Predicting Out-of-Office Blood Pressure in the Clinic (PROOF-BP): Derivation and Validation of a Tool to Improve the Accuracy of Blood Pressure Measurement in Clinical Practice

Cutoffs for white-coat and masked blood pressure effects: an ambulatory blood pressure monitoring study

The values used to define white-coat and masked blood pressure (BP) effects are usually arbitrary. This study aimed at investigating the accuracy of various cutoffs based on the differences (ΔBP) between office BP (OBP) and 24h-ambulatory BP monitoring (ABPM) to identify white-coat (WCH) and masked (MH) hypertension, which are phenotypes coupled with adverse prognosis. This cross-sectional study included 11,350 [Derivation cohort; 45% men, mean age = 55.1 ± 14.1 years, OBP = 132.1 ± 17.6/83.9 ± 12.5 mmHg, 24 h-ABPM = 121.6 ± 11.4/76.1 ± 9.6 mmHg, 25% using antihypertensive medications (AH)] and 7220 (Validation cohort; 46% men, mean age = 58.6 ± 15.1 years, OBP = 136.8 ± 18.7/87.6 ± 13.0 mmHg, 24 h-ABPM = 125.5 ± 12.6/77.7 ± 10.3 mmHg; 32% using AH) unique individuals who underwent 24 h-ABPM. We compared the sensitivity, specificity, positive and negative predictive values and area under the curve (AUC) of diverse ΔBP cutoffs to detect WCH (ΔsystolicBP/ΔdiastolicBP = 28/17, 20/15, 20/10, 16/11, 15/9, 14/9 mmHg and ΔsystolicBP = 13 and 10 mmHg) and MH (ΔsystolicBP/ΔdiastolicBP = -14/-9, -5/-2, -3/-1, -1/-1, 0/0, 2/2 mmHg and ΔsystolicBP = -5 and -3mmHg). The 20/15 mmHg cutoff showed the best AUC (0.804, 95%CI = 0.794-0.814) to detect WCH, while the 2/2 mmHg cutoff showed the highest AUC (0.741, 95%CI = 0.728-0.754) to detect MH in the Derivation cohort. Both cutoffs also had the best accuracy to detect WCH (0.767, 95%CI = 0.754-0.780) and MH (0.767, 95%CI = 0.750-0.784) in the Validation cohort. In secondary analyses, these cutoffs had the best accuracy to detect individuals with higher and lower office-than-ABPM grades in both cohorts. In conclusion, the 20/15 and 2/2 mmHg ΔBP cutoffs had the best accuracy to detect hypertensive patients with WCH and MH, respectively, and can serve as indicators of marked white-coat and masked BP effects derived from 24 h-ABPM.

Investigation and management of young-onset hypertension: British and Irish hypertension society position statement

National and international hypertension guidelines recommend that adults with young-onset hypertension (aged <40 years at diagnosis) are reviewed by a hypertension specialist to exclude secondary causes of hypertension and optimise therapeutic regimens. A recent survey among UK secondary care hypertension specialist physicians highlighted variations in the investigation of such patients. In this position statement, the British and Irish Hypertension Society seek to provide clinicians with a practical approach to the investigation and management of adults with young-onset hypertension. We aim to ensure that individuals receive consistent and high-quality care across the UK and Ireland, to highlight gaps in the current evidence, and to identify important future research questions.

A Continuous Non-Invasive Blood Pressure Prediction Method Based on Deep Sparse Residual U-Net Combined with Improved Squeeze and Excitation Skip Connections

Arterial blood pressure (ABP) serves as a pivotal clinical metric in cardiovascular health assessments, with the precise forecasting of continuous blood pressure assuming a critical role in both preventing and treating cardiovascular diseases. This study proposes a novel continuous non-invasive blood pressure prediction model, DSRUnet, based on deep sparse residual U-net combined with improved SE skip connections, which aim to enhance the accuracy of using photoplethysmography (PPG) signals for continuous blood pressure prediction. The model first introduces a sparse residual connection approach for path contraction and expansion, facilitating richer information fusion and feature expansion to better capture subtle variations in the original PPG signals, thereby enhancing the network's representational capacity and predictive performance and mitigating potential degradation in the network performance. Furthermore, an enhanced SE-GRU module was embedded in the skip connections to model and weight global information using an attention mechanism, capturing the temporal features of the PPG pulse signals through GRU layers to improve the quality of the transferred feature information and reduce redundant feature learning. Finally, a deep supervision mechanism was incorporated into the decoder module to guide the lower-level network to learn effective feature representations, alleviating the problem of gradient vanishing and facilitating effective training of the network. The proposed DSRUnet model was trained and tested on the publicly available UCI-BP dataset, with the average absolute errors for predicting systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) being 3.36 ± 6.61 mmHg, 2.35 ± 4.54 mmHg, and 2.21 ± 4.36 mmHg, respectively, meeting the standards set by the Association for the Advancement of Medical Instrumentation (AAMI), and achieving Grade A according to the British Hypertension Society (BHS) Standard for SBP and DBP predictions. Through ablation experiments and comparisons with other state-of-the-art methods, the effectiveness of DSRUnet in blood pressure prediction tasks, particularly for SBP, which generally yields poor prediction results, was significantly higher. The experimental results demonstrate that the DSRUnet model can accurately utilize PPG signals for real-time continuous blood pressure prediction and obtain high-quality and high-precision blood pressure prediction waveforms. Due to its non-invasiveness, continuity, and clinical relevance, the model may have significant implications for clinical applications in hospitals and research on wearable devices in daily life.

