Number Of Blood Pressure Readings Research Articles

Effect of wearing N95 masks for 10 hours on ambulatory blood pressure in healthy adults.

The impact of wearing a face mask for an extended duration is unknown. This study aimed to determine if wearing a face mask for 10 h impacts blood pressure (BP) and arterial stiffness. Subjects received an ambulatory blood pressure cuff and were asked to wear it for 10 h while readings were taken every 15 min. During the face mask trial, subjects wore an N95 mask for 10 h. During the control, subjects did not wear a mask. Subjects were randomized to start their trial. An accelerometer was given to ensure no physical activity differences. Linear mixed models were used to determine group differences, and McNemar test was used to assess frequency differences when determining BP load. Twelve college-aged (20.5 ± 1.5 years) male (n = 5) and female (n = 7) individuals with normal BP participated in this study. There were no differences in time spent in any physical activity domain (all P > 0.05). There was no difference in brachial SBP (P = 0.688), brachial DBP (P = 0.063), central SBP (P = 0.875), central DBP (P = 0.246), heart rate (P = 0.125), and augmentation pressure (P = 0.158) between conditions. During mask condition, augmentation pressure was reduced by 5.2 ± 3.1% compared to control (P < 0.001). There were no frequency differences in the number of BP readings above 140 mmHg for SBP (P = 0.479) and >90 mmHg for DBP (P = 0.212). The current study found that wearing an N95 mask for 10 h did not affect brachial or central BP but significantly decreased augmentation pressure.

IMPROVED OFFICE BLOOD PRESSURE CONTROL BY AUTOMATIC DELAYED-READING OSCILLOMETRIC DEVICE

Objective: Office blood pressure measurement is a recommended procedure by clinical guidelines. We designed the study to know the degree of blood pressure control by clinical measurement using an automatic delayed-reading oscillometric device. Design and method: During one month we collect demographic and clinical data, office attended systolic blood pressure and diastolic blood pressure measured with an automatic device with a delayed start of the measurement and, if performed, data from ambulatory blood pressure monitoring. Results: We included 102 patients (67 men), with a mean age of 64.9 years, 30% diabetic and 34% with cardiovascular complications. 70% had a controlled hypertesion (&lt;140/90 mmHg) by office blood pressure, the mean systolic blood pressure was 131 ± 16.5 mmHg and the diastolic blood pressure was 73 ± 9.5 mmHg which is a high percentage compared with other studies. Old age and diabetes were associated with uncontrolled hypertension. Thirty three patients had ambulatory blood pressure monitoring data, which allowed them to be classified according to the 24-hour blood pressure into: 30% true normotension, 9% white-coat hypertension, 15% sustained hypertension, and 45% masked hypertension. Therefore, ambulatory measurements did not confirm the good blood pressure control. Conclusions: The use of automatic delayed-reading device reduces the white-coat phenomenon, improving the percentage of patients with office blood pressure controlled. However, this control is not confirmed outside the clinic, showing the importance of ambulatory blood pressure monitoring in the global evaluation of hypertension control. Aspects such as the presence or not of an observer, the number of blood pressure readings and the use of validated automatic devices with or without delayed start of the measurement should be the subject of clinical studies to determine the optimal technique for measuring office blood pressure.

WHAT ARE THE PREFERRED BLOOD PRESSURE MEASUREMENT METHODS BY DOCTORS TO DETECT, DIAGNOSE AND TREAT HYPERTENSION? A SURVEY STUDY IN A CHINESE POPULATION

