[The theory-practice problem of blood pressure assessment].

The theoretical basis for assessment of blood pressure described in the guidelines of the ISH-ESC and in JNC 7 ignores the variability of blood pressure and is therefore not applicable in general practice. Although the guidelines do not meet the daily requirements, they are not questioned by the physician, and are therefore confusing both physicians and millions of patients taking self-recordings. The unsolved problems are: The confidence interval for the single readings and the mean values are ignored. For this reason, the assignment of the patient to the different categories of hypertension is variable and dependent on pure chance. The effects of therapy cannot be detected in a reliable way. Judging the quality of self-recorded data, the blood pressure variability is interpreted as an error of measurement. The problem can be avoided if, instead of single values, mean values out of a sufficient number of measurements and their confidence intervals are assessed.