Smoothing twenty-four-hour ambulatory blood pressure profiles: a comparison of alternative methods.

Three alternative smoothing methods have been proposed for the analysis of 24-h ambulatory blood pressure profiles. These methods were compared using a small data set from a controlled clinical trial. The results showed that either the fourier smoothing or the spline smoothing methods were preferable to conventional hourly summaries which use too many free parameters. Whatever the smoothing method used, a robust estimation procedure is advisable, in order to minimize the influence of artefacts.