OBJECTIVES: This study aims to comprehensively review the utilization of patient-reported outcomes (PROs) in influenza research, focusing on available instruments, their measurement characteristics, and regulatory considerations.

METHODS: A systematic literature review (SLR) conducted in 2023 across MEDLINE and the PRO-specific database ePROVIDE identified English records with no time limitation. Recommendations are provided to facilitate future patient-centered research and decision-making in influenza.

RESULTS: Out of 94 database records identified in the SLR, 32 eligible articles were selected. Among these, 22 articles document the development, psychometric characteristics or clinical application of influenza-specific PRO instruments aimed at capturing patients' experiences, including symptoms, quality of life (QoL), and post-vaccination reactogenicity in immunized respondents. Two United States Food and Drug Administration (FDA) regulatory documents were found, suggesting that change in influenza-like-illness symptoms can be a useful secondary endpoint in trials. Additionally, product labels containing PROs in the clinical section were found for eight influenza symptomatic therapies. The literature suggests that vaccination or disease management strategies likely lead to differential use of PROs. Recommendations stemming from this review advocate for increased patient-centricity in clinical decision-making, drug development and surveillance with focus in three identified concepts of interest: Severity and duration of disease symptoms, impact on QoL, and drug tolerability. Challenges in implementing PROs include the selection of instruments with evidence of acceptable psychometric properties in the intended context of use, addressing patient compliance issues, safeguarding privacy, and ensuring equitable access. Psychometric evidence on available PRO instruments varies in quality and is limited to its underlying clinical setting.

CONCLUSIONS: PROs provide a unique perspective on the individual’s perceived course of influenza and a complementary method for evaluating drug tolerability. This review offers critical insights for healthcare professionals, researchers, and decision-makers to effectively integrate PROs into research on influenza prophylaxis or symptomatic treatment.