Diagnostic Accuracy of Office Blood Pressure Measurement and Home Blood Pressure Monitoring for Hypertension Screening Among Adults: Results From the IDH Study

BACKGROUND

Using high awake blood pressure (BP; ≥130/80 mm Hg) on ambulatory BP monitoring (ABPM) as a reference, the purpose of this study was to determine the accuracy of high office BP (≥130/80 mm Hg) at an initial visit and high confirmatory office BP (≥130/80 mm Hg), and separately, high home BP (≥130/80 mm Hg) among participants with high office BP (≥130/80 mm Hg) at an initial office visit.

METHODS AND RESULTS

The accuracy of office BP measurements using the oscillometric method for detecting high BP on ABPM was determined among 379 participants with complete office BP and ABPM data in the IDH (Improving the Detection of Hypertension) study. For detecting high BP on ABPM, the accuracy of high confirmatory office BP using the oscillometric method and, separately, high home BP was also determined among the subgroup of 122 participants with high office BP at an initial visit and complete home BP monitoring data. High office BP had moderate sensitivity (0.61 [95% CI, 0.53-0.68]) and high specificity (0.85 [95% CI, 0.80-0.90]) for high awake BP. High confirmatory office BP and high home BP had moderate sensitivity (0.69 [95% CI, 0.59-0.79] and 0.79 [95% CI, 0.71-0.87], respectively) and low and moderate specificity (0.44 [95% CI, 0.27-0.61] and 0.72 [95% CI, 0.56-0.88], respectively).

CONCLUSIONS

Many individuals with high BP on ABPM do not have high office BP. Confirmatory office BP and home blood pressure monitoring also had limited ability to identify individuals with high BP on ABPM.

Predicting Out-of-Office Blood Pressure in a Diverse US Population

BACKGROUND

The PRedicting Out-of-OFfice Blood Pressure (PROOF-BP) algorithm accurately predicted out-of-office blood pressure (BP) among adults with suspected high BP in the United Kingdom and Canada. We tested the accuracy of PROOF-BP in a diverse US population and evaluated a newly developed US-specific algorithm (PROOF-BP-US).

METHODS

Adults with ≥2 office BP readings and ≥10 awake BP readings on 24-hour ambulatory BP monitoring from 4 pooled US studies were included. We compared mean awake BP with predicted out-of-office BP using PROOF-BP and PROOF-BP-US. Our primary outcomes were hypertensive out-of-office systolic BP (SBP) ≥130 mm Hg and diastolic BP (DBP) ≥80 mm Hg.

RESULTS

We included 3,058 adults, mean (SD) age was 52.0 (11.9) years, 38% were male, and 54% were Black. The area under the receiver-operator characteristic (AUROC) curve (95% confidence interval) for hypertensive out-of-office SBP was 0.81 (0.79-0.82) and DBP was 0.76 (0.74-0.78) for PROOF-BP. For PROOF-BP-US, the AUROC curve for hypertensive out-of-office SBP was 0.82 (0.81-0.83) and for DBP was 0.81 (0.79-0.83). The optimal predicted out-of-office BP ranges for out-of-office BP measurement referral were 120-134/75-84 mm Hg for PROOF-BP and 125-134/75-84 mm Hg for PROOF-BP-US. The 2017 American College of Cardiology/American Heart Association BP guideline (referral range 130-159/80-99 mm Hg) would refer 93.1% of adults not taking antihypertensive medications with office BP ≥130/80 mm Hg in the National Health and Nutrition Examination Survey for out-of-office BP measurement, compared with 53.1% using PROOF-BP and 46.8% using PROOF-BP-US.

CONCLUSIONS

PROOF-BP and PROOF-BP-US accurately predicted out-of-office hypertension in a diverse sample of US adults.

