Table 1. Prevalence of tinnitus according to the participants’ characteristics.

	Total	Any tinnitus		Severe tinnitus
	n (%)a	n (%)b	OR (95% CI)	n (%)	OR (95% CI)
Total	1593 (100)	755 (46.0)		154 (9.1)
School Level
Middle school	848 (51.1)	326 (37.2)	1 (Ref)	57 (7.5)	1 (Ref)
High school	745 (48.9)	429 (55.1)	2.07 (1.73–2.48)**	97 (10.9)	1.52 (1.03–2.23)*
Gender
Male	804 (51.8)	315 (38.9)	1 (Ref)	57 (5.6)	1 (Ref)
Female	789 (48.2)	440 (53.7)	1.82 (1.44–2.31)**	97 (12.9)	2.47 (1.53–3.99)**
Household income per month, US$
< 2,000	259 (13.5)	124 (52.1)	1 (Ref)	25 (11.6)	1 (Ref)
2,000–3,000	310 (19.0)	148 (46.4)	0.80 (0.58–1.09)	32 (9.7)	0.83 (0.48–1.41)
3,000–4,000	402 (25.2)	191 (44.6)	0.74 (0.52–1.06)	35 (9.1)	0.76 (0.39–1.49)
> 4,000	622 (42.3)	292 (44.7)	0.74 (0.55–1.02)	62 (8.1)	0.68 (0.40–1.16)
BMI, kg/m2
< 25	1349 (84.5)	633 (45.7)	1 (Ref)	131 (9.5)	1 (Ref)
≥ 25	244 (15.5)	122 (47.9)	1.09 (0.81–1.48)	23 (6.9)	0.71 (0.49–1.01)
Smoking status
Never	1453 (90.7)	684 (45.0)	1 (Ref)	134 (8.5)	1 (Ref)
Ever	140 (9.3)	71 (55.7)	1.53 (1.11–2.12)*	20 (15.0)	1.89 (0.88–4.03)
Alcohol consumption
Never	1282 (81.4)	568 (43.4)	1 (Ref)	113 (8.7)	1 (Ref)
Ever	311 (18.6)	187 (57.6)	1.77 (1.30–2.42)**	41 (11.0)	1.30 (0.83–2.04)
History of sinusitis
No	1438 (89.7)	673 (45.1)	1 (Ref)	131 (8.8)	1 (Ref)
Yes	155 (10.3)	82 (53.7)	1.41 (1.13–1.76)*	23 (12.3)	1.46 (0.96–2.20)
History of ear infection
No	1435 (90.4)	662 (44.5)	1 (Ref)	128 (8.0)	1 (Ref)
Yes	158 (9.6)	93 (60.0)	1.87 (1.32–2.66)**	26 (19.8)	2.84 (1.46–5.53)*

^a Unweighted frequencies and weighted percentages

^b Unweighted frequencies and weighted row percentages.

* P < 0.05

** P < 0.001

OR, odds ratio; CI, confidence interval; BMI, body mass index; Ref, reference