Validation of a new algorithm for the BPM-100 electronic oscillometric office blood pressure monitor

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.

Accuracy of abbreviated protocols for unattended automated office blood pressure measurements, a retrospective study

Background

Blood pressure measurement (BPM) is one of the most often performed procedures in clinical practice, but especially office BPM is prone to errors. Unattended automated office BPM (AOBPM) is somewhat standardised and observer-independent, but time and space consuming. We aimed to assess whether an AOBPM protocol can be abbreviated without losing accuracy.

Design

In our retrospective single centre study, we used all AOBPM (AOBPM protocol of the SPRINT study), collected over 14 months. Three sequential BPM (after 5 minutes of rest, spaced 2 minutes) were automatically recorded with the patient alone in a quiet room resulting in three systolic and diastolic values. We compared the mean of all three (RefProt) with the mean of the first two (ShortProtA) and the single first BPM (ShortProtB).

Results

We analysed 413 AOBPM sets from 210 patients. Mean age was 52±16 years. Mean values for RefProt were 128.3/81.3 mmHg, for ShortProtA 128.4/81.4 mmHg, for ShortProtB 128.8/81.4 mmHg. Mean difference and limits of agreement for RefProt vs. ShortProtA and ShortProtB were -0.1±4.2/-0.1±2.8 mmHg and -0.5±8.1/-0.1±5.3 mmHg, respectively. With ShortProtA, 83% of systolic and 92% of diastolic measurements were within 2 mmHg from RefProt (67/82% for ShortProtB). ShortProtA or ShortProtB led to no significant hypertensive reclassifications in comparison to RefProt (p-values 0.774/1.000/1.000/0.556).

Conclusion

Based on our results differences between the RefProt and ShortProtA are minimal and within acceptable limits of agreement. Therefore, the automated procedure may be shorted from 3 to 2 measurements, but a single measurement is insufficient.

Reliability of Office, Home, and Ambulatory Blood Pressure Measurements and Correlation With Left Ventricular Mass

BACKGROUND

Determining the reliability and predictive validity of office blood pressure (OBP), ambulatory BP (ABP), and home BP (HBP) can inform which is best for diagnosing hypertension and estimating risk of cardiovascular disease.

OBJECTIVES

This study aimed to assess the reliability of OBP, HBP, and ABP and evaluate their associations with left ventricular mass index (LVMI) in untreated persons.

METHODS

The Improving the Detection of Hypertension (IDH) study, a community-based observational study, enrolled 408 participants who had OBP assessed at 3 visits, and completed 3 weeks of HBP, 2 24-h ABP recordings, and a 2-dimensional echocardiogram. Mean age was 41.2 ± 13.1 years, 59.5% were women, 25.5% African American, and 64.0% Hispanic.

RESULTS

The reliability of 1 week of HBP, 3 office visits with mercury sphygmomanometry, and 24-h ABP were 0.938, 0.894, and 0.846 for systolic and 0.918, 0.847, and 0.843 for diastolic BP, respectively. The correlations among OBP, HBP, and ABP, corrected for regression dilution bias, were 0.74 to 0.89. After multivariable adjustment including OBP and 24-h ABP, 10 mm Hg higher systolic and diastolic HBP were associated with 5.07 (standard error [SE]: 1.48) and 3.92 (SE: 2.14) g/m² higher LVMI, respectively. After adjustment for HBP, neither systolic or diastolic OBP nor ABP was associated with LVMI.

CONCLUSIONS

OBP, HBP, and ABP assess somewhat distinct parameters. Compared with OBP (3 visits) or 24-h ABP, systolic and diastolic HBP (1 week) were more reliable and more strongly associated with LVMI. These data suggest that 1 week of HBP monitoring may be the best approach for diagnosing hypertension.

Prevalence of high blood pressure under 2017 ACC/AHA guidelines: a systematic review and meta-analysis

To understand the prevalence of high blood pressure among the general adult population under the new diagnostic criteria. PubMed and Embase databases were systematically searched. Two investigators independently performed data extraction and quality assessment, and the disagreements were resolved by consensus with a third investigator. The random-effects model was performed to pool the prevalence of high blood pressure among the population. Subgroup and meta-regression analyses were performed to explore the source of heterogeneity. The study protocol has been registered with PROSPERO, number CRD42019147330. In total, 52 articles included in the meta-analysis with a total of 54 studies. An obvious increase in the prevalence of high blood pressure was identified by the application of new diagnostic criteria. The pooled prevalence of high blood pressure among the population was 53.01% (95% confidence interval 51.13-54.88%). Subgroup analysis showed that the WHO region, national, and age could significantly influence the prevalence of hypertension (P < 0.01). Meta-regression analyses revealed that study quality and sex ratio (male, %) did not contribute to the heterogeneity of the results (P > 0.05). The sensitivity analysis showed that the results were stable. With the use of new diagnostic criteria, the prevalence of high blood pressure has shown an upward trend, especially in Europe countries. Prevention and control measures should focus more on improving cardiovascular and cerebrovascular status in Europe countries. Standard electronic blood pressure monitors were recommended for use in future studies, and at least two more readings should be taken during a visit.

Obstructive sleep apnea is more severe in men but not women with refractory hypertension compared with controlled resistant hypertension

OBJECTIVES

Obstructive sleep apnea (OSA) is associated with treatment-resistant hypertension (RHTN) and may contribute to refractory hypertension (RfHTN). The objective of the current study was to test the hypothesis that patients with RfHTN have more severe OSA compared with patients with controlled RHTN.

METHODS

Patients (n = 187) referred to the University of Alabama at Birmingham Hypertension Clinic for evaluation and treatment of RHTN, defined as uncontrolled blood pressure (BP) (SBP ≥ 130 mmHg or DBP ≥ 80 mmHg) despite the use of at least three antihypertensive medications including a diuretic, were enrolled following completion of at least three follow-up clinic visits. RfHTN was defined as uncontrolled high BP despite treatment with five or more antihypertensive agents of different classes, including a long-acting thiazide-type diuretic and a mineralocorticoid receptor antagonist. Following enrollment, all patients (n = 130) completed 24-h ambulatory BP measurement and overnight diagnostic polysomnography during normal nightly use of continuous positive airway pressure. Analyses examined the severity of OSA and related sleep characteristics among patients with RfHTN versus controlled RHTN.

