Question

The association between induced abortion and breast cancer has been the subject of several epidemiological studies. Cohort studies have found no association, while at least one case-control study has found a positive association. Possible explanations for the different results in case-control and cohort studies of this topic include:

O 1. The method of disease classification is different in case-control and cohort studies
O 2. Case-control studies are prone to selection bias, whereas cohort studies are not vulnerable to selection bias
O 3. Recall bias might explain the association observed in a case-control study, but this would not be a problem in prospective cohort studies
O 4. All of the above

Answer 1

Possible explanations for the different results in case-control and cohort studies on the association between induced abortion and breast cancer include differences in disease classification, the vulnerability to selection bias, and the presence of recall bias. The correct choice will be O 4. All of the above.

Step-by-step explanation:

Possible explanations for the different results in case-control and cohort studies on the association between induced abortion and breast cancer include:

1. The method of disease classification is different in case-control and cohort studies. Case-control studies collect data retrospectively, relying on self-reported recall data, while cohort studies collect data prospectively, directly from the participants, which is likely to be more accurate.
2. Case-control studies are prone to selection bias, whereas cohort studies are not vulnerable to selection bias. In case-control studies, the selection of cases and controls may not accurately represent the general population, leading to biased results. Cohort studies, on the other hand, follow a defined group of subjects, reducing the risk of selection bias.
3. Recall bias might explain the association observed in a case-control study, but this would not be a problem in prospective cohort studies. Recall bias occurs when participants in a case-control study inaccurately recall past behaviors, leading to biased results. In prospective cohort studies, the data are collected periodically over time, reducing the reliance on recall.