Objectives: This systematic review aimed to identify independent prognostic factors of severe pneumonia.
Methods: A systematic search was undertaken in Pubmed, Embase, and Web of Science from inception to March 2023 to find cohort studies investigating the association between prognostic factors and adverse outcomes of severe pneumonia in adult patients. The study selection process involved screening the title and abstract of articles to identify relevant studies on severe pneumonia in adult patients. Inclusion criteria included studies with a prospective or retrospective longitudinal design, investigating prognostic factors, and performing multivariate analysis. Exclusion criteria included non-English or non-Chinese studies, studies focusing on severe pneumonia in children, studies conducting only univariate analysis, and conference abstracts, reviews, and case reports. The risk of bias was assessed by the Quality In Prognosis Studies (QUIPS) tool.
Results: A total of 27 published studies, including both prospective and retrospective cohort studies, were included. These studies reported on 53 different prognostic factors and covered four unique outcomes. The quality assessment indicated that 59.3% of the studies had a low risk of bias. Age, functional dependence, heart rate, and oxygen saturation/respiratory rate index were found to be associated with mortality. Additionally, various laboratory indexes, such as serum cholinesterase, albumin, and blood urea nitrogen to creatinine ratio, demonstrated either protective or risk factors for prognosis. Injury and comorbidities, including acute renal failure, chronic lung disease, and Glasgow Coma Scale, were identified as risk factors for mortality. Scoring tools like Acute Physiological and Chronic Health Evaluation (APACHE) II score, CURB-65 score, and Pneumonia Severity Index (PSI) score showed associations with mortality. Lastly, certain treatment protocols, such as vasoactive agent use, vasopressor use, and mechanical ventilation, were found to increase the risk of mortality, while invasive mechanical ventilation and the use of remdesivir and steroids had a positive impact on prognosis. These findings provide valuable insights for clinicians in predicting and managing severe pneumonia outcomes.
Conclusion: This most comprehensive review identified 53 unique prognostic factors of severe pneumonia, which provided a reference for subsequent researchers to construct models to predict clinical outcomes in patients with severe pneumonia for clinical use. By identifying prognostic factors through multivariate analysis, healthcare providers can better assess the severity and prognosis of individual patients. This knowledge can aid in treatment planning, resource allocation, and determining the appropriate level of care for patients with severe pneumonia. Additionally, understanding the prognostic factors can help identify high-risk patients who may require more intensive monitoring or interventions. Overall, this study provides valuable insights that can inform clinical practice and improve patient outcomes in the management of severe pneumonia.