Assessing the effects of nondifferential misclassification of exposures in occupational studies

Details

• Personal Author:
  Checkoway, Harvey ; Heyer NJ ; Savitz DA
• Description:
  A discussion was presented of the utility of indirect methods for assessing the potential extent of bias in effect estimates resulting from nondifferential exposure misclassification. Misclassification from retrospective assessment could occur for many reasons, including heterogeneous job groupings, erroneous exposure ratings, measurement instrument error, nonrepresentative exposure monitoring, incorrect imputation of missing values and failure to account for exposure controls. Indirect assessment of effects of misclassification bias was based on correction of observed effect estimates for a plausible range of misclassification rates. Misclassification of a primary study variable and of confounders could be evaluated. Nondifferential misclassification tended to obscure exposure response relationships and bias results toward the null. Hypothetical examples were presented illustrating misclassification for a simple dichotomous comparison and for one using exposure level categories. Equations were presented for correcting observed effect estimates based on cases and person years. Where relevant, time specific exposure misclassification rates were used to estimate corrected summary rate ratios for historical cohort studies. A hypothetical example of this was presented where misclassification rates decreased from 20% to zero over a 49 year time period. Similar approaches could be used to evaluate misclassification of a confounder, such as another occupational exposure, that was highly correlated with the main exposure. The authors conclude that an indirect approach is preferable to a direct approach for evaluating effects of exposure and confounder misclassification because of greater feasibility and nondependence on extrapolated data. Calculating a range of corrected values is recommended. [Description provided by NIOSH]
• Subjects:
  Epidemiology Occupational Exposure Occupational Health Risk Assessment Safety
• Keywords:
  Analytical-methods Contract-91-38661 Exposure-levels Mathematical-models NIOSH-Contract NIOSH-Publication Occupational-exposure Occupational-health Risk-analysis
• ISSN:
  1047-322X
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  6
• Issue:
  6
• NIOSHTIC Number:
  nn:00200889
• Citation:
  Appl Occup Environ Hyg 1991 Jun; 6(6):528-533
• Federal Fiscal Year:
  1991
• Peer Reviewed:
  True
• Source Full Name:
  Applied Occupational and Environmental Hygiene
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:48c340b006be513dd8a65d67a5ee5da4ffa2e2545c2a2eed253ae9e23498db52640265007ec39d2765d0c3c423c5de6b02d59b7b54df2f532b74b8b5bfb874ce
• Download URL:
  https://stacks.cdc.gov/view/cdc/204195/cdc_204195_DS1.pdf
• File Type:
  [PDF - 822.84 KB ]