History and evolution of blood pressure measurement.

Hypertension is the leading cause of morbidity and mortality worldwide. Hypertension mostly accompanies no symptoms, and therefore blood pressure (BP) measurement is the only way for early recognition and timely treatment. Methods for BP measurement have a long history of development and improvement. Invasive method via arterial cannulation was first proven possible in the 1800's. Subsequent scientific progress led to the development of the auscultatory method, also known as Korotkoff' sound, and the oscillometric method, which enabled clinically available BP measurement. However, hypertension management status is still poor. Globally, less than half of adults are aware of their hypertension diagnosis, and only one-third of them being treated are under control. Novel methods are actively investigated thanks to technological advances such as sensors and machine learning in addition to the clinical needs for easier and more convenient BP measurement. Each method adopts different technologies with its own specific advantages and disadvantages. Promises of novel methods include comprehensive information on out-of-office BP capturing dynamic short-term and long-term fluctuations. However, there are still pitfalls such as the need for regular calibration since most novel methods capture relative BP changes rather than an absolute value. In addition, there is growing concern on their accuracy and precision as conventional validation protocols are inappropriate for cuffless continuous methods. In this article, we provide a comprehensive overview of the past and present of BP measurement methods. Novel and emerging technologies are also introduced with respect to their potential applications and limitations.

Performance of the Aktiia optical blood pressure measurement device in the elderly: a comparison with double blinded auscultation in different body positions.

BACKGROUND: Accurate blood pressure (BP) measurement is essential for the correct diagnosis and management of hypertension (HTN) especially in the elderly population. As with of all BP devices, the accuracy of cuffless devices must be verified. This study (NCT04027777) aimed to evaluate the performance of a wrist cuffless optical BP device in an elderly population cohort in different body positions with auscultation as the reference measurement. DESIGN AND METHODS: Patients aged 65-85 years with different BP categories but without diabetes were recruited. After an initial calibration based on auscultatory measurements, BP estimation from the Aktiia Bracelet (Aktiia SA, Switzerland) were compared to reference double-blinded auscultatory measurements in sitting, standing and lying positions on four separate visits distributed over one month. In the absence of a universal standard for cuffless BP device at the time of the study, modified ISO81060-2 criteria were used for performance analysis. RESULTS: Thirty-five participants were included in the analysis fulfilling the inclusion requirements of ISO 81060-2. A total of 469 paired measurements were obtained with overall 83% acceptance rate. Differences (mean ± SD)   between Aktiia Bracelet and auscultation for systolic BP were -0.26 ± 9.96 mmHg for all body positions aggregated (sitting 1.23 ± 7.88 mmHg, standing -1.81 ± 11.11 mmHg, lying -1.8 ± 9.96 mmHg). Similarly, differences for diastolic BP were -0.75 ± 7.0 mmHg (0.2 ± 5.55 mmHg, -5.35 ± 7.75 mmHg and -0.94 ± 7.47 mmHg, respectively). Standard deviation of the averaged differences per subject for systolic/diastolic BP was 3.8/2.5 mmHg in sitting and 4.4/3.7 mmHg for all body positions aggregated. CONCLUSIONS: Overall, this study demonstrates a similar performance of the Aktiia Bracelet compared to auscultation in an elderly population in body positions representative of daily activities. The use of more comfortable, non-invasive, and non-occlusive BP monitors during long periods may facilitate e-health and may contribute to better management of HTN, including diagnosis and treatment of HTN, in the elderly.

Accuracy of blood pressure measurements is essential in the diagnosis and the follow-up of patients with high blood pressure. As with any blood pressure measuring device, a validation is necessary. In this study including a elderly population, we compared values obtained by the cuffless Aktiia Bracelet (Aktiia SA, Switzerland) after an initial calibration with the reference auscultatory method during four separate study days distributed over one month. We show that the accuracy of the Aktiia Bracelet is similar to auscultation. The accuracy varies depending on the position in which the measurement is performed. Overall, the accuracy is not modified by a higher age category. The use of a cuffless device in the elderly population characterized by high prevalence of hypertension may facilitate the follow-up of blood pressure with more comfort and minimal constraints.