RESULTS

Of the 130 evaluated patients, 37 (28.5%) had RfHTN and 93 (71.5%) had controlled RHTN. In unadjusted analyses, there was not a significant difference in OSA severity, oxygen saturation, or hypoxemia time in patients with RfHTN versus controlled RHTN (P > 0.05). Men with RfHTN had more severe OSA compared with men with controlled RHTN (P = 0.044). In adjusted analyses, OSA severity was associated with sex (P < 0.0001), but not hypertension phenotype (P = 0.17).

CONCLUSION

The severity of OSA may contribute to RfHTN status in men but not women.

Reserpine Substantially Lowers Blood Pressure in Patients With Refractory Hypertension: A Proof-of-Concept Study

BACKGROUND

Refractory hypertension (RfHTN), a phenotype of antihypertensive treatment failure, is defined as uncontrolled automated office blood pressure (AOBP) ≥130/80 mm Hg and awake ambulatory blood pressure (ABP) ≥130/80 mm Hg on ≥5 antihypertensive medications, including chlorthalidone and a mineralocorticoid receptor antagonist. Previous studies suggest that RfHTN is attributable to heightened sympathetic tone. The current study tested whether reserpine, a potent sympatholytic agent, lowers blood pressure (BP) in patients with RfHTN.

METHODS

Twenty-one out of 45 consecutive patients with suspected RfHTN were determined to be fully adherent with their antihypertensive regimen. Seven patients agreed to participate in the current clinical trial with reserpine and 6 patients completed the study. Other sympatholytic medications, such as clonidine or guanfacine, were tapered and discontinued before starting reserpine. Reserpine 0.1 mg daily was administered in an open-label fashion for 4 weeks. All patients were evaluated by AOBP and 24-hour ABP at baseline and after 4 weeks of treatment.

RESULTS

Reserpine lowered mean systolic and diastolic AOBP by 29.3 ± 22.2 and 22.0 ± 15.8 mm Hg, respectively. Mean 24-hour systolic and diastolic ABPs were reduced by 21.8 ± 13.4 and 15.3 ± 9.6 mm Hg, mean awake systolic and diastolic ABPs by 23.8 ± 11.8 and 17.8 ± 9.2 mm Hg, and mean asleep systolic and diastolic ABPs by 21.5 ± 11.4 and 13.7 ± 6.4 mm Hg, respectively.

CONCLUSIONS

Reserpine, a potent sympatholytic agent, lowers BP in patients whose BP remained uncontrolled on maximal antihypertensive therapy, lending support to the hypothesis that excess sympathetic output contributes importantly to the development of RfHTN.

Validation of the BIOS BD240 home blood pressure monitor in a multi-racial, multi-morbid Canadian population according to the International Standards Organization 2018 Protocol

OBJECTIVE

Assess the accuracy of the BIOS BD240 home blood pressure (BP) monitor and wide-range cuff according to the International Organization for Standardization (ISO) 2018 standard.

METHODS

Eighty-five subjects (aged ≥18 y) with arm circumferences between 24 and 43 cm were studied. Blinded, two-observer, mercury-based auscultation performed using a two-piece cuff chosen for upper arm size was used for reference measurements. Accuracy criteria 1 and 2 of the ISO standard were determined and Bland-Altman plots generated.

RESULTS

Sixty percent of the study sample was female and 42% had hypertension. Mean device-to-reference standard differences in SBP/DBP were 0.0 ± 6.2/-0.2 ± 6.3 for criterion 1 and 0.0 ± 4.8/-0.2 ± 5.8 for criterion 2.

CONCLUSION

The BIOS BD240 passed the requirements of the American National Standards Institute/Association for the Advancement of Medical Instrumentation/ISO standard for both SBP and DBP and can be recommended for use.

Aortic blood pressure and arterial stiffness in patients with controlled resistant and non-resistant hypertension

The purpose of the current study was to determine whether aortic blood pressure (BP) and arterial stiffness are greater in patients with controlled resistant hypertension (RHTN) than controlled non-resistant hypertension (non-RHTN) despite similar clinic BP level. Participants were recruited from University of Alabama at Birmingham (UAB) Hypertension Clinic. Controlled hypertension was defined as automated office BP measurement with BP < 135/85 mm Hg. A total of 141 participants were evaluated by pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (cf-PWV). Among them, 75 patients had controlled RHTN with use of 4 or more antihypertensive medications and 56 patients had controlled non-RHTN with use of 3 or less antihypertensive medications. Compared to patients with controlled non-RHTN, those with controlled RHTN were more likely to be African American and had a higher prevalence of diabetes mellitus and congestive heart failure. The mean number of antihypertensive medications was greater in patients with controlled RHTN (4.4 ± 0.8 vs 2.3 ± 0.7, P < .001). Clinic brachial BP, aortic BP, augmentation pressure (AP), augmentation index normalized for heart rate of 75 beats per minute (AIx@75) and cf-PWV were similar in both groups. In summary, there was no significant difference in central BP or arterial stiffness between patients with controlled RHTN and controlled non-RHTN. These findings suggest that the higher residual cardiovascular risk observed in patients with RHTN after achieving BP control compared to patients with more easily controlled hypertension is not likely attributable to persistent differences in central BP and arterial stiffness.

Communication skills training for physicians improves health literacy and medical outcomes among patients with hypertension: a randomized controlled trial

Background

Improving the training of physicians about communication skills and patient health literacy (HL) is a major priority that remains an open question. We aimed to examine the effectiveness of communication skills training for physicians on the hypertension outcomes and the health literacy skills, self-efficacy and medication adherence in patients with uncontrolled blood pressure (BP).

Methods

A randomized, controlled trial method was conducted on 240 hypertensive patients and 35 physicians presenting to healthcare clinics in the Mashhad, Iran, from 2013 to 2014. Using stratified blocking with block sizes of 4 and 6, eligible patients with uncontrolled blood pressure were randomly allocated to the intervention and control groups. Physicians in the intervention group received educational training over 3 sessions of Focus –Group Discussion and 2 workshops. The control group received the routine care. The primary outcome was a reduction in systolic and diastolic BP from baseline to 6 months. The secondary outcome was promoting HL skills in hypertensive patients. Data were analyzed using the regression model and bivariate tests.

Results

After the physician communication training, there was a significant improvement in physicians-patient communication skills, hypertension outcomes, medication adherence, and self-efficacy among the patients being managed by the physicians receiving training, compared to the control group.

