Estimating the effect of occupational noise exposure on hearing thresholds: the importance of adjusting for confounding variables.
OBJECTIVE
To evaluate whether valid estimation of the effect of occupational noise exposure on hearing thresholds requires adjustment for factors other than age, sex, and race, which also influence hearing function.


METHODS
Multivariate regression analyses were performed in the 1999-2002 National Health and Nutrition Examination Survey (N = 3527).


RESULTS
Occupational noise exposure was significantly associated with educational level, leisure time and firearm noise, and smoking. Incomplete adjustment for these factors leads to an overestimation of the effect of occupational noise exposure.


CONCLUSIONS
Current methods of estimating the effect of occupational noise exposure (e.g., Annex C of American National Standards Institute S3.44) require better consideration of these confounding factors.
Agrawal
Yuri
Y
Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. yagrawa1@jhmi.edu
Niparko
John K
JK
Dobie
Robert A
RA
D000328:Adult; D000368:Aged; D001299:Audiometry; D001309:Auditory Threshold; D005260:Female; D005389:Firearms / Q000706:statistics & numerical data; D006306:Health Surveys; D006317:Hearing Loss, Noise-Induced / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009623:Noise, Occupational / Q000706:statistics & numerical data*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D055815:Young Adult