Objective: Hypertension(HT) is the most common chronic disease and is the leading cause of morbidity and mortality. Its detection, diagnosis and management depend heavily on accurate blood pressure(BP) measurement. It is recommended that the diagnosis of HT should be confirmed or assisted by out-of-office BP measurement, including ambulatory BP measurement(ABPM) and home BP measurement(HBPM). When office BP is used, automated BP measurement(AOBP), which automatically provides an average of 3–5 BP readings, is preferred. This study aimed to describe the BP measurement methods used by doctors working in primary care to detect, diagnose and treat hypertension. Design and method: This is a cross-sectional survey. All doctors registered in the “Primary Care Directory” were mailed a questionnaire, asking their preferred methods to detect, diagnose and treat hypertension. Furthermore, the number of BP readings they usually obtained on office BP or HBPM to diagnose or manage HT was asked. Results: Four hundred and forty-five doctors responded. Manual measurement by a mercury or aneroid devices was the commonest method to detect(63.1%), diagnose(56.4%), and manage(72.4%) HT. There was an underuse of ABPM and only 1.6% of doctors used ABPM to diagnose HT. 22.2% of doctors used HBPM to diagnose HT; and 56.8% of doctors used HBPM to manage HT. A quarter (26.7%) of participants only obtained one BP reading when they used office BP. Only 40% of participants obtained at least 12 BP readings when HBPM was used. Doctors who obtained specialist qualification in family medicine were more likely to use AOBP in clinics and to obtain enough office BP readings for diagnosis and management of HT. Conclusions: Doctors in primary care in Hong Kong prefer to use manual office BP, especially mercury or aneroid devices, to screen, diagnose and treat HT. There is an underuse of AOBP and out-of-office BP. Studies are needed to understand the underlying reasons and to minimize the gap between real-life clinical practice and scientific advances.

Abstract P606: Hemodynamic Predictors of Multiple Recurrent Strokes in the Patients With Prior Lacunar Stroke

Background: Recurrent stroke has higher morbidity and mortality than incident stroke. We evaluated hemodynamic risk factors for multiple recurrent strokes. Methods: We included patients in the SPS3 trial. The primary predictor was the top tertile, compared to the bottom tertile, of the mean systolic blood pressure (mSBP) and blood pressure variability represented as standard deviation (sdSBP) using blood pressures from day 30 of the trial to the end of follow-up. We excluded blood pressures from the first 30 days to reduce confounding from the trial’s intervention. We fit a logistic regression model to ≥2 recurrent strokes from day 30 to the end of follow-up and, to accurately analyze the multiple failure-time data, we ordered the multiple failure events to the Prentice, Williams and Peterson extension of the Cox proportional-hazards model. Results: We included 2,882 patients, of which 223 had a recurrent stroke and 41/223 had ≥2 recurrent strokes for a total of 272 strokes. The mean (SD) number of blood pressure readings was 78.0 (37.4). The etiology of the 272 strokes was 161 (59.2%) lacunar, 22 (8.1%) intracranial atherosclerosis, 10 (3.7%) extracranial atherosclerosis, 24 (8.8%) cardioembolic, and 55 (20.2%) cryptogenic or other. In both unadjusted and adjusted logistic regression models and PWP Cox models, the top tertile of sdSBP was consistently predictive of multiple recurrent strokes, while mSBP was not (Tables 1/2). Conclusions: We found that in patients with an index lacunar stroke, higher SBP variability, but not mean SBP, was predictive of multiple recurrent strokes of varying mechanisms.

Abstract TMP91: Increased Blood Pressure Variability in the SPS3 Trial is Associated With Recurrent Stroke

Introduction: Hypertension is the leading cause of small-vessel stroke; however, mechanisms of stroke related to blood pressure variability (BPV) are not well understood. Hypothesis: Greater BPV will be correlated with increased ischemic stroke recurrence in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial. Methods: All blood pressures in the 30 days after randomization were excluded to reduce confounding from the study intervention. The study exposure was BPV, defined as standard deviation (SD) and coefficient of variation of the systolic blood pressure, during days 30-365 of SPS3. Cox proportional hazards regression was used to calculate hazard ratios relating BPV to stroke events during the remainder of study follow-up. Patients were excluded if they had stroke during the exposure period. Results: This analysis included 2,764 patients, 157 (5.7%) of whom developed stroke. Mean±SD follow-up was 1091±699 days and number of blood pressure readings per patient was 39±14. The SD was higher in patients who developed recurrent stroke (Table 1). A 10 mm Hg shift in SD was associated with a hazard ratio of 1.53 for stroke (Table 2). This association was not affected by SPS3 blood pressure treatment arm. Conclusion: Greater BPV was associated with a minor increase in the risk of recurrent stroke in SPS3. Additional research is needed to understand the causal mechanism and methods to reduce BPV.

Methodological factors affecting quantification of blood pressure variability: a scoping review.

