Abstract
Background The COVID-19 pandemic has had a profound impact on global healthcare systems, often compared to seasonal influenza due to similarities in clinical presentation. This study aims to compare the clinical characteristics, comorbidities, and outcomes of critically ill patients with COVID-19 and those with influenza admitted to a tertiary care hospital in Islamabad, Pakistan. Methods This retrospective cohort study included 120 patients, 60 with confirmed COVID-19 and 60 with confirmed influenza, all of whom required ICU admission and mechanical ventilation between January 1, 2021, and January 1, 2024. Data were collected from electronic medical records, including demographic information, comorbidities, and clinical outcomes. Descriptive statistics were used to compare the two groups. Results The median age of COVID-19 patients was 55 years (range 30-78), while that of influenza patients was 58 years (range 31-80). Both groups had a slight male predominance (COVID-19: 66.7%, Influenza: 63.3%). Comorbidities were common in both groups, with 75.0% of COVID-19 patients and 83.3% of influenza patients having at least one comorbidity. The most common comorbidities included hypertension (COVID-19: 30.0%, Influenza: 33.3%) and diabetes (COVID-19: 20.0%, Influenza: 25.0%). Clinical outcomes revealed a higher mortality rate among influenza patients (43.3%) compared to COVID-19 patients (28.3%). ICU admission rates were identical for both groups at 66.7%, and mechanical ventilation was required for 66.7% of ICU-admitted patients in both groups. The presence of cardiovascular comorbidities significantly impacted patient outcomes, with higher mortality observed in influenza patients with such comorbidities (44.7%) compared to COVID-19 patients (28.9%). Conclusion This study highlights the significant burden of both COVID-19 and influenza on critically ill patients, particularly those with cardiovascular comorbidities. While influenza patients in this cohort exhibited higher mortality rates, both groups demonstrated substantial ICU admission rates and a need for mechanical ventilation.