Serum Uric Acid Control for Prevention of Gout Flare in Patients With
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Inflammatory arthritis Ann Rheum Dis: first published as 10.1136/annrheumdis-2021-220439 on 22 June 2021. Downloaded from EPIDEMIOLOGICAL SCIENCE Serum uric acid control for prevention of gout flare in patients with asymptomatic hyperuricaemia: a retrospective cohort study of health insurance claims and medical check- up data in Japan Ruriko Koto ,1 Akihiro Nakajima,2 Hideki Horiuchi,1 Hisashi Yamanaka3,4,5 Handling editor Josef S ABSTRACT Key messages Smolen Objectives In patients with gout, treating to target serum uric acid levels (sUA) of ≤6.0 mg/dL is universally ► Additional supplemental What is already known about this subject? material is published online recommended to prevent gout flare. However, there is ► For adequate management of gout, guidelines only. To view, please visit the no consensus on asymptomatic hyperuricaemia. Using around the world consistently recommend the journal online (http:// dx. doi. Japanese health insurance claims data, we explored use of urate- lowering therapy (ULT) to maintain org/ 10. 1136/ annrheumdis- potential benefits of sUA control for preventing gout 2021- 220439). serum uric acid levels (sUA) of ≤ 6.0 mg/dL. flare in subjects with asymptomatic hyperuricaemia. 1 Methods This retrospective cohort study analysed the Medical Science Department, What does this study add? Teijin Pharma Limited, Chiyoda- JMDC Claims Database from April 2012 through June In both patients population with asymptomatic ku, Tokyo, Japan 2019. Subjects with sUA ≥8.0 mg/dL were identified, and ► 2Pharmaceutical Development hyperuricaemia and those with gout, our disease status (prescriptions for urate-lowering therapy Administration Department, study indicates that the occurrence of gout (ULT), occurrence of gout flare, sUA) was investigated for Teijin Pharma Limited, Chiyoda- flare can be lowered by using ULT to maintain ku, Tokyo, Japan 1 year. Time to first onset and incidence rate of gout flare 3 sUA≤6.0 mg/dL. Rheumatology, Sanno Medical were determined by disease status subgroups for 2 years Center, Tokyo, Japan or more. The relationship between gout flare and sUA 4Department of Rheumatology, How might this impact clinical practice or control was assessed using multivariable analysis. International University of future developments? Health and Welfare, Chiba, Results The analysis population was 19 261 subjects This study suggests that, in subjects with Japan who met eligibility criteria. We found fewer occurrences ► 5 asymptomatic hyperuricaemia, control of sUA Institute of Rheumatology, of gout flare, for both gout and asymptomatic Tokyo Women’s Medical may provide long- term benefits by reducing or hyperuricaemia, in patients who achieved sUA ≤6.0 mg/ University, Tokyo, Japan eliminating future occurrences of gout flare. dL with ULT than in patients whose sUA remained Correspondence to >6.0 mg/dL or who were not receiving ULT. In particular, Ruriko Koto, Medical Science analysis by a Cox proportional- hazard model for time to Department, Teijin Pharma first gout flare indicated that the HRas w lowest, at 0.45 gout flare under specific conditions.4 5 However, Limited, Chiyoda- ku, Tokyo (95% CI 0.27 to 0.76), in subjects with asymptomatic there is no consensus on whether ULT should be http://ard.bmj.com/ 100-8585, Japan; prescribed prophylactically for patients with asymp- r. koutou@ teijin. co. jp hyperuricaemia on ULT (5.0<sUA ≤ 6.0 mg/dL), compared with untreated subjects (sUA ≥8.0 mg/dL). tomatic hyperuricaemia before the first gout flare. Portions of these data were Conclusions Occurrences of gout flare were reduced European and US guidelines do not recommend presented in abstract form at by controlling sUA at ≤6.0 mg/dL in subjects with ULT for asymptomatic hyperuricaemia. This may the ACR Convergence 2020 asymptomatic hyperuricaemia as well as in those with be because there is insufficient accumulated data (5–9 November 2020). gout. from patients with asymptomatic hyperuricaemia in on October 1, 2021 by guest. Protected copyright. Received 26 March 2021 Trial registration number UMIN000039985. those countries to provide appropriate guidance. In Accepted 5 June 2021 contrast, Japanese guidelines for gout and hyper- uricaemia recommend the introduction of ULT under specific conditions to prevent gout flare in INTRODUCTION patients having asymptomatic hyperuricaemia with In gout, hyperuricaemia causes abnormal urate sUA of ≥8.0 mg/dL.2 6 As a result, real- world treat- deposition throughout the body.1 2 The disease ment outcome data from patients with asymptom- manifests as painful gout flares, which occur atic hyperuricaemia have been collected in Japan in © Author(s) (or their episodically in many patients with gout and consti- the course of daily clinical practice. Previously, we employer(s)) 2021. Re- use tute a significant clinical burden.3 For adequate found that most patients with gout or asymptomatic permitted under CC BY- NC. No management