Conclusion

The educational intervention leads to better BP control; it may have been sufficient training of physicians change to impact counseling, HL and self-efficacy and adherence. The quality of physician-patient communication is an important modifiable element of medical communication that may influences health outcomes in hypertensive Iranian patients.

Trial registration

Iranian Registry of Clinical Trials (IRCT), IRCT20160710028863N24. Registered April 4, 2018 [retrospectively registered].

Antihypertensive Medication Adherence and Confirmation of True Refractory Hypertension

Refractory hypertension (RfHTN) is a phenotype of antihypertensive treatment failure defined as uncontrolled BP despite the use of effective doses of ≥5 antihypertensive medications including a long-acting thiazide-like diuretic (chlorthalidone) and a mineralocorticoid receptor antagonist. The degree of medication nonadherence is unknown among patients with RfHTN. In this prospective evaluation, 54 patients with apparent RfHTN were recruited from the University of Alabama at Birmingham Hypertension Clinic after having uncontrolled BP at 3 or more clinic visits. All patients' BP was evaluated by automated office BP and 24-hour ambulatory BP monitoring (n=49). Antihypertensive medication adherence was determined by measuring 24-hour urine specimens for antihypertensive medications and their metabolites by high-performance liquid chromatography-tandem mass spectrometry (n=45). Of the 45 patients who completed 24-hour ambulatory BP monitoring, 40 (88.9%) had confirmed RfHTN based on an elevated automated office BP (≥130/80 mm Hg), mean 24-hour ABP (≥125/75 mm Hg), and mean awake (day-time) ABP (≥130/80 mm Hg). Out of the 40 fully evaluated patients with RfHTN, 16 (40.0%) were fully adherent with all prescribed medications. Eighteen (45.0%) patients were partially adherent and 6 (15.0%) had none of the prescribed agents detected in their urine. Of 18 patients who were partially adherent, 5 (12.5%) were adherent with at least 5 medications, including chlorthalidone and the mineralocorticoid receptor antagonist, consistent with true RfHTN. Of patients identified as having apparent RfHTN, 52.5% were adherent with at least 5 antihypertensive medications, including chlorthalidone and a mineralocorticoid receptor antagonist, confirming true RfTHN. These findings validate RfHTN as a rare, but true phenotype of antihypertensive treatment failure.

Out-of-Clinic Sympathetic Activity Is Increased in Patients With Masked Uncontrolled Hypertension

Masked uncontrolled hypertension (MUCH) is defined as controlled automated office blood pressure (BP; AOBP <135/85 mm Hg) in-clinic in patients receiving antihypertensive medication(s) but uncontrolled BP out-of-clinic by 24-hour ambulatory BP monitoring (ABPM; awake ≥135/85 mm Hg). We hypothesized that MUCH patients have greater out-of-clinic sympathetic activity compared with true controlled hypertensives. Patients being treated for hypertension were prospectively recruited after 3 or more consecutive clinic visits. All patients were evaluated by in-clinic automated office BP, plasma catecholamines, and spot-urine/plasma metanephrines. In addition, out-of-clinic 24-hour ABPM, 24-hour urinary for catecholamines and metanephrines was done. Out of 237 patients recruited, 169 patients had controlled in-clinic BP of which 156 patients had completed ABPM. Seventy-four were true controlled hypertensives, that is controlled by clinic automated office BP and by out-of-clinic ABPM. The remaining 82 were controlled by clinic automated office BP, but uncontrolled during out-of-clinic ABPM, indicative of MUCH. After exclusion of 4 patients because of inadequate or lack of 24-hour urinary collections, 72 true controlled hypertensive and 80 MUCH patients were analyzed. MUCH patients had significantly higher out-of-clinic BP variability and lower heart rate variability compared with true controlled hypertensives, as well as higher levels of out-of-clinic urinary catecholamines and metanephrines levels consistent with higher out-of-clinic sympathetic activity. In contrast, there was no difference in in-clinic plasma catecholamines and spot-urine/plasma levels of metanephrines between the 2 groups, consistent with similar levels of sympathetic activity while in clinic. MUCH patients have evidence of heightened out-of-clinic sympathetic activity compared with true controlled hypertensives, which may contribute to the development of MUCH.

Masked Uncontrolled Hypertension Is Not Attributable to Medication Nonadherence

Masked uncontrolled hypertension (MUCH) in treated hypertensive patients is defined as controlled automated office blood pressure (BP; <135/85 mm Hg) in-clinic but uncontrolled out-of-clinic BP by ambulatory BP monitoring (awake [daytime] readings ≥135/85 mm Hg or 24-hour readings ≥130/80 mm Hg). To determine whether MUCH is attributable to antihypertensive medication nonadherence. One hundred eighty-four enrolled patients were confirmed to have controlled office BP; of these, 167 patients were with adequate 24-hour ambulatory BP recordings. Of 167 patients, 86 were controlled by in-clinic BP assessment but had uncontrolled ambulatory awake BP, indicative of MUCH. The remaining 81 had controlled in-clinic and ambulatory awake BP, consistent with true controlled hypertension. After exclusion of 9 patients with missing 24-hour urine collections, antihypertensive medication adherence was determined based on the detection of urinary drugs or drug metabolites by high-performance liquid chromatography-tandem mass spectrometry. Of the 81 patients with MUCH, 69 (85.2%) were fully adherent and 12 (14.8%) were partially adherent (fewer medications detected than prescribed). Of the 77 patients with true controlled hypertension, 69 (89.6%) were fully adherent with prescribed antihypertensive medications and 8 (10.4%) were partially adherent. None of the patients in either group were fully nonadherent. There was no statistically significant difference in complete or partial adherence between the MUCH and true controlled groups (P=0.403). Measurement of urinary drug and drug metabolite levels demonstrates a similarly high level of antihypertensive medication adherence in both MUCH and truly controlled hypertensive patients. These findings indicate that MUCH is not attributable to antihypertensive medication nonadherence.

