Association of chronic medical conditions with severe outcomes among non-pregnant adults 18-49 years old hospitalized with influenza, FluSurv-NET, 2011-2019
Efemona A Famati, Dawud Ujamaa, Alissa O’Holloran, Pam Daily Kirley, Shua J Chai, Isaac Armistead, Nisha B Alden, Kimberly Yousey-Hindes, Kyle P Openo, Patricia A Ryan, Maya L Monroe, Anna Falkowski, Sue Kim, Ruth Lynfield, Melissa McMahon, Kathy M Angeles, Sarah A Khanlian, Nancy L Spina, Nancy M Bennett, Maria A Gaitán, Eli Shiltz, Krista Lung, Ann Thomas, H Keipp Talbot, William Schaffner, Andrea George, Holly Staten, Catherine Bozio, Shikha Garg- Infectious Diseases
- Oncology
Abstract
Background
Older age and chronic conditions are associated with severe influenza outcomes; however, data are only comprehensibly available for adults ≥65 years old. Using data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), we identified characteristics associated with severe outcomes in adults 18-49 years old hospitalized with influenza.
Methods
We included FluSurv-NET data from non-pregnant adults 18-49 years old hospitalized with laboratory-confirmed influenza during the 2011-12 through 2018-19 seasons. We used bivariate and multivariable logistic regression to determine associations between select characteristics and severe outcomes including intensive care unit (ICU) admission, invasive mechanical ventilation (IMV), and in-hospital death.
Results
16,140 patients aged 18-49 years old and hospitalized with influenza were included in the analysis; median age was 39 years and 26% received current season influenza vaccine prior to hospitalization. Obesity, asthma, and diabetes mellitus were the most common chronic conditions. Conditions associated with a significantly increased risk of severe outcomes included: age group 30-39 or 40-49 years respectively (IMV adjusted odds ratio (aOR) 1.25; 1.36; death aOR 1.28; 1.69), being unvaccinated (ICU aOR 1.18; IMV aOR 1.25; death aOR 1.48), and having chronic conditions including extreme obesity and chronic lung, cardiovascular, metabolic, neurologic or liver diseases (ICU range aOR 1.22-1.56; IMV range aOR 1.17-1.54; death range aOR 1.43-2.36).
Discussion
To reduce the morbidity and mortality associated with influenza among adults aged 18-49 years, health care providers should strongly encourage receipt of annual influenza vaccine, and lifestyle/behavioral modifications particularly among those with chronic medical conditions.