Agreement of Oscillometric and Auscultatory blood pressure measurement methods: An ambulance noise simulation study.

OBJECTIVE: Although noise is known to negatively affect blood pressure (BP) measurements, its impact on different BP measurement methods remains unclear. The aim of this study is to compare the agreement of oscillometric and auscultatory BP measurement methods under in-ambulance noise levels. METHODS: This method-comparison study was conducted on 50 healthy volunteers in a tertiary emergency department (ED). Participants were divided into two groups of 25, and BP was measured using auscultatory and oscillometric methods in noisy and ambient environments by 2 emergency medicine technicians (EMT). The primary object of the study was to compare the agreement of auscultatory mercury sphygmomanometers and automated auscillometric BP measurements in ambient and noisy environments. RESULTS: We examined the agreement between auscultative and oscillometric measurements of BP conducted in an ambient environment (46.75 [IQR (41.2--55.18)] dB) and found that both systolic and diastolic BP were within the level of agreement (LoA) established before the study (systolic BP [-13.96 to 8.48 mmHG], diastolic BP [-7.44 to 8.08 mmHg]); whereas, in noisy environment (92.35 [IQR 88-96.55] dB) both systolic and diastolic BP were outside the range of LoA (systolic BP [-37.77 to 9.94 mmHg], diastolic BP [-21.73 to 16.37 mmHg]). Additionally, we found that in ambient environments, concordance correlation coefficients were higher than in noisy environments (0.943 [0.906-0.966], 0.957 [0.93-0.974]; 0.574 [0.419-0.697], 0.544 [0.326-0.707]; systolic and diastolic BP, respectively). CONCLUSION: The results of this study demonstrate that noise significantly affects the agreement between oscillometric and auscultatory blood pressure measurement methods.

Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit.

Background: The multiparameter monitor (MPM) is replacing mercury column sphygmomanometers (MCS) in acute care settings. However, data on the former's accuracy in critically ill children are scarce and mostly extrapolated from adults. We compared non-invasive blood pressure (NIBP) measurements by MPMs with MCS in pediatric intensive care unit (PICU). Patients: Adequately sedated and hemodynamically stabilized children (age, 1-144 months) were prospectively enrolled. Materials and methods: Three NIBP measurements were obtained from MCS (Diamond®, India) and MPM (Intellivue MX800® or Ultraview SL®) in rapid succession in the upper limb resting in supine position. Respective three measurements were averaged to obtain a paired set of NIBP readings, one each from MCS and MPM. Such readings were obtained thrice a day. NIBP readings were then compared, and agreement was assessed. Results: From 39 children [median age (IQR), 30 (10-72) months], 1,690 sets of NIBP readings were obtained. A-third of readings were from infants and children >96 months, while 383 (22.6%) readings were from patients on inotropes. Multiparameter monitors gave significantly higher NIBP readings compared to MCS [median systolic blood pressure (SBP), 6.5 (6.4-6.7 mm Hg); diastolic blood pressure (DBP), 4.5 (4.3-4.6 mm Hg); mean arterial pressure (MAP), 5.3 (5.1-5.4 mm Hg); p < 0.05]. It was consistent across age, gender, and critical care characteristics. Multiparameter monitors overestimated SBP in 80% of readings beyond the maximal clinically acceptable difference (MCAD). Conclusions: Non-invasive blood pressure readings from MCS and MPMs are not interchangeable; SBP was 6-7 mm Hg higher with the latter. Overestimation beyond MCAD was overwhelming. Caution is required while classifying systolic hypotension with MPMs. Confirmation with auscultatory methods is advisable. More studies are required to evaluate currently available MPMs in different pediatric age groups. How to cite this article: Khan AA, Gupta PK, Baranwal AK, Jayashree M, Sahoo T. Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit. Indian J Crit Care Med 2023;27(3):212-221.

