APR	Abdominoperineal resection
AUC	Area under the curve
CDI	Clostridioides difficile infection
CHF	Congestive heart failure
CI	Confidence interval
CKD	Chronic kidney disease
COPD	Chronic obstructive pulmonary disease
CRC	Colorectal cancer
CRT	Chemoradiotherapy
DM	Diabetus mellitus
HAR	High anterior resection
HAI	Hospital-acquired infection
HAP	Hospital-acquired pneumonia
HTA	Hypertension
ICU	Intensive care unit
IAC	Intra-abdominal collection
IQR	Interquartile range
LAR	Low anterior resection
LOS	Length of stay
mFI-5	5-item modified frailty index
NA	Not applicable
OS	Overall survival
ROC	Receiver operating characteristic
SD	Standard deviation
SE	Standard error
SSI	Surgical site infection
STROBE	Strengthening the Reporting of Observational Studies in Epidemiology