Uncontrolled Serum Uric Acid and Healthcare Resource Use

Cincinnati—Gout, an inflammatory arthritis, is characterized by intense pain. It is caused by the formation of monosodium urate crystals in joint and other tissues and is associated with hyperuricemia (elevated levels of uric acid [sUA]). The incidence of gout has been increasing over the past few decades and it is now the most common inflammatory joint disease in males and older females.

Studies have shown that individuals with gout have higher use of healthcare resources compared with those who do not have gout. Within the population of those with gout, research has observed higher healthcare resource use among those whose sUA is uncontrolled compared with those with controlled sUA. Those with higher gout severity also have higher healthcare resource use compared with patients with lower gout severity.

Researchers recently conducted a study designed to evaluate the impact of uncontrolled sUA on resource utilization among veterans with gout in the United States. They reported study results during a poster session at the AMCP meeting. The poster was titled Healthcare Resource Utilization Associated with Uncontrolled Serum Uric Acid in Patients with Gout.

The study used electronic medical record data from the Veterans Integrated Service Network (VISN) from January 1, 2002, to January 1, 2011. The data included demographics, inpatient and outpatient records, pharmacy prescriptions, results of laboratory tests, and vital data for each patient. Patients with a sUA level of <7 were classified as having uncontrolled sUA.

Following application of inclusion and exclusion criteria, the study included 2553 patients. Inclusion criteria were male, continuous enrollment for at least 6 months prior to and 12 months following the first sUA measurement date, ≥18 years of age as of the index date, 2 sUA measurements within the eligibility period, at least 2 gout diagnoses, and no inflammatory disease.

The majority (52%) of the patients were white, average age was 63.5 years, average follow-up time was 6 years, and mean body mass index was 31.1 kg/m². The most common comorbidities at baseline were hypertension, hyperlipidemia, cardiovascular disease, and diabetes.

The analyses revealed that uncontrolled sUA was associated with an increased risk of all-cause and gout-related hospitalizations as well as all-cause and gout-related outpatient visits. Among the veterans with gout, uncontrolled sUA was also associated with an increased number of all-cause and gout-related hospitalizations as well as an increased number of gout-related outpatient visits.

Finally, uncontrolled sUA levels exhibited similar trends in utilization when 6 mg/dL was chosen as a cut-off point.

Study limitations cited by the authors included (1) use of the VISN database, which does not capture all of the clinical activities of the included patients; (2) while efforts were made to control for confounding differences between the group with uncontrolled sUA and those with controlled sUA, unobserved confounding factors may have led to bias that was not fully adjustable; and (3) all of the patients were enrolled in the Veterans’ Access Network and most of them were from Mississippi, which may have reduced the representativeness of the study sample.

In summary, the researchers said, “Uncontrolled sUA levels were associated with an increased risk and number of hospitalizations and outpatient visits among patients with gout. Gout could impose a greater burden on the healthcare system if left untreated.”

This study was supported by Takeda Pharmaceutical International.