Table 5. Multivariate-adjusted effect estimates (95% CI) of hearing thresholds (dBHL) with IQR increment in occupational noise exposure (dBA), stratified according to occupational exposure to ototoxic chemicals.

Stratification variable		Per noise IQRa				p-value for interaction
	No.	Estimate	(95% CI)
Overall	30072	2.35	(2.05, 2.64)*
Heavy metals						<.001
Non exposure	22164	1.98	(1.65, 2.31)*
Exposure	7908	3.25	(2.58, 3.92)*
Organic solvents						<.001
Non exposure	27382	2.06	(1.75, 2.37)*
Exposure	2690	4.43	(3.43, 5.42)*

Models were adjusted for age, age², sex, BMI, and hypertension, defined in Model C, Table 3.

CI, confidence interval.

^aPTA (dBHL) change per interquartile range (IQR) of occupational noise, 94.26 dBA - 84.74 dBA: 9.52 dBA.

*p<0.05.