Raised blood pressure is the biggest single risk factor responsible for mortality worldwide. Despite this, the majority of people with hypertension are unaware of having it, are untreated, or are on treatment but uncontrolled. May Measurement Month is a global campaign initiated by the International Society of Hypertension with the aim of raising awareness of high blood pressure. In the first year of the campaign in 2017, over 1.2 million people were screened in 80 countries across the world, finding over 100 000 people with hypertension who were not on treatment and over 150 000 people on anti-hypertensive treatment who were not controlled. The individual national results from 39 countries are presented in this supplement. In this article, we discuss the background to the campaign, along with some of the logistical and methodological challenges that were faced in setting up the campaign, and in collecting and analysing the data from such a large cross-sectional study. With the lessons learned from the 2017 campaign, the campaign was repeated in 2018 and is to be repeated again in 2019.

: High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-to-middle-income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.

In September 2017, KDIGO (Kidney Disease: Improving Global Outcomes) convened a Controversies Conference titled Blood Pressure in Chronic Kidney Disease (CKD). The purpose of the meeting was to consider which recommendations from the 2012 KDIGO Clinical Practice Guideline for the Management of Blood Pressure in CKD should be reevaluated based on new evidence from clinical trials. Participants included a multidisciplinary panel of clinical and scientific experts. Discussions focused on the optimal means for measuring blood pressure (BP) as well as managing BP in CKD patients. Consistent with the 2012 Guideline, the conference did not address BP management in patients on maintenance dialysis.

: In the past 30 years, several organizations have developed protocols for clinical validation of blood pressure measuring devices. An international initiative was recently launched by the US Association for the Advancement of Medical Instrumentation (AAMI), the European Society of Hypertension Working Group on Blood Pressure Monitoring (ESH) and the International Organization for Standardization (ISO), aiming to reach consensus on a universal AAMI/ESH/ISO validation standard. The purpose of this statement by the ESH Working Group on Blood Pressure Monitoring is to provide practical guidance for investigators performing validation studies according to the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018), to ensure that its stipulations are meticulously implemented and data are fully reported. Thus, this statement provides: a list of key recommendations for validation studies of intermittent non-invasive automated blood pressure measuring devices according to the AAMI/ESH/ISO Universal Standard; practical stepwise guidance for researchers performing these validation studies; a checklist for authors and reviewers of such studies; an example of a complete validation study report.

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. Restricted use of mercury devices, increased use of oscillometric devices, discrepancies between clinic and out-of-clinic BP, and concerns about measurement error with manual BP measurement techniques have resulted in uncertainty for clinicians and researchers. The National Heart, Lung, and Blood Institute of the U.S. National Institutes of Health convened a working group of clinicians and researchers in October 2017 to review data on BP assessment among adults in clinical practice and clinic-based research. In this report, the authors review the topics discussed during a 2-day meeting including the current state of knowledge on BP assessment in clinical practice and clinic-based research, knowledge gaps pertaining to current BP assessment methods, research and clinical needs to improve BP assessment, and the strengths and limitations of using BP obtained in clinical practice for research and quality improvement activities.

There is increasing interest in unattended automated office blood pressure (OBP) measurement, which gives lower blood pressure values than the conventional auscultatory OBP. Whether unattended automated OBP differs from standardized attended automated OBP performed using the same device and measurement protocol remains uncertain. A systematic review and meta-analysis of studies (aggregate data) comparing unattended vs attended automated OBP using the same device and measurement protocol (conditions, number of measurements, visits) was performed. Ten eligible studies (n = 1004, weighted age 60.8 ± 4.2 [SD] years, 55% males) were analyzed. Unattended OBP (pooled systolic/diastolic 133.9 [95% CI: 129.7, 138]/80.6 [95% CI: 77, 84.2] mm Hg) did not differ from attended OBP (135.3 [95% CI: 130.9, 139.6]/81 [95% CI: 77.6, 84.3] mm Hg); pooled systolic OBP difference -1.3, 95% CI: -4.3, 1.7 mm Hg and diastolic -0.4, 95% CI: -1.2, 0.3 mm Hg. Nine of ten studies achieved high quality score and no publication bias was identified. Meta-regression analysis did not reveal any effect of age, gender, or attended systolic OBP on the unattended-attended systolic OBP difference (P = NS for all). However, there was a trend toward higher attended than unattended OBP at higher OBP levels. These data suggest that, when the same device and measurement protocol are used, attended automated OBP provides similar blood pressure values as unattended automated OBP. Although unattended automated OBP is theoretically advantageous as it ensures that standardized conditions and measurement protocol are used, attended automated OBP, if carefully performed, appears to be a reasonable and practical alternative.

