Statistical pitfalls in the analysis of age-related effects in antihypertensive therapy.

Much of the literature concerning age-related effects in antihypertensive therapy suffers from serious deficiencies in statistical design and analysis. The problems include those relating to the choice of a suitable control group, the measurement of response to treatment, response to baseline blood pressure, interpreting post hoc analyses, and the pooling of data from a number of related studies. These problems are discussed and we attempt to identify solutions that give a satisfactory balance between scientific validity and the real-life problems of conducting clinical trials. We conclude by outlining a protocol for future studies in this area.