Cost-Effectiveness of Masked Hypertension Screening and Treatment in US Adults With Suspected Masked Hypertension: A Simulation Study

BACKGROUND

Recent US blood pressure (BP) guidelines recommend using ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM) to screen adults for masked hypertension. However, limited evidence exists of the expected long-term effects of screening for and treating masked hypertension.

METHODS

We estimated the lifetime health and economic outcomes of screening for and treating masked hypertension using the Cardiovascular Disease (CVD) Policy Model, a validated microsimulation model. We simulated a cohort of 100,000 US adults aged ≥20 years with suspected masked hypertension (i.e., office BP 120-129/<80 mm Hg, not taking antihypertensive medications, without CVD history). We compared usual care only (i.e., no screening), usual care plus ABPM, and usual care plus HBPM. We projected total direct healthcare costs (2021 USD), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios. Future costs and QALYs were discounted 3% annually. Secondary outcomes included CVD events and serious adverse events.

RESULTS

Relative to usual care, adding masked hypertension screening and treatment with ABPM and HBPM was projected to prevent 14.3 and 20.5 CVD events per 100,000 person-years, increase the proportion experiencing any treatment-related serious adverse events by 2.7 and 5.1 percentage points, and increase mean total costs by $1,076 and $1,046, respectively. Compared with usual care, adding ABPM was estimated to cost $85,164/QALY gained. HBPM resulted in lower QALYs than usual care due to increased treatment-related adverse events and pill-taking disutility.

CONCLUSIONS

The results from our simulation study suggest screening with ABPM and treating masked hypertension is cost-effective in US adults with suspected masked hypertension.

Hypertension, its correlates and differences in access to healthcare services by gender among rural Zambian residents: a cross-sectional study

OBJECTIVES

To examine the prevalence of hypertension and access to related healthcare services among rural residents of Mumbwa district in Zambia.

DESIGN

Cross-sectional study with probability cluster sampling.

SETTING

Rural Zambia.

PARTICIPANTS

We recruited 690 residents from Mumbwa district aged 25-64 years who had been living in the study area for ≥6 months and had adopted the lifestyle of the study area. Pregnant women and women who had given birth in the past 6 months were excluded. The data collection-questionnaire survey and anthropometric and biological measurements-was conducted between May and July 2016.

RESULTS

In the overall sample, 39.7% and 33.5% of the men and women had hypertension (systolic blood pressure (BP)≥140 or diastolic BP ≥90 mm Hg), respectively. Among the participants without a previous diagnosis of hypertension, 30.3% presented with hypertension at the time of measurement. In the multivariable analysis, alcohol intake and urban residence in men, and older age group, higher education and body mass index ≥25 kg/m² in women were significantly associated with hypertension. Among the 21.8% who never had their BP measured, 83.8% were men; among these men, older age (adjusted OR (AOR), 0.43; 95% CI 0.25 to 0.73) and HIV positive status (AOR, 0.37; 95% CI 0.14 to 0.97) were negatively associated, while current smoker status (AOR, 2.09; 95% CI 1.19 to 3.66) was positively associated with the lack of BP measurements.

CONCLUSION

We found that hypertension is prevalent in the target rural area. However, many were not aware of their hypertension status and many never had their BP measured, indicating a serious gap in cardiovascular disease prevention services in Zambia. There is an urgent need for health promotion and screening for hypertension, especially in the primary health services of rural Zambia. Issues related to healthcare accessibility in men require particular attention.

BMI and blood pressure control among United States adults with hypertension

OBJECTIVES

Less than half of United States adults with hypertension have controlled blood pressure (BP). Higher BMI is associated with an increased risk for hypertension but the association between BMI and BP control is not well characterized. We examined hypertension awareness, antihypertensive medication use, and BP control, by BMI category.

METHODS

Data for 3568 United States adults aged at least 18 years with hypertension (BP at least 140/90 mmHg or taking antihypertensive medication) from the 2015 to 2018 National Health and Nutrition Examination Survey were analyzed. BMI was categorized as normal (<25 kg/m2), overweight (25 to <30 kg/m2), class 1 obesity (30 to <35 kg/m2), or class 2 or 3 obesity (≥35 kg/m2). Hypertension awareness and antihypertensive medication use were self-reported. BP control was defined as BP less than 140/90 mmHg using the average of up to three measurements.

RESULTS

Among United States adults with hypertension, 15.6% had normal BMI, 31.3% had overweight, 26.2% had class 1 obesity, and 26.8% had class 2 or 3 obesity. Among those with normal BMI, overweight, class 1 obesity, and class 2 or 3 obesity: 67.9, 76.8, 84.0, and 87.8% were aware they had hypertension, respectively; 88.1, 88.1, 90.9, and 90.2% of those aware were taking antihypertensive medication, respectively; 63.5, 65.9, 71.1, and 64.1% of those taking antihypertensive medication had controlled BP, respectively; and 37.1, 44.3, 53.8, and 50.8% of those with hypertension had controlled BP, respectively.

