Background/Purpose: Gout is a progressive systemic inflammatory disease that is widely prevalent, estimated to effect 3.9% or 8.3 million people of the United State (US) population. The underlying pathogenic feature of gout is hyperuricemia, and appropriate management of gout requires achieving uric acid levels at a minimum of <6 mg/dL to mobilize and clear deposited urate. Uncontrolled gout patients who fail to reach serum uric acid (sUA) level goals do worse in terms of clinical outcomes including gout flares and resolution of visible tophi. Herein, we quantify the cost burden for uncontrolled versus controlled gout patients from a large US payer de-identified database. 

Methods: A retrospective review of Humana Healthcare data from 2007 to 2016 in private pay and medicare patients was performed for patients with gout diagnosis codes (ICD9/10) to identify patients with at least 1 gout diagnosis (N=539,802) and 90 days of continuous urate-lowering therapy within 1 year of diagnosis. Two cohorts of patients were categorized according to their sUA levels after at least 90 days of gout therapy: sUA<6.0 mg/dL (controlled) and sUA ≥8 mg/dL (uncontrolled). Patients must have had more than 1 serum uric acid test to be included.

Results: The controlled gout group (sUA<6 mg/dL) included 5,473 patients and the uncontrolled gout group (sUA≥8 mg/dL) had 1,358 patients. The two groups were comparable in terms of demographic features, though the controlled group was slightly younger with an adjusted mean age of 72.5 years compared to mean age of 69.1 in the uncontrolled patients. Costs were higher among the patients in the uncontrolled gout group (figure 1). Among total costs, the controlled group mean/patient/year was $14,892 as compared to the uncontrolled gout patients of $23,339 (p<0.0001). The cost difference was primarily driven by increased hospital costs within the refractory group, where the cost was $7,255/patient/year greater than the controlled group (p<0.0001, figure 1).

Conclusion: Accepted guidelines for gout management recommend treating to uric acid levels of <6 mg/dL for all patients and <5 mg/dL for tophaceous or symptomatic patients. This analysis sought to quantify costs associated with uncontrolled hyperuricemia (≥8 mg/dL) in early diagnosed gout patients, and found that uncontrolled gout patients had significantly higher per-patient mean total costs and costs from hospitalizations. This disparity may likely be greater in patients with long-standing gout. This finding suggests an increased financial burden associated with uncontrolled gout, and warrants further study.

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Figure 1: