A cross-sectional study of the relationship between blood type and the risk of cataracts will produce misleading results because you cannot tell the correct temporal relationship between the exposure (blood type) and disease (cataracts).

Question

Quizplus · Accepted Answer

A cross-sectional study can determine the association between blood type and cataracts, but it cannot establish causality or the temporal sequence of events. However, since blood type is a genetic trait present from birth, its temporal relationship with cataracts is inherently established.

A Cross-Sectional Study of the Relationship Between Blood Type and the Risk