CONCLUSION

United States adults with hypertension and normal BMI were less likely to be aware they had hypertension and have controlled BP compared with those with overweight or obesity.

Algorithm for diagnosing hypertension using out-of-office blood pressure measurements

The authors developed and validated a diagnostic algorithm using the optimal upper and lower cut‐off values of office and home BP at which ambulatory BP measurements need to be applied. Patients presenting with high BP (≥140/90 mm Hg) at the outpatient clinic were referred to measure office, home, and ambulatory BP. Office and home BP were divided into hypertension, intermediate (requiring diagnosis using ambulatory BP), and normotension zones. The upper and lower BP cut‐off levels of intermediate zone were determined corresponding to a level of 95% specificity and 95% sensitivity for detecting daytime ambulatory hypertension by using the receiver operator characteristic curve. A diagnostic algorithm using three methods, OBP‐ABP: office BP measurement and subsequent ambulatory BP measurements if office BP is intermediate zone; OBP‐HBP‐ABP: office BP, subsequent home BP measurement if office BP is within intermediate zone and subsequent ambulatory BP measurement if home BP is within intermediate zone; and HBP‐ABP: home BP measurement and subsequent ambulatory BP measurements if home BP is within intermediate zone, were developed and validated. In the development population (n = 256), the developed algorithm yielded better diagnostic accuracies than 75.8% (95%CI 70.1–80.9) for office BP alone and 76.2% (95%CI 70.5–81.3) for home BP alone as follows: 96.5% (95%CI: 93.4–98.4) for OBP‐ABP, 93.4% (95%CI: 89.6–96.1) for OBP‐HBP‐ABP, and 94.9% (95%CI: 91.5–97.3%) for HBP‐ABP.  In the validation population (n = 399), the developed algorithm showed similarly improved diagnostic accuracy. The developed algorithm applying ambulatory BP measurement to the intermediate zone of office and home BP improves the diagnostic accuracy for hypertension.

Statistical model building: Background "knowledge" based on inappropriate preselection causes misspecification

Background

Statistical model building requires selection of variables for a model depending on the model’s aim. In descriptive and explanatory models, a common recommendation often met in the literature is to include all variables in the model which are assumed or known to be associated with the outcome independent of their identification with data driven selection procedures. An open question is, how reliable this assumed “background knowledge” truly is. In fact, “known” predictors might be findings from preceding studies which may also have employed inappropriate model building strategies.

Methods

We conducted a simulation study assessing the influence of treating variables as “known predictors” in model building when in fact this knowledge resulting from preceding studies might be insufficient. Within randomly generated preceding study data sets, model building with variable selection was conducted. A variable was subsequently considered as a “known” predictor if a predefined number of preceding studies identified it as relevant.

Results

Even if several preceding studies identified a variable as a “true” predictor, this classification is often false positive. Moreover, variables not identified might still be truly predictive. This especially holds true if the preceding studies employed inappropriate selection methods such as univariable selection.

Conclusions

The source of “background knowledge” should be evaluated with care. Knowledge generated on preceding studies can cause misspecification.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-021-01373-z).

Blood Pressure in Young Adults and Cardiovascular Disease Later in Life

Cardiovascular disease (CVD) mortality has declined markedly over the past several decades among middle-age and older adults in the United States. However, young adults (18-39 years of age) have had a lower rate of decline in CVD mortality. This trend may be related to the prevalence of high blood pressure (BP) having increased among young US adults. Additionally, awareness, treatment, and control of hypertension are low among US adults between 20 and 39 years of age. Many young adults and healthcare providers may not be aware of the impact of high BP during young adulthood on their later life, the associations of BP patterns with adverse outcomes later in life, and benefit-to-harm ratios of pharmacological treatment. This review provides a synthesis of the related resources available in the literature to better understand BP-related CVD risk among young adults and better identify BP patterns and levels during young adulthood that are associated with CVD events later in life, and lastly, to clarify future challenges in BP management for young adults.

Rates, risks and routes to reduce vascular dementia (R4vad), a UK-wide multicentre prospective observational cohort study of cognition after stroke: Protocol

BACKGROUND

Stroke commonly affects cognition and, by definition, much vascular dementia follows stroke. However, there are fundamental limitations in our understanding of vascular cognitive impairment, restricting understanding of prevalence, trajectories, mechanisms, prevention, treatment and patient-service needs.

