Question

A report in a medical journal notes that the risk of developing Alzheimer’s disease among subjects who regularly opted to take the drug ibuprofen was about half the risk of those who did not.

Is this good evidence that ibuprofen is effective in preventing Alzheimer’s disease?

A)Yes, because the study was a randomized, comparative experiment.

B)No, because the effect of ibuprofen is confounded with the placebo effect.

C)No, because this is an observational study. An experiment would be needed to confirm (or not confirm) the observed effect.

D)Yes, because a 50% reduction can't happen just by chance.

E)Yes, because the results were published in a reputable professional journal.

Answer 1

The best answer is C) No, because this is an observational study. An experiment would be needed to confirm (or not confirm) the observed effect.
An observational study is a type of research that involves collecting data from existing sources, without manipulating any variables or assigning any treatments1. Observational studies can show associations or correlations between variables, but they cannot establish causation or test hypotheses1. Therefore, an observational study that reports a lower risk of Alzheimer’s disease among ibuprofen users does not prove that ibuprofen is effective in preventing Alzheimer’s disease.

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