Table 4.

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

Variable	Non-ICU (N = 553)		ICU (N = 373)
	IRR (95% CI)	P Value	IRR (95% CI)	P Value
Time†	0.93 (0.90–0.96)	<0.001	0.98 (0.96–1.01)	0.15
Teaching hospital	0.96 (0.73–1.26)	0.77	0.96 (0.88–1.06)	0.45
Rural hospital	0.89 (0.78–1.01)	0.07	0.85 (0.78–0.91)	<0.001
Critical-access hospital	0.95 (0.82–1.10)	0.47	0.81 (0.67–0.98)	0.03
Hospital size (per 100-bed increase)‡	0.98 (0.95–1.02)	0.38	1.02 (1.01–1.04)	0.01

^*IRRs are shown for changes from baseline in catheter use, which was calculated as the number of catheter-days per number of patient-days. Negative binomial models were fit, with random intercepts for hospital and unit.

^†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 = 0.004 for the comparison between non-ICUs and ICUs.

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