Data Analysis of Ambulatory Blood Pressure Readings

Before p Values
  • L. A. Clark
  • L. Denby
  • D. Pregibon
Part of the The Springer Series in Behavioral Psychophysiology and Medicine book series (SSBP)


The nature of ambulatory blood pressure (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 patterns 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 the effects of primary interest. In this chapter we report our experience with the exploratory analysis which should precede the calculation of p values. Our experience has been primarily with large samples. When the sample size is large, computing resources can be severely strained and statistical significance (via a p value) takes a backseat to practical significance. We do not discuss the interpretation of significance tests in any detail but refer readers to the discussions by Ware, Mosteller, and Ingelfinger (1986) and Royall (1986).


Diurnal Variation Blood Pressure Level Ambulatory Blood Pressure Ambulatory Monitoring Daily Activity Pattern 
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Copyright information

© Springer Science+Business Media New York 1989

Authors and Affiliations

  • L. A. Clark
    • 1
  • L. Denby
    • 1
  • D. Pregibon
    • 1
  1. 1.AT&T Bell LaboratoriesMurray HillUSA

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