The analysis of a blood pressure diary for a patient report

In order to make a more valid assessment of blood pressure (BP), self-monitoring of BP by the patient is generally advised. Self-monitoring usually results in a lower BP level. We are currently investigating whether the BP lowering effect of self-monitoring may be enhanced by not only monitoring BP but also monitoring physical and emotional status at the moment of and activity prior to the BP measurement in a diary. In this article we focus on the individual feedback that the participating patients received. Various methods that can be used for this purpose are described. For our individual reports we first assessed linear trends in the variables. When a trend was present, residuals were calculated. Then a principal-components analysis on BP measurements, BP estimates, symptoms, moods, and activities was performed. Results are presented for two hypertensive patients.