title: Acoustic neuroma: potential risk factors and audiometric surveillance in the aluminium industry.
abstract: OBJECTIVE
  To look for an association between acoustic neuroma (AN) and participation in a hearing conservation programme (HCP) and also for an association between AN and possible occupational risk factors in the aluminium industry.
  
  
  METHODS
  We conducted a case-control analysis of a population of US aluminium production workers in 8 smelters and 43 other plants. Using insurance claims data, 97 cases of AN were identified between 1996 and 2009. Each was matched with four controls. Covariates included participation in a HCP, working in an aluminium smelter, working in an electrical job and hearing loss.
  
  
  RESULTS
  In the bivariate analyses, covariates associated with AN were participation in the HCP (OR=1.72; 95% CI 1.09 to 2.69) and smelter work (OR=1.88; 95% CI 1.06 to 3.36). Electrical work was not significant (OR=1.60; 95% CI 0.65 to 3.94). Owing to high participation in the HCP in smelters, multivariate subanalyses were required. In the multivariate analyses, participation in the HCP was the only statistically significant risk factor for AN. In the multivariate analysis restricted to employees not working in a smelter, the OR was 1.81 (95% CI 1.04 to 3.17). Hearing loss, an indirect measure of in-ear noise dose, was not predictive of AN.
  
  
  CONCLUSIONS
  Our results suggest the incidental detection of previously undiagnosed tumours in workers who participated in the company-sponsored HCP. The increased medical surveillance among this population of workers most likely introduced detection bias, leading to the identification of AN cases that would have otherwise remained undetected.
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Oyebode
authors.initials: O
authors.lastname: Taiwo
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Deron
authors.initials: D
authors.lastname: Galusha
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Baylah
authors.initials: B
authors.lastname: Tessier-Sherman
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Kirsche
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Cantley
authors.affiliation: Department of Occupational & Environmental Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Slade
authors.affiliation: Division of General Medical Disciplines, Stanford School of Medicine, Stanford, California, USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Cullen
authors.affiliation: Alcoa of Australia, Applecross, Western Australia, Australia.
authors.forename: A Michael
authors.initials: AM
authors.lastname: Donoghue
mesh_terms: D000328:Adult; D000535:Aluminum / Q000633:toxicity*; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis; D006801:Humans; D008297:Male; D066192:Manufacturing Industry; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D012307:Risk Factors; D014481:United States
chemical_list: D000535:Aluminum