Table 3.

Type II workplace violence-related injuries^a, incidence rates, and incidence rate ratios (IRRs) over time, Intervention vs. Control group (n=41 study units)

	Intervention Group		IRR within group (compared to baseline)	Control Group		IRR within group (compared to baseline)	IRR Intervention/ Control
	Injuries (n)	Rateb	IRR (95% CI)	Injuries (n)	Rateb	IRR (95% CI)	IRR (95% CI)
Baseline (3-year average)c	79	3.24		69	3.43
6 months post- intervention	12	3.22	0.99 (0.55, 1.78)	14	4.90	1.41 (0.81, 2.46)	0.70 (0.31, 1.58)
12-months post- intervention	11	3.00	0.92 (0.49, 1.73)	8	2.83	0.81 (0.39, 1.70)	1.13 (0.43 , 2.98)
18-months post- intervention	6	1.70	0.52 (0.23, 1.21)	3	1.14	0.33 (0.10, 1.05)	1.60 (0.38, 6.69)
24-months post- intervention	10	2.81	0.87 (0.46, 1.63)	21	8.09	2.33 (1.41, 3.84)d	0.37 (0.17, 0.83)e

^aType II violence-related injuries are a subset of the total number of Type II events

^bRate = number of injuries/100 Full-time equivalents (FTEs)/year annualized

^cAnalyses accounted for variability in group rates at each 6-month interval within the 3-year pre-intervention period (September 2010-August 2013)

^dp<.01

^ep<.05