Epidemiology of psoriatic arthritis in northwest Greece, 1982-2001.

OBJECTIVE: To investigate the frequency and distribution of psoriatic arthritis (PsA) in a defined area of Northwest Greece, with a population of about 500,000 inhabitants.

METHODS: Cases were recorded from in- and outpatients referred to the Rheumatology Clinics of the Ioannina University Hospital and the Ioannina General Hospital, and from patients referred to private rheumatologists practicing in the study area. All patients recorded between January 1, 1982, and December 31, 2001, resident in the study area, were included. The study area included the Department of Epirus and the northern part of the Department of Ionian Islands. Diagnosis was based on the European Spondylarthropathy Study Group criteria. Incidence and prevalence rates were calculated as number of cases per 100,000 inhabitants. Population data were based on the National Census.

RESULTS: The age-adjusted prevalence of PsA was 56.6 cases per 100,000 adults on December 31, 2001. A total of 221 new cases were diagnosed during the study period, giving an age-adjusted mean incidence rate of 3.02 cases per 100,000 adults. There was no significant difference observed between men and women. The peak of incidence was observed in the age group 45-64 years. Incidence of diagnosed PsA increased during the study period.

CONCLUSION: The incidence and prevalence of PsA in Northwest Greece was roughly half that reported in studies from the US and Northern Europe. This frequency tended to increase in the last decade.