Blood pressure (BP) variability (BPV) may offer independent prognostic information. However, data supporting this notion are inconsistent, and this may be due to the wide variety of methodologies used for measuring BPV. A systematic analysis on the effect of BPV methodologies on BPV itself has never been undertaken and was the aim of this study. We also sought to determine the effect of participant characteristics on BPV. A scoping review process was used to identify the effect of BPV methodologies on BPV magnitude. Key methodological factors assessed were the number of BP readings or visits used to quantify BPV and the duration of BP monitoring. In addition, the relationship between age and mean BP level on BPV was investigated. Analyses were performed across studies that measured BPV over the short-term (using 24-h BP), mid-term (using home BP in the morning, evening or day-to-day) and long-term (using visit-to-visit clinic BP). Data were extracted from 96 studies. The number of BP readings and visits used to quantify BPV were positively associated with mid-term and long-term BPV. Duration was weakly associated with mid-term (morning) BPV. Age was positively associated with long-term and mid-term (day-to-day), but not short-term BPV. Mean BP level was positively associated with BPV, except mid-term BPV (morning and evening). The methodology used to quantify BPV, as well as age and mean BP level, affects the magnitude of BPV itself. This highlights the need to standardize BPV protocols, particularly regarding the number of BP readings and visits.

Abstract TP425: Post-stroke Blood Pressure Trajectory and Mortality Risk: Analysis of Racial/Ethnic Differences in the New York City Health and Hospitals Corporation

Background: The racial/ethnic differences in post-stroke blood pressure (BP) trajectory and mortality risk are not fully understood. The current paper investigated differences in average systolic BP (SBP) during the 6 months following stroke and effects of average post-stroke BP on mortality risk among Blacks and Hispanics. Hypothesis: Greater post-stroke BP levels will increase risk of mortality Methods: We examined BP measurements in 6,016 stroke survivors within the New York City Health and Hospitals Corporation (NYC HHC) during the 6 months following stroke. Based on the average of all SBP measurements in this period, patients were classified into three groups: (1) SBP =140 mm Hg and =150 mm Hg). We used inverse probability weighting (IPW) to control for group differences in demographic factors, comorbidity, and anti-hypertensive medication use. We examined how 6 month SBP average related to mortality following stroke using Cox regression analysis. The mean duration of follow up after stroke was 2.6±1.5 years. Results: The mean age was 57.9±13.0 years, 57.4% of patients were female, 49.1% were Black and 37.3% were Hispanic. Blacks were more likely than Hispanics to have an average post-stroke SBP &gt;=150mm Hg (27% versus 17%). Group 1 (SBP &lt;140) and Group 3 (SBP&gt;=150) had higher risks of mortality (Group 1 HR=1.26, 95%CI=1.13-1.41; Group 3 HR=1.29, 95%CI=1.13-1.48) when compared to Group 2 (SBP 140-150). When controlling for ethnicity, these differences are no longer significant. In stratified analyses, the increased hazard in Group 1 was maintained in the sub-sample of Blacks (HR=1.47, 95%CI=1.25-1.72) but not in Hispanics (HR=0.95, 95%CI=0.79-1.15). The difference between Group 2 and Group 3 was not significant in either Black or Hispanic sub-samples. Conclusion: Our findings demonstrate that having a post-stroke SBP below 140 mm Hg or above 150 mm Hg significantly increased individuals’ mortality risk, adjusting for demographic factors, comorbidity, number of BP readings, and location of healthcare. Post-stroke BP trajectory differed between Blacks and Hispanics, and had different effects on mortality. These findings have important implications for post-stroke hypertension care.

Telemetric Ambulatory Arterial Stiffness Index, a Predictor of Cardio–Cerebro–Vascular Mortality, is Associated with Aortic Stiffness‐Determining Factors

Ambulatory arterial stiffness index (AASI) has been proposed as a new measure of arterial stiffness for predicting cardio-cerebro-vascular morbidity and mortality. However, there has been no research on the direct relationships between AASI and arterial stiffness-determining factors. We utilized beat-to-beat intra-aortic blood pressure (BP) telemetry to characterize AASI in Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). By determination of aortic structural components and analysis of their correlations with AASI, we provided the first direct evidence for the associations between AASI and arterial stiffness-determining factors including the collagen content and collagen/elastin. Ambulatory arterial stiffness index was positively correlated with pulse pressure in both WKY and SHR, less dependent on BP and BP variability than pulse pressure, and relatively stable, especially the number of BP readings not less than ~36. The correlations between AASI and aortic components were comparable for various AASI values derived from BP readings not less than ~36. Not only AASI but also BP variability and pulse pressure demonstrated a direct relationship with arterial stiffness. These findings indicate AASI may become a routine measure in human arterial stiffness assessment. It is recommended to use a cluster of parameters such as AASI, BP variability, and pulse pressure for evaluating arterial stiffness.

