The company says the study was based on a summary of separate studies, when the proper way to determine the drug's effects is to conduct long-term clinical trials of patients taking Avandia.

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Significantly, UpToDate generally offers not just a summary of recommendations but also an explanation of the associated physiology and a review of relevant clinical studies.

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For an objective summary of the evidence, see the articles by neurologist Steven Novella here and here, which summarize a dozen epidemiological studies.

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