Evaluation of the Omron HEM-907 automated blood pressure device: comparison with office and ambulatory blood pressure readings

Blood pressure (BP) measured in the clinic is subject to the white coat effect and does not always indicate the 'usual' BP. Ambulatory BP is the current gold standard, but remains inconvenient for routine use. Interest in automated BP, where the healthcare professional is absent from the examination room during BP measurement, is growing, as this reduces the white coat effect and yields BP values that are close to ambulatory readings. The aim of this study was to investigate how well automated office BP (AOBP), measured using the Omron HEM-907 device, compares with observed office BP (OOBP, healthcare professional remains in the examination room) and awake ambulatory BP (AABP) measurements. OOBP, AOBP and AABP were measured in 108 participants, with OOBP and AOBP measurements repeated 1 week later, following a standardised protocol. Average BP readings for visit one were 134 ± 18/77 ± 11 for OOBP, 131 ± 16/75 ± 11 for AOBP, and 133 ± 15/82 ± 12 for AABP. On both visits, automated readings were significantly lower than observed readings for both systolic and diastolic BP (P < 0.001 for both). Automated readings were also significantly lower than ambulatory readings, with a mean difference in systolic/diastolic BP of - 2 ± 11/- 7 ± 10 (P < 0.001 for both), with high correlations between the two modalities (r = 0.75 and r = 0.64, for systolic and diastolic BP, respectively, P < 0.001 for both). AOBP measured by the Omron HEM-907 is not associated with a white coat effect, unlike observed readings, and provides reproducible results and good correlations with ambulatory readings. Automated BP measured using the Omron HEM-907 is, therefore, a useful alternative to observed office readings.

Refractory Hypertension Is not Attributable to Intravascular Fluid Retention as Determined by Intracardiac Volumes

Refractory hypertension (RfHTN) is an extreme phenotype of antihypertensive treatment failure defined as lack of blood pressure control with ≥5 medications, including a long-acting thiazide and a mineralocorticoid receptor antagonist. RfHTN is a subgroup of resistant hypertension (RHTN), which is defined as blood pressure >135/85 mm Hg with ≥3 antihypertensive medications, including a diuretic. RHTN is generally attributed to persistent intravascular fluid retention. It is unknown whether alternative mechanisms are operative in RfHTN. Our objective was to determine whether RfHTN is characterized by persistent fluid retention, indexed by greater intracardiac volumes determined by cardiac magnetic resonance when compared with controlled RHTN patients. Consecutive patients evaluated in our institution with RfHTN and controlled RHTN were prospectively enrolled. Exclusion criteria included advanced chronic kidney disease and masked or white coat hypertension. All enrolled patients underwent biochemical testing and cardiac magnetic resonance. The RfHTN group (n=24) was younger (mean age, 51.7±8.9 versus 60.6±11.5 years; P=0.003) and had a greater proportion of women (75.0% versus 43%; P=0.02) compared with the controlled RHTN group (n=30). RfHTN patients had a greater left ventricular mass index (88.3±35.0 versus 54.6±12.5 g/m²; P<0.001), posterior wall thickness (10.1±3.1 versus 7.7±1.5 mm; P=0.001), and septal wall thickness (14.5±3.8 versus 10.0±2.2 mm; P<0.001). There was no difference in B-type natriuretic peptide levels and left atrial or ventricular volumes. Diastolic dysfunction was noted in RfHTN. Our findings demonstrate greater left ventricular hypertrophy without chamber enlargement in RfHTN, suggesting that antihypertensive treatment failure is not attributable to intravascular volume retention.

Health providers' communication skills training affects hypertension outcomes

OBJECTIVE

Hypertension is a common cardiovascular risk factor within the Iranian population, and this may be improved through changes in lifestyle. We aimed at improving hypertension outcomes and health literacy skills among hypertensive patients through communication skills training targeting health providers.

METHODS

A randomized controlled trial method was used to enroll 35 health providers and 240 hypertensive patients attending community-based healthcare practices in the Mashhad, Iran. We evaluated the effects of a communication skills intervention for primary care providers compared to usual care controls, on the hypertension outcomes, patient medication adherence, and self-efficacy, assessed at baseline and post-intervention. Bivariate analysis and the regression model were used to assess whether the health provider training improved outcomes.

RESULTS

Majority of participating patients were female (77.3%), less than high school education (80.3%), married (82.3%), and low income (82.3%), with mean age of 37 years. Following the educational intervention, there was a significant improvement (p < 0.05) in patient communication skills, self-efficacy, adherence to medication, and hypertension outcomes in the intervention compared to the control group.

CONCLUSIONS

The brief communication skills training for health care providers appear to be an efficient way to improve patient-provider communication skills and hypertension outcome among patients with uncontrolled BP.

Interarm Difference in Systolic Blood Pressure in Different Ethnic Groups and Relationship to the "White Coat Effect": A Cross-Sectional Study

BACKGROUND

Interarm differences (IADs) ≥10 mm Hg in systolic blood pressure (BP) are associated with greater incidence of cardiovascular disease. The effect of ethnicity and the white coat effect (WCE) on significant systolic IADs (ssIADs) are not well understood.

METHODS

Differences in BP by ethnicity for different methods of BP measurement were examined in 770 people (300 White British, 241 South Asian, 229 African-Caribbean). Repeated clinic measurements were obtained simultaneously in the right and left arm using 2 BPTru monitors and comparisons made between the first reading, mean of second and third and mean of second to sixth readings for patients with, and without known hypertension. All patients had ambulatory BP monitoring (ABPM). WCE was defined as systolic clinic BP ≥10 mm Hg higher than daytime ABPM.

RESULTS

No significant differences were seen in the prevalence of ssIAD between ethnicities whichever combinations of BP measurement were used and regardless of hypertensive status. ssIADs fell between the 1^st measurement (161, 22%), 2^nd/3^rd (113, 16%), and 2^nd–6^th (78, 11%) (1^st vs. 2^nd/3^rd and 2^nd–6^th, P < 0.001). Hypertensives with a WCE were more likely to have ssIADs on 1^st, (odds ratio [OR] 1.73 (95% confidence interval 1.04–2.86); 2^nd/3^rd, (OR 3.05 (1.68–5.53); and 2^nd–6^th measurements, (OR 2.58 (1.22–5.44). Nonhypertensive participants with a WCE were more likely to have a ssIAD on their first measurement (OR 3.82 (1.77 to −8.25) only.

CONCLUSIONS

ssIAD prevalence does not vary with ethnicity regardless of hypertensive status but is affected by the number of readings, suggesting the influence of WCE. Multiple readings should be used to confirm ssIADs.

