Table 4.

Test doses improved antimicrobial therapy in the post-guideline period (n=183)

Antibiotic or class of antibiotic No.( %)	Before test dose	After test dose	P Value*
Penicillins †	3 (2)	35 (19)	<0.001
Piperacillin-tazobactam	4 (2)	2 (1)	>0.5
Cephalosporins ‡
1st generation	1 (0.6)	18 (10)	<0.001
3rd generation	9 (5)	54 (30)	<0.001
4th generation	12 (7)	58 (32)	<0.001
Aztreonam	21 (12)	1 (0.6)	<0.001
Carbapenem	18 (10)	11 (6)	0.21
Clindamycin	3 (2)	2 (1)	>0.5
Daptomycin	2 (1)	2 (1)	>0.5
Fluoroquinolone	28 (15)	6 (3)	<0.001
Gentamycin	11 (6)	2 (1)	0.004
Linezolid	7 (4)	4 (2)	0.45
Vancomycin	125 (68)	68 (37)	<0.001

^*McNemar's test

^†Other than piperacillin-tazobactam, considered separately due to its broad coverage

^‡No patients were treated with 2nd generation cephalosporins