Quiz 5, Module Casual
5. The authors state in the results, "Controlling for baseline characteristics, youth who watched >5 hours of television per day were 5.99 times more likely to initiate smoking behaviors than those youth who watched 0-2 hours per day." What does this piece of information tell us?
- Watching >5 hours of television per day causes youths to initiate smoking.
- There is a statistical association between watching >5 hours of television per day and initiation of smoking after taking into account other baseline characteristics of youth who watched television that were measured in this study.
- If kids watch less TV, they will be less likely to initiate smoking.
Answer (a) —
incorrect:
They are simply stating the statistical association that they found in their data; this information does not tell us if this association is causal.
Answer (b) —
correct:
They are stating that there is an association between the exposure and outcome, but cannot determine on the basis of these data alone whether this association is causal. They also report that their finding is "adjusted for" baseline differences between children who watch television and those who do not. Adjustment is a way to control for possible differences in the two comparison groups which could be independently associated with differences in television viewing patterns (
confounding
).
Answer (c) —
incorrect:
They are stating that there is an association between the exposure and outcome, but cannot determine on the basis of these data alone whether this association is causal. They also report that their finding is "adjusted for" baseline differences between children who watch television and those who do not. Adjustment is a way to control for possible differences in the two comparison groups which could be independently associated with differences in television viewing patterns (
confounding
).
