Background: This study was undertaken to acquire the incidences of type 1 diabetes among children in the Beijing area in the period of 1997-2000 and to compare these data with those in the period of 1988-1996.

Methods: According to the WHO capture-recapture protocol, we collected data from children under 15 years who had been diagnosed as having type 1 diabetes in the Beijing area in the period of 1997 and 2000. The incidence of the disease was calculated from the demographic data and the age-adjusted incidence from the data from the Chinese population of 2000. Confidence intervals of 95% were established with the Poisson distribution, and statistical significance of differences was tested with the chi-square test.

Results: In the period of 1997-2000, the incidence of type 1 diabetes ranged from 0.759 cases per 100 000 to 1.215 cases per 100 000 with an average annual incidence of 1.014/100 000 (95% confidence interval 0.98/100 000 to 1.16/100 000). No significant difference was found in the incidence in this period as compared with the period of 1988-1996, nor in age adjusted incidence (age-adjusted incidence 0.83/100 000 for 1988-1996 vs 0.86/100 000 for 1997-2000). The incidence of the disease was significantly higher in 10- to 14-year-old children than in younger groups (P=0.002). No gender-specific differences were found.

Conclusions: The study did not reveal any statistical difference when comparing the two periods of 1988-1996 and 1997-2000 in the age-adjusted incidence of type 1 diabetes in children in the Beijing area. The results were not consistent with those reported from other countries. Although the economic and social conditions in Beijing changed considerably in the periods of our study, we did not find their influence on the incidence of type 1 diabetes in the pediatric population. Immigration of people from other parts of China to the Beijing area was an intervening factor in this study.