Bacterial superinfection rates in SARS-CoV-2 (COVID-19) range from 8% to 49.6%, but the diagnosis remains a challenge. We conducted a study to determine the utility of the Pneumonia Severity Index (PSI) to predict the risk of superinfections and outcomes in COVID-19 patients.

A cross-sectional retrospective study was conducted on COVID-19 positive patients admitted during 2020–2022. The PSI scores were calculated at admission and at every 72-hour intervals. Data regarding clinical course, antibiotic use and overall outcome were collected.

A total of 149 patients were included, with a mean age of 67 years. The PSI score at admission and the mean PSI score were higher for those who required antibiotics, intensive care unit (ICU) admission, or succumbed. Patients with a PSI score >107 at admission had a high risk of ICU admission, >113 had a high risk of antibiotic requirements, and >110 had a higher risk of death. An increase in PSI score ≥25 between the day of admission and day 3 of hospitalization; or between day 3 and day 6 of hospitalization, predicted a higher chance of mortality; but had no association with the development of superinfections.

The PSI score at admission can be used to predict the severity of disease requiring ICU admission, antibiotic requirement, and overall mortality, with serial monitoring of the score predicting possible clinical deterioration and increased mortality. However, it was not helpful in predicting the chances of developing superinfections and the need for antibiotic therapy.

The PSI score can be used to prognosticate the outcome in patients admitted with COVID-19, but further studies are needed to determine its utility in predicting the risk of superinfections.