AIMS

Rates, Risks and Routes to Reduce Vascular Dementia (R4VaD) is an observational cohort study of post-stroke cognition. We aim to recruit a wide range of patients with stroke, presenting to geographically diverse UK hospitals, into a longitudinal study to determine rates of, and risk factors for, cognitive and related impairments after stroke, to assess potential mechanisms and improve prediction models.

METHODS

We will recruit at least 2000 patients within six weeks of stroke with or without capacity to consent and collect baseline demographic, clinical, socioeconomic, lifestyle, cognitive, neuropsychiatric and informant data using streamlined patient-centred methods appropriate to the stage after stroke. We will obtain more detailed assessments at four to eight weeks after the baseline assessment and follow-up by phone and post yearly to at least two years. We will assess diagnostic neuroimaging in all and high-sensitivity inflammatory markers, genetics, blood pressure and diffusion tensor imaging in mechanistic sub-studies.Planned outputs: R4VaD will provide reliable data on long-term cognitive function after stroke, stratified by prior cognition, stroke- and patient-related variables and improved risk prediction. It will create a platform enabling sharing of data, imaging and samples. Participants will be consented for re-contact, facilitating future clinical trials and providing a resource for the stroke and dementia research communities.

Impact of Self-Monitoring of Blood Pressure on Processes of Hypertension Care and Long-Term Blood Pressure Control

Background Self-monitoring of blood pressure (SMBP) improves blood pressure (BP) outcomes at 12-months, but information is lacking on how SMBP affects hypertension care processes and longer-term BP outcomes. Methods and Results We pooled individual participant data from 4 randomized clinical trials of SMBP in the United Kingdom (combined n=2590) with varying intensities of support. Multivariable random effects regression was used to estimate the probability of antihypertensive intensification at 12 months for usual care versus SMBP. Using these data, we simulated 5-year BP control rates using a validated mathematical model. Trial participants were mostly older adults (mean age 66.6 years, SD 9.5), male (53.9%), and predominantly white (95.6%); mean baseline BP was 151.8/85.0 mm Hg. Compared with usual care, the likelihood of antihypertensive intensification increased with both SMBP with feedback to patient or provider alone (odds ratio 1.8, 95% CI 1.2-2.6) and with telemonitoring or self-management (3.3, 2.5-4.2). Over 5 years, we estimated 33.4% BP control (<140/90 mm Hg) with usual care (95% uncertainty interval 27.7%-39.4%). One year of SMBP with feedback to patient or provider alone achieved 33.9% (28.3%-40.3%) BP control and SMBP with telemonitoring or self-management 39.0% (33.1%-45.2%) over 5 years. If SMBP interventions and associated BP control processes were extended to 5 years, BP control increased to 52.4% (45.4%-59.8 %) and 72.1% (66.5%-77.6%), respectively. Conclusions One year of SMBP plus telemonitoring or self-management increases the likelihood of antihypertensive intensification and could improve BP control rates at 5 years; continuing SMBP for 5 years could further improve BP control.

The prevalence of masked hypertension in a group of young healthy soldiers

BACKGROUND

To assess the prevalence of masked hypertension (MH) in young Saudi National Guard soldiers based on 24h ambulatory blood pressure monitoring (ABPM).

METHODS

A prospective study of 196 soldiers, aged between 21-50 years, without a history of hypertension or antihypertensive medication use. Each participant was fitted with a 24h-ABPM. Patients were considered to have MH if the office blood pressure (OBP) was <140/90 mm Hg and the 24h-ABPM average was ≥130/80 mmHg.

RESULTS

The mean age of the MH group was 34.5 years compared to 32.4 years of the normotensive group. By pairing the average OBP with the 24h-ABPM, the prevalence of MH was estimated to be 29/196 (14.8%), with the SBP (systolic blood pressure) and DPB MH (diastolic BP) prevalence 12.8% and 7.7%, respectively. For the systolic BP, the OBP compared with the 24h-ABPM was 120.0±8.1 vs. 134.7±4.5 (P<0.001) and for the diastolic BP, 70.7±7.0 vs. 79.9±4.2 (P<0.001).

CONCLUSIONS

The prevalence of MH among this sample of healthy military soldiers was 14.8%. It is important not to rely solely on the OBP and to consider MH when screening for hypertension in apparently healthy individuals.

Ambulatory blood pressure monitoring in the 21st century

In clinical practice, ambulatory blood pressure monitoring (ABPM) tends to be used solely for diagnosing hypertension, especially to identify white-coat and masked hypertension. However, ABPM can provide additional information to guide the management and drug treatment of hypertension. In this brief review, the general principles governing the use of ABPM in clinical practice, such as the devices and software, recording requirements, the thresholds for the day, night and 24-hour periods and how often to repeat ABPM are summarized. The use of ABPM for diagnosing, determining the efficacy of treatment, and assessing the long-term control of hypertension are discussed.