George Phillip Cammann (1804-1863): A physician's contribution to the modern stethoscope and auscultatory percussion.

In the middle third of the 19th century, George Phillip Cammann became known for the stethoscope improvement that came to bear his name and for the development of the then-popular diagnostic technique of auscultatory percussion. During his postgraduate training at the Paris hospitals in 1828-1830, he acquired a special interest in auscultation while attending lectures given by a friend and colleague of Laennec's, French physician Pierre-Charles-Alexandre Louis (1787-1872). In his New York City practice, caring primarily for the working poor, he recognized the need for a better stethoscope and developed a modification that came to bear his name. He conducted research aimed at increasing the accuracy of physical diagnosis by improving and reporting on the technique of auscultatory percussion. An examination of the medical literature, both textbooks and journals, reveals the extent of influence that Cammann had on clinical practice resulting from his contributions to the improvement of the stethoscope and auscultatory percussion.

Blood pressure measurements and hypertension in infants, children, and adolescents: from the postmercury to mobile devices.

A mercury sphygmomanometer (MS) has been the gold standard for pediatric blood pressure (BP) measurements, and diagnosing hypertension is critical. However, because of environmental issues, other alternatives are needed. Noninvasive BP measurement devices are largely divided into auscultatory and oscillometric types. The aneroid sphygmomanometer, the currently used auscultatory method, is inferior to MS in terms of limitations such as validation and regular calibration and difficult to apply to infants, in whom Korotkoff sounds are not audible. The oscillometric method uses an automatic device that eliminates errors caused by human observers and has the advantage of being easy to use; however, owing to its measurement accuracy issues, the development of an international validation protocol for children is important. The hybrid method, which combines the auscultatory and electronic methods, solves some of these problems by eliminating the observer bias of terminal digit preference while maintaining measurement accuracy; however, the auscultatory method remains limited. As the age-related characteristics of the pediatric group are heterogeneous, it is necessary to reconsider the appropriate BP measurement method suitable for this indication. In addition, the mobile application-based BP measurement market is growing rapidly with the development of smartphone applications. Although more research is still needed on their accuracy, many experts expect that mobile application-based BP measurement will effectively reduce medical costs due to increased ease of access and early BP management.

Comparing Intra-Arterial, Auscultatory, and Oscillometric Measurement Methods for Arterial Blood Pressure.

AIM: This study aimed to compare the measurement results of arterial blood pressure obtained through intra-arterial, auscultatory, and oscillometric methods. METHOD: This prospective and descriptive study was conducted with 180 patients hospitalized in the intensive care units of cardiovascular surgery and anesthesia. Arterial blood pressures of the patients in the study were measured with 3 methods, and the mean arterial pressure values obtained by each method were analyzed to find out whether they were different or consistent. RESULTS: The average systolic blood pressure value using the intra-arterial method was found to be 125.47 ± 21.39 mm Hg, and the average of diastolic blood pressure measurement obtained using the oscillometric method was the highest (73.91 ± 10.62 mm Hg). The highest correlation was seen between the arterial BP measurements of the intra-arterial and auscultatory methods (systolic [0.96] and diastolic [0.90]). According to the British and Irish Hypertension Society protocol, a very good agreement between the diastolic blood pressure values and a good agreement between the systolic blood pressure values were obtained. CONCLUSION: The measurement results obtained through the auscultatory method more consistent with the results obtained through the intra-arterial method compared with those obtained using the oscillometric method.

Effects of measurement intervals on the values of repeated auscultatory blood pressure measurements.

