History of diabetes is based on self-report. For any given cycle, this value indicates reported diabetes in past history or in at least one follow-up cycle up to and including that cycle. Participants are asked to respond "yes", "suspect or possible", or "no" to each of the following questions:

1. Have you ever been told by a doctor, nurse, or therapist that you had diabetes, or sugar in the urine, or high blood sugar?
2. Has a doctor, nurse, or therapist ever told you to take insulin or injections for your high blood sugar?
3. Has a doctor, nurse, or therapist ever told you to take medicine by mouth for your blood sugar?

Additionally, participants supplied all medications prescribed by a doctor, vitamins, supplements, and over-the-counter remedies and medicines taken in the 2 weeks prior to the evaluation. Use of diabetes medication was documented by direct visual inspection by the interviewer at each visit.

Note: This cumulative variable is longitudinal up to and including index follow-up.