Trends in Diabetes Mellitus Among Privately Insured Children, 1998-2002

Objective: To evaluate trends in health care administrative claims for childhood diabetes mellitus. Methods: We conducted a serial cross-sectional study of a national sample of privately insured children ≤18 years old. The number of subjects ranged from 306 991 in 1998 to 974 407 in 2002. We classified diabetes type by 2 schemes: one based on encounter claims only, and the other based on both encounter and pharmacy claims. The prevalence of diabetes was determined after adjusting for demographic changes in the study population, including age, proportion enrolled in managed care, and urban residence. Results: The adjusted prevalence of diabetes overall increased from 183 (95% confidence interval [CI], 169-198) cases per 100 000 enrollees in 1998 to 218 (95% CI, 208-228) cases per 100 000 enrollees in 2002, primarily because of an increase in type 1 diabetes (based on both encounter and pharmacy claims, 135 [95% CI, 123-148] cases per 100 000 enrollees in 1998 to 167 [95% CI, 158-176] cases per 100 000 enrollees in 2002). Conclusions: Our estimate of the overall prevalence of diabetes is consistent with national data. However, our finding that rising prevalence of type 1 diabetes appear to account for most of the increase in diabetes claims is surprising. Future research will be needed to validate these results.