Improving Blood Pressure Control Using Smart Technology

Abstract

Background:

The authors sought to determine if wireless oscillometric home blood pressure monitoring (HBPM) that integrates with smartphone technology improves blood pressure (BP) control among patients with new or existing uncontrolled hypertension (HTN).

Methods:

A prospective observational cohort study monitored BP control before and after an educational intervention and introduction to HBPM. Patients in the intervention group were instructed to track their BP using a smartphone device three to seven times per week. Cases were matched to controls at a 1:3 allocation ratio on several clinical characteristics over the same period and received usual care. The proportion of patients with controlled BP was compared between groups at pre- and postintervention, ∼9 months later.

Results and Materials:

The total study population included 484 patients with mean age 60 years (range 23–102 years), 47.7% female, and 84.6% Caucasian. Mean preintervention BP was 137.8 mm Hg systolic and 81.4 mm Hg diastolic. Mean BP control rates improved for patients who received HBPM from 42% to 67% compared with matched control patients who improved from 59% to 67% (p < 0.01).

Conclusion:

HBPM with smartphone technology has the potential to improve HTN management among patients with uncontrolled or newly diagnosed HTN. Technology needs to be easy to use and operate and would work best when integrated into local electronic health record systems. In systems without this capability, medical assistants or other personnel may be trained to facilitate the process. Nurse navigator involvement was instrumental in bridging communication between the patients and provider.

Introduction

Home blood pressure monitoring (HBPM) has a well-established primary role in diagnosis, treatment adjustment, and follow-up for patients with hypertension (HTN), and current guidelines recommend its wide use in clinical practice.^1,2 There are many types of HBPM, including those that use wireless technology that link wireless sensors through radio signals to smartphones and computers. Wireless technology is a promising and innovative method for managing healthcare in patients with chronic illness. Until 2010, no wireless connectivity technology met all the requirements needed for widespread adoption, that is, interoperability, low-power operation, customized software, compatibility, transmission, and sensors needed to communicate with services. Bluetooth low energy technology is an innovative technology that meets all these requirements.³ Today, wireless technology has become more affordable and acceptable, especially in low-resource settings, making it an opportune time to adopt smart technology to better engage patients in the self-management of chronic diseases.^4
–6 However, challenges to the adoption of any technology include the rapidly changing nature of technology development and the cost of new technology.³

Two 2010 studies summarized the evidence available on the clinical usefulness and current limitations of wireless technology in healthcare and found that home blood pressure (BP) wireless monitoring represents a promising technology to help improve the diagnosis and management of HTN, increase the rate of BP control, and at the same time reduce the risk of overmedication in hypertensive patients.^7,8 They concluded that the transmission of BP values could be considered a potentially useful complement to conventional HBPM when managed in the community, with patients taking an active role in their disease management.⁷

Recent studies suggested that technology alone is not sufficient to improve BP control, but rather attention needs to be focused on accompanying workflow changes, information flow, and additional personnel resources. Device connectivity and usability may present challenges, and motivated patients are most likely to be successful.^9,10 Providers have mixed responses to the change in workflow necessitated by technology. E-messages may create disruption of the normal workflow, and may create additional work for which the provider is not paid. Providers are not clear whether BP technology has shown that the “immediacy” of the response to the treatment plan has been proven to be better than the normal face-to-face office visit, where more in-depth communication and planning can be discussed.¹⁰ In contrast, North and colleagues noted that e-messages save patients the cost of a face-to-face visit and also increase access to visits for other patients.¹¹ In another study, it was reported that of all the secure messages providers receive, BP related messages compromised only 1.2% and of those, 17% required a change in medication dose or prescription.¹² As home healthcare continues to grow, home monitoring is not likely to go away. Efforts to improve workflow processes that are not intrusive will reduce the use of both acute and chronic care services in healthcare organizations.

This study was designed to test the use of wireless smartphone HBPM to improve BP control among patients with newly diagnosed or persistently uncontrolled HTN. The study protocol included the enhanced use of electronic health records (EHRs) to allow care providers to easily monitor their patients' home measurements. The authors hypothesized that patients' awareness of their disease, facilitated by easy and frequent self-monitoring, and their healthcare providers' access to enhanced information would improve this population's HTN control.

