Incidence, prevalence, and utilisation of urate-lowering therapy in Hong Kong: a population-based study

Abstract

Introduction: The prevalence of gout has increased significantly over the past decade in Western populations. We conducted this population study in Hong Kong to determine the incidence and prevalence of gout and the utilisation of urate-lowering therapy (ULT) among patients with gout. Methods: A total of 2 741 862 patients who attended any out-patient clinics or accident and emergency department (with or without hospitalisation) in 2005 were identified from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority. Patients who died before 2006 were excluded. All patients were followed up until the end of 2016 or death. Patient demographics, diagnosis of gout, serum urate levels, and ULT prescriptions were retrieved from CDARS. Gout was defined as the physician diagnosis coding in CDARS. The serum urate level achieved after prescribing ULT was taken as the mean of all serum urate levels 6 months after prescription. Results were analysed by R statistics version 3.3.3 with package ‘prevalence’ version 0.4.0. Results: The crude incidence of gout increased from 113.05/100 000 person-years in 2006 to 211.62/100 000 personyears in 2016. The crude prevalence of gout increased from 1.28% in 2006 to 2.92% in 2016. Only 25.55% of patients with gout were prescribed ULT in 2016. Among them, 28.1% achieved a serum urate level <6 mg/dL. Conclusion: Population ageing has led to increases in the incidence and prevalence of gout in Hong Kong. In 2016, the crude prevalence of gout in Hong Kong was 2.92%, which is similar to figures reported in Western countries. Only one in four patients with gout were prescribed ULT.