The Road to Implementing Home Blood Pressure Monitoring: Are We There Yet?

Home blood pressure monitoring (HBPM) is recognized by several guidelines and scientific statements as a key component of hypertension diagnosis and management.^1–3 HBPM involves self-monitoring blood pressure (BP) at home, typically using an oscillometric device. Societies such as the American College of Cardiology (ACC), American Heart Association (AHA), American Medical Association, and Centers for Disease Control and Prevention have recommended use of HBPM as an adjunct to office-measured BP.^1,2,4 The 2017 ACC/AHA BP guideline supported the use of out-of-office BP measurements, including with HBPM, to confirm the diagnosis of hypertension and to manage treated hypertension.² In the past, studies with national US data have suggested that HBPM is already being performed by adults, particularly those with hypertension. In an analysis from National Health and Nutrition Examination Survey (NHANES), years 2009–2010, Ostchega et al. estimated that 14.5% of adults engaged in monthly or more frequent HBPM measurement.⁵ Among adults with hypertension, 36.6% engaged in monthly or more frequent HBPM. These findings are similar to data from NHANES, years 2011–2014.⁶ Although several guidelines have recommended HBPM for the diagnosis and management of hypertension, there are several obstacles to the widespread use of HBPM in the United States including patient-related barriers such as cost, insurance coverage, and difficulty with following HBPM procedures.⁷ There are also provider-level barriers, including not recommending HBPM to patients, lack of knowledge about the importance of HBPM, cost, and need for patient training.

In this study, Tang and Juraschek examined the sociodemographic and clinical factors associated with self-reported use of HBPM and physician recommendation for HBPM among adults with hypertension; and the associations of HBPM and physician recommendation with measured office BP and antihypertensive medication use⁸. The authors used data from NHANES, years 2009–2014. After applying exclusion criteria, a total of 6,366 adult participants (≥20 years of age) were included. Participants were queried about whether they were told by a doctor to take their BP at home, and whether they took their BP at home during the prior 12 months. Additional measures included office BPs obtained at a mobile examination clinic and self-reported adherence, defined as a participant reporting taking a prescribed medication for high BP/hypertension.

Among adults with hypertension, 30% reported being told to perform HBPM, and 44% reported HBPM use. Of the individuals who reported being told to perform HBPM, 82% reported HBPM use at least once in the prior year. In contrast, of the 70% who did not report being told to perform HBPM, 28% reported HBPM use in the prior year. Having insurance, higher educational attainment, and a prescription for antihypertensive medication were associated with a physician recommendation to perform HBPM. Of those told to perform HBPM, HBPM was associated with a lower systolic and diastolic office BP (−3.1 mm Hg; 95% confidence interval (CI): −5.7, −0.5, and −4.5 mm Hg; 95% CI: −6.2, −2.8, respectively). In contrast, among those who did not report being told to perform HBPM, HBPM use was not associated with a lower systolic office BP (1.2 mm Hg; 95% CI: −0.7, 3.2), but was associated with lower diastolic office BP (−2.0 mm Hg, 95% CI: −3.6, −0.6). Compared with those who did not report a physician recommendation and did not use HBPM, participants who had a physician recommendation but did not perform HBPM had a higher average BP. Among those who reported ever having been prescribed and advised to take an antihypertensive medication, participants who received a physician recommendation and used HBPM were more likely to report taking antihypertensive medication than those who did not receive a recommendation to use and did not use HBPM. These data indicate that (i) physician recommendation was associated with HBPM use, (ii) HBPM use was associated with lower systolic and diastolic BP when participants were told to perform HBPM, and (iii) individuals who received a physician recommendation to perform HBPM and reported using HBPM were more likely to be taking antihypertensive medication if instructed to do so. The findings suggest that physician recommendation to perform HBPM and HBPM use by the participant are both important for better BP control and adherence to prescribed antihypertensive medication. These findings make intuitive sense and speak to the importance of shared decision making in the management of hypertension, a chronic disease.

In addition to addressing an important research question, the study by Tang and Juraschek et al. has other notable strengths. The analysis was performed in NHANES, a nationally representative health survey. Further, NHANES provided important data including accurate physiologic measurements such as research grade office BP as well as sociodemographic variables allowing the authors to examine relevant measures of socioeconomic status.