Validation of clinical prediction models: what does the "calibration slope" really measure?

BACKGROUND AND OBJECTIVES

Definitions of calibration, an aspect of model validation, have evolved over time. We examine use and interpretation of the statistic currently referred to as the calibration slope.

METHODS

The history of the term "calibration slope", and usage in papers published in 2016 and 2017, were reviewed. The behaviour of the slope in illustrative hypothetical examples and in two examples in the clinical literature was demonstrated.

RESULTS

The paper in which the statistic was proposed described it as a measure of "spread" and did not use the term "calibration". In illustrative examples, slope of 1 can be associated with good or bad calibration, and this holds true across different definitions of calibration. In data extracted from a previous study, the slope was correlated with discrimination, not overall calibration. Many authors of recent papers interpret the slope as a measure of calibration; a minority interpret it as a measure of discrimination or do not explicitly categorise it as either. Seventeen of thirty-three papers used the slope as the sole measure of calibration.

CONCLUSION

Misunderstanding about this statistic has led to many papers in which it is the sole measure of calibration, which should be discouraged.

Ambulatory monitoring unmasks hypertension among kidney transplant patients: single center experience and review of the literature

Background

Disagreements between clinic and ambulatory blood pressure (BP) measurements are well-described in the general population. Though hypertension is frequent in renal transplant recipients, only a few studies address the clinic-ambulatory discordance in this population. We aimed to describe the difference between clinic and ambulatory BP in kidney transplant patients at our institution.

Methods

We compared the clinic and ambulatory BP of 76 adult recipients of a kidney allograft followed at our transplant center and investigated the difference between these methods, considering confounding by demographic and clinical variables.

Results

Clinic systolic BP (SBP) and diastolic BP (DBP) were 128 ± 13/79 ± 9 mmHg. Awake SBP and DBP were 147 ± 18/85 ± 10 mmHg. The clinic-minus-awake SBP and DBP differences were − 18 and − 6 mmHg, respectively. The negative clinic-awake ΔSBP was more pronounced at age > 60 years (p = 0.026) and with tacrolimus use compared to cyclosporine (p = 0.046). Sleep SBP and DBP were 139 ± 21/78 ± 11 mmHg. A non-dipping sleep BP pattern was noted in 73% of patients and was associated with tacrolimus use (p = 0.020).

Conclusions

Our findings suggest pervasive underestimation of BP when measured in the kidney transplant clinic, emphasizes the high frequency of a non-dipping pattern in this population and calls for liberal use of ambulatory BP monitoring to detect and manage hypertension.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1442-7) contains supplementary material, which is available to authorized users.

[Diagnostic validity of the isolated measurement of blood pressure in the community pharmacy. Optimum cut-off points]

INTRODUCTION AND OBJECTIVES

The aim of this study is to determine the diagnostic validity of blood pressure measurement in the community pharmacy (CPBP), and to set the cut-off points in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in order to maximise the aforementioned validity, using 24 hour ambulatory blood pressure monitoring (ABPM) as the reference method.

MATERIAL AND METHODS

A cross-sectional study with consecutive selection of patient users of the community pharmacy in Andalusia. The CPBP was measured, followed by 24-hour ABPM, which assessed the diagnostic validity of the CPBP. The AUC of the ROC curve was also calculated for SBP and DBP, along with the positive and negative predictive values, for different prevalences and the variation of sensitivity and specificity for the different cut-off points for SBP/DBP.

RESULTS

A total of 167 community pharmacy participated with 1,170 patients, of which 1,110 were valid. The CPBP showed a sensitivity of 60.41% (95% CI: 56.40-64.29), and a specificity of the 79.77% (95% CI: 76.12-82.99), a positive predictive values of 76.96% (95% CI: 72.89-80.57), and a negative predictive values of 64.31% (95% CI: 60.55%-67.90%). By using the ROC curve method, the optimal cut-off points are 134/81mm Hg, the point where the sensitivity and specificity and are balanced and the Youden index is maximised.

CONCLUSIONS

The sensitivity is relatively low. To improve it tends to lower the cut-off points of SBP and DBP. The calculated optimum is 134/81mm Hg. This provides data on the desirability to review the current cut-off points (140/90), as proposed by the ACC/AHA 2017.

Prospective external validation of the Predicting Out-of-OFfice Blood Pressure (PROOF-BP) strategy for triaging ambulatory monitoring in the diagnosis and management of hypertension: observational cohort study

OBJECTIVE

To prospectively validate the Predicting Out-of-OFfice Blood Pressure (PROOF-BP) algorithm to triage patients with suspected high blood pressure for ambulatory blood pressure monitoring (ABPM) in routine clinical practice.

