Objective: To determine the incidence and clinical presentation of Wegener's granulomatosis (WG) in Finland during the 20-year period 1981-2000.
Methods: We performed a study with retrospective data retrieval using the hospital discharge register in Finland. All available hospital case reports were reviewed. We included those patients diagnosed with and treated for WG. Demographic and clinical data at diagnosis were recorded.
Results: Of the 492 patients diagnosed with WG, 49% were male. Mean age at diagnosis was 53.2 years (SD 18.1). The highest rate of incidence occurred in men and women aged 65-74 years. The annual incidence per million of the population increased from 1.9 (95% CI 1.4 to 2.6) during 1981-1985 to 9.3 (95% CI 8.1 to 10.6) during 1996-2000 with gender age-adjusted incidence rate ratio 4.5 (CI 3.6 to 5.7). Only minor changes in the signs and symptoms at diagnosis occurred during the 20-year span. In 83% of cases, the ACR criteria (>or=2 criteria) were fulfilled. The mean age at diagnosis rose from 45.8 to 55.0 years and the median diagnostic delay decreased from 17 to 4 months during the two decades.
Conclusion: The incidence of WG has increased during the last two decades with little change in clinical symptoms at presentation. At the same time, the mean age of the patients has increased and the diagnostic delay has considerably shortened.