Symptom Burden of Acute Influenza Infection Among US Adults: An Interim Analysis of a Nationwide Prospective Study
Author(s)
Tianyan Hu, Ph.D.1, Laura Lupton, MHA, MD2, Alon Yehoshua, PharmD1, Joseph C. Cappelleri, MPH, MS, PhD1, Meghan Gavaghan, MPH1, Verna Welch, PhD, MPH1, Santiago M.C. Lopez, MD1, Manuela Di Fusco, PhD1, Xiaowu Sun, PhD2.
1Pfizer Inc., New York, NY, USA, 2CVS Health, Woonsocket, RI, USA.
1Pfizer Inc., New York, NY, USA, 2CVS Health, Woonsocket, RI, USA.
Presentation Documents
OBJECTIVES: This study characterized the frequency and severity of acute symptoms among outpatients with test-confirmed influenza in the US during the 2024/2025 season.
METHODS: The study enrolled symptomatic adults testing positive for influenza infection at CVS Health. Individuals were recruited between 10/24/2024-1/3/2025 (CT.gov: NCT05160636). Socio-demographics, clinical characteristics, and vaccination status were self-reported at enrollment (Day 1) via an online survey. Frequency and severity of 11 acute symptoms were assessed at enrollment and recalled for the pre-infection baseline. Severity was measured using a 4-point scale (0=none, 1=mild, 2=moderate, 3=severe). Numbers of total acute symptoms and moderate/severe acute symptoms were summarized using descriptive statistics. Outcomes were compared between Day 1 and pre-infection baseline using paired t-tests.
RESULTS: Of 124 participants in this interim analysis, mean age was 41.6 (SD: 12.4), 75.8% were female, 42.7% had ≥1 comorbidity, and 47.6% received influenza vaccinations within the current respiratory season. At enrollment, participants had a mean of 8.4 (SD: 1.7) acute symptoms, with cough (97.6%), fatigue or tired (96.0%), and stuffy or running nose (96.0%) being the most frequent. Relative to pre-infection baseline, there was a significant increase in the number of acute symptoms at enrollment (+7.1; p<0.001). Participants reported a mean of 6.3 (SD: 2.7) moderate/severe acute symptoms at enrollment, which was a statistically significant increase from the pre-infection baseline (+6.2; p<0.001). The acute symptoms most often reported as moderate/severe at enrollment were fatigue or tiredness (81.5%) and cough (79.0%).
CONCLUSIONS: The interim data of this study show that the burden of influenza-related respiratory symptoms is sizable and persists in the most current season in the US, with most symptoms self-reported as moderate or severe. These findings underscore the need for continued monitoring and evaluation of symptom progression. The data raises awareness of patient burden and the importance of preventative measures such as influenza vaccination.
METHODS: The study enrolled symptomatic adults testing positive for influenza infection at CVS Health. Individuals were recruited between 10/24/2024-1/3/2025 (CT.gov: NCT05160636). Socio-demographics, clinical characteristics, and vaccination status were self-reported at enrollment (Day 1) via an online survey. Frequency and severity of 11 acute symptoms were assessed at enrollment and recalled for the pre-infection baseline. Severity was measured using a 4-point scale (0=none, 1=mild, 2=moderate, 3=severe). Numbers of total acute symptoms and moderate/severe acute symptoms were summarized using descriptive statistics. Outcomes were compared between Day 1 and pre-infection baseline using paired t-tests.
RESULTS: Of 124 participants in this interim analysis, mean age was 41.6 (SD: 12.4), 75.8% were female, 42.7% had ≥1 comorbidity, and 47.6% received influenza vaccinations within the current respiratory season. At enrollment, participants had a mean of 8.4 (SD: 1.7) acute symptoms, with cough (97.6%), fatigue or tired (96.0%), and stuffy or running nose (96.0%) being the most frequent. Relative to pre-infection baseline, there was a significant increase in the number of acute symptoms at enrollment (+7.1; p<0.001). Participants reported a mean of 6.3 (SD: 2.7) moderate/severe acute symptoms at enrollment, which was a statistically significant increase from the pre-infection baseline (+6.2; p<0.001). The acute symptoms most often reported as moderate/severe at enrollment were fatigue or tiredness (81.5%) and cough (79.0%).
CONCLUSIONS: The interim data of this study show that the burden of influenza-related respiratory symptoms is sizable and persists in the most current season in the US, with most symptoms self-reported as moderate or severe. These findings underscore the need for continued monitoring and evaluation of symptom progression. The data raises awareness of patient burden and the importance of preventative measures such as influenza vaccination.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
PCR254
Topic
Patient-Centered Research
Topic Subcategory
Patient-reported Outcomes & Quality of Life Outcomes
Disease
SDC: Infectious Disease (non-vaccine)