Factors predicting non-ventilated hospital-acquired pneumonia: systematic review and meta-analysis

Hospital-acquired pneumonia (HAP) results in approximately 15–20% of all infections in hospitals, with more than two-thirds being in patients not using mechanical ventilation. The incidence of non-ventilated hospital-acquired pneumonia (NVHAP) is increasing, and it is associated with a longer length of stay, the need for intensive care unit hospitalization and mechanical ventilation use, and higher mortality. To identify, quantify, and summarize predictive factors for NVHAP in adult patients admitted to non-intensive care units as determined by previous observational studies. PubMed, Embase, Scopus, and LILACS were systematically searched. Case–control and cohort studies were included, and a meta-analysis was performed for all factors studied more than once. National Institute of Health assessment tools were applied to assess the quality of the studies. Thirty-eight articles showing 204 predictive factors were included. A meta-analysis was performed for 58 factors, 32 of which were significantly associated with NVHAP. When the sensitivity analysis was performed without poor-quality studies, 24 factors remained associated with NVHAP. Although there is a lack of good-quality studies to establish predictive factors for NVHAP, the results of this study showed 24 factors associated with the development of this infectious complication. Knowledge of the significant predictive factors for NVHAP will enable the identification of patients most likely to develop it.