Question

You conduct a study and find that men are twice as likely as women to be diagnosed with thyroid cancer. You hypothesize that men are more likely to be employed in occupations with radiation exposure. After stratifying for occupation type (exposed or unexposed), you compute the RR in each strata and find that the association between sex and cancer no longer exists. This is an example of:

Group of answer choices

information bias

over-matching

selection bias

confounding

Answer 1

Confounding is correct answer.

Confounding factors are associated with both risk factors and its outcome.

As here radiation exposure is the confounding factor and when this confounding is removed then association of sex and cancer disappear.

Rest of the options are incorrect because there is neither selection bias(removed by stratification) nor information bias(no data is concealed) there is no inappropriate matching.

Association of sex and cancer disappeared as soon as confounding factor is removed after stratification.

Hope this helps. All the best?