Methods

In 2013, four healthcare organizations partnered with AMGA in a pilot project to improve BP control using HBPM smartphone technology. AMGA, a trade association representing multispecialty medical groups and integrated systems of care across the United States, is composed of more than 170,000 physicians, delivering care to one in three Americans. The program was part of AMGA Foundation's Measure Up/Pressure Down^® national campaign to improve BP control across the country. Primary campaign goals were to mobilize medical groups and health systems to achieve measurable improvements in high BP prevention, detection, and control (80% of patients at goal by 2016). Secondarily, the campaign sought to engage and empower patients to actively manage their health, by raising awareness of the dangers of uncontrolled high BP and to encourage consumers to obtain regular BP screenings, partner with their healthcare provider, make lifestyle changes, and take their BP medication as prescribed. This project allowed the healthcare organizations to contribute research or quality improvement findings to this campaign, engage patients in education about the risks of uncontrolled HTN, and encourage primary care providers to use the home monitoring values entered into the EHR to better manage their patients' disease.

This observational study used a prospective cohort design. Patients with newly diagnosed or uncontrolled BP were recruited for the project from four geographically dispersed primary care clinics across the country, all of which were primarily fee-for-service. Three sites focused on quality improvement measures, and the fourth conducted a study (referred from here on as the study site). Three EHRs were represented as follows: Cerner, Allscripts, and GE Centricity.

Patients were recruited to participate in August–September, 2014, using a variety of methods. Most organizations received direct referrals from primary care providers, usually from family practice and internal medicine practices, who were asked to refer patients with newly diagnosed or persistently uncontrolled BP, that is, ≥140/90 mm Hg, during regularly scheduled office visits. Providers who referred patients were included in the study by their action of patient referral, an implicit agreement to participation. Patients were either referred directly to the project or patient names were provided to project staff for subsequent follow-up. Project staff was often present during clinic hours to enroll patients. At some sites, potential patients were identified in advance of their visit. These patients were approached during a regularly scheduled visit or contacted through phone or patient portal. In addition, recruitment included direct outreach to clinic employees. There were no notable patient and provider selection differences by site. Patients were required to be 18 years or older and have access to any phone or tablet with smart technology. Upon consent, patients were enrolled on site and received training on the use of the smart technology and how to correctly take their BP with the wireless monitor. Because the monitor manufacturer provided only one cuff size that fit arms 9–17 inches, patients with arm circumferences out of that range were excluded. Arm circumference was measured when size was potentially out of range. Educational materials about HTN were distributed and discussed with the patients. Enrollment, education, and training lasted ∼30 min. Validation occurred by research staff with a sample of individual cuffs.

All four sites used the same Food and Drug Administration-approved BP monitor intended for use in measuring adult BP and pulse rates. The operational principle is oscillometric and silicon integrated with pressure sensor technology that calculates the systolic and diastolic BP. The monitor integrates with iPhone, iPad, iPod Touch, or Android devices and connects through Bluetooth or a USB cable. All sites used the same software application.

At the study site, patients took the BP monitors home and were asked to take their BP three to seven times per week, for the 9-month study period, at the same time each day (1 h after medications and/or 1 h after eating). Nurses or providers monitored the BP database for uploaded values from project patients at a minimum of once per week. Patients with out-of-range values, per the JNC-8 guidelines,¹⁴ were flagged, and primary care providers were notified through internal EHR messaging, as appropriate. Out-of-range values were compiled in weekly reports communicated by a nurse navigator to the nurse practitioner (NP) or provider. Patients were called by phone to encourage engagement and adherence to study protocols. Patients were encouraged to contact the nurse navigator with any problems using the monitors. Face-to-face visits were scheduled to address technological problems unsolved by phone. There were no required face-to-face visits as part of this study except for the final visit during which BP monitors were turned in and a postintervention survey was completed. Patients at the three quality improvement sites followed similar protocols.

