A comparison between standard methods and structural nested modelling when bias from a healthy worker survivor effect is suspected: an iron-ore mining cohort study.
Occup Environ Med
; 72(7): 536-42, 2015 Jul.
Article
en En
| MEDLINE
| ID: mdl-25713154
ABSTRACT
OBJECTIVES:
Iron-ore miners are exposed to extremely dusty and physically arduous work environments. The demanding activities of mining select healthier workers with longer work histories (ie, the Healthy Worker Survivor Effect (HWSE)), and could have a reversing effect on the exposure-response association. The objective of this study was to evaluate an iron-ore mining cohort to determine whether the effect of respirable dust was confounded by the presence of an HWSE.METHODS:
When an HWSE exists, standard modelling methods, such as Cox regression analysis, produce biased results. We compared results from g-estimation of accelerated failure-time modelling adjusted for HWSE with corresponding unadjusted Cox regression modelling results.RESULTS:
For all-cause mortality when adjusting for the HWSE, cumulative exposure from respirable dust was associated with a 6% decrease of life expectancy if exposed ≥15â years, compared with never being exposed. Respirable dust continued to be associated with mortality after censoring outcomes known to be associated with dust when adjusting for the HWSE. In contrast, results based on Cox regression analysis did not support that an association was present.CONCLUSIONS:
The adjustment for the HWSE made a difference when estimating the risk of mortality from respirable dust. The results of this study, therefore, support the recommendation that standard methods of analysis should be complemented with structural modelling analysis techniques, such as g-estimation of accelerated failure-time modelling, to adjust for the HWSE.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Sesgo
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Modelos Estadísticos
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Exposición Profesional
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Contaminantes Ocupacionales del Aire
/
Hierro
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Minería
/
Enfermedades Profesionales
Tipo de estudio:
Etiology_studies
/
Incidence_studies
/
Observational_studies
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Prognostic_studies
/
Risk_factors_studies
Límite:
Aged
/
Humans
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Male
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Middle aged
Idioma:
En
Revista:
Occup Environ Med
Asunto de la revista:
MEDICINA OCUPACIONAL
/
SAUDE AMBIENTAL
Año:
2015
Tipo del documento:
Article
País de afiliación:
Suecia