Trends in Serum Urate Monitoring Assessed Among Patients With Gout Receiving ULT

In a longitudinal cohort of patients who received long-term urate-lowering (ULT) therapy, more than half had a documented serum urate (SU) measurement and the majority reached the recommended SU target, according to study results published in Arthritis Care & Research.

In a retrospective observational study, researchers extracted data from the American College of Rheumatology’s (ACR) Rheumatology Informatics System for Effectiveness (RISE) registry. The ACR RISE registry includes data collected during routine clinical care at participating rheumatology practices across the United States.

The study included adult patients with a diagnostic code for gout who attended at least 1 outpatient visit with a rheumatologist in both 2018 and 2019. Eligible patients were continuous users of ULT for at least 12 months prior to 2019. Researchers assessed whether patients had a valid SU measurement recorded during the measurement year (ie, 2019).

The primary outcome was the percentage of patients with a valid SU measurement who achieved target SU levels (<6.0 mg/dL).

Multilevel logistic regression models were used to assess the relationship between patient and practice characteristics and the achievement of target SU.

A total of 9560 patients from 188 practices were included in this analysis, among whom 73.5% were men; 67.7% were non-Hispanic White; and 31.1% were aged between 65 and 74 years.

The most commonly used ULT was allopurinol (75%), followed by febuxostat (18%), probenecid (1.3%), and lesinurad (0.1%). More than 5% of patients received more than 1 ULT medication. Overall, 55.8% of patients had at least 1 documented SU test during the measurement year.

A gradient effect was observed with age, with older vs younger patients less likely to receive SU monitoring (P <0.5). Patients with vs without chronic kidney disease were more likely to receive monitoring (60.7% vs 57.4%; P <.05). A greater number of recorded clinic visits was associated with greater likelihood of recorded SU values. Among patients with at least 1 SU recorded in 2019, 73.8% achieved the SU target.

In multivariate models adjusted for clinical and demographic characteristics, Hispanic vs non-Hispanic White patients were less likely to achieve target SU (62.1% vs 74%; P <.05). Patients aged less than 55 years vs older patients were less likely to achieve the target. Patients who received febuxostat vs allopurinol were less likely to be at target (71.5% vs 75.0%; P <.05). Further, the percentage at target was lower for patients receiving other ULTs (60.6%). The median percentage of patients achieving SU was 74.4% (66.7%-81.0%).

Study limitations included the fact that patients may have received SU monitoring in settings outside the registry and that data on medication adherence were not collected.

“Routine monitoring of serum urate will be a first step toward improving quality of care for patients with gout, and efforts will need to be redoubled given the effects of the [SARS-CoV-2] pandemic on in-person care and frequency of laboratory monitoring,” the study authors wrote.

Reference

Hammam N, Li J, Kay J, Izadi Z, Yazdany J, Schmajuk G. Monitoring and achievement of target serum urate among gout patients receiving long-term urate lowering therapy in the ACR’s RISE Registry. Arthritis Care Res (Hoboken). Published online August 30, 2022. doi:10.1002/acr.25009