Data Collection and Statistical Analysis

Data from all four sites were downloaded from the protected web portal and then imported into the study dataset. Patients could not manipulate which readings were transferred; all available readings were transferred and were date and time stamped. No information about patients' position or activity level was recorded. No data were automatically uploaded into the local EHRs. Following an Intent to Treat (ITT) protocol, project patients (cases) were retrospectively matched to control patients using a 1:3 ratio on healthcare organization and exact date of baseline BP reading. Patients with no to minimal participation were retained. If a follow-up BP was not available, the baseline reading was used for follow-up. The proportion of patients with controlled BP was compared, at pre- and postintervention, as measured by office readings for controls and HBPM reading for cases. The reason for using the HBPM readings for cases was that there were no available office readings in a comparable date range. Although HBPM readings are typically lower than office readings, in this case they were higher, due to study recruitment criteria of uncontrolled BP or new HTN diagnosis. Initial and final BPs were taken under similar circumstances and locations and comprised the first and last readings in the intervention period. Cases were compared to matched controls using a difference-in-differences approach, to control for differences at baseline. In addition, logistic regression models controlled for age, baseline BP control status, duration in study, and presence of a diabetes diagnosis as a proxy for severity of illness.

Patient-level outcomes included measured improvements in the proportion of patients with BP considered “controlled,” defined as <140/90 for patients aged <60 or <150/90 for patients ≥60; patient satisfaction with the device, the smartphone application, the data, and their relationship with their provider; and patient's sense of well-being. Chart reviews were conducted on all patients at the study site to determine providers' actions based on information obtained from the wireless BP monitors, specifically elevated readings identified by the study nurse navigator. Thirty-seven patient charts were reviewed to determine if medication changes were made during the study period.

This study was approved by the community Institutional Review Board of Billings.

Results and Materials

Data were collected from October 2014 to May 2015; 131 patients were included in the analyses, and no patients were excluded due to out-of-range arm circumference. Following an ITT protocol, all patients, regardless of participation in the intervention, were retained in the analysis. Thirty-seven patients with 17 unique providers, representing 3 clinic sites, participated at the study site; 94 additional patients were enrolled in parallel quality improvement projects at the other 3 clinics, followed similar protocols, and used the identical device. A total of 353 matched control patients were included for comparison. Table 1 shows preintervention characteristics of the overall sample; statistically significant differences were identified in age, diabetes diagnosis, duration in study, and baseline BP control. These variables were therefore included in the logistic regression model. The results from the logistic regression analysis are included in Table 2. Use of the smartphone BP monitor was found to be an independent predictor of improved BP control when controlling for age, baseline diabetes diagnosis, and baseline BP control status (p < 0.05). Cases and matched controls were compared on pre- and postintervention rates of BP control at the four clinics combined. Average BP control rates improved from 42% to 67% among cases compared to 59–67% among matched controls. A difference-in-differences analysis found a statistically significant improvement among the cases (confidence interval: 1.08–2.62; p < 0.01) controlling for duration in study, age, diabetes diagnosis, and baseline systolic BP.

Table 1.

Preintervention Participant Characteristics

	CONTROLS	CASES
	(N = 353)	(N = 131)
Participating clinic, n (%)
Clinic A	82 (23.2)	32 (24.4)
Clinic B	97 (27.5)	34 (26.0)
Clinic C	99 (28.1)	37 (28.2)
Clinic D	75 (21.3)	28 (21.4)
Female sex, n (%)	169 (47.9)	62 (52.7)
Age group, ≥60 years,^* n (%)	210 (59.5)	48 (36.6)
Race, n (%)
White	293 (84.7)	107 (84.3)
Black	37 (10.7)	14 (11.0)
Other	16 (4.6)	6 (4.7)
Hypertension, n (%)	332 (96.5)	121 (96.8)
Diabetes,^** n (%)	142 (41.3)	64 (51.2)
Office BP, mm Hg, mean (SD)
Systolic	137.6 (21.8)	138.4 (16.8)
Diastolic	80.6 (10.2)	84.2 (10.4)
BP control,^*** n (%)	208 (58.9)	55 (42.0)
Duration in study,^* mean days (SD)	57 (66.4)	125 (53.2)

p < 0.0001; ^** p < 0.10; ^*** p < 0.001.

BP, blood pressure; SD, standard deviation.

Table 2.

