Incidence of type 1 diabetes in Philadelphia is higher in black than white children from 1995 to 1999: epidemic or misclassification?
OBJECTIVE
To determine the epidemiology of type 1 diabetes in children in Philadelphia, Pennsylvania, from 1995 through 1999 and compare these data with previous cohorts.


METHODS
This is a report of a retrospective population-based registry maintained since 1985. Hospital records meeting the following criteria were reviewed: newly diagnosed type 1 diabetes, age 0-14 years, residing in Philadelphia at the time of diagnosis, and diagnosed from 1 January 1995 to 31 December 1999. The secondary source of validation was the School District of Philadelphia. Incidence rates by race and age were compared with 1985-1989 and 1990-1994 cohorts.


RESULTS
A total of 234 case subjects were identified, and the registry was determined to be 96% complete. The overall age-adjusted incidence rate in Philadelphia was 14.8 per 100,000/year. Incidence rates in Hispanic children (15.5 per 100,000/year) and white children (12.8 per 100,000/year) have been relatively stable over 15 years. The incidence in black children (15.2 per 100,000/year), however, has increased dramatically, rising 64% in children 5-9 years of age (14.9 per 100,000/year) and 37% in the 10- to 14-year age-group (26.9 per 100,000/year).


CONCLUSIONS
The overall incidence of type 1 diabetes in Philadelphia is increasing and is similar to other U.S. registries. These are the first data reporting a higher incidence in black children in a registry of children 0-14 years of age. The etiology of the marked increase in incidence in the black population is unknown and underscores the need to establish type 1 diabetes as a reportable disease, so that environmental risk factors may be thoroughly investigated.
Lipman
Terri H
TH
CRNP, University of Pennsylvania School of Nursing, 420 Guardian Dr., Philadelphia, PA 19104, USA. lipman@nursing.upenn.edu
Jawad
Abbas F
AF
Murphy
Kathryn M
KM
Tuttle
Alan
A
Thompson
Rebecca L
RL
Ratcliffe
Sarah J
SJ
Levitt Katz
Lorraine E
LE
D000293:Adolescent; D044383:Black People / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology*; D004196:Disease Outbreaks; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015143:Philadelphia / Q000453:epidemiology; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American