Objective: For repeated measurements of blood pressure (BP) using the auscultatory method, current guidelines recommend intervals of 1-2 minutes; however, evidence to support this recommendation is insufficient. In the present study, the effects of intervals among repeated BP measurements using the auscultatory method were evaluated.Methods: Systolic and diastolic BPs were measured using the auscultatory method in 37 participants. The measurements were repeated 5 times each at intervals of 15, 30, 60, 90, and 120 seconds. The changes in the BP along with the increasing the number of repetitions were assessed at each measurement interval using a linear mixed model.Results: With an increasing number of measurements, the systolic and diastolic BPs showed significant progressive decrease and increase (p < 0.05), respectively, when the measurement interval was 15 seconds. However, the precision of BP measurements was not affected by performing the measurements at intervals of 30 seconds or longer.Conclusion: Repeated BP measurements using the auscultatory method need to have an interval of at least 30 seconds, which is shorter than the intervals recommended by the current guidelines.

Experience of auscultatory percussion for vertebral compression fracture / 全日本鍼灸学会雑誌

A vertebral compression fracture is a red flag for low back pain. The closed-fist percussion sign is a useful physical examination, but there is a possibility of misdiagnosis. A 58-year-old woman complaining of low back pain with suddenly developed pain at rest. Physical examination using x-rays and closed-fist percussion sign were negative, but auscultatory percussion was positive. As a result, vertebral compression fracture was diagnosed by magnetic resonance imaging (MRI). Auscultatory percussion is a method that can determine a vertebral compression fracture without causing pain, and is necessary to improve accuracy in the future.

Deep learning-based automatic blood pressure measurement: evaluation of the effect of deep breathing, talking and arm movement.

Objectives: It is clinically important to evaluate the performance of a newly developed blood pressure (BP) measurement method under different measurement conditions. This study aims to evaluate the performance of using deep learning-based method to measure BPs and BP change under non-resting conditions.Materials and methods: Forty healthy subjects were studied. Systolic and diastolic BPs (SBPs and DBPs) were measured under four conditions using deep learning and manual auscultatory method. The agreement between BPs determined by the two methods were analysed under different conditions. The performance of using deep learning-based method to measure BP changes was finally evaluated.Results: There were no significant BPs differences between two methods under all measurement conditions (all p > .1). SBP and DBP measured by deep learning method changed significantly in comparison with the resting condition: decreased by 2.3 and 4.2 mmHg with deeper breathing (both p < .05), increased by 3.6 and 6.4 mmHg with talking, and increased by 5.9 and 5.8 mmHg with arm movement (all p < .05). There were no significant differences in BP changes measured by two methods (all p > .4, except for SBP change with deeper breathing).Conclusion: This study demonstrated that the deep learning method could achieve accurate BP measurement under both resting and non-resting conditions.Key messagesAccurate and reliable blood pressure measurement is clinically important. We evaluated the performance of our developed deep learning-based blood pressure measurement method under resting and non-resting measurement conditions.The deep learning-based method could achieve accurate BP measurement under both resting and non-resting measurement conditions.

To what extent can the chosen blood pressure measurement technique affect the outcomes of an observational survey?

Aim: We analyzed to what extent measurement protocol influenced individual blood pressure (BP) and achievement of treatment target in patients with coronary heart disease. Methods: In a subsample of Czech EUROASPIRE III-V survey participants (n = 913), we compared the per-protocol BP measurement (by automated oscillometric device OMRON at the beginning of survey procedure) with control auscultatory measurement (by physician during interview). Results: Per-protocol approach produced significantly (p < 0.0001) higher BP values (by 9/6 mmHg in median) than auscultatory measurements and led to markedly higher proportion of patients over target BP (less than 140/90 mmHg; 59.3 vs 34.9% [p < 0.0001], per-protocol vs auscultatory technique, respectively). Conclusion: Per-protocol oscillometric technique was not equivalent to conventional auscultatory measurement and seriously over-rated the real nonachievement of BP target in observational surveys.

Factors influencing the accuracy of non-invasive blood pressure measurements in patients admitted for cardiogenic shock.

