Pharmaceutical Economics & Health Policy| Volume 20, ISSUE 1, P160-168, January 1998

Potential biases in assessing the risks of pharmacotherapy due to mismeasurement of drug exposure

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      We undertook this review to propose a minimum set of standards with which any evaluation of pharmacotherapy should comply, to review the evidence on which the relative risks of calcium channel blocker therapy for hypertension are based, and to evaluate published studies against these proposed standards. We selected English-language primary study reports published in peer-reviewed biomedical journals between 1995 and 1997. All the reviewed studies suffer from either possible misclassification of antihypertensive drug therapy, mismeasurement of drug exposure, or both. Given the inadequate documentation of subjects' drug therapy, resulting relative risk estimates cannot be substantiated.


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