The Impact of Influenza on Health-Related Quality of Life, Work Productivity, and Activity Impairment Among Symptomatic US Patients with Influenza

Evidence on the impact of influenza on health-related quality of life (HRQoL) and work productivity and activity impairment (WPAI) remains limited. This study evaluated changes in the EuroQol Visual Analogue Scale (EQ-VAS), EuroQol Utility Index (EQ-UI), absenteeism, presenteeism, work productivity loss, and activity impairment over 1 month during the high-severity 2024–2025 influenza season in the USA. Symptomatic adults (≥ 18 years) with a positive influenza test at ambulatory care clinics within a national US retail pharmacy chain (10/24/2024–4/15/2025) and symptom onset ≤ 4 days of positive test were included. HRQoL was assessed on days 1–7, 10, 14, and week 4 and WPAI on days 1, 7, 14, and week 4. Mixed models for repeated measures estimated mean changes and standard error (SE) from baseline, adjusting for relevant covariates. The analysis included 724 adults (mean [standard deviation (SD)] age: 42.0 [13.0] years; 74.2% female). HRQoL declined following infection: EQ-VAS decreased by 26.6 points (SE 0.9) on day 1 (p < 0.001) and 3.8 (0.8) on day 10 (p < 0.001), while EQ-UI scores decreased by 0.20 (0.01) on day 1 (p < 0.001) and 0.02 (0.01) on day 7 (p < 0.001). Compared with baseline, absenteeism rose by 58.3% (1.9) on day 1 and 34.9% (1.9) on day 7 (p < 0.001); presenteeism increased by 59.2% (2.0), 43.2% (2.0), and 8.8% (1.7) on days 1, 7, and 14 respectively (p < 0.001). Work productivity loss rose by 76.3% (1.7) on day 1, 55.5% (2.1) on day 7, and 8.1% (1.8) on day 14 (p < 0.001). Activity impairment increased by 62.6% (1.6) on Day 1, 43.6% (1.8) on day 7, and 6.6% (1.6) on day 14 (p < 0.001). Influenza was associated with marked declines in HRQoL, productivity, and daily functioning in symptomatic outpatients, highlighting the importance of patient-reported outcomes in capturing influenza’s real-world burden. ClinicalTrials.gov identifier. Graphical Abstract available for this article. Influenza (the flu) can seriously disrupt people’s lives, but there is limited long-term research on how it affects persons who are infected but not hospitalized especially during severe flu seasons in the USA. This study followed patients who had flu symptoms and tested positive for flu at ambulatory care clinics in a national retail pharmacy chain for 1 month. This study looked at how the flu impacted patients’ quality of life, ability to work, and daily activities. Patients reported worse quality of life during the first 2 weeks, people missed more work during the first week (up to day 7), continued working while sick for up to two weeks (day 14), and had difficulty working overall and with daily tasks for up to 2 weeks. These findings show that the flu can have lasting effects on individuals’ quality of life, work and everyday activities, even for those who are not hospitalized. It also shows the value of understanding patients’ experiences to show the full impact of the flu. Findings highlights why public health efforts including getting vaccinated against influenza are important for protecting quality of life and reducing missed work.