Gout Flares Are Common, Even with Allopurinol Use

A recent study published in Arthritis Research & Therapy evaluated the frequency of flares in gout patients and the association between flares and use of allopurinol.

Estimates of gout prevalence worldwide range from 0.1% to 10%, according to the study authors. “Furthermore, despite advances in understanding of the pathophysiology, risk factors, and therapy, gout remains a burden on the individual’s health-related quality of life (HRQoL) and on healthcare resources.” And despite established guidelines for patients who experience frequent flares, more than half of patients reportedly do not consult their doctor in the event of a flare, “suggesting most gout flares are self-managed in the community and that the ‘treatment gap’ may be under-estimated.”

To evaluate the prevalence of gout, researchers queried the 2017 South Australian Health Omnibus Survey (HOS)—an annual survey consisting of face-to-face interviews with patients aged ≥ 15 years. The 2017 HOS survey, conducted between September 2017 and December 2017, included data from 2,977 interviews from 5,300 households. The survey included three questions pertaining to gout: “Have you ever been told by a doctor that you have gout?” (response options: “Yes,” “No,” or “Do not know/ refused”), “Do you currently take/have you taken allopurinol for gout?” (response options: “No, never taken” [never], “No, previously taken” [prior], or “Yes, still taking” [current]), and “If you have gout, how many gout attacks have you had over the last 12 months?” (response options: “None,” “One,” “Two,” “Three,” “Four,” or “Five or more”).

Flares: Risk Factors and Prevalence

Of the 2,778 participants (all aged ≥ 25 years) included in the final analysis, gout prevalence was 6.5%. Compared to non-gout patients, those with gout were more likely to be male (48.7% vs. 79.2%) and older (mean ages, 52.3 years vs. 63.3 years); gout patients also had a higher mean body mass index (BMI, mean 27.5 kg/m² vs. 30.3 kg/m²).

Among the gout patients, 37.1% reported current allopurinol use; prior use was reported by 23.2% (discontinuation rate, 38%), and 39.7% had never used it. Gout patients also had high rates of comorbidities, including heart disease (24%), diabetes (33%), high blood pressure (54%), and high cholesterol (40%).

Although more than half (58%) of patients with gout said they did not have any flares in the last year, a quarter reported experiencing two or more flares during this time. Among those with more than two flares in the last 12 months, about half (51%) were current allopurinol users. The covariates most strong correlated with flares were age (P = 0.002), BMI (P = 0.005), and allopurinol use (P = 0.031).

“Older age was most strongly associated with a decreased probability of flares (contrast − 0.013, 95% − 0.021, − 0.006, p = 0.001),” the researchers observed, adding, “A higher BMI was associated with an increased probability of flares (contrast 0.025, 95% CI 0.003, 0.046, p = 0.027), and within participants with flares, a higher probability of ≥ 2 flares (contrast 0.017, 95%CI − 0.001, 0.035, p = 0.068). Current allopurinol use, within participants with flares, was most strongly associated with a higher probability of ≥ 2 flares (contrast 0.36, 95% CI 0.13, 0.60, p = 0.002).”

The study authors concluded that, although treatment options are available, gout remains a poorly managed disease.