AC	acute cholecystitis
ASA	American Society of Anesthesiologists
AUC	area under the curve
BMI	body mass index
CALLY	C-reactive protein–albumin–lymphocyte
CI	confidence interval
CRP	C-reactive protein
DLC	difficult laparoscopic cholecystectomy
IQR	interquartile range
LC	laparoscopic cholecystectomy
OR	odds ratio
ROC	receiver operating characteristic
TG18	Tokyo Guidelines 2018
TRIPOD	Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis