The healthy worker effect in US chemical industry workers

• Published in: Occupational medicine (Oxford) Vol. 61; no. 1; pp. 40 - 44
• Main Authors: BURNS, C. J, BODNER, K. M, JAMMER, B. L, COLLINS, J. J, SWAEN, G. M. H
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 2011
• Subjects: Bias; Biological and medical sciences; Cause of Death; Chemical Industry - statistics & numerical data; Confidence Intervals; Female; Healthy Worker Effect; Humans; Male; Medical sciences; Neoplasms - mortality; Occupational Diseases - mortality; Smoking - epidemiology; Survivors - statistics & numerical data; Tobacco, tobacco smoking; Toxicology; United States - epidemiology; United States; North America; America; USA; Human; Chemical industry; Tobacco; Health promotion; Tobacco smoking; smoking; Worker; Occupational exposure; Epidemiology; occupational health; Healthy worker effect; Occupational medicine
• ISSN: 0962-7480; 1471-8405
• DOI: 10.1093/occmed/kqq168

Occupational studies typically observe a 20% deficit in overall mortality, broadly characterized as the healthy worker effect (HWE). Components of the HWE may be addressed by various analytical approaches.
To explore the HWE in a modern industrial cohort.
Standardized mortality ratios (SMRs) were calculated for 114,683 US chemical industry employees, who worked at least 3 days between 1960 and 2005.
SMRs were 79 (95% confidence interval 78-80) for all causes, 81 (95% confidence interval 79-82) for heart disease, 70 (95% confidence interval 67-73) for non-malignant respiratory disease, 83 (95% confidence interval 81-85) for smoking-related cancers (buccal, cervix, oesophagus, stomach, pancreas, lung, larynx, bladder and kidney) combined and 97 (95% confidence interval 95-100) for other cancers.
The low SMRs observed in this study are likely due to differential smoking between the cohort and the background population. Future considerations to control for the HWE should take this into account.