A vast majority gout cases diagnosed in primary care fulfill classification criteria and are valid for research, according to study results published in The Journal of Rheumatology.
Researchers surveyed a total of 1444 patients who received a diagnosis of gout at 1 of 12 primary care centers in Sweden. Participants completed a questionnaire regarding gout-specific parameters, demographics, and other comorbidities. With these data, the investigators aimed to validate the diagnosis of gout using the Netherlands and Mexico classification criteria. The primary outcome measured was the positive predictive value for gout diagnosis with respect to each set of classification criteria.
After analysis, the researchers found that the positive predictive value for gout diagnosis was 80% and 71% for the Mexico and Netherlands criteria, respectively. In addition, they reported that the most frequently seen symptom was maximum inflammation within 24 hours (86%). They also noted that only 42% of patients had knowledge of increased serum urate levels.
One key limitation of the study was the low survey response rate.
“The Mexico and Netherlands criteria have been validated in two published studies compared to monosodium urate crystal assessment in rheumatology settings,” the researchers wrote.
“The vast majority of gout cases in primary care fulfill classification criteria and are valid for research purposes,” they concluded.
Dehlin M, Landgren AJ, Bergsten U, Jac LTH. The validity of gout diagnosis in primary care, results from a patient survey [published online April 1, 2019]. J Rheumatol. doi:10.3899/jrheum.180989