Table 2.

Incidence rate (IR) of naloxone administration per 1,000 person-years and incidence rate ratios (IRR) for 2015 vs. 2013 and 2017 vs. 2015 by demographic characteristics.

	2013		2015		2017		2015 vs. 2013		2017 vs. 2015
	IR	(95% CI)	IR	(95% CI)	IR	(95% CI)	IRR	(95% CI)	IRR	(95% CI)
Total	3.2	(1.2, 8.1)	5.4	(2.1, 13.9)	11	(4.3, 28.3)	1.6	(1.6, 1.7)	2.2	(2.1, 2.3)
Sex
Female	2.2	(2.1, 2.4)	3.3	(3.1, 3.5)	6.1	(5.8, 6.4)	1.5	(1.3, 1.6)	1.8	(1.7, 2.0)
Male	4.8	(4.5, 5.0)	8.6	(8.3, 9.0)	19.7	(19.2, 20.3)	1.8	(1.7, 2.0)	2.3	(2.2, 2.4)
	χ^2 (1)=226.4, p < .001		χ^2 (1)=226.4, p < .001		χ^2 (1)=1713.2, p < .001		χ^2 (1)=10.3, p = .001		χ^2 (1)=20.2, p < .001
Race/ethnicity
White	3.4	(3.1, 3.7)	5.1	(4.7, 5.4)	10.3	(9.8, 10.8)	1.5	(1.3, 1.7)	2.0	(1.9, 2.2)
African American	2.6	(2.5, 2.8)	5.0	(4.7, 5.2)	11.6	(11.2, 12.0)	1.9	(1.7, 2.0)	2.3	(2.2, 2.5)
Other	0.9	(0.6, 1.2)	1.8	(1.5, 2.3)	4.2	(3.6, 4.8)	2.1	(1.4, 3.1)	2.3	(1.8, 3.0)
	χ^2 (2)=73.5, p < .001		χ^2 (2)=79.6, p < .001		χ^2 (2)=188.4, p < .001		χ^2 (2)=10.4, p = .006		χ^2 (2)=7.5, p = .02
Age
15–19	0.7	(0.5, 1.1)	0.8	(0.5, 1.1)	0.7	(0.5, 1.0)	1.0	(0.6, 1.8)	0.9	(0.5, 1.6)
20–24	1.9	(1.5, 2.3)	2.8	(2.3, 3.3)	5.0	(4.4, 5.7)	1.5	(1.1, 2.0)	1.8	(1.5, 2.2)
25–29	2.2	(1.8, 2.6)	3.7	(3.3, 4.2)	8.1	(7.4, 8.8)	1.7	(1.4, 2.1)	2.2	(1.9, 2.5)
30–34	2.9	(2.5, 3.4)	4.0	(3.5, 4.6)	9.8	(9.0, 10.7)	1.4	(1.1, 1.7)	2.4	(2.1, 2.9)
35–39	3.0	(2.5, 3.6)	5.7	(5.0, 6.5)	11.2	(10.2, 12.3)	1.9	(1.5, 2.4)	2.0	(1.7, 2.3)
40–44	5.0	(4.3, 5.8)	7.3	(6.5, 8.3)	13.0	(11.8, 14.2)	1.5	(1.2, 1.8)	1.8	(1.5, 2.1)
45–49	6.2	(5.4, 7.0)	11.0	(10.0, 12.2)	22.0	(20.5, 23.6)	1.8	(1.5, 2.1)	2.0	(1.8, 2.2)
50–54	7.1	(6.4, 8.0)	11.8	(10.8, 12.9)	25.1	(23.6, 26.7)	1.6	(1.4, 1.9)	2.1	(1.9, 2.4)
55–59	5.3	(4.6, 6.0)	9.5	(8.6, 10.5)	23.9	(22.4, 25.4)	1.8	(1.5, 2.1)	2.5	(2.2, 2.8)
60–64	3.7	(3.2, 4.4)	6.2	(5.5, 7.1)	15.7	(14.4, 17.0)	1.7	(1.3, 2.1)	2.5	(2.2, 2.9)
65–69	2.2	(1.8, 2.9)	4.5	(3.8, 5.4)	11.4	(10.2, 12.8)	2.0	(1.5, 2.7)	2.5	(2.0, 3.1)
70–74	1.5	(1.0, 2.2)	3.6	(2.8, 4.6)	5.9	(4.9, 7.1)	2.4	(1.5, 3.7)	1.6	(1.2, 2.2)
75–79	1.4	(0.9, 2.2)	2.5	(1.8, 3.5)	4.8	(3.7, 6.1)	1.8	(1.0, 3.3)	1.9	(1.3, 2.9)
80–84	2.3	(1.5, 3.5)	3.7	(2.7, 5.2)	4.8	(3.6, 6.4)	1.6	(1.0, 2.8)	1.3	(0.8, 2.0)
85 or older	2.0	(1.3, 3.1)	4.0	(3.0, 5.4)	3.7	(2.7, 5.1)	2.0	(1.2, 3.4)	0.9	(0.6, 1.4)
	χ^2 (14)=461.2, p < .001		χ^2 (14)=785.9, p < .001		χ^2 (14)=1819.4, p < .001		χ^2 (14)=15.9, p = .33		χ^2 (14)=59.7, p < .001

*Chi-Square tests used for testing significant variation in each demographic characteristic group.