White-Coat Effect Is Uncommon in Patients With Refractory Hypertension

Refractory hypertension is a recently described phenotype of antihypertensive treatment failure defined as uncontrolled blood pressure (BP) despite the use of ≥5 different antihypertensive agents, including chlorthalidone and spironolactone. Recent studies indicate that refractory hypertension is uncommon, with a prevalence of ≈5% to 10% of patients referred to a hypertension specialty clinic for uncontrolled hypertension. The prevalence of white-coat effect, that is, uncontrolled automated office BP ≥135/85 mm Hg and controlled out-of-office BP <135/85 mm Hg, by awake ambulatory BP monitor in hypertensive patients overall is ≈30% to 40%. The prevalence of white-coat effect among patients with refractory hypertension has not been previously reported. In this prospective evaluation, consecutive patients referred to the University of Alabama at Birmingham Hypertension Clinic for uncontrolled hypertension were enrolled. Refractory hypertension was defined as uncontrolled automated office BP ≥135/85 mm Hg with the use of ≥5 antihypertensive agents, including chlorthalidone and spironolactone. Automated office BP measurements were based on 6 serial readings, done automatically with the use of a BpTRU device unobserved in the clinic. Out-of-office BP measurements were done by 24-hour ambulatory BP monitor. Thirty-four patients were diagnosed with refractory hypertension, of whom 31 had adequate ambulatory BP monitor readings. White-coat effect was present in only 2 patients, or 6.5% of the 31 patients with refractory hypertension, suggesting that white-coat effect is largely absent in patients with refractory hypertension. These findings suggest that white-coat effect is not a common cause of apparent lack of BP control in patients failing maximal antihypertensive treatment.

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

Are Automated Blood Pressure Monitors Comparable to Ambulatory Blood Pressure Monitors? A Systematic Review and Meta-analysis

Ambulatory blood pressure (BP) monitoring (ABPM) provides an accurate assessment of BP and cardiovascular risk. BpTRU (BpTRU Medical Devices Ltd, Coquitlam, British Columbia, Canada) and other automated oscillometric BP monitors (AOBPs) have been proposed to replace ABPM. A systematic review was carried out to determine the accuracy of AOBP measurement, compared with ABPM. A literature search was performed using MedLine, EMBASE and CINAHL databases until Oct 28, 2016. We selected all studies that included intraindividual comparisons between AOBP monitoring and ABPM. Study selection, demographic characteristics, and BP values including details of BP measurement techniques were abstracted in duplicate. Quantitative synthesis was performed to report the weighted mean difference between systolic and diastolic BP measured using the 2 methods. From the 859 nonduplicate citations from the search, 19 full-text articles were selected for the systematic review. The median sample size was 226 (range, 17-654). In the pooled analysis, the weighted mean difference between the 2 methods for systolic BP was -1.52 mm Hg (95% confidence interval [CI], -3.29 to 0.25 mm Hg; P = 0.09) and for diastolic BP was 0.33 mm Hg (95% CI, -0.97 to 1.64; P = 0.62). The study-level difference in means for systolic BP ranged from -9.7 to 9 mm Hg with significant heterogeneity (Cochran Q = 270; I² = 93.3; P < 0.001) and for diastolic BP ranged from -4 to 6 mm Hg with significant heterogeneity (Cochran Q = 382; I² = 95.3; P < 0.001). Because of the significant heterogeneity we believe that use of the AOBP should not replace awake ambulatory BP (ABPM) as the reference standard.

Promoting Cardiovascular Health among Older Adults: A Pilot Study with Community Pharmacists

This project enabled us to develop procedures for organizing and running successful pharmacy blood pressure sessions. The knowledge gained from this pilot was used in the multicentred Community Health Awareness Program (CHAP).

Running blood pressure sessions in community pharmacies and using a multidisciplinary approach, including volunteer health educators and support from public health, was a feasible way to raise awareness of cardiovascular health among the older adults who participated in our project.

This pilot project included pharmacist involvement at several stages, from the planning of the blood pressure sessions and development of the documentation forms, to participation in the pilot and feedback after project completion. With its multidisciplinary approach, the pilot showed that it is feasible for a community pharmacist to be involved in research projects that can benefit patient care and enhance their professional roles.

Prevalence of pseudoresistant hypertension due to inaccurate blood pressure measurement

The prevalence of pseudoresistant hypertension (HTN) due to inaccurate BP measurement remains unknown. Triage BP measurements and measurements obtained at the same clinic visit by trained physicians were compared in consecutive adult patients referred for uncontrolled resistant HTN (RHTN). Triage BP measurements were taken by the clinic staff during normal intake procedures. BP measurements were obtained by trained physicians using the BpTRU (VSM Med Tech Ltd. Coquitlam, Canada) device. The prevalence of uncontrolled RHTN and differences in BP measurements were compared. Of 130 patients with uncontrolled RHTN, 33.1% (n = 43) were falsely identified as having uncontrolled RHTN based on triage BP measurements. The median (inter-quartile range) of differences in systolic BP between pseudoresistant and true resistant groups were 23 (17-33) mm Hg and 13 (6-21) mm Hg, respectively (P = .0001). The median (inter-quartile range) of differences in diastolic BP between the two groups were 12 (7-18) mm Hg and 8 (4-11) mm Hg, respectively (P = .001). Triage BP technique overestimated the prevalence of uncontrolled RHTN in approximately 33% of the patients emphasizing the importance of obtaining accurate BP measurements.

Predicting out-of-office blood pressure level using repeated measurements in the clinic: an observational cohort study

OBJECTIVES

Identification of people with lower (white-coat effect) or higher (masked effect) blood pressure at home compared to the clinic usually requires ambulatory or home monitoring. This study assessed whether changes in SBP with repeated measurement at a single clinic predict subsequent differences between clinic and home measurements.

METHODS

This study used an observational cohort design and included 220 individuals aged 35-84 years, receiving treatment for hypertension, but whose SBP was not controlled. The characteristics of change in SBP over six clinic readings were defined as the SBP drop, the slope and the quadratic coefficient using polynomial regression modelling. The predictive abilities of these characteristics for lower or higher home SBP readings were investigated with logistic regression and repeated operating characteristic analysis.

RESULTS

The single clinic SBP drop was predictive of the white-coat effect with a sensitivity of 90%, specificity of 50%, positive predictive value of 56% and negative predictive value of 88%. Predictive values for the masked effect and those of the slope and quadratic coefficient were slightly lower, but when the slope and quadratic variables were combined, the sensitivity, specificity, positive and negative predictive values for the masked effect were improved to 91, 48, 24 and 97%, respectively.

