Long-term exposure to air pollution and the risk of developing sudden sensorineural hearing loss

Table 4 Adjusted HR of SSNHL in the moderate and high concentration groups compared to the values in the low concentration group

Pollutants	Levels	n of SSNHL	Person-Years	IR	aHR	95%CI		p
PM_2.5 (μg/m³)	Continuous				1.01	0.99	1.02	0.311
	Low	92	251,573	0.37	Reference
	Moderate	133	238,157	0.56	1.56	1.20	2.04	0.001
	High	128	262,340	0.49	1.33	1.01	1.75	0.043
SO₂ (ppb)	Continuous				1.01	0.96	1.05	0.811
	Low	127	253,994	0.50	Reference
	Moderate	111	231,810	0.48	1.01	0.78	1.31	0.927
	High	115	266,267	0.43	0.96	0.74	1.24	0.754
CO (ppm)	Continuous				2.16	1.50	3.11	< 0.001
	Low	124	265,999	0.47	Reference
	Moderate	93	226,689	0.41	0.96	0.73	1.26	0.754
	High	136	259,382	0.52	1.27	0.99	1.65	0.065
NO (ppb)	Continuous				1.02	1.01	1.03	< 0.001
	Low	119	255,830	0.47	Reference
	Moderate	109	237,175	0.46	1.14	0.86	1.49	0.363
	High	125	259,066	0.48	1.22	0.93	1.61	0.151
NO₂ (ppb)	Continuous				1.02	1.01	1.04	0.012
	Low	114	235,391	0.48	Reference
	Moderate	101	250,758	0.40	0.93	0.71	1.23	0.625
	High	138	265,922	0.52	1.25	0.96	1.63	0.105

n of SSNHL: number of patients with hearing loss; IR: incidence rate (per 1000 person-years); IR: incidence rate; aHR: adjusted hazard ratio in the multivariate analysis after adjusting for age, insurance fee, urbanization, HT, DM, stroke, head injury, CKD, IHD, alcoholism, nicotine dependence, COPD, asthma, RA, impacted cerumen, suppurative and unspecified otitis media, chronic serous otitis media, and otosclerosis

ISSN: 1479-5876