of gout, guidelines around the world hyperuricaemia failed to meet their sUA targets in commercial re- use. See rights 9 and permissions. Published consistently recommend the use of urate- lowering Japan. Meanwhile, questions remain on whether by BMJ. therapy (ULT) in a treat- to- target approach to ULT- induced reduction of sUA truly improves the maintain serum uric acid levels (sUA) of ≤6.0 mg/ patient’s subsequent clinical course or reduces To cite: Koto R, Nakajima A, dL.1 2 4–6 disease burden. In addition, although randomised Horiuchi H, et al. Ann Rheum Dis Epub ahead The risk of gout flare can be reduced by intro- controlled trials (RCTs) of patients with asymp- of print: [please include Day ducing ULT early in the clinical course of the tomatic hyperuricaemia have shown that the ULT Month Year]. doi:10.1136/ disease,7 8 and European and US guidelines now febuxostat suppresses gout flares compared with annrheumdis-2021-220439 generally recommend initiation of ULT at the first placebo10 or control,11 12 real- world evidence is not Koto R, et al. Ann Rheum Dis 2021;0:1–8. doi:10.1136/annrheumdis-2021-220439 1 Inflammatory arthritis Ann Rheum Dis: first published as 10.1136/annrheumdis-2021-220439 on 22 June 2021. Downloaded from Index date (sUA ≥8.0 mg/dL) Follow-up date Medical check-up Medical check-up from 1 April 2013 after 1 year to 31 March 2016 Index period Period 1 Period 2 (1 year) (1 year) (2 years or more) Investigation of Assessment of gout flare in disease status relation to sUA control Figure 1 Study design. sUA, serum uric acid levels. yet available on the relationship between gout flare and sUA in with gout (ICD10 code M10) or asymptomatic hyperuricaemia such patients. (ICD10 code E790). Subjects were also excluded if they were We used data from health insurance claims and medical prescribed ULT or if they were diagnosed with malignant check- ups in a real- world setting to explore the research ques- tumours (ICD10 code C00- C97, D00- D09) during that period. tion, ‘In patients with asymptomatic hyperuricaemia, is control ULT was defined as any drug designated with ATC code M04 of sUA (measured by whether or not sUA is maintained at (antigout preparations), except for colchicine. Definitions of ≤6.0 mg/dL or exceeds that amount) associated with subsequent patient characteristics and drugs are presented in online supple- risk of gout flare?’ mental table S1. METHODS Study measures Study design and setting During period 1, disease status was investigated for each indi- This retrospective cohort study incorporated data from the vidual subject, including the presence or absence of a ULT JMDC Claims Database, including records of Japanese health prescription, the presence or absence of gout flare and sUA at insurance claims and medical check-ups from April 2012 through the follow- up date. June 2019. JMDC collects information from multiple in- country During period 2, the relationship between gout flare and sUA organisations that provide health insurance coverage to Japa- control was assessed, including time to first onset and incidence nese employees and their dependents.13 Data include diagnostic rate of gout flare. These data were calculated for each disease codes, drug prescriptions and information from annual medical status subgroup as determined in period 1. http://ard.bmj.com/ check- ups for each person. In this study, we used the term ‘gout flare’ when two param- Subjects with sUA ≥8.0 mg/dL at one or more medical eters were satisfied. The first was a diagnosis of gout (ICD10 check- ups from 1 April 2013 to 31 March 2016 were identified. code M10) and prescriptions for antirheumatics, non- steroidal The study consisted of three distinct periods: the index period, plain (ATC code M01A1) or oral corticosteroids, plain (ATC period 1 and period 2. The index date was defined as the time of code H02A2) or colchicine (generic name), shown on the same the earliest medical check- up showing sUA ≥8.0 mg/dL, and the insurance claim form. For the second, we confirmed the inter- month of that medical check-up was termed the index month. vals between prescriptions for the above- mentioned drugs. We on October 1, 2021 by guest. Protected copyright. The index period was the year prior to (and excluding) the index interpreted an interval of ≥14 days between the end of prescrip- date. Period 1 started on the index date and ended on the date tion for one drug and start of prescription for another drug as of the subject’s next annual medical check- up (follow- up date). evidence of newly occurring gout flare. We used the term ‘subject Period 2 started on the day after the follow- up date (figure 1). with gout’ to indicate a subject who experienced gout flare, as defined above, during period 1, excluding subjects for whom Participants treatment was not required (no prescription for ULT, and sUA Subjects were included in the study if they had sUA≥8.0 mg/ <8.0 mg/dL at the follow- up date) under Japanese treatment 2 dL at one or more medical check- ups from 1 April 2013 to 31 guidelines.