The measurement of blood pressure in the office (OBP) remains the basis for hypertension diagnosis and management for more than half a century. Despite the increasing use of out-of-office blood pressure measurement using home and less so ambulatory monitoring and their endorsement by hypertension societies, at present and for some time to come it is likely that in many people the diagnosis and management of hypertension will be based on OBP measurement alone. OBP measurement is a very variable method affected by multiple factors, which have major impact on the OBP level, reproducibility and prognostic ability. Thus, there are several types of OBP measurement, depending on the device type, conditions, observer's presence and the number of readings. The 4 main OBP types are: Type I: Auscultatory OBP in clinical practice; Type II: Automated attended OBP in clinical practice; Type III: Research setting OBP; Type IV: Unattended automated OBP. These OBP types have different standardization level, different reproducibility, different clinical relevance and different thresholds for hypertension diagnosis. Unless the methodological details of OBP measurement are reported, any conclusions based on such measurements in clinical research and in practice are questionable.

: Studies using ambulatory blood pressure (BP) monitoring have shown that BP during night-time sleep is a stronger predictor of cardiovascular outcomes than daytime ambulatory or conventional office BP. However, night-time ambulatory BP recordings may interfere with sleep quality because of the device cuff inflation and frequency of measurements. Hence, there is an unmet need for obtaining high quality BP values during sleep. In the last two decades, technological development of home BP devices enabled automated BP measurements during night-time. Preliminary data suggest that nocturnal home BP measurements yield similar BP values and show good agreement in detecting nondippers when compared with ambulatory BP monitoring. Thus, nocturnal home BP measurements might be a reliable and practical alternative to ambulatory BP monitoring to evaluate BP during sleep. As the use of home BP devices is widespread, well accepted by users and has relatively low cost, it may prove to be more feasible and widely available for routine clinical assessment of nocturnal BP. At present, however, data on the prognostic relevance of nocturnal BP measured by home devices, the optimal measurement schedule, and other methodological issues are lacking and await further investigation. This article offers a systematic review of the current evidence on nocturnal home BP, highlights the remaining research questions, and provides preliminary recommendations for application of this novel approach in BP management.

The 2017 US guidelines for pediatric hypertension place considerable emphasis on blood pressure measurements, which are the cornerstone for hypertension diagnosis and management. It is recognized that when the diagnosis of hypertension is based solely on office blood pressure measurements, many children are misclassified (over- or underdiagnosed). Therefore, out-of-office blood pressure evaluations using ambulatory or home blood pressure monitoring are often necessary to obtain an accurate diagnosis. Strong evidence for the diagnostic and clinical value of ambulatory blood pressure monitoring in children has justified its central role in decision making in recent pediatric recommendations. However, ambulatory blood pressure monitoring is not widely accessible in primary care. There is little evidence for home blood pressure monitoring in children, yet this method is widely available and feasible for the evaluation of elevated blood pressure in children. This article presents a case for using home blood pressure monitoring for the management of children with suspected or treated hypertension in clinical practice in comparison to using office measurements or ambulatory blood pressure monitoring, as well as its optimal application. More research on home blood pressure monitoring in children is urgently needed.

Hypertension is now recognized as a major global cause of morbidity and death. All decisions relating to the epidemiology, diagnosis, and management of hypertension are dependent on being able to measure blood pressure accurately. Scientists have developed protocols to assess the accuracy of blood pressure-measuring devices, but little attention has been given to informing users which devices are accurate and inaccurate. This article identifies a recipient audience of researchers, clinicians, and scientists, the public, healthcare executives and administrators, and consumer and regulatory bodies, and discusses how best to communicate the results of device accuracy to these groups with the aim of improving the accurate measurement of blood pressure.

According to the established validation protocols, a typical validation study of a blood pressure (BP) monitor includes general population adults with normal or elevated BP. It is recognized, however, that the automated (oscillometric) BP monitors may have different accuracy or uses in some special populations compared with adults in the general population. Thus, an automated BP monitor with proven accuracy in a general population of adults may not be accurate in a special population, and therefore separate validation is needed. Recognized special populations deserving separate validation are those for which there is theoretical, and also clinical evidence, that the accuracy of BP monitors in these groups differs from that in the general population. Young children, pregnant women (including those with preeclampsia), individuals with arm circumference >42 cm, and patients with atrial fibrillation are regarded as special populations. Adolescents, individuals older than 80 years, and patients with end-stage renal disease or diabetes mellitus have also been considered as possible special groups, but there is still inadequate evidence of altered accuracy of BP monitors in these subjects. Validation studies should be performed in special populations and evaluated separately after the BP-measuring device has successfully undergone a validation study in a general population (unless the test device is intended only for a special population). This article discusses issues relating to the measurement of BP and the diagnosis of hypertension in selected special populations, as well as in low-resource settings, where a simplified yet efficient evaluation strategy is necessary.

Blood pressure variability is an entity that characterizes the continuous and dynamic fluctuations that occur in blood pressure levels throughout a lifetime. This phenomenon has a complex and yet not fully understood physiological background and can be evaluated over time spans ranging from seconds to years. The present paper provides a short overview of methodological aspects, clinical relevance, and potential therapeutic interventions related to the management of blood pressure variability.