Table 3
Comparison of occupational exposure assessment sources
| Assessment sources | Birth certificates | Interview | Company records | Registers |
|---|---|---|---|---|
| Advantage | Ease of access and low cost Less recall bias The recorded paternal occupation seems more reliable than maternal occupation | Detailed information about occupational exposure can be acquired in standard way Confounder information may be available | Not subject to recall bias and tend to be more complete in recording occupational exposure | Ease of assess and low cost Less recall bias The recorded paternal occupation seems more reliable than maternal occupation Investigator can get the outcome information at any time |
| Disadvantage | Incompleteness Limited to the title of occupation, information bias is more likely Job changing may introduce the possibility of misclassification of exposure status Limited confounder information related to congenital malformation | Expensive and time consuming Certainty depends on the education level and professional knowledge Easy to contact effect Interview of the spouse may not provide valid and complete information Information bias is more likely | May lack the updating information about changing of exposure status over time for individual or certain job title The completeness and validity of data obtained may be not available Information of potential confounders may be insufficient | Confounding information may be scanty Problem of miscoding and wrong data entry may exist |
