The Epidemiological Trends of Hospitalized Pneumonia Patients in Taiwan in 2019 and 2020: A Population-based Nationwide Study.

BACKGROUND: Pneumonia remains a leading cause of hospitalization and mortality worldwide, particularly among children and older adults. Disease outcomes may vary based on the causative pathogens, disease severity, and comorbidities; furthermore, the emergence of SARS-CoV-2 might have altered pneumonia-related hospitalization trends. METHODS: We conducted a population-based study using Taiwan's National Health Insurance Database to analyze pneumonia hospitalizations, length of stay (LOS), and mortality in 2019 and 2020, focusing on pneumonia type, age, comorbidities, and severity. Hospitalizations were classified into four categories: all pneumonia, viral, bacterial, and "other" (including atypical and unidentified). We identified comorbidities and defined severity by general ward or ICU admission. RESULTS: Pneumonia hospitalizations decreased from 335,806 in 2019 to 264,672 in 2020. "Other" pneumonia was the most common type. Viral pneumonia was more prevalent in pediatric patients, while bacterial pneumonia dominated in those ≥ 65 years. LOS increased across all types, especially for bacterial pneumonia. Mortality increased with age and was higher in 2020 across all types. Among comorbidities, diabetes mellitus (DM) and chronic obstructive pulmonary disease (COPD) were the most common, while end-stage renal disease (ESRD) had the highest in-hospital mortality. ICU patients had the longest LOS. Bacterial pneumonia had the highest mortality in general wards, while "other" pneumonia in the ICU. CONCLUSIONS: We examined pneumonia hospitalizations in Taiwan in 2019 and 2020, providing hospitalization proportion, LOS and mortality rate by pathogen types, age group, comorbidities, and severity level. Enhancing vaccination programs, strengthening rapid diagnostics, and managing comorbidities are essential to reduce severe cases, improve outcomes, and lessen healthcare burdens.