Human Metapneumovirus–, Respiratory Syncytial Virus–, and Influenza-Associated Pneumonia Hospitalizations in Colorado Adults Aged ≥50 Years, 2016–2023

BACKGROUND: The study objectives were to identify the frequency and risk factors for intensive care unit (ICU) admission and mortality associated with respiratory syncytial virus (RSV), influenza, and human metapneumovirus (HMPV) pneumonia hospitalizations and to compare these rates with patients admitted with other acute respiratory infections (ARIs) caused by these viruses. METHODS: This study identified hospitalization encounters of adults aged 50-88 years with RSV, influenza, and HMPV pneumonia between 2016 and 2023 in the Colorado Hospital Association database. Multivariate logistic regression was used to estimate the odds of ICU admission and mortality. RESULTS: Of 2210 hospitalized patients with RSV pneumonia, 780 (35%) were admitted to ICU and 205 (9.3%) died. Similar proportions were observed for HMPV pneumonia (27.5% and 5.9%) and influenza pneumonia (32.5% and 7.6%) ICU admissions and mortality, respectively. Dementia had the highest odds for ICU admission in patients with RSV pneumonia (adjusted odds ratio [aOR], 4.2 [95% confidence interval {CI}, 1.34-13.18]); chronic pulmonary disease (CPD) for influenza pneumonia (aOR, 2.99 [95% CI, 2.45-3.66]), and chronic obstructive pulmonary disease (COPD) without asthma for HMPV pneumonia (aOR, 5.04 [95% CI, 2.92-8.7]). Increasing age was associated with increased mortality for RSV and influenza. CPD and COPD had >2-fold greater odds of mortality in patients with pneumonia for all 3 viruses. Increasing numbers of comorbidities significantly increased ICU admission and mortality in all 3 groups. CONCLUSIONS: Pneumonia is a severe manifestation of ARI with RSV, influenza, and HMPV, with differing risk factors for ICU admission and mortality.