The development and application of a new tool to assess the adequacy of the content and timing of antenatal care

BackgroundCurrent measures of antenatal care use are limited to initiation of care and number of visits. This study aimed to describe the development and application of a tool to assess the adequacy of the content and timing of antenatal care.MethodsThe Content and Timing of care in Pregnancy (CTP) tool was developed based on clinical relevance for ongoing antenatal care and recommendations in national and international guidelines. The tool reflects minimal care recommended in every pregnancy, regardless of parity or risk status. CTP measures timing of initiation of care, content of care (number of blood pressure readings, blood tests and ultrasound scans) and whether the interventions were received at an appropriate time. Antenatal care trajectories for 333 pregnant women were then described using a standard tool (the APNCU index), that measures the quantity of care only, and the new CTP tool. Both tools categorise care into 4 categories, from 'Inadequate' (both tools) to 'Adequate plus' (APNCU) or 'Appropriate' (CTP). Participants recorded the timing and content of their antenatal care prospectively using diaries. Analysis included an examination of similarities and differences in categorisation of care episodes between the tools.ResultsAccording to the CTP tool, the care trajectory of 10,2% of the women was classified as inadequate, 8,4% as intermediate, 36% as sufficient and 45,3% as appropriate. The assessment of quality of care differed significantly between the two tools. Seventeen care trajectories classified as 'Adequate' or 'Adequate plus' by the APNCU were deemed 'Inadequate' by the CTP. This suggests that, despite a high number of visits, these women did not receive the minimal recommended content and timing of care.ConclusionsThe CTP tool provides a more detailed assessment of the adequacy of antenatal care than the current standard index. However, guidelines for the content of antenatal care vary, and the tool does not at the moment grade over-use of interventions as 'Inappropriate'. Further work needs to be done to refine the content items prior to larger scale testing of the impact of the new measure.

Audit of management of eclampsia and severe pre-eclampsia against RCOG standards

IntroductionConfidential enquiries into maternal deaths show substandard care in a significant percentage of the deaths from eclampsia.1 The RCOG Green Top Guideline No 10(A) (2006)2 makes recommendations to standardise the...

Role of home blood pressure telemonitoring in hypertension management

Despite the increasing use of home blood pressure monitoring (HBPM) in daily practice and the growing awareness in the scientific community about its positive impact on the diagnostic and therapeutic management of patients with high blood pressure (BP), the potential advantages offered by HBPM have not yet been fully exploited. Indeed, use of the information offered by HBPM is often incomplete and imprecise, with the BP values reported by patients in handwritten logbooks being frequently inaccurate, illegible to physicians, or unreliable. Although a practical solution for improvement may come from the use of devices equipped with a storage memory, a step forward in this regard has been taken more recently with the introduction and refinement of systems for the remote telemonitoring of BP values measured at home. However, although several studies have provided evidence on the clinical usefulness of HBPM, only limited data are available on the clinical impact of home blood pressure (HBP) telemonitoring, because of a number of reasons. First, most of the available studies are characterized by a small sample size, and in some cases, the patients were neither randomized nor even matched with a control group. Moreover, technological solutions used in the different studies carried out so far are often heterogeneous, some of them being particularly difficult to use for the patients, thus limiting the effectiveness of the results. BP monitoring programmes, number of BP readings and transmission schedules are often different among the various studies. In addition, patient selection criteria are different from study to study. Finally, different study objectives and important diversities in the types of centres involved (ranging from general practices, to specialists' offices, hospitals or university centres) may have also influenced the quality of results. Large-scale randomized controlled studies, based on easy-to-use technologies, are thus still needed to show the superiority and clinical usefulness of HBP telemonitoring as compared with conventional HBPM. This study summarizes the evidence available on the clinical usefulness and current limitations of this approach, highlighting the results of meta-analyses and randomized controlled trials on this issue. The role of HBP teletransmission in the context of integrated patients' management programmes is also addressed, with indications for further progress in this field.

