Claims data from a medium-sized health plan were retrieved for the period between 2001 and 2004. HEDIS2006 criteria[8] were used retrospectively to identify the enrollees in the health plan who had diabetes. These criteria are similar to those used in a study by Hux et al.,[14] which achieved a sensitivity of 0.86 and a positive predictive value of 0.80, thus demonstrating it to be a valid identification algorithm for diabetes.