CONCLUSION

Characteristics obtainable from multiple SBP measurements in a single clinic in patients with treated hypertension appear to reasonably predict those unlikely to have a large white-coat or masked effect, potentially allowing better targeting of out-of-office monitoring in routine clinical practice.

Results and lessons from the Spironolactone To Prevent Cardiovascular Events in Early Stage Chronic Kidney Disease (STOP-CKD) randomised controlled trial

OBJECTIVES

To determine whether low-dose spironolactone can safely lower arterial stiffness in patients with chronic kidney disease stage 3 in the primary care setting.

DESIGN

A multicentre, prospective, randomised, placebo-controlled, double-blinded study.

SETTING

11 primary care centres in South Birmingham, England.

PARTICIPANTS

Adult patients with stage 3 chronic kidney disease. Main exclusion criteria were diagnosis of diabetes mellitus, chronic heart failure, atrial fibrillation, severe hypertension, systolic blood pressure < 120 mm Hg or baseline serum potassium ≥ 5 mmol/L.

INTERVENTION

Eligible participants were randomised to receive either spironolactone 25 mg once daily, or matching placebo for an intended period of 40 weeks.

OUTCOME MEASURES

The primary end point was the change in arterial stiffness as measured by pulse wave velocity. Secondary outcome measures included the rate of hyperkalaemia, deterioration of renal function, barriers to participation and expected recruitment rates to a potential future hard end point study.

RESULTS

From the 11 practices serving a population of 112,462, there were 1598 (1.4%) patients identified as being eligible and were invited to participate. Of these, 134 (8.4%) attended the screening visit of which only 16 (1.0%) were eligible for randomisation. The main reasons for exclusion were low systolic blood pressure (<120 mm Hg: 40 patients) and high estimated glomerular filtration rate (≥ 60 mL/min/1.73 m(2): 38 patients). The trial was considered unfeasible and was terminated early.

CONCLUSIONS

We highlight some of the challenges in undertaking research in primary care including patient participation in trials. This study not only challenged our preconceptions, but also provided important learning for future research in this large and important group of patients.

TRIAL REGISTRATION NUMBER

ISRCTN80658312.

Results from the Trial Using Motivational Interviewing, Positive Affect, and Self-Affirmation in African Americans with Hypertension (TRIUMPH)

OBJECTIVE

Our objective was to determine the effectiveness of combining positive affect and self-affirmation strategies with motivational interviewing in achieving blood pressure control among hypertensive African Americans (AA) compared with AA hypertensives in an education-only control group.

DESIGN

Randomized trial.

SETTING

Ambulatory practices in the South Bronx and Harlem, New York City.

PARTICIPANTS

African American adults with uncontrolled hypertension.

INTERVENTIONS

Participants were randomized to a positive affect and self-affirmation intervention or an education control group. The positive affect and self-affirmation intervention involved having participants think about things that made them happy and that reminded them of their core values on a daily basis. These strategies were reinforced every two months through motivational interviewing. The control arm received a workbook of strategies on blood pressure control. All participants were called every two months for one year.

MAIN OUTCOMES

Blood pressure control rate.

RESULTS

A total of 238 participants were randomized. The average age was 56 ± 11 years, approximately 70% were female, 80% were not married, and up to 70% had completed high school. There was no difference in control rates between the intervention and the control group. However, at one year, female participants were more likely to be controlled. Participants with high depressive symptoms or high perceived stress at baseline were less likely to be controlled.

CONCLUSIONS

While this study did not demonstrate an intervention effect, it does provide important insight into the psychosocial factors that may underlie blood pressure control in African Americans. Implications for future behavioral intervention trials are discussed.

Comparing Guidelines for Statin Treatment in Canada and the United States

Background

New guidelines for cardiovascular disease risk assessment and statin eligibility have recently been published in the United States by the American College of Cardiology and the American Heart Association (ACC-AHA). It is unknown how these guidelines compare with the Canadian Cardiovascular Society (CCS) recommendations.

Methods and Results

Using data from the Canadian Health Measures Survey 2007–2011, we estimated the cardiovascular disease risk and proportion of the Canadian population, aged 40 to 75 years without cardiovascular disease, who would theoretically be eligible for statin treatment under both the CCS and ACC-AHA guidelines. The survey sample used (n=1975) represented 13.1 million community dwelling Canadians between the ages of 40 and 75 years. In comparing the CVD risk assessment methods, we found that calculated CVD risk was higher based on the CCS guidelines compared with the ACC-AHA guidelines. Despite this, a similar proportion and number of Canadians would be eligible for statin treatment under the 2 sets of recommendations. Some discordance in recommendations was found within subgroups of the population, with the CCS guidelines recommending more treatment for individuals who are younger, with a family history of CVD, or with chronic kidney disease. The ACC-AHA recommend more treatment for people who are older (age 60+ years). These results likely overestimate the treatment rate under both guidelines because, in primary prevention, a clinician–patient discussion must occur before treatment and determines uptake.

Conclusions

Implementing the ACC-AHA lipid treatment guidelines in Canada would not result in an increase in individuals eligible for statin treatment. In fact, the proportion of the population recommended for statin treatment would decrease slightly and be targeted at different subgroups of the population.

Ethnicity and differences between clinic and ambulatory blood pressure measurements

BACKGROUND

This study investigated the relationship of ethnicity to the differences between blood pressure (BP) measured in a clinic setting and by ambulatory blood pressure monitoring (ABPM) in individuals with a previous diagnosis of hypertension (HT) and without a previous diagnosis of hypertension (NHT).

METHODS

A cross-sectional comparison of BP measurement was performed in 770 participants (white British (WB, 39%), South Asian (SA, 31%), and African Caribbean (AC, 30%)) in 28 primary care clinics in West Midlands, United Kingdom. Mean differences between daytime ABPM, standardized clinic (mean of 3 occasions), casual clinic (first reading on first occasion), and last routine BP taken at the general practitioner practice were compared in HT and NHT individuals.