Prognostic Value of Reading-to-Reading Blood Pressure Variability Over 24 Hours in 8938 Subjects From 11 Populations

In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects (mean age: 53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we assessed BP variability from the SD and average real variability in 24-hour ambulatory BP recordings. We computed standardized hazard ratios (HRs) while stratifying by cohort and adjusting for 24-hour BP and other risk factors. Over 11.3 years (median), 1242 deaths (487 cardiovascular) occurred, and 1049, 577, 421, and 457 participants experienced a fatal or nonfatal cardiovascular, cardiac, or coronary event or a stroke. Higher diastolic average real variability in 24-hour ambulatory BP recordings predicted (P<or=0.03) total (HR: 1.14) and cardiovascular (HR: 1.21) mortality and all types of fatal combined with nonfatal end points (HR: >or=1.07) with the exception of cardiac and coronary events (HR: <or=1.02; P>or=0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (P<0.05) total (HR: 1.11) and cardiovascular (HR: 1.16) mortality and all fatal combined with nonfatal end points (HR: >or=1.07), with the exception of cardiac and coronary events (HR: <or=1.03; P>or=0.54). SD predicted only total and cardiovascular mortality. While accounting for the 24-hour BP level, average real variability in 24-hour ambulatory BP recordings added <1% to the prediction of a cardiovascular event. Sensitivity analyses considering ethnicity, sex, age, previous cardiovascular disease, antihypertensive treatment, number of BP readings per recording, or the night:day BP ratio were confirmatory. In conclusion, in a large population cohort, which provided sufficient statistical power, BP variability assessed from 24-hour ambulatory recordings did not contribute much to risk stratification over and beyond 24-hour BP.

Underdiagnosis of Hypertension in Children and Adolescents

Pediatric hypertension is increasing in prevalence with the pediatric obesity epidemic. Diagnosis of hypertension in children is complicated because normal and abnormal blood pressure values vary with age, sex, and height and are therefore difficult to remember. To determine the frequency of undiagnosed hypertension and prehypertension and to identify patient factors associated with this underdiagnosis. A cohort study of 14,187 children and adolescents aged 3 to 18 years who were observed at least 3 times for well-child care between June 1999 and September 2006 in the outpatient clinics in a large academic urban medical system in northeast Ohio. For children and adolescents who met criteria for hypertension or prehypertension at 3 or more well-child care visits, the proportion with a hypertension-related International Classification of Diseases, Ninth Revision code in the diagnoses list, problem list, or past medical history list of any visit was determined. Proportion of children and adolescents with 3 or more elevated age-adjusted and height-adjusted blood pressure measurements at well-child care visits and with a diagnosis of hypertension or prehypertension documented in the electronic medical record. Multivariate logistic regression identified patient factors associated with a correct diagnosis. Of 507 children and adolescents (3.6%) who had hypertension, 131 (26%) had a diagnosis of hypertension or elevated blood pressure documented in the electronic medical record. Patient factors that increased the adjusted odds of a correct diagnosis were a 1-year increase in age over age 3 (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.03-1.16), number of elevated blood pressure readings beyond 3 (OR, 1.77; 95% CI, 1.21-2.57), increase of 1% in height-for-age percentile (OR, 1.02; 95% CI, 1.01-1.03), having an obesity-related diagnosis (OR, 2.61; 95% CI, 1.49-4.55), and number of blood pressure readings in the stage 2 hypertension range (OR, 1.68; 95% CI, 1.29-2.19). Of 485 children and adolescents (3.4%) who had prehypertension, 55 (11%) had an appropriate diagnosis documented in the electronic medical record. Patient factors that increased the adjusted odds of being diagnosed with prehypertension included a 1-year increase in age over age 3 (OR, 1.21; 95% CI, 1.09-1.34) and number of elevated blood pressure readings beyond 3 (OR, 3.07; 95% CI, 2.20-4.28). Hypertension and prehypertension were frequently undiagnosed in this pediatric population. Patient age, height, obesity-related diagnoses, and magnitude and frequency of abnormal blood pressure readings all increased the odds of diagnosis.

