aOR	adjusted odd ratio
AUC	area under the receiver operating characteristic curve
BMI	body mass index
CCI	Charlson Comorbidity Index
CI	confidence interval
DD	diaphragmatic displacement
DTF	diaphragm thickening fraction
D-RSBI	respiratory rate divided by half the sum of the right and left diaphragmatic displacement
DTi-RSBI	respiratory rate divided by the product of diaphragmatic displacement and diaphragm inspiratory time
EF	ejection fraction
FiO2	fraction of inspired oxygen
ICU	intensive care unit
ROC	receiver operating characteristic
RR	respiratory rate
RSBI	rapid shallow breathing index
SBT	spontaneous breathing trial
SOFA	sequential organ failure assessment
Ti	diaphragm inspiratory time
TV	tidal volume