title: Hospital contacts for noise-related hearing loss among Danish seafarers and fishermen: a population-based cohort study.
abstract: OBJECTIVE
  Noise-induced hearing loss (NIHL) is a leading occupational disease and some seafarers and fishermen may be at high risk. We present here standardized hospital contact ratios (SHCRs) for hearing loss among Danish seafarers and fishermen.
  
  
  METHODS
  Cohorts of all Danish seafarers registered by the Danish Maritime Authority (DMA) and fishermen retrieved from a 1989-1998 pension registry were linked to the nationwide Occupational Hospitalisation Registry (OHR) with follow-up for NIHL from 1994 to 2003, using rates specific for age and calendar time for the entire Danish workforce as a reference.
  
  
  RESULTS
  We found high SHCRs for NIHL: 165 [95% confidence interval (CI) 131-206] among officers, 113 (79-157) for nonofficers and 119 (85-162) for fishermen. The increased SHCR for hearing impairment among seafarers was solely found in engine room personnel (SHCR = 222; 95% CI 178-277). Compared to other seafarers, the engine room personnel had a relative risk ratio of 2.39 (95% CI: 1.74-3.26). Short-term employment is common in many trades. No duration response pattern was observed which may suggest a secondary healthy worker effect.
  
  
  CONCLUSIONS
  These findings indicate that hearing problems are frequent among men who work in the engine rooms on ships. Long-term cumulative effects of employment were not shown.
authors.affiliation: Research Unit of Maritime Medicine, University of Southern Denmark, Esbjerg, Denmark. L.kaerlev@dadlnet.dk
authors.forename: Linda
authors.initials: L
authors.lastname: Kaerlev
authors.forename: Anker
authors.initials: A
authors.lastname: Jensen
authors.forename: Per Sabro
authors.initials: PS
authors.lastname: Nielsen
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.forename: Harald
authors.initials: H
authors.lastname: Hannerz
authors.forename: Finn
authors.initials: F
authors.lastname: Tüchsen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005398:Fisheries; D034381:Hearing Loss / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects; D009792:Oceans and Seas; D011159:Population Surveillance; D011446:Prospective Studies; D012042:Registries; D012306:Risk; D012307:Risk Factors; D012767:Ships / Q000706:statistics & numerical data*; D013997:Time Factors