A systematic review of comorbidities and outcomes of adult patients with pleural infection

Abstract

Background: Pleural infection remains an important cause of mortality. This study aimed to investigate worldwide patterns of pre-existing comorbidities and clinical outcomes of patients with pleural infection.

Methods: Studies reporting on adults with pleural infection between 2000 and 2017 were identified from a search of Embase and MEDLINE. Articles reporting exclusively on tuberculous, fungal or post-pneumonectomy infection were excluded. Two reviewers assessed 20 980 records for eligibility.

Results: 211 studies met the inclusion criteria. 134 articles (227 898 patients, mean age 52.8 years) reported comorbidity and/or outcome data. The majority of studies were retrospective observational cohorts (n=104, 78%) and the most common region of reporting was East Asia (n=33, 24%) followed by North America (n=27, 20%). 85 articles (50 756 patients) reported comorbidity. The median (interquartile range (IQR)) percentage prevalence of any comorbidity was 72% (58-83%), with respiratory illness (20%, 16-32%) and cardiac illness (19%, 15-27%) most commonly reported. 125 papers (192 298 patients) reported outcome data. The median (IQR) length of stay was 19 days (13-27 days) and median in-hospital or 30-day mortality was 4% (IQR 1-11%). In regions with high-income economies (n=100, 74%) patients were older (mean 56.5 versus 42.5 years, p<0.0001), but there were no significant differences in prevalence of pre-existing comorbidity nor in length of hospital stay or mortality.

Conclusion: Patients with pleural infection have high levels of comorbidity and long hospital stays. Most reported data are from high-income economy settings. Data from lower-income regions is needed to better understand regional trends and enable optimal resource provision going forward.

FIGURE 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart showing the identification, screening, eligibility and inclusion process.

FIGURE 2

Pre-existing prevalence of comorbidity in studies of patients with pleural infection. Percentage prevalence of comorbidities in each study were extracted and data from high-income and lower-income economies were compared. a) Percentage prevalence of comorbidity, smoking, alcohol excess and disease by organ system affected; b) percentage prevalence of comorbidity by specific diseases. Data are presented as median (interquartile range). Mann–Whitney test was used to compare median prevalence of diabetes mellitus in high-income and lower-income economies. COPD: chronic obstructive pulmonary disease.

FIGURE 3

Prevalence of outcomes in studies of patients with pleural infection. Percentage prevalence of outcomes in each study were extracted and data from high-income and lower-income economies were compared. a) Mean length of hospital stay; b) percentage prevalence of mortality, patients requiring fibrinolysis and patients requiring surgical treatment. Data are presented as median (interquartile range).