An analyte measurement system includes one or more handheld analyte meters and/or measurement devices and a means for collecting data, preserving data integrity, and uniquely identifying patient data received from multiple sources. For example, provided herein is a means to uniquely identify patients and their data when the data is collected from one or more measurement devices. By providing a way to allow the patients to use multiple sources to collect data, the system described herein provides patients with more flexibility, which should encourage better compliance to protocols. Further, by having a way to uniquely identify patients' data without requiring a patient to only use one analyte meter, for example, data can be centralized and analysis can be done with more assurance that all of the patient's data is being considered in the analyses.