OBJECTIVE: This study aimed to identify the essential content and amount of information to be collected from people with migraine via a patient-facing smartphone-based migraine tracker for them to share with clinicians during live discussions to assist in optimizing migraine management. The proposed tracker is intended for use in non-interventional research to evaluate disease burden in episodic migraine and chronic migraine patients as assessed by demographic and clinical characteristics and health resource utilization in an integrated delivery network setting. The proposed tracker is not intended for commercial purposes. BACKGROUND: Epidemiological studies suggest migraine is underdiagnosed and undertreated. Studies of patient-clinician interactions suggest that effective medical communication may help address these issues. METHODS: Four migraine practice leaders, an epidemiologist with extensive migraine experience, and a measurement expert took part in a modified Delphi panel process to identify data elements that could be collected from people with migraine through a smartphone-based migraine tracker. Importantly, the proposed tracker would not be intended to replace the patient-clinician encounter but to support the encounter through enabling the patient to document migraine symptoms and experiences in a timely and accurate manner for sharing with a clinician as part of a broader face-to-face discussion. The panel reviewed questions derived from the existing migraine diaries in the public domain, those used in clinical trials, and patient-centric surveys assessing the impact of migraine on physical function and other related concepts. Key considerations included identification of the most clinically useful data elements for a shared communication tool for people with migraine under the care of a clinician. The panel also identified numerous functionality requirements for such a tool and provided recommendations on the most effective way to present results to a clinician. RESULTS: The expert panel opined that people with migraine may value the ability to capture a relatively broad range of information for their own migraine-tracking purposes, while clinicians will likely find greater value in a small set of data relevant to the management of migraine. The panel identified the 3 most essential concepts in categories of data for a clinician, for which they coined the term "The 3 Fs": Frequency of days with headache; Frequency of acute medication usage; and Functional impairment. Information on the frequency of days with headache was felt to combine with the information on the frequency of acute medication usage to provide essential insights into current migraine management strategy and its outcomes, and to assist considerations of preventive measures. Functional impairment was treated as an effective surrogate for headache severity and was assessed based on the following: degree of difficulty in performing activities of daily living, impact on absenteeism (taking leave from work or cancelling/avoiding other activities) and presenteeism (performing work or other daily activities, with reduced productivity/capability), and amount of rest required as a result of a migraine attack. The modified Delphi panel process resulted in the selection of 13 questions in 8 categories to elicit sufficient and meaningful data comprising headache occurrence, symptoms, daily/preventive and as-needed/acute medication usage, triggers, ability to concentrate, and functional impairment. The panel also agreed that the tracker should generate 2 distinct reports: one for people with migraine that would include a wider range of data about symptoms and perceived triggers, and a targeted report for the clinician that would place prime emphasis on the 3 Fs for aggregating the results of each headache occurrence and the trend over time. CONCLUSIONS: A system that easily captures critical data elements about migraine, with specific feedback displays for patients to share with clinicians during live discussions, may offer some benefit to people with migraine and their clinicians by facilitating more objective communication and optimizing management. The tracker's output may enable people with migraine to track a wide range of data for their own purposes, allowing them to better understand their condition, while a synthesized view of the selected data may support more informed clinical decision-making for the clinician and individualized, evidence-based discussion with the patient. As a result, this shared decision-making tool may enable patients to more accurately convey essential migraine information during live patient-clinician discussions to drive improved management and patient outcomes.