Variability Of Blood Pressure Measurements Research Articles

Measuring blood pressure in the elderly: does atrial fibrillation increase observer variability?

To compare the interobserver and intraobserver variability of blood pressure measurements in geriatric patients in atrial fibrillation and in sinus rhythm. Prospective assessment of blood pressure measurements carried out in random order in two groups of elderly patients by five doctors unaware of the aims of the study. Acute assessment wards for geriatric medicine, Cardiff Royal Infirmary. 50 Elderly patients in sinus rhythm and 50 in atrial fibrillation. Interobserver and intraobserver variability of blood pressure measurements in the two groups expressed as the coefficient of variability and compared by the Mann-Whitney U test. Interobserver variability was significantly greater in the patients with atrial fibrillation for both systolic and diastolic pressures. Intraobserver variability was significantly greater in the atrial fibrillation group for diastolic pressures but the difference was not significant for systolic pressures. These differences were not related to pulse rate, age, or level of blood pressure. The findings suggest that in the presence of atrial fibrillation physicians' interpretations of Korotkoff sounds are less uniform, which may have important clinical implications. Possibly a standardised methodology may overcome this problem.

An Evaluation of Two Indirect Methods of Blood Pressure Measurement in Ill Patients

Direct (intraarterial) and two indirect (using a mercury sphygmomanometer [MS] and an automatic [auscultatory] device) methods of blood pressure measurement were compared in intensive care patients (N = 32). One trained observer blind to both automatic and direct measurements obtained all indirect MS measurements. All direct and indirect measurements were made on the same arm. Direct measurements were obtained from 10-second strip chart recordings. In normotensive patients both indirect measurements of systolic blood pressure (SBP) underestimated the direct SBP; however, only the SBP value obtained with the automatic device (106 mm Hg) was significantly different, p less than .05, from the direct SBP value (120 mm Hg). No significant difference was noted between methods in measurement of normotensive diastolic blood pressure. In hypertensive patients direct SBP was significantly greater, p less than .05, from both values obtained by indirect measurement. In patients without hypotension the automatic device may be substituted for the MS and direct blood pressure methods. The automatic device may offer the advantage of decreasing observer bias and variability in blood pressure measurement.

Observations on blood pressure measurements in high-school athletes.

The purpose of this study is to identify possible evidence of hypertension in athletic adolescents. In addition to sex and age, the effects of various physical factors that may influence blood pressure are measured. The data were collected from the annual screening physicals of local high-school athletic program participants. Nine of the 11 measured physical factors account for 10 percent to 20 percent of the variability in blood pressure measurements. These include age, weight, height, pulse, quadriceps girth, heel cord flexibility, jump reach, hang time, and grip strength. These variables are incorporated into formulae that adjust the range of "normal" values of systolic and diastolic blood pressure to reduce the effects of these confounding factors, thereby increasing the accuracy of the "normal" or "hypertensive" determination for each individual.

The variability of blood pressure measurements in children.

This study examined the sources and amount of variation present in the blood pressures of 99 third grade children, using data collected from three repeated measurements made on three separate visits. The results highlight factors to consider when planning or evaluating studies designed to relate children's blood pressure levels to environmental conditions. Factors include variability both between and within children by visit and between observers; periodic restandardization of observers during the course of a study is desirable.

Variability in blood pressure measurements

Variability in blood pressure measurements

Variability of blood pressure measurements in 8786 children of white, black, and hispanic origins: Paul M. Insel, American Institutes for Research, Palo Alto, Calif.; Roland L. Phillips, Loma Linda University, Loma Linda, Calif.; Joseph H. Chadwick, SRI International, Menlo Park, Calif

Variability of blood pressure measurements in 8786 children of white, black, and hispanic origins: Paul M. Insel, American Institutes for Research, Palo Alto, Calif.; Roland L. Phillips, Loma Linda University, Loma Linda, Calif.; Joseph H. Chadwick, SRI International, Menlo Park, Calif

Evaluation of performance of selected devices for measuring blood pressure

Standardization of blood pressure measurements is critical for the implementation of screening programs, and especially so for a multicenter, collaborative investigation of community blood pressure control. This need arises from numerous well known sources of variability in blood pressure measurements, some of which are attributable to performance characteristics of instruments and observers. A number of instruments have been developed in recent years with the aim of overcoming certain aspects of this measurement variation. Consequently, the Coordinating Center of the National Heart and Lung Institute Hypertension Detection and Follow-up Program (HDFP) undertook to evaluate several of these devices in order to permit selection for this Program of optimal methods of blood pressure measurement. The mercury sphygmomanometer, which is the basis of most available epidemiologic data on blood pressure, was taken as the standard. In the first experiment, based upon a Graeco-Latin square design, none of the five automated devices tested compared favorably with the standard mercury sphygmomanometer, as judged by the mean values of multiple readings for each of the two specimens of each device. In a series of paired readings, all but one of the automated devices showed marked deviation from readings by the standard mercury sphygmomanometer. Qualitative observations on machine performance were also recorded and indicated serious operating difficulties with several devices—including, unfortunately, the device that had performed well in the second experiment. For the purposes of the Program, none of the automated devices tested performed adequately to recommend their substitution for the standard mercury sphygmomanometer. A modified type of mercury sphygmomanometer, designed to reduce observer bias, was included in this evaluation, did compare well, and will be used by the Program in conjunction with the standard device.