Clinical and laboratory features of patients with rheumatoid arthritis diagnosed at rheumatology services in the Brazilian municipality of Cascavel, PR, Brazil.

INTRODUCTION Brazilian epidemiological studies on rheumatoid arthritis are scarce, thus all data currently available originate from the international literature. OBJECTIVES To determine the incidence and some clinical and laboratory characteristics of patients with rheumatoid arthritis in the municipality of Cascavel, state of Paraná, Brazil. PATIENTS AND METHODS Data were collected between August 2010 and July 2011 in all health services of the municipality of Cascavel that provided health care in Rheumatology: a university-affiliated hospital, a public outpatient clinic and four private clinics. RESULTS We identified 38 patients diagnosed with rheumatoid arthritis, resulting in an estimated incidence of 13.4 cases per 100,000 inhabitants/year. Thirty two patients were females, whose mean age was 47.6 years. The age group with the highest incidence was over 40 years. The mean time between first symptoms and diagnosis was 12.4 months. Rheumatoid factor was positive in 68.4% of the patients, and 18.4% already had radiological abnormalities at diagnosis. The pharmacological treatment of patients was also assessed and proved to be in accordance with those found in the literature. CONCLUSION The incidence of rheumatoid arthritis obtained in the municipality of Cascavel was lower than those reported in international studies.