REFERENCE VALUES FOR SELF-RECORDED BLOOD-PRESSURE - A METAANALYSIS OFSUMMARY DATA

Background: The widespread clinical use of self-recorded blood pressur e measurement is limited by the lack of generally accepted reference v alues. The purpose of this study was therefore to perform a metaanalys is of summary data in an attempt to determine an operational threshold for self-recorded blood pressures. Studies and Methods: Seventeen stu dies, including a total of 5422 subjects, were reviewed. Eight of thes e 17 studies included both normotensive and untreated hypertensive sub jects, while the other 9 reports included normotensive subjects only. Within each study an operational cutoff point between normotension and hypertension was derived by means of the mean+2 SDs and the 95th perc entiles of the self-recorded blood pressure in normotensive subjects. These 2 methods were contrasted with 2 other techniques that have been applied in the literature to calculate (1) the self-recorded pressure s equivalent to a conventional pressure of 140 mm Hg systolic and 90 m m Hg diastolic by means of regression analysis and (2) the self-record ed blood pressures at the percentiles corresponding to a conventional pressure of 140/90 mm Hg. The latter 2 methods were applied in untreat ed treated subjects not selected on the basis of their blood pressure. Results: With weighting for the number of subjects included in the va rious studies, the self-recorded blood pressure averaged 115/71 mm Hg in normotensive persons and 119/74 mm Hg in untreated subjects not sel ected on the basis of their blood pressure. The reference values for s elf-recorded blood pressures determined by the mean+2 SDs (137/89 mm H g) or the 95th percentile (135/86 mm Hg) of the distribution in normot ensive subjects were concordant within 2/3 mm Hg, whereas the cutoff p oints derived with the regression and percentile methods were consider ably lower, ie, 125/79 and 129/84 mm Hg, respectively. Conclusions: Un til the relationship between self-recorded pressure and the incidence of cardiovascular morbidity and mortality is further clarified by pros pective studies, a mean self-recorded blood pressure above 135 mm Hg s ystolic or 85 mm Hg diastolic may be considered hypertensive.