An apparatus comprises receiving a user prompt in a blood glucose (BG) management device to start a determination of an effective correction factor, receiving sampled blood glucose data of a patient obtained during a specified time duration, including a time duration after delivery of an initial insulin correction bolus, determining the effective correction factor using the BG management device according to a determined decrease in the blood glucose level of the patient and an amount of insulin in the initial insulin correction bolus, and cancelling the determination of the effective correction factor if a blood glucose level of the patient is outside of a specified range of blood glucose levels.