title: A structural approach to address the healthy-worker survivor effect in occupational cohorts: an application in the trucking industry cohort.
abstract: BACKGROUND
  Occupational cohort studies are often challenged by the Healthy Worker Survivor Effect, which may bias standard methods of analysis. G-estimation of structural failure time models is an approach for reducing this type of bias. Accelerated failure time models have recently been applied in an occupational cohort but cumulative failure time models have not.
  
  
  METHODS
  We used g-estimation of a cumulative failure time model to assess the effect of working as a long-haul driver on ischaemic heart disease mortality in a cohort of 30 448 men employed in the unionised US trucking industry in 1985. Exposure was defined by job title and based on work records. We also applied g-estimation of an accelerated failure time model as a sensitivity analysis and approximated HRs from both models to compare them.
  
  
  RESULTS
  The risk ratio (RR) obtained from the cumulative failure time model, comparing the observed risk under no intervention to the risk had nobody ever been exposed as a long-haul driver, was 1.09 (95% CI 1.02 to 1.16). The RR comparing the risk had everyone been exposed as long-haul driver for 8 years to the risk had nobody ever been exposed was 1.20 (95% CI 1.04 to 1.46). After HR approximations, accelerated failure time model results were similar.
  
  
  CONCLUSIONS
  The cumulative failure time model can effectively control time-varying confounding by Healthy Worker Survivor Effect, and provides an easily interpretable effect estimate. RRs estimated from the cumulative failure time model indicate an elevated ischaemic heart disease mortality risk for long-haul drivers in the US trucking industry.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Neophytou
authors.forename: Sally
authors.initials: S
authors.lastname: Picciotto
authors.forename: Jaime E
authors.initials: JE
authors.lastname: Hart
authors.forename: Eric
authors.initials: E
authors.lastname: Garshick
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Eisen
authors.forename: Francine
authors.initials: F
authors.lastname: Laden
mesh_terms: D015982:Bias; D015331:Cohort Studies; D004812:Epidemiologic Methods; D015989:Healthy Worker Effect; D006801:Humans; D007221:Industry; D008175:Lung Neoplasms / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D018986:Motor Vehicles; D017202:Myocardial Ischemia / Q000401:mortality; D009784:Occupational Diseases / Q000401:mortality*; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations; D016017:Odds Ratio; D017741:Survivors; D001335:Vehicle Emissions
chemical_list: D001335:Vehicle Emissions
keywords: Methodology, speciality
references.citation: Am J Epidemiol. 2013 May 1;177(9):989-96
references.pmid: 23558355
references.citation: Epidemiology. 1992 Jul;3(4):319-36
references.pmid: 1637895
references.citation: Environ Health Perspect. 2008 Oct;116(10):1327-32
references.pmid: 18941573
references.citation: Environ Sci Technol. 2006 Jul 1;40(13):4226-32
references.pmid: 16856739
references.citation: Environ Health Perspect. 2009 Nov;117(11):1690-6
references.pmid: 20049118
references.citation: Epidemiology. 1993 Jul;4(4):336-41
references.pmid: 8347744
references.citation: Am J Epidemiol. 1996 Jan 15;143(2):202-10
references.pmid: 8546122
references.citation: J Environ Monit. 2006 Jul;8(7):711-20
references.pmid: 16826284
references.citation: J Occup Environ Hyg. 2007 Nov;4(11):848-54
references.pmid: 17885912
references.citation: Lifetime Data Anal. 2010 Jan;16(1):71-84
references.pmid: 19894116
references.citation: Circulation. 2004 Jan 6;109(1):71-7
references.pmid: 14676145
references.citation: Environ Health Perspect. 2000 Oct;108(10):941-7
references.pmid: 11049813
references.citation: N Engl J Med. 2000 Dec 14;343(24):1742-9
references.pmid: 11114312
references.citation: Br J Prev Soc Med. 1976 Dec;30(4):225-30
references.pmid: 1009272
references.citation: Int J Epidemiol. 1991 Mar;20(1):82-7
references.pmid: 2066248
references.citation: Epidemiology. 2010 Jan;21(1):13-5
references.pmid: 20010207
references.citation: J Chronic Dis. 1987;40 Suppl 2:139S-161S
references.pmid: 3667861
references.citation: Am J Epidemiol. 2000 Jan 15;151(2):174-81
references.pmid: 10645820
references.citation: Am J Epidemiol. 1982 Jul;116(1):177-88
references.pmid: 7102651
references.citation: Occup Environ Med. 1996 Jul;53(7):455-62
references.pmid: 8704869
references.citation: Pharmacoepidemiol Drug Saf. 2005 Jul;14(7):477-91
references.pmid: 15660442
references.citation: J Am Stat Assoc. 2012;107(499):
references.pmid: 24347749
references.citation: Epidemiology. 2004 Sep;15(5):615-25
references.pmid: 15308962
references.citation: Environ Health Perspect. 2007 Aug;115(8):1192-6
references.pmid: 17687446
references.citation: Epidemiology. 2011 Jul;22(4):599-606
references.pmid: 21543985
references.citation: N Engl J Med. 1993 Dec 9;329(24):1753-9
references.pmid: 8179653
references.citation: Ann Epidemiol. 2004 Oct;14(9):633-9
references.pmid: 15380793
references.citation: Epidemiology. 1994 Mar;5(2):189-96
references.pmid: 8172994
references.citation: Occup Environ Med. 2013 Aug;70(8):523-8
references.pmid: 22992341
references.citation: Epidemiology. 2012 Mar;23(2):212-9
references.pmid: 22317804
references.citation: Environ Health Perspect. 2007 Mar;115(3):472-82
references.pmid: 17431501
references.citation: Occup Environ Med. 1996 Apr;53(4):235-40
references.pmid: 8664960
references.citation: Am J Epidemiol. 2003 Oct 1;158(7):687-94
references.pmid: 14507605
references.citation: Br J Prev Soc Med. 1977 Jun;31(2):96-100
references.pmid: 884402
references.citation: Occup Environ Med. 2001 Apr;58(4):253-60
references.pmid: 11245742