A Comparison of Self-report and Health Care Provider Data to Assess Surveillance Definitions of Influenza-like Illness in Outpatients

ObjectiveSeveral surveillance definitions of influenza-like illness (ILI) have been proposed, based on the presence of symptoms. Symptom data can be obtained from patients, medical records, or both. Past research has found that agreements between health record data and self-report are variable depending on the specific symptom. Therefore, we aimed to explore the implications of using data on influenza symptoms extracted from medical records, …