Confounding Visual Exercise 2 -- Low-birth Weight
Does drinking coffee have an effect on low-birth weight?
| Cases | Controls |
|---|---|
|
|
However, we note that many coffee drinkers are also smokers.
2×2 Table
| Smokers | Non-smokers | |
|---|---|---|
| Coffee | 28 | 5 |
| No Coffee | 7 | 20 |
Odds Ratio = 16.0
