout initiating urate-lowering therapy (ULT), serum urate (SUA) monitoring was found to be suboptimal, though testing may be improving over time, according to study findings published in Arthritis Care & Research.
Treatment guidelines in patients with gout recommend SUA monitoring, with target levels below crystallization thresholds. The American College of Rheumatology (ACR) recommends that SUA levels be measured within 6 months of ULT initiation. Although previous studies have assessed rates of SUA monitoring in gout, little research is available on the temporal trends.
Researchers aimed to describe the percentage of older adults with gout undergoing SUA testing within 6 months of ULT initiation, as well as the patient and physician factors associated with SUA testing.
A population-based retrospective study was conducted in Ontario, Canada. Individuals were selected from the Ontario Drug Benefit (ODB) program with prescription medications for ULT from 2010 to 2019. Individuals aged at least 66 years with a diagnosis code for gout were included in the study.
Primary study outcome was the presence of SUA testing within 6 and 12 months of ULT initiation.
A total of 44,438 patients were evaluated, of whom 64.1% and 75.2% received at least 1 SUA test within 6 and 12 months of starting ULT, respectively. Stratified by specialty, rheumatologists, followed by nephrologists and internists, were found to have the most consistent SUA testing.
Temporal trends were notable for increasing SUA testing over time, with a 67.4% (from 54.9%) improvement for family medicine. The highest increase was seen among patients of rheumatologists (75.8% in 2010 to 93.9% in 2019).
Logistic regression analysis indicated that increasing patient age (odds ratio [OR], 0.99, 95% CI, 0.99-1.00), patients residing in rural areas (OR, 0.81; 95% CI, 0.77-0.86), and those in the lowest income quintile (OR, 0.91; 95% CI, 0.85-0.97) were all associated with lower odds of having SUA testing.
Subgroup analysis found that rheumatologists were most likely to conduct SUA testing than primary care physicians, followed by 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 all other combined specialties (OR, 0.25; 95% CI, 0.21-0.29).
One of the study limitations included a lack of clinical information on gout severity, as this may have affected clinician adherence to SUA testing.
The study authors stated, “There is large variation in practice patterns for monitoring across different physician specialties, with rheumatologists and family physicians having the highest and lowest percentages of their patients having SUA testing, respectively.”
They concluded, “There is a need to further study the causal mechanisms behind which factors ultimately influence SUA testing and pinpoint tangible areas for improvement.”
Kwok TSH, Kuriya B, Hawker G, Li P, Choy G, Widdifield J. Serum urate monitoring amongst older adults with gout initiating urate lowering therapy in Ontario, Canada. Arthritis Care Res (Hoboken). Published online May 29, 2023. doi:10.1002/acr.25167