What are Specialist and Primary Care Clinicians’ Attitudes and Practices Regarding Home Blood Pressure Monitoring for Hypertensive Patients?

Abstract

Practice guidelines recommend home blood pressure monitoring (HBPM) in the management of hypertension. We surveyed generalists and subspecialists regarding HBPM attitudes and practices in hypertensive patients. Both use HBPM for diagnostic and therapeutic purposes but question the evidence regarding HBPM efficacy. Standardized implementation and monitoring methods to improve HBPM practices are absent. Both generalists and specialists have concerns about HBPM instrument capabilities and perceive patient physical limitations and negative attitudes as additional barriers to effective blood pressure monitoring outside the office.

Introduction

Home Blood Pressure Monitoring (HBPM) or self-blood pressure monitoring is recognized as an accepted practice by providers and patients in the management of hypertension.¹ HBPM can account for the white coat effect,² confirm the diagnosis of hypertension, and provide further evidence for blood pressure (BP) control and medication effectiveness.³ HBPM is a stronger predictor for target organ damage, and related morbidity and mortality than clinic office blood pressure.^{3, 4} Although existing practice guidelines recommend the use of HBPM in the management of hypertension^5–7, there are few studies regarding physicians practices of home blood pressure monitoring in hypertensive patients in the US. Cheng et al. assessed primary care physicians beliefs about the usefulness of HBPM and found reluctance to fully endorse and incorporate HBPM into practice.⁸ Viera et al. surveyed hypertensive patients to determine the use of HBPM and found the factor most strongly associated with HBPM was recalling a doctor’s recommendation to do so. They suggested that physicians provide guidance to their patients about HBPM to improve or maintain BP control.⁹ In Europe, Tisler and others reported a high rate of home blood pressure monitoring use and acceptance by physicians and patients.^10–12 In a Canadian study by Logan et al., the majority of primary care physicians reported they recommend HBPM to their patients but only half of the patients reported receiving this information from their physicians.¹³

A study done in Singapore, reported that among hypertensive participants, 61% of the subjects were aware of HBPM but only 24% of them were using it.¹⁴ Cappuccio reported in a meta-analysis of ambulatory clinic hypertensive patients that blood pressure monitoring by patients at home is associated with better blood pressure values and improved control of hypertension than usual blood pressure monitoring in the health care system. It could be considered a useful, though adjunctive practice to involve patients more closely in the management of their blood pressure.¹⁵ In another review of the literature, Agarwal et al. concluded that HBPM compared to clinic BP monitoring has the potential to overcome therapeutic inertia and lead to small but significant reduction in systolic and diastolic blood pressure. However, they cautioned that simple monitoring of BP is of little value without more specific programs for management.¹⁶

We surveyed primary care and subspecialty physicians to assess their knowledge, attitudes and practices regarding HBPM in their hypertension patients.

Methods

The study was approved by the University of Missouri Health Sciences Institutional Review Board.

Study Participants

Primary care physicians in Family and Community Medicine, General Internal Medicine and Cardiology and Nephrology subspecialists who care for hypertensive patients in the ambulatory setting at the University of Missouri Health System clinics were eligible to participate. Departmental directories were used to identify eligible subjects. Physicians’ participation was voluntary.

Data Collection

Physician Survey

A 29-item questionnaire developed by Logan and colleagues¹³ was used to determine the “views and practices” of clinicians. It was modified by the addition of questions to ascertain physician practice characteristics. The questionnaire assessed three domains: the clinical value of HBPM; device recommendations and patient training; and, the use of HBPM in hypertensive patients.¹³ The structured survey used a multiple choice format with fixed responses. The physicians were asked to complete the surveys at faculty departmental meetings. Those who were absent were mailed a copy of the survey with a self-addressed envelope to be returned by campus mail.

Data Analysis

All the survey responses were entered into a database, verified and analyzed. Frequencies for clinician characteristics and percentages of the responses to each question were computed using SPSS statistical software version 15.0 (SPSS Inc., Chicago, IL). Chi-square statistic was used to test for differences in survey responses comparing the primary care and subspecialty subgroups.

