Table 2: Annual change in the incidence rate (slope*) of VRE-positive blood cultures before, after and slope change† after versus before discontinuation of VRE screening and isolation (in ceased-screening cohort) and June 2012 (in screening cohort) in unadjusted and adjusted analysis and sensitivity analyses restricting analyses to 1) acute teaching hospitals, 2) cases attributable to the reporting facility and 3) lagged-effect models incorporating a 3-month lag and 6-month lag

Variable	Unadjusted incidence rate ratio			Slope change p value	Adjusted incidence rate ratio			Slope change p value
Variable	Slope before	Slope after	Slope change (95% CI)	Slope change p value	Slope before	Slope after	Slope change (95% CI)	Slope change p value
Main analysis (n = 395 cases)
Ceased-screening cohort
No lag	0.80	1.09	1.37 (1.04-1.80)	0.03	0.90	1.12	1.25 (1.01-1.54)	0.04
3-mo lag	0.80	1.20	1.51 (1.14-2.00)	0.004	0.90	1.24	1.38 (1.07-1.79)	0.01
6-mo lag	0.80	1.35	1.70 (1.27-2.27)	0.0004	0.90	1.39	1.56 (1.19-2.03)	0.001
Screening cohort
No lag	1.32	1.06	0.80 (0.59-1.09)	0.2	1.31	1.06	0.81 (0.56-1.15)	0.2
3-mo lag	1.32	1.23	0.93 (0.68-1.28)	0.7	1.31	1.23	0.94 (0.66-1.33)	0.7
6-mo lag	1.32	1.52	1.15 (0.83-1.60)	0.4	1.31	1.52	1.16 (0.81-1.66)	0.4
Acute teaching hospitals (n = 287 cases)
Ceased-screening cohort
No lag	0.84	1.12	1.34 (0.99-1.83)	0.06	0.84	1.13	1.35 (1.13-1.60)	< 0.01
3-mo lag	0.84	1.25	1.49 (1.09-2.05)	0.01	0.84	1.25	1.49 (1.19-1.88)	< 0.01
6-mo lag	0.84	1.41	1.68 (1.22-2.32)	0.002	0.84	1.41	1.68 (1.32-2.14)	< 0.001
Screening cohort
No lag	1.23	0.88	0.72 (0.46-1.13)	0.2	1.23	0.88	0.72 (0.45-1.15)	0.2
3-mo lag	1.23	1.01	0.82 (0.52-1.30)	0.4	1.23	1.01	0.82 (0.53-1.27)	0.4
6-mo lag	1.23	1.40	1.13 (0.70-1.83)	0.6	1.23	1.40	1.13 (0.98-1.88)	0.6
Cases attributable to reporting facility (n = 309 cases)
Ceased-screening cohort
No lag	0.86	1.16	1.35 (0.99-1.85)	0.06	0.93	1.18	1.27 (0.95-1.70)	0.1
3-mo lag	0.86	1.30	1.51 (1.09-2.08)	0.01	0.93	1.32	1.42 (0.96-2.10)	0.08
6-mo lag	0.86	1.40	1.62 (1.17-2.26)	0.004	0.93	1.42	1.53 (1.05-2.23)	0.03
Screening cohort
No lag	1.47	1.00	0.68 (0.48-0.97)	0.03	1.46	1.00	0.69 (0.48-0.98)	0.04
3-mo lag	1.47	1.14	0.77 (0.54-1.11)	0.2	1.46	1.14	0.78 (0.55-1.11)	0.2
6-mo lag	1.47	1.41	0.96 (0.66-1.39)	0.8	1.46	1.41	0.96 (0.67-1.39)	0.8

Note: CI = confidence interval, VRE = vancomycin-resistant Enterococcus.

*Defined as the year-over-year ratio change in incidence. For example, a slope of 1.1 would represent a 10% multiplicative growth in the incidence rate per year, and a slope of 0.9 would represent a 10% reduction in incidence per year.

†Defined as the ratio of the slope after the cessation of screening divided by the slope before the cessation of screening in the ceased-screening cohort (and after June 2012 v. before June 2012 in the screening cohort).