Quiz 10, Module Bias
10. What is the effect of this misclassification on the odds ratio?
Answer —
The Effect:
| Scenario 5 | |||
|---|---|---|---|
|
Breast cancer +
|
Breast cancer -
|
Total
|
|
| Ever used lawn/garden pesticides |
996
|
1489
|
2485
|
| Never used lawn/garden pesticides |
212
|
333
|
545
|
| Total |
1208
|
1822
|
3030
|
OR = (996/212)/(1489*333) = 1.05
Your effect estimates have been biased to the null (almost to the null of 1.0!). Why? Look at your cells and the magnitude of disease misclassification. This too is an example of non-differential misclassification because misclassification of disease was not linked to exposure status.
