ASA	American Society of Anesthesiologists
CAE	Community-acquired empyema
CCI	Charlson Comorbidity Index
CI	Confidence interval
CNS	Central nervous system
COPD	Chronic obstructive pulmonary disease
CPE	Complicated parapneumonic effusion
CPPE	Complicated parapneumonic pleural effusion
CRP	C-reactive protein
CT	Computed tomography
CRediT	Contributor Roles Taxonomy
DNase	Deoxyribonuclease
HAE	Hospital-acquired empyema
HCAE	Healthcare-associated empyema
HR	Hazard ratio
ICU	Intensive care unit
IET	Intrapleural enzyme therapy
IPFT	Intrapleural fibrinolytic therapy
LDH	Lactate dehydrogenase
LOS	Length of hospital stay
MD	Mean difference
MeSH	Medical Subject Headings
MNPI	Microbiological-negative pleural infection
MPPI	Microbiological-positive pleural infection
NLR	Neutrophil-to-lymphocyte ratio
NOS	Newcastle–Ottawa Scale
OR	Odds ratio
PECO	Population, Exposure, Comparator, Outcome
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PROSPERO	International Prospective Register of Systematic Reviews
Q	Cochran’s Q statistic
RAPID	Renal function, Age, Purulence, Infection source, and Dietary factors
REML	Restricted maximum likelihood
RR	Risk ratio
SD	Standard deviation
tPA	Tissue plasminogen activator
VATS	Video-assisted thoracoscopic surgery
I2	Higgins’ inconsistency statistic
τ2	Between-study variance