Background The prevalence of gout has been studied in several Western countries and has been estimated to vary from 0.9 to 3.9%. The prevalence of gout remained unknown in France.
Objectives To design a tool that allows a confident diagnosis of gout in an epidemiological setting and to assess the current prevalence of gout in France.
Methods This was a two-phase study. In phase one, we designed a questionnaire to detect gout that would be suitable for telephone interviews by non-physicians. A 62-item questionnaire covering clinical features, co-morbidities and treatment of gout was administered by phone, by non physicians unaware of the patient diagnoses in a case control study. 102 people with crystal-proven gout and 142 controls who had other types of arthritis with joint effusion and no urate crystal in their synovial fluid were included. Logistic regression analysis and classification and regression trees (CARTs) were used to select items discriminating cases from controls. In phase two, a random sample of 10 000 adult residents in metropolitan France was derived from the national telephone (fixed and mobile) directory. The results were weighted to be representative of the French population distribution according to socio-demographic characteristics. The telephone questionnaire was administered by non-physicians. Models derived from phase one were used to estimate the gout prevalence in subjects who acknowledged present or past non traumatic acute pain in a peripheral joint.
Results In phase one, two logistic regression models (sensitivity 88.0% and 87.5%; specificity 93.0% and 89.8%, respectively) and one CART model (sensitivity 81.4%; specificity 93.7%) revealed 11 informative items that allowed correct classification of 90.0%, 88.8% and 88.5% of patients respectively. In the second phase the response rate varied between 34% (fixed phone sample) and 38% (mobile sample). 10,026 participants were interviewed between March and June 2013. 373 declared having suffered from acute, non traumatic joint pain, of whom a diagnosis of gout was made in 84 to 102 subjects, according to the algorithm used. This led to an estimated prevalence of gout of 0.9% (95% CI: 0.8, 1.1) in the general population, with no significant geographic variation.
Conclusions Gout prevalence in the adult population of metropolitan France in 2013 was estimated to be 0.9%.
Disclosure of Interest T. Bardin Consultant for: Ipsen, Menarini, Novartis, Sobi, Astra Zeneca, Savient, Speakers bureau: ipsen, Menarini, Novartis, Savient, S. Bouée Consultant for: Menarini, Ipsen, P. Clerson Consultant for: Ipsen, Menarini, G. Chalès Consultant for: Mayoli Spinder, Menarini, Ipsen, Novartis, Speakers bureau: Ipsen, Menarini, M. Doherty Consultant for: Menarini, Ardea, Novartis, R.-M. Flipo Consultant for: Ipsen, Menarini, Savient, C. Lambert Employee of: Ipsen, F. Lioté Consultant for: Ipsen, Menarini, Savient, Novartis, Astra Zeneka, Sobi, Mayoli Splindle, Ardea, Speakers bureau: Ipsen, Menarini, Savient, T. poiraud Employee of: Menarini, T. Schaeverbeke Consultant for: Ipsen, Menarini, P. Richette Consultant for: Ipsen, Menarini, Savient, Novartis, Astra Zeneka, Speakers bureau: Ipsen, Menarini, Savient