RESULTS

Daytime systolic and diastolic ABPM readings were similar to standardized clinic BP (systolic: 128 (SE 0.9) vs. 125 (SE 0.9) mm Hg (NHT) and 132 (SE 0.7) vs. 131 (SE 0.7) mm Hg (HT)) and were not associated with ethnicity to a clinically important extent. When BP was taken less carefully, differences emerged: casual clinic readings were higher than ABPM, particularly in the HT group where the systolic differences approached clinical relevance (131 (SE 1.2) vs. 129 (SE 1.0) mm Hg (NHT) and 139 (SE 0.9) vs. 133 (SE 0.7) mm Hg (HT)) and were larger in SA and AC hypertensive individuals (136 (SE 1.5) vs. 133 (SE 1.2) mm Hg (WB), 141 (SE 1.7) vs. 133 (SE 1.4) mm Hg (SA), and 142 (SE 1.6) vs. 134 (SE 1.3) mm Hg (AC); mean differences: 3 (0-7), P = 0.03 and 4 (1-7), P = 0.01, respectively). Differences were also observed for the last practice reading in SA and ACs.

CONCLUSIONS

BP differences between ethnic groups where BP is carefully measured on multiple occasions are small and unlikely to alter clinical management. When BP is measured casually on a single occasion or in routine care, differences appear that could approach clinical relevance.

MEthods of ASsessing blood pressUre: identifying thReshold and target valuEs (MeasureBP): a review & study protocol

Despite progress in automated blood pressure measurement (BPM) technology, there is limited research linking hard outcomes to automated office BPM (OBPM) treatment targets and thresholds. Equivalences for automated BPM devices have been estimated from approximations of standardized manual measurements of 140/90 mmHg. Until outcome-driven targets and thresholds become available for automated measurement methods, deriving evidence-based equivalences between automated methods and standardized manual OBPM is the next best solution. The MeasureBP study group was initiated by the Canadian Hypertension Education Program to close this critical knowledge gap. MeasureBP aims to define evidence-based equivalent values between standardized manual OBPM and automated BPM methods by synthesizing available evidence using a systematic review and individual subject-level data meta-analyses. This manuscript provides a review of the literature and MeasureBP study protocol. These results will lay the evidenced-based foundation to resolve uncertainties within blood pressure guidelines which, in turn, will improve the management of hypertension.

Prevalence of metabolic syndrome among college football linemen

OBJECTIVE

To determine the prevalence of metabolic syndrome among Canadian amateur football players.

METHODS

University football players from Saskatchewan were invited to participate in this study. Each subject underwent screening for blood pressure using a BpTRU monitor, and serum cholesterol and fasting blood glucose using a Cholestech LDX analyzer. Waist circumference was recorded and body composition was measured by dual-energy x-ray absorptiometry. RESULTS were compared between linemen and non-linemen using independent sample t-tests for continuous data and chi-square for dichotomous variables.

RESULTS

Out of 39 players who consented to participate, 14% of linemen (3/21) and no non-linemen satisfied metabolic syndrome criteria. Compared to non-linemen, linemen had a higher waist circumference (108.0 vs. 82.9 cm; p<0.001), higher total body fat composition (26.4% vs. 11.2%; p<0.001), lower mean high-density lipoprotein cholesterol (0.93, vs. 1.12 mmol/L; p=0.021) and higher fasting blood glucose (5.22 vs. 4.77 mmol/L; p<0.001).

CONCLUSION

Despite their young age and participation in an elite-level athletic program, many collegiate-level football linemen had features of metabolic syndrome. Although our study focused on a single team, we suspect these trends may be consistent across the country.

Spironolactone to prevent cardiovascular events in early-stage chronic kidney disease (STOP-CKD): study protocol for a randomized controlled pilot trial

BACKGROUND

Chronic kidney disease is associated with increased arterial stiffness even in the early stages and this is thought to be a key mediator in the pathophysiology of the increased cardiovascular risk associated with this condition. The use of low-dose spironolactone has previously been shown to improve arterial stiffness and reduce left ventricular mass safely in early-stage chronic kidney disease in the context of careful monitoring at a university hospital. However, the majority of patients with chronic kidney disease are managed by their general practitioners in the community. It is not known whether similar beneficial effects can be achieved safely using spironolactone in the primary care setting. The aim of this study is to determine whether low-dose spironolactone can safely lower arterial stiffness in patients with stage 3 chronic kidney disease in the primary care setting.

METHODS/DESIGN

STOP-CKD is a multicentre, prospective, randomized, double-blind, placebo-controlled pilot trial of 240 adult patients with stage 3 chronic kidney disease recruited from up to 20 general practices in South Birmingham, England. Participants will be randomly allocated using a secured web-based computer randomization system to receive either spironolactone 25 mg once daily or a matching inactive placebo for 40 weeks, followed by a wash-out period of 6 weeks. Investigators, outcome assessors, data analysts and participants will all be blinded to the treatment allocation. The primary endpoint is improved arterial stiffness, as measured by carotid-femoral pulse wave velocity between baseline and 40 weeks. The secondary endpoints are incidence of hyperkalaemia, change in estimated glomerular filtration rate, change in urine albumin:creatinine ratio, change in brachial blood pressure, change in pulse waveform characteristics and overall tolerability of spironolactone. An additional quality control study, aiming to compare the laboratory serum potassium results of samples processed via two methods (utilizing routine transport or centrifugation on site before rapid transport to the laboratory) for 100 participants and a qualitative research study exploring patients' and general practitioners' attitudes to research and the use of spironolactone in chronic kidney disease in the community setting will be embedded in this pilot study.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN80658312.

Allopurinol is an independent determinant of improved arterial stiffness in chronic kidney disease: a cross-sectional study

Background

Arterial stiffness is increased in patients with CKD and is a powerful predictor of cardiovascular morbidity and mortality. Use of the xanthine oxidase inhibitor allopurinol has been shown to improve endothelial function, reduce left ventricular hypertrophy and possibly improve cardiovascular outcome. We explored the relationship between use of allopurinol and arterial stiffness in patients with chronic kidney disease (CKD).

Methods

Cross-sectional observational study of 422 patients with CKD with evidence of, or at high risk of, renal disease progression. Arterial stiffness was determined by carotid-femoral pulse wave velocity (PWV).

