Table 1. List of antimicrobial agents considered in the study.

For each of these antibiotics and each admission event, binary variables record whether the antibiotic: a) was currently prescribed, b) has been prescribed to the same patient in a previous admission, c) resistant isolate was detected, d) susceptible isolate was detected, e) was prescribed within 72 hrs of admission (early prescription); other variables record f) the number of times resistant isolates were detected in previous admissions, d) the number of times susceptible isolates were detected in previous admissions. The 4th and 5th columns report the number of admissions which had resistance tested and outcome positive (R) and negative (S), respectively. Resistance during the current admission to the four drugs marked with a star (AUG, CIP, MEM, and TAZ) are outcomes set to be predicted by four different AI classifiers.

Drug	Abbr.	Class	No. R	No. S
*Co-amoxiclav	AUG	Penicillin/β-lactamase inhibitor	1455	2529
*Ciprofloxacin	CIP	Fluoroquinolone	1241	3883
*Meropenem	MEM	Carbapenem	532	4658
*Piperacillin/tazobactam	TAZ	Penicillin/β-lactamase inhibitor	1026	3376
Amikacin	AK	Aminoglycoside	384	1408
Aztreonam	ATM	Monobactam	644	134
Ceftazidime	CAZ	Cephalosporin	664	4065
Cefotaxime	CTX	Cephalosporin	367	3293
Ertapenem	ETP	Carbapenem	1259	3931
Gentamicin	GT	Aminoglycoside	745	4338
Temocillin	TEM	β-lactamase-resistant penicillin	103	2767