Nakhla M, Simard M, Dube M, et al. - Using health administrative data, researchers sought to define and validate a pediatric diabetes case ascertainment algorithm (including any form of childhood-onset diabetes). They undertook a two-stage method; in stage 1, chart data from a large urban region was linked to health administrative data and the diagnostic accuracy of various algorithms was compared. They selected those that performed best for validation in stage 2. In stage 2, validation of the most accurate algorithms with chart data within two other geographic areas in the province of Quebec was done. Four physician claims or one hospitalization or using only four physician claims in 2 years were required for accurate identification of diabetes in children (ages ≤ 15 years). The positive predictive value of all algorithms tested increased on separating the physician claims by 30 days. These findings suggest that accurate identification of patients with child-onset diabetes can be done within health administrative databases providing a valid source of information for healthcare resource planning and evaluation.