Blood pressure reductions during self-recording of home blood pressure.

Blood pressure readings were taken at home twice a day for one month by 60 subjects with essential hypertension. The average change-perday value based on quadratic curves fit to each subject's data (for the entire month or to the day of medication change) was negative and was statistically significant for both systolic and diastolic and for a.m. and p.m. readings. Clinically significant decreases in blood pressure, defined as systolic and/or diastolic decreases ≥ 10 mm. Hg from the first two to the last two days, occurred in 43 per cent of the subjects.The observed blood pressure decreases may have been due to (1) placebo effects and/or increased compliance associated with the change of treatment program, (2) increased attention of health care practitioners, (3) habituation of blood pressure to the conditions of measurement, or (4) biofeedback effects. The most likely explanation for the initial blood pressure decrease in habituation. The smaller but continuing decrease after the first two days was probably due, at least in part, to a biofeedback effect. If further studies support such an hypothesis, then home blood pressure readings should be used on a wider scale for treatment purposes. They are easier to administer than other behavioral treatments and the observed decreases appear to be of the same order of magnitude.Regardless of the treatment potential of this type of biofeedback, the decreases in home blood pressures while patients are taking their own pressures daily at home suggest the importance of a diagnostic waiting period until blood pressure stabilizes and before pharmacological treatment is prescribed. This period may last a month or longer for some patients.