Dipping Deeper Into the Ambulatory Arterial Stiffness Index

To the Editor: Methodologic and conceptual issues seriously weaken the conclusions of Schillaci et al1 on the ambulatory arterial stiffness index (AASI), as published in the May 2007 issue of Hypertension . Schillaci et al1 reported that, in 515 untreated patients, AASI depended on the nocturnal blood pressure fall. We confirmed this observation in our Flemish population study.2 The correlation coefficients were similar to those in the report by Schillaci et al1: −0.24 versus −0.28 for systolic blood pressure (2-sided P value computed by Fisher’s Z transformation, 0.42), and −0.39 versus −0.46 for diastolic blood pressure ( P =0.11). However, the ambulatory recording of 1 of the representative patients of Schillaci et al1 included ≈25 nighttime and ≈35 daytime readings. The night:day ratio of the number …

Relationship between the Frequency of Blood Pressure Self-Measurement and Blood Pressure Reduction with Antihypertensive Therapy

This subanalysis of the OLMETEL (OLMEsartan TELemonitoring blood pressure) study in patients with essential hypertension assessed the relationship between the frequency of blood pressure self-measurement (BPSM) and the response to blood pressure (BP)-lowering therapy with olmesartan medoxomil, and the number of BP readings per week necessary to detect a mean systolic or diastolic BP reduction > or =5mm Hg. A total of 53 patients with essential hypertension received treatment with olmesartan medoxomil 10, 20 or 40 mg daily for 12 weeks. BPSM was performed for the first 9 weeks using a TensioPhone TP2 device. Patients were instructed to measure BP at least twice daily (morning and evening). After the first 9 weeks of the 12-week treatment period, the extent of BP reduction correlated with the number of BPSMs. Systolic/diastolic BP reductions in patients with a 100% adherence to at least two BP measurements daily were -16.6/-8.0mm Hg compared with -0.2/-3.3mm Hg in patients with only a 75% adherence to at least one BP measurement daily. Obtaining five home BP readings per week resulted in a sensitivity of 94.8% and a specificity of 90.0% to detect a BP reduction of > or =5mm Hg. Patients adhering to the instructions for BPSM (at least two measurements daily) had a better response to antihypertensive treatment with olmesartan medoxomil. Whether BPSM per se resulted in an improved adherence to therapy or whether the number of recordings was an indicator of already existing adherence remains to be determined. Obtaining at least five home BP readings per week was identified as the threshold for correctly predicting response to olmesartan medoxomil treatment.

Assessment of body position to quantify its effect on nocturnal blood pressure under ambulatory conditions

Nocturnal blood pressure readings may be influenced by body position because of variation in the vertical distance between heart and cuff level. To quantify the effect of body position on nocturnal blood pressure and to assess whether this effect influences the reproducibility of nocturnal blood pressure. In 16 individuals (three normotensive and 13 hypertensive) 24 h ambulatory measurement of blood pressure and body position was performed twice, separated by an interval of 2-6 weeks. Body position was measured with five acceleration sensors, which were mounted on the trunk and legs. During the first night, 43 +/- 31% of blood pressure values were measured while participants were in the supine position, 29 +/- 28% when they were lying on their side with the cuffed arm down and 28 +/- 29% when they were lying on their side with the cuffed arm up. During the second night these percentages were 40 +/- 29%, 32 +/- 29% and 28 +/- 25% respectively. Blood pressure readings obtained while individuals were lying with the cuffed arm up were about 10 mmHg lower than those obtained with the individual in either the supine position or lying with the cuffed arm down. After correction for the underestimation attributable to 'cuff-up' readings, nocturnal blood pressure increased by 3 mmHg and the number of non-dippers increased from two to four. Correction did not affect the reproducibility of nocturnal blood pressure measurements (standard deviation of the differences 8.3 mmHg for systolic and 6.0 mmHg for diastolic blood pressure after correction). Dipping status was reproduced in 88% of individuals before correction, and in 87% after correction. Under ambulatory conditions, a highly variable but sometimes substantial number of blood pressure readings are taken with the cuffed arm above heart level. These readings result in underestimation of nocturnal blood pressure and hence influence dipper-non-dipper classification. However, body position does not seem to have an important influence on the reproducibility of nocturnal blood pressure or dipping status.

