Table 3.

Multivariable-Regression Estimates of Changes in Catheter-Associated UTI Rates, According to Unit Type.^*

Variable	Non-ICU (N = 553)		ICU (N = 373)
	IRR (95% CI)	P Value	IRR (95% CI)	P Value
Time†‡	0.68 (0.56–0.82)	<0.001	1.01 (0.87–1.17)	0.90
Teaching hospital	1.76 (1.03–3.01)	0.04	1.92 (1.32–2.80)	0.001
Rural hospital	0.90 (0.66–1.23)	0.51	0.83 (0.58–1.18)	0.30
Critical-access hospital	2.36 (1.65–3.37)	<0.001	2.60 (0.94–7.20)	0.07
Hospital size (per 100-bed increase)‡	0.97 (0.90–1.05)	0.45	1.09 (1.02–1.16)	0.01

^*Incidence rate ratios (IRRs) are shown for changes from baseline in the rates of catheter-associated UTI. On the basis of the definition used by the Centers for Disease Control and Prevention’s National Healthcare Safety Network, the catheter-associated UTI rate was calculated as the number of urinary tract infections per 1000 catheter-days. Negative binomial models were fit, with random intercepts for hospital and unit. CI denotes confidence interval.

^†Time was defined as the number of days from the end of the baseline period (day 0) to the end of the sustainability period (day 427). Thus, the IRR indicates the percentage change from the end of baseline to the end of the study period.

^‡P = 0.001 for the comparison between non-ICUs and ICUs.