BACKGROUND: Although invasively measured blood pressure (invBP) is regarded as a "gold standard" in critically ill cardiac patients, the non-invasive BP is still widely used, at least at the initiation of medical care. The erroneous interpretation of BP can lead to clinical errors. We therefore investigated the agreement of both methods with respect to some common clinical situation. METHODS: We included 85 patients hospitalized for cardiogenic shock. We measured BP every 6 h for the first 72 h of hospitalization, in all patients. Each set of BP measurements included two invasive (invBP), two auscultatory (auscBP), and two oscillometric (oscBP) BP measurements. InvBP was considered as a gold standard. Mean non-invasive arterial pressure (MAP) was calculated as (diastolic pressure + (pulse pressure ÷ 3)). We used Bland-Altman analysis and we calculated concordance correlation coefficients to assess agreement between different BP methods. RESULTS: We obtained 967 sets of BP measurements. AuscMAP and oscMAP were on average only 0.4 ± 8.2 and 1.8 ± 8.5 mmHg higher than invMAP, respectively. On the other hand, auscSBP and oscSBP were on average - 6.1 ± 11.4 and - 4.1 ± 9.8 mmHg lower than invSBP, respectively. However, the mean differences and variability for systolic and diastolic BP variability were large; the 2 standard deviation differences were ± 24 and 18 mmHg. In hypotension, non-invasive BP tended to be higher than invBP while the opposite was true for high BP values. Clinical conditions associated with hypotension generally worsened the accuracy of non-invasive MAP. CONCLUSIONS: Mean arterial pressure measured non-invasively appears to be in good agreement with invasive MAP in patients admitted for cardiogenic shock. Several clinical associated with hypotension can affect accuracy of non-invasive measurement. Auscultatory and oscillometric measurements had similar accuracy even in patients with arrhythmia.

A novel deep learning based automatic auscultatory method to measure blood pressure.

BACKGROUND: It is clinically important to develop innovative techniques that can accurately measure blood pressures (BP) automatically. OBJECTIVES: This study aimed to present and evaluate a novel automatic BP measurement method based on deep learning method, and to confirm the effects on measured BPs of the position and contact pressure of stethoscope. METHODS: 30 healthy subjects were recruited. 9 BP measurements (from three different stethoscope contact pressures and three repeats) were performed on each subject. The convolutional neural network (CNN) was designed and trained to identify the Korotkoff sounds at a beat-by-beat level. Next, a mapping algorithm was developed to relate the identified Korotkoff beats to the corresponding cuff pressures for systolic and diastolic BP (SBP and DBP) determinations. Its performance was evaluated by investigating the effects of the position and contact pressure of stethoscope on measured BPs in comparison with reference manual auscultatory method. RESULTS: The overall measurement errors of the proposed method were 1.4 ± 2.4 mmHg for SBP and 3.3 ± 2.9 mmHg for DBP from all the measurements. In addition, the method demonstrated that there were small SBP differences between the 2 stethoscope positions, respectively at the 3 stethoscope contact pressures, and that DBP from the stethoscope under the cuff was significantly lower than that from outside the cuff by 2.0 mmHg (P < 0.01). CONCLUSION: Our findings suggested that the deep learning based method was an effective technique to measure BP, and could be developed further to replace the current oscillometric based automatic blood pressure measurement method.

Cardiac Murmurs in Children: A Challenge For The Primary Care Physician.