Results

Of 110 eligible subjects 69 (63%) completed the survey. The sample included 33 (48%) subspecialty and 36 (52%) primary care clinicians. Overall, there were no significant differences in the specialists and primary care sub-groups based on gender, year of graduation or number of patients seen in clinic each week. However, 74% of the subspecialty clinicians reported that 30% or more of patients they saw had hypertension compared to 36% of the primary care clinicians (P > 0.02). Nearly three fourths of both groups reported they had less than a total of 50 patients monitoring their BP at home.

Attitudes About Clinical Use of Home Blood Pressure Monitoring

More than three-fourths of all respondents indicated that home blood pressure monitoring was “considered part of standard hypertensive care” in their practice. Nearly ninety percent reported that they almost always “request or encourage their hypertensive patients to monitor their own blood pressure at home,” with no significant difference between the two groups. Although prevalent for both groups, subspecialty clinicians were more likely to use HBPM for diagnostic purposes, than primary care respectively (100% vs 75%; P = 0.002). (See Figure 1.) More than 90% of both groups use HBPM to detect white coat hypertension, and nearly 60% use it to diagnose drug-resistant hypertension, and, or interpret low blood pressure symptoms. There were no significant differences between groups for any of the diagnostic uses including during pregnancy or to assess cardiovascular risk.

Figure 1.

Physicians’ Responses Regarding the Use of HBPM in Making Diagnostic Decision

When asked about the use of HBPM to make therapeutic decisions more than 90% of primary care and subspecialty physicians use it to guide antihypertensive therapy; and two-thirds of both groups use it to improve patient compliance with treatment. About 50% of the subspecialty and primary care physicians use HBPM to determine the 24 hour effect of medications. Although more specialists than primary care providers use HBPM to determine the best time of the day for patients to take medications the difference was not significant.

Physician Barriers to Home Blood Pressure Monitoring

Physicians were asked “what must happen for them to recommend the use of HBPM to manage patient hypertension” more often in their patients. (See Figure 2.) The only significant difference between groups is specialists were more likely than primary care physicians use HBPM if hypertension experts recommended its general use (40.7% vs 9.4%, P = 0.01). Primary care providers were more concerned about: an available list of validated devices; better methods to record and display home readings; and cheaper devices. More specialists wanted “ better scientific evidence that HBPM improves blood pressure”, and a facility to teach patients how to measure it reliably at home. However none of these differences were statistically significant.

Figure 2.

Perceived Physician Barriers to HBPM

*P < 0.05

Patient Barriers to Home Blood Pressure Monitoring

The physicians were also asked “what are the reasons why some patients do not use blood pressure monitoring devices?” (See Figure 3.) There were no significant differences between the specialists and generalists for any of the responses. Nearly half in each group indicated that: patients are not physically able or their eyesight is poor; patients are not confident in taking blood pressure properly; and, patients prefer to have their blood pressure taken by the doctor or office staff. Nearly one third indicated that their patients would become anxious if they discovered their blood pressure was not controlled; and patients had been told that the devices are inaccurate. However the physicians’ practices also posed a barrier in that over 40% in each physician group indicated there was no one available to teach patients to use the machines properly.

Figure 3.

Patient Barriers to the Use of HBPM

Device and Patient Training

Additional questions addressed clinician attitudes regarding the use of specific devices and patient HBPM education and training. Subspecialty clinicians were less likely to provide patients specific guidance as to the type of home blood pressure monitor to buy, although not statistically significant, (32 % vs 17 %, P = .12). Specialty physicians were less likely to give the name of device that they found reliable to their patients (subspecialty (12 %) vs primary (44%), P = .02). Over eighty percent of both clinician groups responded that they recommend a device with the upper arm-cuff.

Although not statistically significant, specialists were less likely to indicate that the instruction booklet supplied with the home device was sufficient for training (18% vs 28%, P = .34), and less likely to encourage patients to ask the supplier to teach them the proper technique (46% vs 57%, P = .40). More than ninety percent of both groups responded that HBPM devices should be covered by insurance. Both indicated that patients would be more likely to use HBPM if they were cheaper to buy specialist 22% vs primary 34%, P = .30). Three fourths from each group responded that they periodically check their patients’ readings against measures in the office to ensure that the device has not become faulty through continuous use.

