POS0530 ANALYSIS OF APPROPRIATE DURATION OF COLCHICINE PROPHYLAXIS TO MAXIMIZE THE PERSISTENCE OF XANTHINE OXIDASE INHIBITORS AS THE FIRST-LINE URATE LOWERING THERAPY IN PATIENTS WITH GOUT USING THE KOREAN HEALTH INSURANCE REVIEW AND ASSESSMENT SERVICE DATABASE: DOES 6 MONTHS’ DURATION MATTER?

Abstract

BackgroundInternational guidelines for gout recommend at least 3 to 6 months of prophylaxis against gout attack for gout patients who start urate lowering therapy (ULT)[1-3], but there is lack of strong evidences supporting whether up to 6 months duration of gout flare prophylaxis is associated with the improvement the long-term adherence of ULT in real-world clinical settings.ObjectivesWe aimed to investigate the appropriate duration of colchicine prophylaxis to maximize the long-term persistence of xanthine oxidase inhibitors (XOIs) as the first-line ULT in patients with gout using nationwide claim database. In particular, we attempt to compare which one is more effective in adherence to ULT between 6 months and 3 months duration of colchicine prophylaxis.MethodsThis is a nationwide population-based retrospective cohort study using the Korean Health Insurance Review and Assessment (HIRA) database. Gout patients ≥ 20 years who newly initiated allopurinol or febuxostat as the first-line ULT from July 2015 and June 2017 and received XOIs for ≧6 months were analyzed. Patients were followed-up to Jun 2019. Persistence of ULT was defined as continuation of allopurinol or febuxostat without an interruption for a period longer than 60 days (permissible gap), the time duration from the index date to the discontinuation of ULT. XOIs persistence was compared according to the 6 months of duration of colchicine prophylaxis such as (1) ≥6 months and proportion of days covered (PDC) ≥0.8 (“≥ 6 months group”) and (2) <6 months or PDC <0.8 (“< 6 months group”). For additional subgroup analysis, we also compared the persistence of XOIs according to the 3 months of duration of colchicine prophylaxis (“≥ 3 months group” vs “< 3 months group”).ResultsA total of 43,926 eligible gout patients (colchicine prophylaxis ≥6 months: n=2,784, colchicine prophylaxis <6 months: n=41,142 and colchicine prophylaxis ≥3 months: n=3,333, colchicine prophylaxis <3 months: n=40,593) were identified in HIRA database. The majority was male (82.6%) and the mean age was 58.6 years. Allopurinol (65.2%) was more frequently prescribed than febuxostat (34.8%). During the study period, 23,475 (53.4%) patients stopped XOIs. XOIs discontinuation occurred in 1,498 (53.8%) and 21,977 (53.4%) gout patients in the ≥ 6 months group and < 6 months group, respectively. In addition, 1,777 (53%) and 21,698 (53.5%) patients in the ≥ 3 months group and < 3 months group stopped XOIs, respectively. In multivariable Cox regression models revealed that colchicine prophylaxis ≥6 months did not significantly reduce the risk for discontinuation of XOIs compared with colchicine prophylaxis <6 months (HR=0.961, p=0.139). Otherwise, colchicine prophylaxis ≥3 months was significantly associated with a lower risk of non-persistence to XOIs after adjusting confounding factors (HR=0.95, p=0.041).ConclusionOur data suggest that at least 3 months of colchicine prophylaxis may be more appropriate than at least 6 months’ duration in terms of maximizing the persistence of XOIs in gout patients.