Table 1.

Univariate Meta-Regression for the Effects of Antibiotic Restriction on Prevalence of Antimicrobial Resistance^a

	Carbapenem			Cephalosporins			Fluoroquinolones
	N	exp(β) (95% CI)	P	N	exp(β) (95% CI)	P	N	exp(β) (95% CI)	P
Relative difference in antibiotic usage (%)	11	0.99 (0.97–1.01)	.17	9	1.00 (0.99–1.02)	.60	14	1.01 (1.00–1.02)	.07
Bacteria
Enterobacterales	5	Ref		9	Ref		8	Ref
Nonfermenters	6	0.63 (0.16–2.51)	.47	8	1.19 (0.57–2.50)	.62	7	0.63 (0.34–1.16)	.13
Gram-positive	0	--		0	--		1	1.34 (0.44–4.05)	.58
Prevalence antimicrobial resistance preintervention (%)	11	0.99 (0.94–1.04)	.73	17	0.98 (0.97–0.99)	.04	14	0.98 (0.97–0.99)	.04
Duration of intervention (years)	11	0.86 (0.66–1.14)	.26	14	1.34 (0.83–2.17)	.21	16	0.98 (0.88–1.09)	.69
Type of Infection
Nonspecified	5	Ref		8	Ref		13	Ref
Nosocomial	6	1.57 (0.33–7.39)	.53	6	0.60 (0.26–1.38)	.21	3	1.03 (0.38–2.76)	.95
Setting
Hospital	7	Ref		7	Ref		10	Ref
ICU	4	2.78 (1.01–7.65)	.04	7	0.41 (0.20–0.84)	.02	6	0.74 (0.35–1.55)	.40

Abbreviations: CI, confidence interval; ICU, intensive care unit; N, number of antibiotic-pathogen combinations included; Ref, Reference variable.

^aThe reduction in resistance prevalence after antibiotic restriction was significantly stronger because the exponentiated regression coefficient (β) was significantly less than one and vice versa. “—,” no studies pertained to these categories and hence the parameter estimate could not be calculated. Analysis was not performed for first- and second-generation cephalosporins and piperacillin-tazobactam due to limited numbers of antibiotic-pathogen combinations.