DESIGN

Prospective observational cohort study.

SETTING

10 primary care practices and one hospital in the UK.

PARTICIPANTS

887 consecutive patients aged 18 years or more referred for ABPM in routine clinical practice. All underwent ABPM and had the PROOF-BP applied.

MAIN OUTCOME MEASURES

The main outcome was the proportion of participants whose hypertensive status was correctly classified using the triaging strategy compared with the reference standard of daytime ABPM. Secondary outcomes were the sensitivity, specificity, and area under the receiver operator characteristic curve (AUROC) for detecting hypertension.

RESULTS

The mean age of participants was 52.8 (16.2) years. The triaging strategy correctly classified hypertensive status in 801 of the 887 participants (90%, 95% confidence interval 88% to 92%) and had a sensitivity of 97% (95% confidence interval 96% to 98%) and specificity of 76% (95% confidence interval 71% to 81%) for hypertension. The AUROC was 0.86 (95% confidence interval 0.84 to 0.89). Use of triaging, rather than uniform referral for ABPM in routine practice, would have resulted in 435 patients (49%, 46% to 52%) being referred for ABPM and the remainder managed on the basis of their clinic measurements. Of these, 69 (8%, 6% to 10%) would have received treatment deemed unnecessary had they received ABPM.

CONCLUSIONS

In a population of patients referred for ABPM, this new triaging approach accurately classified hypertensive status for most, with half the utilisation of ABPM compared with usual care. This triaging strategy can therefore be recommended for diagnosis or management of hypertension in patients where ABPM is being considered, particularly in settings with limited resources.

A Comparison of the Diagnostic Accuracy of Common Office Blood Pressure Measurement Protocols

BACKGROUND

The optimal approach to measuring office blood pressure (BP) is uncertain. We aimed to compare BP measurement protocols that differed based on numbers of readings within and between visits and by assessment method.

METHODS

We enrolled a sample of 707 employees without known hypertension or cardiovascular disease, and obtained 6 standardized BP readings during each of 3 office visits at least 1 week apart, using mercury sphygmomanometer and BpTRU oscillometric devices (18 readings per participant) for a total of 12,645 readings. We used confirmatory factor analysis to develop a model estimating "true" office BP that could be used to compare the probability of correctly classifying participants' office BP status using differing numbers and types of office BP readings.

RESULTS

Averaging 2 systolic BP readings across 2 visits correctly classified participants as having BP below or above the 140 mm Hg threshold at least 95% of the time if the averaged reading was <134 or >149 mm Hg, respectively. Our model demonstrated that more confidence was gained by increasing the number of visits with readings than by increasing the number of readings within a visit. No clinically significant confidence was gained by dropping the first reading vs. averaging all readings, nor by measuring with a manual mercury device vs. with an automated oscillometric device.

CONCLUSIONS

Averaging 2 BP readings across 2 office visits appeared to best balance increased confidence in office BP status with efficiency of BP measurement, though the preferred measurement strategy may vary with the clinical context.

Current practice of usual clinic blood pressure measurement in people with and without diabetes: a survey and prospective 'mystery shopper' study in UK primary care

OBJECTIVES

Hypertension trials and epidemiological studies use multiple clinic blood pressure (BP) measurements at each visit. Repeat measurement is also recommended in international guidance; however, little is known about how BP is measured routinely. This is important for individual patient management and because routinely recorded readings form part of research databases. We aimed to determine the current practice of BP measurement during routine general practice appointments.

DESIGN

(1) An online cross-sectional survey and (2) a prospective 'mystery shopper' study where patients agreed to report how BP was measured during their next appointment.

SETTING

Primary care.

PARTICIPANTS

Patient charity/involvement group members completing an online survey between July 2015 and January 2016. 334 participants completed the prospective study (51.5% male, mean age=59.3 years) of which 279 (83.5%) had diabetes.

PRIMARY OUTCOME

Proportion of patients having BP measured according to guidelines.

RESULTS

217 participants with (183) and without diabetes (34) had their BP measured at their last appointment. BP was measured in line with UK guidance in 63.7% and 60.0% of participants with and without diabetes, respectively. Initial pressures were significantly higher in those who had their BP measured more than once compared with only once (p=0.016/0.089 systolic and p<0.001/p=0.022 diastolic, in patients with/without diabetes, respectively).

CONCLUSIONS

Current practice of routine BP measurement in UK primary care is often concordant with guidelines for repeat measurement. Further studies are required to confirm findings in broader populations, to confirm when a third repeat reading is obtained routinely and to assess adherence to other aspects of BP measurement guidance.

