A systematic review of factors associated with poor prognosis despite appropriate antibiotics usage for pneumonia

Treatment with appropriate antibiotics does not seem to be associated with prognosis among elderly patients with pneumonia. Identifying factors associated with poor prognosis despite the use of appropriate antibiotics might help withhold aggressive antibiotic treatment in patients with pneumonia. This systematic review aims to identify the risk factors associated with unfavored outcomes despite using appropriate antibiotics for pneumonia. The PubMed database was searched for studies focusing on appropriate antibiotic use in patients with pneumonia (assessed on Aug 7, 2024). Appropriate antibiotics were defined as those sensitive to microorganisms isolated from patients. The risk of bias was evaluated using the Risk of Bias Assessment tool for nonrandomized Studies utilized for controlled observational studies. A total of 1563 studies were identified from the database, and eight observational studies were included in this review: ventilator-associated pneumonia (n = 4), community-onset pneumonia (n = 2), P. aeruginosa pneumonia (n = 1), and S. maltophilia pneumonia (n = 1). Advanced age was the most commonly evaluated factor associated with mortality. Additionally, high severity scores were related to the unfavored outcomes even after treatment with appropriate antibiotics. Advanced age and high severity scores may be associated with increased mortality despite appropriate antibiotic usage for pneumonia. Broad-spectrum antibiotics might not be indicated in elderly pneumonia patients with high severity status who do not wish to receive aggressive antibiotic treatments.