TRENDS IN THE INCIDENCE OF POLYCYTHEMIA-VERA AMONG OLMSTED COUNTY, MINNESOTA RESIDENTS, 1935-1989

To investigate the suggestion that the incidence of polycythemia vera has increased in recent decades, we ascertained secular trends in the incidence of polycythemia vera in Olmsted County, Minnesota, over the 55-year period, 1935-1989. The inpatient and outpatient medical record s of all potential cases of polycythemia vera in Olmsted County reside nts were reviewed and the diagnostic criteria of the Polycythemia Vera Study G roup were applied. We found no indication of an increase in t he age- and sex-adjusted incidence of polycythemia vera, which average d 1.9 per 100,000 person-years (95% C.I., 1.4-2.5) over the study peri od. Incidence rates increased with age, and age-adjusted incidence rat es were greater for men (2.8 per 100,000 person-years; 95% C.I., 1.8-3 .9) than for women (1.3 per 100,000 person-years; 95% C.I., 0.7-1.9), with the highest incidence rate (23.5 per 100,000 person-years) among men aged 70-79 years. Survival was reduced in this inception cohort of 50 cases, compared to that expected for individuals of like age and s ex (P < 0.0001); median survival following diagnosis was 7.2 years. (C ) 1994 Wiley-Liss, Inc.