Congenital heart disease is present in almost 1% of live births and despite current progress in prenatal screening a significant percentage has delayed diagnosis or remain undiagnosed. A cardiac murmur may be the first or unique clinical sign of congenital heart disease in childhood, however, less than 1% of auscultated murmurs are of an organic cause. Distinguishing between an innocent and a pathologic murmur can be challenging and the experience of the examiner is crucial for identifying the distinctive properties of an innocent murmur. Timely diagnosis of underlying cardiovascular pathology is of great significance so that prompt management is provided and morbidity or mortality are restricted. Of similar importance is the avoidance of unnecessary anxiety for the parents and unreasonable referrals to Paediatric Cardiologists. Indications for referral include a medical history suggestive of a cardiac abnormality, such as the presence of relevant symptoms, the identification of abnormal findings on clinical examination, auscultatory findings suggestive of an organic murmur, and very young patient age. ECG and a chest X-ray are not usually part of the diagnostic approach of a child with a cardiac murmur, as they do not increase the success rate of diagnosing heart disease, as compared to a detailed medical history accompanied by a thorough physical examination. In conclusion, the recognition of suspicious distinctive features of cardiac murmurs is crucial and requires skills based on sufficient training and experience.

A convenient method to verify the accuracy of oscillometric blood pressure monitors by the auscultatory method: A smartphone-based app.

It is recommended that oscillometric devices be calibrated by auscultation when first used, but this is difficult in practice. Here, we introduce a smartphone-based technique to verify the accuracy of blood pressure monitors (BPMs). We enrolled 99 consecutive subjects and tested 6 brands of BPMs in this study. During measurements of electronic oscillometric BPMs, Korotkoff sounds were simultaneously collected using a stethoscope head beneath a cuff connected to a smartphone, and an app named Accutension Stetho could then yield an auscultatory BP reading as a reference. Next, differences in BP between the different BPMs and Accutension Stetho were determined. The percentage of BP differences falling within 5, 10, and 15 mm Hg; the mean (MD) value; and the standard deviation (SD) of BP differences and deflation errors were analyzed among all the BPMs. We found that the percentages of SBP differences falling within 5 mm Hg of the 6 BPMs were 80%, 79%, 77%, 72%, 68%, and 63%, in turn. The deflation rates among the 6 BPMs were 2.23, 3.48, 6.10, 2.44, 3.66, and 4.85 mm Hg/beat, respectively. Deflation errors, which were defined as deflation prior to the end of the Korotkoff sounds, existed in 4 BPMs. In conclusion, Accutension Stetho could detect BP differences between oscillometric BPM readings and simultaneous auscultatory readings. Diastolic BP was overestimated when the device deflated prior to the end of the Korotkoff sounds. Using the app, it is possible to evaluate the accuracy of BPMs among the same subjects.

Unobserved automated office BP is similar to other clinic BP measurements: A prospective randomized study.

Results of the SPRINT study have been disputed, based on the assumption that unattended BP measurements do not correlate with usual BP measurements. In this study, the authors investigated the correlation of unattended SPRINT-like measurements with other conventional measurements. All BP measurements were taken with the patient seated in a comfortable chair with the legs uncrossed and not speaking during the procedure. For the purpose of this study, sixty-five patients, mostly male (93%), were recruited from our hypertension clinic and all were on antihypertensive medication (av 3.0 ± 1.1). Patients were at high cardiovascular risk with high rates of comorbidities, av age 68 ± 12 years, 49% with diabetes, 34% with mild CKD (CKD 1-3, average eGFR 55.0 ± 13 mL/min/1.73 m2 ), and 20% with history of stable coronary artery disease. All BP measurements were similar with no statistically significant difference (one-way ANOVA, P = 0.621). Compared to unattended SPRINT BP values (139.77 ± 19.22/75.42 ± 11.72 mm Hg), the clinic BP measurements were numerically slightly higher but with a NS P value (P = 0.163). Similarly, unattended BP measurements were similar to values taken by the clinic physician. In a smaller cohort of 11 patients, the authors compared unobserved vs observed SPRINT-like BP measurements, and in 13 patients, the authors compared unobserved SPRINT-like BP measurements to average home BP measurements (Table 3). There were no significant differences between any of the subgroups (one-way ANOVA, P = 0.816 for systolic and P = 0.803 for diastolic). The authors conclude that unattended BP measurements taken (the SPRINT way) are similar to other conventional office blood pressure measurements.