Clinical value of ambulatory blood pressure monitoring in the assessment of antihypertensive therapy

Non-invasive ambulatory blood pressure monitoring (ABPM) is particularly useful for assessing the efficacy of antihypertensive drugs. It provides a large number of blood pressure readings during daytime as well as night-time, which results in a more precise assessment of prevailing blood pressure than can be obtained from sporadic measurements taken by a doctor. Because of this greater precision ABPM reduces the number of patients required in clinical trials to demonstrate differences. It also allows one to define precisely the profile of the blood-pressure-lowering effect of a given drug. Placebo has little effect on ABPM. Thus, a placebo phase is not absolutely necessary. ABPM makes it possible to evaluate the efficacy of an antihypertensive medication by analysing data for patients with a placebo effect separately from data for true responders to the medication. In everyday practice ABPM helps one to detect among patients with hypertension refractory to treatment those who exhibit controlled blood pressures outside the medical environment, thus permitting one to avoid an unnecessary step-up of treatment. In addition ABPM can also help one to identify symptoms occurring during antihypertensive treatment that are related to excessive drug-induced changes in blood pressure.

Structured patient education for out-patients with hypertension in general practice: a model project in Germany.

In a model project, office-based physicians in two regions of Germany provided a structured treatment and teaching programme for out-patients with hypertension. The project was carried out in co-operation with the German Hypertension League and designed to evaluate the practicability and efficacy of the implementation in routine primary health care. A total of 111 primary health care practices in two German districts who had participated in a training course were interviewed. In 43 of these offices documented data of all patients who had received the standardised treatment and teaching were evaluated. The programme was well received by the physicians of which 81% rated the training course and 93% the teaching material as 'very good' or 'good'. A total of 466 patients were trained. Data collected on 272 patients (22 weeks after the intervention) demonstrated the efficacy of the programme at treatment level: reduction of body weight (2 kg, P < 0.001) and blood pressure (from systolic 158+/-18 to 148+/-17 mm Hg, P < 0.001; diastolic 91 +/-9 to 86+/-9, P < 0.001). Sixty-five per cent of patients learned for the first time how to perform blood pressure self-monitoring during the programme. The number of blood pressure readings by the patients' increased significantly from 1+/-3 measurements per week before, to 8+/-7 measurements per week after the programme (P < 0.001). The results of the study demonstrate the practicability and efficacy of the implementation of the programme for patients with hypertension into routine primary health care.

Increase in blood pressure reproducibility by repeated semi-automatic blood pressure measurements in the clinic environment

To evaluate whether increasing the number of blood pressure readings obtained in the clinic environment increases the blood pressure reproducibility. Thirteen mild essential hypertensive patients studied in the outpatient clinics, following withdrawal of antihypertensive treatment for 4 weeks. The systolic and diastolic blood pressures were measured three times, using a mercury sphygmomanometer, with the patient in the sitting position. Measurements were then performed with the patient in the lying position using an oscillometric device (SpaceLabs 90202 or 90207). The device was operated semi-automatically at 3-min intervals until 25 readings had been collected. The same procedure was repeated 4 weeks later. The systolic blood pressure, diastolic blood pressure and heart rate were averaged by considering a progressively greater number of readings, from 1 to 25. The reciprocal of the standard deviation (1/SD) of the mean difference after 4 weeks was taken as the measure of reproducibility. 1/SD increased progressively as the number of semi-automatic blood pressure readings from which the average was calculated increased. For a similar number of blood pressure readings the reproducibility was similar for semi-automatic readings to that for automatic readings obtained by 24-h ambulatory blood pressure monitoring. Multiple blood pressure readings obtained semi-automatically in the outpatient clinics increase blood pressure reproducibility and make the value similar to that obtained by ambulatory blood pressure monitoring. The advantage of an increase in reproducibility for studies on antihypertensive drugs thus depends on the number of readings, and can also be obtained by semi-automatic measurements in the clinic environment.

Sequential screening for hypertension in primary care

Plans are presented for the sequential screening of hypertension in primary care. The plans depend upon: (i) the number of stages k; (ii) the number of blood pressure readings per stage n; (iii) a threshold for true mean blood pressure gq 1, above which pharmacological treatment is believed desirable; (iv) a threshold for true mean blood pressure gq 0 below which pharmacological treatment is believed undesirable and (v) error probabilities associated with falsely classifying a person with mean blood pressure less than gq 0. The plans are chosen to maximize the probability of correctly classifying a person with mean blood pressure greater than gq 1.