Embodiments provide systems, methods, and apparatus for reducing the impact of user-entered data errors in a data management system (DMS) such as for diabetes. Embodiments include storing user-entered data received from a user into a primary DMS database; storing secondary data received from a source other than the user into a secondary tracking database; associating the secondary data with one or more events described by the user-entered data; cross-checking the user-entered data against the associated secondary data; evaluating user-entered data based on the cross-checking results; presenting for review evaluated user-entered data; treating user-entered data in the primary DMS database based on review results; and determining a diabetes management plan based on the treated user-entered data. Numerous other aspects are provided.