Table 4.

Bivariate and multivariable associations with carriage of any N. meningitidis among carriage evaluation participants at an Oregon university, March 2015–February 2016

		Bivariate analysis1		Multivariable analysis (N=2723)
	N	Prevalence Ratio (95% CI)2	p-value	Prevalence Ratio (95% CI)2	p-value
Round	4225
1		Ref
2		1.2 (1.1–1.5)	0.01	1.0 (0.7–1.5)	0.9
3		0.8 (0.7–1.0)	0.08	0.8 (0.6–1.1)	0.1
4		1.2 (1.0–1.5)	0.02	1.2 (0.8–1.7)	0.3
Gender	4131
Female		Ref
Male		1.5 (1.3–1.7)	<0.0001	1.2 (1.0–1.5)	0.03
Year in school	4163
Freshman		Ref
Sophomore		1.4 (1.2–1.7)	0.0008	0.8 (0.6–1.1)	0.2
Junior		1.3 (1.0–1.5)	0.03	0.7 (0.5–1.1)	0.2
Senior		1.2 (0.9–1.4)	0.2	0.8 (0.5–1.4)	0.5
Age	4194
18		Ref
19		1.5 (1.2–1.9)	0.0004	1.2 (0.9–1.6)	0.3
20		1.8 (1.4–2.2)	<0.0001	1.6 (1.1–2.3)	0.02
21		1.4 (1.1–1.8)	0.006	1.1 (0.7–1.8)	0.7
22		1.4 (1.0–1.8)	0.04	0.8 (0.5–1.5)	0.6
23–29		0.8 (0.5–1.1)	0.2	0.8 (0.4–1.5)	0.5
30+		0.8 (0.3–1.9)	0.6	1.8 (0.7–5.2)	0.4
Live on- vs. off-campus	3961
On-campus		Ref
Off-campus		1.2 (1.1–1.5)	0.0008	1.3 (0.7–2.2)	0.4
Type of residence	3809
Residence hall		Ref
Apartment/house		1.2 (1.0–1.4)	0.02	0.9 (0.5–1.8)	0.8
Sorority/fraternity		2.5 (1.9–3.3)	<0.0001	1.3 (0.7–2.4)	0.4
Roommates	3765
0		Ref
1		1.0 (0.7–1.3)	0.8	1.0 (0.7–1.4)	1.0
2		1.3 (0.9–1.7)	0.2	1.0 (0.7–1.5)	1.0
3+		1.5 (1.1–2.0)	0.003	1.2 (0.8–1.7)	0.3
Live with family		0.4 (0.2–0.7)	0.0005	0.6 (0.3–1.4)	0.2
Recent upper respiratory symptoms3	4166
Yes		1.2 (1.1–1.4)	0.003	1.1 (0.9–1.3)	0.2
No		Ref
Smoking4	4142
Yes		2.1 (1.8–2.4)	<0.0001	1.4 (1.2–1.7)	0.0008
No		Ref
Second-hand smoke4	4163
Never		Ref
Some days		1.4 (1.2–1.7)	<0.0001	1.1 (0.9–1.3)	0.4
Every day		1.9 (1.4–2.6)	0.001	1.2 (0.8–1.7)	0.4
Recent antibiotic use4	4104
Yes		0.5 (0.4–0.7)	<0.0001	0.4 (0.3–0.7)	<0.0001
No		Ref
Attend bars, clubs, parties	4177
<1/week or never		Ref
1/week		2.1 (1.7–2.5)	<0.0001	2.0 (1.6–2.5)	<0.0001
2–3/week		3.1 (2.6–3.7)	<0.0001	2.8 (2.2–3.6)	<0.0001
≥4/week		3.1 (2.2–4.4s)	0.0003	2.7 (1.6–4.4)	0.01
Received MenACWY vaccine	3431
Yes		1.0 (0.7–1.3)	0.8	--	--
No		Ref
Received MenB vaccine doses5	3732
0 doses		Ref
1 dose MenB-FHbp		1.1 (0.9–1.3)	0.2	1.0 (0.8–1.4)	0.8
2 doses MenB-FHbp		1.2 (1.0–1.5)	0.07	1.2 (0.9–1.6)	0.2
3 doses MenB-FHbp		1.5 (1.0–2.3)	0.1	1.3 (0.7–2.2)	0.4
1 dose MenB-4C		0.9 (0.5–1.7)	0.7	0.9 (0.4–1.9)	0.7
2 doses MenB-4C		2.0 (1.4–2.7)	0.002	1.5 (1.0–2.3)	0.08

Bivariate and multivariable analysis was conducted using Poisson regression with generalized estimating equations (GEE) to account for individuals participating in multiple rounds.

¹See table 1 for N included for each variable

²Prevalence ratios account for repeat participants using generalized estimating equation methods

³In the past 30 days

⁴In the past 2 weeks

⁵Includes only vaccine doses received ≥2 weeks before specimen collection