Australia’s official statistics underestimate the burden of gout as a chronic condition because of flawed disease definitions used by statisticians, rheumatologists say.

Gout was recorded as having a prevalence of only 0.8% in the most recent Australian Institute of Health and Welfare (AIHW) report on chronic musculoskeletal conditions in Australia, released in 2019, according to clinicians writing in the MJA.

But this figure is  almost ten-fold lower than the doctor-diagnosed gout rate of 6.8% noted in population-based studies in Australia, according to the letter penned by Dr Helen Keen of Perth and three colleagues.

The discrepancy is likely due to the AIHW staff asking their survey sample if they believed their medical condition was something they expected to last for 6 months or more

“Given that for most patients gout manifests as an intermittently flaring disease, with most flares lasting 7–10 days, respondents would likely not report their gout to be “current” or

“likely to last 6 months” unless they have a clear understanding that gout is a chronic disease of monosodium urate crystal deposition,” they write.

The difference in counting methods means that gout would only be assumed to affect 187,000 Australians according to the AIHW’s 0.8% prevalence rate whereas a 6.8%  prevalence would be equivalent to around 1.6 million people with the chronic condition.

Dr Keen and colleagues says the under-reporting is another example of how gout is misperceived only as an acute condition based on disease flares rather than as a chronic disease that should have risk factors and triggers treated as in conditions such as diabetes

“Like many chronic diseases, flares of gout and their long term consequences can be prevented with daily medication. However, both international and Australian evidence demonstrates that gout is inadequately treated, that persistence to urate-lowering therapies is low, with suboptimal outcomes for patients.”

“It is important that the burden of gout in Australia is understood and accurately measured to allow optimal use of limited health resources, reduce burden on society, and improve outcomes for people with this condition.

They suggest that a validated case definition, such as “self-reported gout” or “urate-lowering therapies use”, be used in future Australian epidemiological studies.