Social Science Statistics Blog

Some people believed that the early results were due to misclassification of former drinkers with cardio-vascular diseases ("CVD") as never-drinkers. This raised the CVD rate among the non-drinkers group. Another possible story is that the studies didn't properly control for confounders -- apparently some risk factors for CVD are more prevalent among non-drinkers, and the non-randmized studies didn't control well enough for those. But as the note points out, confounding could bias results both in favor or against a protective effect. Heavy drinking offers really good protection but those people don't live healtily lifes, and the health benefits would be obscured.

But don't fear, the British Heart Foundation says that low to moderate alcohol consumption probably doesn't do your heart any harm. For protection against CVD you should really quit smoking, do sports, and eat a balanced diet. Not quite as appealing as a good glass of wine, of course.

In any case, food for thought and a great 2-page piece for your next causal inference class. Cheers to that.