Detection of Clostridium difficile infection clusters, using the temporal scan statistic, in a community hospital in southern Ontario, Canada, 2006–2011

Table 5 **Multivariable regression model* of variables associated with the rate of CDI cases**

Variable	Description	IRR	95% CI	P-value
Year	2006	Referent
	2007	0.43	0.22 – 0.83	0.013
	2008	0.11	0.04 – 0.29	< 0.001
	2009	0.14	0.06 – 0.32	< 0.001
	2010	0.43	0.22 – 0.83	0.012
Season	Fall	Referent
	Winter	0.81	0.36 – 1.80	0.606
	Spring	2.07	1.10 – 3.89	0.023
	Summer	1.29	0.73 – 2.29	0.379
Service	Medicine¹	Referent
	Surgery	1.15	0.20 – 6.53	0.871
	Other²	0.74	0.18 – 2.95	0.667

^*Multivariable multilevel negative binomial regression model with a random intercept for ward.
CDI = Clostridium difficile infection.
IRR = Incidence rate ratio.
CI = Confidence interval.
¹Included the following departments: intensive care (adult and neonatal), oncology, pediatrics, and internal medicine.
²Included the following departments: psychiatry, rehabilitation, hospice, childbirth, and nursery.

ISSN: 1471-2334