OBJECTIVE— To determine the epidemiology of type I diabetes in children in Philadelphia, particularly with respect to racial differences.
RESEARCH DESIGN AND METHODS— This is a descriptive epidemiological study using a retrospective population-based registry in Philadelphia, Pennsylvania, a city with large white, black, and Hispanic populations. All hospitals in Philadelphia that admit children were identified. All charts meeting the following criteria were reviewed: 1) newly diagnosed IDDM, 2) 0–14 yr of age, 3) residing in Philadelphia at the time of diagnosis, and 4) diagnosed from 1 January 1985 to 31 December 1989. Standard IDDM registry data were abstracted from the charts. Ascertainment of the completeness of the hospital registry was validated by two secondary sources: 1) diabetes camp records, 2) Philadelphia School District data.
RESULTS— A total of 215 cases were identified, and the combined hospital, camp, and school registry was determined to be 93% complete. The overall age-adjusted incidence rate in Philadelphia was 13.4/100,000/yr. The highest incidence rate was in Hispanics (15.16), followed by whites (13.31), and blacks (10.95).
CONCLUSIONS— The incidence of IDDM in Philadelphia is similar to what has been found in other U.S. registries. The unexpected finding was that the incidence in the Puerto Rican Hispanic population was the highest in the city. This is the first data reported on this population, and more studies are needed to elucidate the genetic and environmental causes of this high incidence of IDDM.