Obtaining occupational exposure histories in epidemiologic case-control studies

Area of Science:

• Occupational Epidemiology
• Environmental Health
• Toxicology

Background:

• Assessing occupational exposures is crucial for understanding cancer etiology.
• Previous methods often lack detail or are difficult to apply to large populations.
• Hypothesis generation requires robust exposure data.

Purpose of the Study:

• To present an innovative methodology for inferring chemical exposures in a population-based case-control study.
• To enable hypothesis generation regarding cancer sites and occupational exposures.
• To develop semi-quantitative exposure indices for epidemiological analyses.

Main Methods:

• Utilized a large population-based case-control study design.
• Employed a probing interview to detail job histories.
• Implemented exposure coding by chemists and hygienists using a checklist of ~300 exposures.
• Recorded exposure level, frequency, mode, and coder confidence.
• Drew upon expert experience, consultants, and literature for coding decisions.

Main Results:

• Developed a detailed system for coding occupational chemical exposures.
• Generated semi-quantitative exposure indices from interview and coding data.
• The methodology allows for flexible data combination for various analyses.
• Provided a framework for assessing exposure confidence.

Conclusions:

• The presented methodology offers a robust and innovative approach to inferring occupational chemical exposures.
• This method facilitates hypothesis generation in epidemiological studies linking cancer and occupational factors.
• The semi-quantitative indices derived are valuable for future cancer research and risk assessment.