Automated database case definition for diabetes mellitus. * Confirmation of initial diabetes related medical encounters were required when such encounters were identified from secondary inpatient ICD-9-CM diagnosis codes, outpatient ICD-9-CM diagnosis codes, or filled prescriptions for diabetes medications (see Table 1 for complete definitions for diabetes-related medical encounters and diabetes confirmation). Confirmation was needed in order to limit potential misclassification. Medical encounters identified from ICD-9-CM diagnosis codes were confirmed by a subsequent prescription for diabetes medications. Medical encounters identified form prescriptions were confirmed by subsequent ICD-9-CM diabetes diagnosis codes or by a subsequent diabetes medication prescription with a procedure indicating diabetes management.