Background/Purpose: Gout flares may often be self-managed, but there is a paucity of population-based data. The aim of this study was to determine the prevalence of self-reported gout and gout flares, the use of urate-lowering therapy, and the association of gout flares with health-related quality of life (HRQoL) in a large community sample.

Methods: The South Australian Health Omnibus Survey is an annual, face-to-face population-based survey. Data collected in the 2017 survey (n = 2977; 65.3% participation rate) included self-reported medically diagnosed gout, allopurinol use (current, previous, never), the number of gout attacks (flares) in the last 12 months, age, gender, body mass index (BMI), relevant comorbidities, socioeconomic status (Index of Relative Socioeconomic Advantage and Disadvantage score, IRSAD) and HRQoL (SF-12). Allopurinol use was used to determine urate-lowering therapy, as this is mandated first line therapy in Australia. Data were weighted to the Australian Bureau of Statistics 2016 census data to reflect the South Australian population. Only participants 25 years and over (n = 2778) were included in the analysis.

Results: The prevalence of self-reported gout was 6.5% (95% CI: 5.5, 7.5), and was more frequent in males, older age, higher BMI, or lower IRSAD groups (p<0.05 in all cases). There was a higher prevalence of ischaemic heart disease (24%), diabetes mellitus (33%), hypertension (54%) and high cholesterol (40%) among participants with gout than amongst those without gout. Only diabetes remained associated after adjustment for sociodemographic variables (p <0.001).

Amongst gout participants, 37.1% (95% CI 29.6, 45.3) reported currently using allopurinol, while 23.2% (95% CI 16.9, 21.0) reported prior use (38% discontinuation rate). Females were less likely to have ever used allopurinol (p = 0.002) and more likely to have discontinued it (p = 0.029).

Frequent flares (defined as >=2 in the last year) were reported by 25% of participants with gout, but only 51% of this group reported current allopurinol use. Frequent gout flares were also more likely with younger age, higher BMI, or current allopurinol use (p<0.05 in all cases). The frequency of gout flares was associated with a lower physical HRQoL (Table 1).

Conclusion: This is the first study to investigate gout flares using a population-based sample. A quarter of gout participants reported frequent gout flares that were associated with reduced physical HRQoL. Current allopurinol use was associated with frequent gout flares, suggesting undertreated disease and suboptimal use of the drug. Determining predictors of flares and ineffective allopurinol use may identify means of improving treatment and reducing flares.

Table 1: HRQoL (SF12) physical component score (PCS) by the frequency of flares among participants with gout, adjusted for sociodemographic variables. Brackets enclose 95% confidence intervals.