Risk factors of stroke complicated with hospital-acquired pneumonia: a systematic review and meta-analysis of cohort studies

Background: Hospital-acquired pneumonia (HAP) is a common type of nosocomial infection and a common complication experienced by stroke patients during hospitalization. HAP can aggravate patients' primary disease condition and lead to death. Clinically, a variety of factors may affect the occurrence of HAP in patients. In this study, we conducted a meta-analysis of the literature to investigate the risk factors of stroke with HAP for clinical reference. Methods: The PubMed, Medline, Embase and Cochrane Library databases were selected as the sources for the literature search. English- language publications were included. The articles related to stroke with HAP were published from January 2000 to January 2021. The articles were screened and their quality was evaluated using the Newcastle-Ottawa Scale. A meta-analysis was performed of the factors affecting the incidence of HAP using Revman 5.4 software. Results: Ultimately, 7 articles with a total of 1,172 patients were included in the meta-analysis. Of the 1,172 patients, 352 (30.03%) had an HAP infection. The results of the meta-analysis showed that patient age [mean difference (MD) =4.91, 95% confidence interval (CI): 3.90 to 5.93; P<0.00001], National Institutes of Health Stroke Scale (NIHSS) score (MD =3.84, 95% CI: 3.01 to 4.67; P<0.00001), and patient malnutrition [odds ratio (OR) =1.85, 95% CI: 1.13 to 3.04; P=0.02] were risk factors for the development of HAP, while gender, stroke history, smoking history, and comorbidities (diabetes, hypertension, coronary heart disease, and hyperlipidemia) were not risk factors for the development of HAP. Discussion: A total of 7 articles were included in this meta-analysis examining the influencing factors of HAP in stroke patients. The results showed that age, NIHSS score, and malnutrition were risk factors of HAP in stroke patients, while gender, stroke history, smoking history, and complications (diabetes, hypertension, coronary heart disease, and hyperlipidemia) were not influencing factors of HAP.