The study must also be interpreted within the context of its potential limitations and the presence of several unanswered questions. Physician recommendation to perform HBPM, HBPM use, and antihypertensive medication use were all self-reported. The study was cross-sectional and therefore it was not able to determine causation. For participants who reported using HBPM, it is unknown if HBPM measurements were obtained in a standardized manner consistent with recommendations from clinical guidelines (i.e., seated and after an appropriate period of rest; proper position of the measurement arm, legs, and feet; correct cuff size, etc.),^2,3 and whether participants followed a recommended BP monitoring schedule (i.e., 2 readings in the morning and 2 readings in the evening for a minimum of 3 days with an optimal period of 7 days).^2,3 It is unknown how, or even if, physicians instructed patients to perform HBPM. It is also unclear if participants used validated BP devices that have been tested for clinical accuracy. While only validated BP measurement devices are recommended for clinical use,² many devices available for patients to purchase online are not validated or fail to meet established criteria for clinical accuracy.⁹ Another limitation of this study is that it uses data from NHANES 2009 to 2014 which preceded recent recommendations from the 2017 ACC/AHA BP guideline.² Physician and patient views on HBPM may have changed in recent years.

A final unanswered question is how often cointerventions such as telemonitoring, web-based or phone support, patient education, and tele-counseling were used when individuals performed HBPM. Cointerventions are a key component to using HBPM to reduce BP. Meta-analyses have demonstrated that, compared with usual care, the use of HBPM alone without cointerventions leads to reductions in systolic and diastolic BP at 6 months but no difference at 12 months.^10,11 In contrast, there is evidence for reductions in systolic and diastolic BP at 12 months when HBPM is accompanied by moderate to high levels of cointervention support.¹² Therefore, simply recommending that patients use a HBPM device without the support of cointerventions is insufficient for long-term BP control. This issue is emphasized by the 2017 ACC/AHA BP guideline which recommended the use of HBPM to manage hypertension in conjunction with telehealth counseling or clinical interventions.²

The study by Tang and Juraschek et al. also demonstrated that most adults in the United States neither were told by a physician to perform HBPM nor reported using HBPM. To ensure the wider implementation of HBPM in the United States, there should be investment to support education and training activities for clinicians and patients about recent guideline recommendations and the use of proper HBPM measurement protocols and device selection; and implementation of cointerventions, health information technology including telemonitoring, electronic transmission of home BP data, and integration of HBPM with the electronic health record.

Finally, the cost of HBPM is a concern that has been raised by patients and providers.^13,14 As of 1 January 2020, 2 CPT codes have been available to support HBPM: CPT 99473, self-measured BP using a device validated for clinical accuracy with patient education/training and device calibration; and CPT 99474 separate self-measurements of 2 readings 1 minute apart, twice daily over a 30-day period (minimum of 12 readings), collection of data reported by the patient and/or caregiver to the physician or other qualified health care professional, with report of average BP and communication of a treatment plan to the patient. Medicare coverage for HBPM devices depends on the type of Medicare plan and eligibility criteria. HBPM devices are excluded from the list of DME that Medicare Part B covers.¹⁵ Medicaid coverage for HBPM devices varies by state. Further, a small number of private and commercial payers providing coverage for HBPM devices. Whether changes in coverage will increase utilization of HBPM remains to be seen.

In summary, the findings by Tang and Juraschek et al. indicate the importance of a physician recommendation and a partnership between patients and physicians for the performance of HBPM to reduce BP levels. With hypertension remaining a leading risk factor for cardiovascular disease and morbidity and mortality worldwide, there exists a persistent and urgent need to more effectively manage this chronic disease and reduce its healthcare burden. Strong evidence has demonstrated that HBPM is superior to office BP for predicting end-organ damage and cardiovascular disease events, and adds value to office BP measurement for the management of hypertension.^16,17 HBPM is an important tool in hypertension control, however its implementation cannot be achieved without addressing current barriers to its use and trying to overcome them.

Funding

D.S. received research support through grants R01HL117323 and K24-HL125704 from the National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute (NHLBI).

DISCLOSURE

The authors declared no conflict of interest.