Current Practices with Home Blood Pressure Monitoring

Nearly half of physicians in both groups recommended for diagnostic purposes that patients take pressure readings a few times per week until the subsequent visit. Nineteen percent of the subspecialty clinicians recommend that their patients check blood pressure several times each day until next office visit compared to none of primary care physicians. In contrast the physician recommendations of HBPM for therapeutic reasons varied considerably in several instances. Figure 4 shows the recommendations to monitor hypertension therapy. As with diagnostic recommendations, the majority subspecialty and primary care physicians recommended that patients measure their BP a few times a week until the office visit. However, primary care clinicians were more likely to recommend that patients measure their blood pressure a few times per month than subspecialty clinicians (19.4% vs 3%), P = .03, respectively.

Figure 4.

Physicians’ Recommendations of HBPM for Therapy

*P < 0.05

Approximately ninety percent of all clinicians encourage their patients to call the office, particularly if they had persistently high or low BP readings or if they had high or low readings accompanied by symptoms. When patients bring a list of HBPM readings, 60% of both specialists and primary care providers review them and make notes. Few subspecialists (6.3%) and fewer primary care (17.1%) clinicians responded that they averaged the readings and use the average to assess trends.

Discussion

Our findings indicate that both physicians groups regard HBPM to be a standard part of their practice and encourage hypertensive patients to monitor their own blood pressure at home. Both use HBPM for diagnostic and therapeutic purposes i.e. to detect white coat hypertension, diagnose drug-resistant hypertension, to guide anti-hypertensive therapy and to improve patient compliance with treatment, consistent with published practice guidelines. Subspecialty clinicians recommend their patients measure their blood pressure more frequently than primary care clinicians, consistent with the increased disease severity of their patients.

Both physician groups indicate that they consider patient concerns about the readings and difficulty in preforming HBPM as barriers to the implementation of HBPM. These results support and expand on previous reports of similar concerns among physicians.^11,14 Another potential barrier is the need for better methods to record and display home readings. Yet many devices have memory that record and store readings. Both also indicate that HBPM devices would be more utilized if the devices were affordable for their patients. However recommended validated devices with memory are available for U.S. $60, comparable to a single office visit that may be unnecessary with a patient phone call to report their HBPM results. The fact that specialists want better scientific evidence that HBPM improves blood pressure control is inconsistent with the published literature showing improvement in patients with congestive heart and renal failure. Finally the evidence from the survey results indicates the need for more specific programs that would address the reported knowledge and process deficits identified in this study considered barriers to successful home blood pressure monitoring.

Regarding the study methods, the generalizability of the study results are limited by the relatively small sample size obtained from a single academic health science center. Nevertheless the results are the first to provide a comparison of subspecialists and generalists who provide a care for patients with hypertension. Also, the results support and expand on the previous literature, especially regarding the barriers that may compromise implementation of HBPM. The study did use a previously validated survey that provided a comprehensive assessment of clinician attitudes and practices as they relate to the use of HBPM.

Conclusion

Both primary care providers and subspecialists who provide care for hypertensive patients support HBPM for diagnostic and therapeutic purposes. However concerns regarding the evidence for its efficacy and perceived patient barriers to its successful use likely contribute to underutilization of HBPM by these clinicians. Clinician education that provides evidence to support the proven efficacy of HBPM practices; as well as additional efforts to mitigate the perceived but unproven patient barriers, may be indicated to improve HBPM practices. Furthermore more formalized office protocols to initiate and monitor home blood pressure monitoring would likely benefit these and other clinician HBPM practices.

Biography

William C. Steinmann, MD, MSc, Rebecca Chitima-Matsiga, MS, MPH & Sarika Bagree, MD, are all in the Department of Internal Medicine, University of Missouri - Columbia School of Medicine.

Contact: chitima-matsigar@health.missouri.edu