Editor—We agree with Robertson that confounding may explain the potential protective benefit of non-steroidal anti-inflammatory drugs (NSAIDs) in our meta-analysis. We specifically addressed the issue of confounding in the discussion of our paper.
We also agree that the results of our meta-analysis are purely hypothesis generating and that a cause and effect relationship cannot be inferred from our results.
Robertson refers to a recent randomised trial that found no benefit with the use of NSAIDs.1 This study is a secondary prevention trial in subjects whose Alzheimer's disease has already been diagnosed, with one year follow up. Our meta-analysis attempts to answer a different question: mainly whether NSAIDs can prevent the development of Alzheimer's disease.
The Alzheimer's disease anti-inflammatory prevention trial (ADAPT) is currently comparing naproxen and celecoxib in the primary prevention of Alzheimer's disease.2 The results of this large randomised trial may finally shed light on this question.
Competing interests: None declared.
References
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