Data Analysis of Ambulatory Blood Pressure Readings: Before p Values

The nature of ambulatory BP monitoring is such that exploratory data analysis is both useful and necessary. In any study using ambulatory monitoring there are many sources of uncontrolled variability including: individual levels of BP; individual diurnal pattern of BP; individual physical activity patterns; individual mental activity (psychological) patterns; and artifactual readings. Failure to properly account for these sources of variation will typically obscure real effects in the data and can bias the estimates of primary interest. In this chapter we report our experience with the exploratory analysis which should precede the calculation of p-values.