The accuracy of SpaceLabs 90207 in blood pressure monitoring in patients with atrial fibrillation.

PURPOSE: Irregular heart rhythm in the course of atrial fibrillation (AFib) results in lower blood pressure (BP) measurements reproducibility which is further limited by various BP-monitors used. Therefore the aim of our study was to estimate accuracy of oscillometric BP measurement (SpaceLabs 90207) with reference to mercury manometer-based readings. MATERIAL AND METHODS: Study was performed in 47 hemodynamically stable patients aged 63 ± 12 yo with paroxysmal or persistent AFib, at baseline. Patients were reassessed within one week after effective cardioversion (SR; n = 29). BP was measured using Y-tube connection allowing for simultaneous measurements on the same arm with SpaceLabs 90207 and referral method. Mean values were tested with paired t-tests. Additionally, concordance correlation coefficient (ρc) and Bland-Altman plots were assessed. Results were confronted with AAMI, and ESH-IP criteria. RESULTS: Both during arrhythmia and sinus rhythm diastolic BP differed significantly (Δ = 4.6 ± 6.0 mm Hg, p < .001 and 2.1 ± 4.0 mm Hg, p < .001; for AFib, and SR, respectively), which was not the case for systolic BP. The ρc during arrhythmia equaled 0.89, and 0.75 for systolic and diastolic BP, respectively, which further improved while SR (0.96 and 0.89, respectively). Results confronted against AAMI and ESH-IP showed that all criteria were met except for one (60% vs. required 65% of paired differences of less than 5 mm Hg) during AFib. CONCLUSIONS: The direct comparisons of BP readings allowed to conclude that diastolic blood pressure tended to be slightly overestimated when assessed with SpaceLabs 90207 in patients with both, AFib and SR, which was not a case for systolic BP. When the results were confronted with available validation protocols requirements, all referral criteria were met except for one. Taken together, our results suggest acceptable BP readings dispersion of SpaceLabs 90207 in BP monitoring of patients with both AFib and SR.

An Assessment of the Accuracy of Home Blood Pressure Monitors When Used in Device Owners.

OBJECTIVE: To examine the accuracy of home blood pressure (BP) devices, on their owners, compared to auscultatory reference standard BP measurements. METHODS: Eighty-five consecutive consenting subjects ≥18 years of age, who owned an oscillometric home BP device (wrist or upper-arm device), with BP levels between 80-220/50-120 mm Hg, and with arm circumferences between 25-43 cm were studied. Pregnancy and atrial fibrillation were exclusion criteria. Device measurements from each subject's home BP device were compared to simultaneous 2-observer auscultation using a mercury sphygmomanometer. Between-group mean comparisons were conducted using paired t-tests. The proportion of patients with device-to-auscultatory differences of ≥5, 10, and 15 mm Hg were tabulated and predictors of systolic and diastolic BP differences were identified using linear regression. RESULTS: Mean age was 66.4 ± 11.0 years, mean arm circumference was 32.7 ± 3.7 cm, 54% were female and 78% had hypertension. Mean BPs were 125.7 ± 14.0/73.9 ± 10.4 mm Hg for home BP devices vs. 129.0 ± 14.7/72.9 ± 9.3 for auscultation (difference of -3.3 ± 7.3/0.9 ± 6.1; P values <0.0001 for systolic and 0.17 for diastolic). The proportion of devices with systolic or diastolic BP differences from auscultation of ≥5, 10, and 15 mm Hg was 69%, 29%, and 7%, respectively. Increasing arm circumference was a statistically significant predictor of higher systolic (parameter estimate 0.61 per cm increase; P value 0.004) and diastolic (0.38; 0.03) BP. CONCLUSIONS: Although mean differences from 2-observer auscultation were acceptable, when tested on their owners, most home BP devices were not accurate to within 5 mm Hg. Ensuring acceptable accuracy of the device-owner pairing should be prioritized.