Background/Purpose: Gout is a common inflammatory arthritis caused by monosodium urate crystal deposition in the joints.  Despite this well-understood pathophysiologic mechanism of disease and ACR and EULAR recommendations for a treat-to-target strategy with urate-lowering therapy (ULT), management of gout is  generally suboptimal. ULT initiation in older patients with gout can be challenging as many of them have substantial comorbidities. We aimed to examine characteristics of older patients newly diagnosed with gout and their patterns of ULT initiation.

Methods: Using Medicare claims data (2007–2016 Parts A/B/D) linked to EHR from 2 health care provider networks, we identified patients newly diagnosed with gout based on the first gout diagnostic code (ICD9 274.00–03, 81, 82, 39, 9; ICD10 M10) after the baseline period of at least 365 days. All patients were required to be continuously enrolled during the baseline period. Patients with age < 65 or use of any gout-related medications (allopurinol, febuxostat, probenecid, colchicine, lesinurad, and pegloticase) in this period were excluded. We described these incident gout patients for their baseline characteristics, subsequent ULT initiation, and treatment patterns at the initiation.

Results: We identified a total of 20,193 patients who we regarded as incident gout patients by our definition. The mean (SD) age was 77.3 (7.7) years and 48.4% were male. Many patients had comorbidities prior to the gout diagnosis (Table 1). Hypertension was the most common comorbidity (86%) followed by hyperlipidemia (75%), diabetes (36.7%), malignancy (30%), and heart failure (25%). Use of cardiovascular medication was also common (e.g., ACE/ARB 53%, diuretics 55%, and statin 60%). 34% experienced hospitalization during the baseline 365-day period. On average, they visited physician offices 14 times (median 12), emergency department 1.6 times, and took 10.8 discrete medications during the baseline period. During the entire follow-up (median 656 days [25th 168, 75th 1454]), only 24.3% had a ULT initiation. Cumulative incidence of ULT initiation was 17.8% at 1 year 21.2% and at 2 years after the diagnosis, handling disenrollment (55%) as censoring and death (21%) as a competing event. Most ULT initiators (95%) started allopurinol. Febuxostat was used in 3% and probenecid in 2%. The median starting doses were low consistent with ACR guidelines (Table 2). However, concomitant use of colchicine for flare prophylaxis was low (allopurinol 26%; febuxostat 31%), except probenecid (80%), which included a combination formulation.

Conclusion: Older patients with incident gout had a substantial comorbidity and medication burden. The overall rate of ULT initiation was low (< 25%) and suboptimal, particularly in the first year after the diagnosis (18%). While the initial ULT doses were appropriately low as recommended; less than a third used gout flare prophylactic treatments at the time of ULT initiation. As the treat-to-target strategy for gout is contingent upon ULT initiation, better understanding of patient and physician barriers to ULT is essential to improving the quality of care in older patients with gout.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/patient-characteristics-and-patterns-of-urate-lowering-treatments-in-older-patients-with-incident-gout/