Predicting Out-of-Office Blood Pressure in the Clinic for the Diagnosis of Hypertension in Primary Care: An Economic Evaluation

Clinical guidelines in the United States and United Kingdom recommend that individuals with suspected hypertension should have ambulatory blood pressure (BP) monitoring to confirm the diagnosis. This approach reduces misdiagnosis because of white coat hypertension but will not identify people with masked hypertension who may benefit from treatment. The Predicting Out-of-Office Blood Pressure (PROOF-BP) algorithm predicts masked and white coat hypertension based on patient characteristics and clinic BP, improving the accuracy of diagnosis while limiting subsequent ambulatory BP monitoring. This study assessed the cost-effectiveness of using this tool in diagnosing hypertension in primary care. A Markov cost-utility cohort model was developed to compare diagnostic strategies: the PROOF-BP approach, including those with clinic BP ≥130/80 mm Hg who receive ambulatory BP monitoring as guided by the algorithm, compared with current standard diagnostic strategies including those with clinic BP ≥140/90 mm Hg combined with further monitoring (ambulatory BP monitoring as reference, clinic, and home monitoring also assessed). The model adopted a lifetime horizon with a 3-month time cycle, taking a UK Health Service/Personal Social Services perspective. The PROOF-BP algorithm was cost-effective in screening all patients with clinic BP ≥130/80 mm Hg compared with current strategies that only screen those with clinic BP ≥140/90 mm Hg, provided healthcare providers were willing to pay up to £20 000 ($26 000)/quality-adjusted life year gained. Deterministic and probabilistic sensitivity analyses supported the base-case findings. The PROOF-BP algorithm seems to be cost-effective compared with the conventional BP diagnostic options in primary care. Its use in clinical practice is likely to lead to reduced cardiovascular disease, death, and disability.

Blood Pressure Measurement Anno 2016

The rational management of hypertension (HT) inevitably starts with accurate measurement of blood pressure (BP). The recently published Systolic Blood Pressure Intervention Trial implemented automated office BP measurement. However, event-driven studies have overwhelmingly indicated that out-of-the-office BP monitoring is a prerequisite for risk stratification and for identifying the need of initiating or adjusting antihypertensive drug treatment. 24-Hour ambulatory BP monitoring is the preferred method of BP measurement and addresses major issues not covered by conventional or automated office BP measurement or home BP monitoring, such as reliably diagnosing nocturnal HT (the time window of the day during which BP is most predictive of adverse cardiovascular outcome), hypotension, or masked HT, a condition that affects 15% of the general populations and carries a risk equal to that of HT on both office and out-of-the-office BP measurement. Moreover, 24-hour ambulatory BP monitoring is cost-effective. Outcome-driven criteria support single BP thresholds that can be applied in both sexes and across the age range. In conclusion, the overall evidence now overwhelmingly shows that ambulatory BP monitoring is mandatory for the proper management of HT. Health care providers should therefore facilitate access to this technique in both primary and specialized care.

Prospective Register Of patients undergoing repeated OFfice and Ambulatory Blood Pressure Monitoring (PROOF-ABPM): protocol for an observational cohort study

INTRODUCTION

The diagnosis and management of hypertension depends on accurate measurement of blood pressure (BP) in order to target antihypertensive treatment appropriately. Most BP measurements take place in a clinic setting, but it has long been recognised that readings taken out-of-office (via home or ambulatory monitoring) estimate true underlying BP more accurately. Recent studies have shown that the change in clinic BP over multiple readings is a significant predictor of the difference between clinic and out-of-office BP. Used in combination with patient characteristics, this change has been shown to accurately predict a patient's out-of-office BP level. The present study proposes to collect real-life BP data to prospectively validate this new prediction tool in routine clinical practice.

METHODS AND ANALYSIS

A prospective, multicentre observational cohort design will be used, recruiting patients from primary and secondary care. All patients attending participating centres for ambulatory BP monitoring will be eligible to participate. Anonymised clinical data will be collected from all eligible patients, who will be invited to give informed consent to permit identifiable data to be collected for data linkage to external outcome registries. Descriptive statistics will be used to calculate the sensitivity, specificity, positive and negative predictive values of the out-of-office BP prediction tool. Area under the receiver operator characteristic curve statistics will be used to examine model performance.

ETHICS AND DISSEMINATION

Ethical approval for this study has been obtained from the National Research. Ethics Service Committee South Central-Oxford A (reference; 15/SC/0184), and site-specific R&D approval has been acquired from the relevant NHS trusts. All findings will be presented at relevant conferences and published in peer-reviewed journals, on the study website and disseminated in lay and social media where appropriate.