Results

The mean age was 63±16 years, median estimated glomerular filtration rate was 25 (interquartile range: 19–31) ml/min/1.73 m² and mean PWV was 10.2±2.4 m/s. Seventy-seven patients (18%) were receiving regular allopurinol, 61% at a dose of 100 mg/day (range: 50–400 mg/day). Patients receiving allopurinol had significantly lower peripheral pulse pressure, central pulse pressure, central systolic blood pressure, serum uric acid level tissue advanced glycation end product levels but comparable high-sensitivity C-reactive protein levels. Use of allopurinol was associated with lower PWV. After adjusting for age, gender, ethnicity, tissue advanced glycation end product level, peripheral pulse pressure, smoking pack years, presence of diabetes mellitus and use of angiotensin converting enzyme inhibitor or angiotensin II receptor blocker, the use of allopurinol remained a significant independent determinant of PWV (mean difference: −0.63 m/s; 95% CI, −0.09 to −1.17 m/s, p = 0.02).

Conclusion

In patients with CKD, use of allopurinol is independently associated with lower arterial stiffness. This study provides further justification for a large definitive randomised controlled trial examining the therapeutic potential of allopurinol to reduce cardiovascular risk in people with CKD.

Optimising the accuracy of blood pressure monitoring in chronic kidney disease: the utility of BpTRU

BACKGROUND

Accurate blood pressure monitoring is critical for the management of chronic kidney disease, but changes in management in secondary care clinics may be based on a single blood pressure reading, with a subsequent lack of accuracy. The aim of this study was to evaluate a fully automated sphygmomanometer for optimising the accuracy of blood pressure measurements in the setting of secondary care renal clinics.

METHODS

Patients had routine blood pressure measurements with a calibrated DINAMAP PRO400 monitor in a clinical assessment room. Patients then underwent repeat assessment with a DINAMAP PRO400 monitor and BpTRU device and subsequent 24 hour ambulatory blood pressure monitoring (ABPM).

RESULTS

The BpTRU systolic (± SD) reading (117.3 ± 14.1 mmHg) was significantly lower than the routine clinic mean systolic blood pressure (143.8 ± 15.5 mmHg; P < 0.001) and the repeat blood pressure taken with a DINAMAP PRO400 monitor in a quiet room (129.9 ± 19.9 mmHg; P < 0.001). The routine clinic mean diastolic (82.4 ± 11.2 mmHg) was significantly higher than the BpTRU reading (78.4 ± 10.0 mmHg; P < 0.001). Clinic BpTRU measurements were not significantly different to the daytime mean or overall mean of 24 hour ABPM.

CONCLUSIONS

In patients with CKD, routine clinic blood pressure measurements were significantly higher than measurements using a BpTRU machine in a quiet room, but there was no significant difference in this setting between BpTRU readings and 24 hour ABPM. Adjusting clinic protocols to utilise the most accurate blood pressure technique available is a simple manoeuvre that could deliver major improvements in clinical practice.

Comparison of the average of five readings with averages from fewer readings for automated oscillometric blood pressure measurement in an outpatient clinic

BACKGROUND AND OBJECTIVES

The optimal number of consecutive measurements for obtaining an average blood pressure (BP) reading in clinical practice is yet undefined by research. This study aimed to compare readings obtained from an average of 5 with averages of 2, 3, and 4, sequential measurements.

SUBJECTS AND METHODS

Using an automated oscillometric device (BpTRU), BP measurement was conducted on 410 consenting adults attending a general outpatients clinic. Comparison of an average of 5 readings with averages of 2, 3, and 4 readings involved evaluation of correlations, Bland-Altman analysis, comparison of means and distribution of readings, and determination of the proportion of differences between compared readings which were clinically non-significant.

RESULTS

397 (96.8%) sets of complete BP readings were suitable for analysis. Clinically non-significant differences (≤5 mm Hg) were found between at least 79.3% (n=315) and 96.5% (n=383) of compared systolic and diastolic readings, respectively. Bland-Altman's analysis revealed that the 95% limits of agreement for the differences between compared readings were approximately 2-4, 3-7, and 4-11 mm Hg for 2, 3 and 4 readings' systolic comparisons while those for diastolic comparisons were 2-3, 3-5, and 4-7 mm Hg, respectively. Statistically non-significant differences were observed in all comparisons of the distributions of readings that were classified as <140 mm Hg or ≥140 mm Hg and <90 mm Hg or ≥90 mm Hg for systolic and diastolic readings, respectively. Strong positive correlations were found between 5 average readings and each of 2, 3, and 4 average readings, respectively.

CONCLUSION

An average of 5 readings may be excessive for routine BP measurement using this device at outpatient clinics.

The effect of patient-provider communication on medication adherence in hypertensive black patients: does race concordance matter?

BACKGROUND

Despite evidence of a positive effect of collaborative patient-provider communication on patient outcomes, our understanding of this relationship is unclear.

PURPOSE

The purpose of this paper is to determine whether racial composition of the relationship modified the association between ratings of provider communication and medication adherence.

METHODS

Effect modification of the communication-adherence association, by racial composition of the relationship, was evaluated using general linear mixed models while adjusting for selected covariates.

RESULTS

Three hundred ninety patients were in race-concordant (black patient, black provider) relationships, while 207 were in race-discordant (black patient, white provider) relationships. The communication-adherence association was significantly modified in race-discordant relationships (p = 0.04). Communication rated as more collaborative in race-discordant relationships was associated with better adherence, while communication rated as less collaborative was associated with poor adherence. There was no significant association between adherence and communication in race-concordant relationships (p = 0.24).

CONCLUSIONS

Collaborative patient-provider communication may play an influential role in black patients' adherence behaviors when receiving care from white providers.

The effect of the first office blood pressure reading on hypertension-related clinical decisions

The effect of the first office blood pressure reading (FBPR) on hypertension-related decisions was evaluated using blood pressure (BP) readings taken with the BpTRU BPM-100 device. BP readings were grouped into three pairs: (1) single readings (first and second readings), (2) computed average of three readings (one including and one excluding the first reading), and (3) computed average of five readings (one including and one excluding the first reading). Categorisation of BP readings under JNC-7 classes and distribution into < 140/90 and ≥ 140/90 mmHg groups were selected as parameters guiding hypertension-related decisions. Readings including FBPR had strong positive correlations to those excluding FBPR (Pearson's correlation coefficient ranged from 0.86-1.00). Also, FBPR-included and FBPR-excluded readings did not differ statistically in JNC-7 categorisation or distribution into < 140/90 or ≥ 140/90 mmHg groups. Our findings suggest that exclusion of FBPR may have no significant impact on hypertension-related clinical decisions.