Logistic Regression Model of Primary Outcome Blood Pressure

VARIABLE	ESTIMATE	ODDS RATIO	STANDARD ERROR	P-VALUE	CONFIDENCE INTERVAL
Intercept	−1.1090	na	0.4705	0.1339	na
Treatment	0.6704	1.96	0.3200	0.0362	1.04–3.66
Baseline BP control	1.7631	5.83	0.2511	<0.0001	3.56–9.54
Baseline diabetes diagnosis	0.1175	1.13	0.2431	0.6290	0.70–1.81
Age	0.0130	1.01	0.0085	0.1249	0.99–1.03
Study duration	−0.0009	1.00	0.0019	0.6486	0.99–1.00

BP control defined as <140/90, or <150/90 if age ≥60.

Chart reviews at the study site revealed that 35% of providers started or added a new medication, 22% increased the dose of an existing medication, and 10% discontinued a medication over the duration of the study. The 57% that added a medication or increased a dose showed greater improvement over the course of the study period in terms of BP control. Lifestyle changes, that is, diet or exercise, were recommended by 68% of providers, 43% recommended a nurse recheck of their BP, and 5% referred patients to a specialist, dietitian, educator, or other healthcare provider.

Patient compliance with the study protocol of taking three BPs per week is displayed in Figure 1. Patients' compliance decreased considerably during the study. Table 3 shows study site patient responses to survey questions on patient experience with the device. Eighty-six percent of the patients at the study site completed surveys and 89% reported positively to questions on ease to use. A total of 74% reported that the device had a positive impact on their BP control and 83% answered positively regarding satisfaction of the device. Informal interviews conducted at the close of the study also revealed that the majority of patients (68%) asked to keep the cuffs to continue to work with their primary care providers on BP control. One patient reported that their primary care provider was more responsive to them when they brought their own validated BP readings to the office, “I could show my doctor what was going on at home and she then realized the extent of the [BP] variability. Now, I have a medication regimen that has stabilized my BP.”

Fig. 1.

Patient compliance with study protocol by week in study (n = 37).

Table 3.

Patient Perceived Ease of Use, Effect on Outcomes, and Patient Engagement (n = 32)

SURVEY ITEMS	(%)
Ease of use
I felt confident that I was using the device correctly.	100
The device was easy for me to use.	75
The instructions I received on how to use the device were comprehensive.	100
I quickly learned how to use the device.	91
Connecting the device to the phone was easy for me to do.	78
Effect on outcomes
The device improved my ability to monitor and control my BP.	81
Use of the device enhanced the ability of my provider and me to improve my BP control.	75
I have seen improvements in my BP since I started using the device.	69
I monitor my BP pressure at home more regularly now that I am using the device.	72
Patient engagement
I feel more confident in my medical provider's ability to help me control my BP since I started using the BP monitor.	72
Use of the device improved communications with my medical provider regarding my BP.	78
I feel more comfortable in my ability to improve my health.	84
The device improved my motivation to try to control my BP.	84
The BP results that I obtained through the device were about what I expected to receive.	84
I get clear feedback on my BP level.	88
I recommend this device to people trying to monitor their BP.	81
Use of device did not disrupt my personal life.	81
BP results obtained through device were clear.	94

All items were measured on a 1–5 Likert scale, 1 = Strongly Disagree, 5 = Strongly Agree; Positive response was defined as a response of Agree or Strongly Agree.

As other studies have demonstrated,^3,10,13 the study site experienced technology/user complications, despite advanced Bluetooth technology. For example, transmission of data could be obstructed if other Bluetooth-enabled devices were within range. In addition, as smartphone technology advanced, the BP monitor manufacturer had to play catch up to maintain patients interface with technology improvements. The manufacturer experienced day-to-day problems such as maintaining the website, acclimating their application to Android phones, and pairing devices. Patients also experienced intermittent access to Internet service in rural settings and while traveling outside the United States. The nurse navigator was able to address or correspond with the manufacturer when necessary to resolve all of these issues.

Discussion

This pilot study was part of AMGA Foundation's Measure Up/Pressure Down national campaign to improve BP control across the country. The study implemented a HBPM program, facilitated by nurse navigator-led workflow improvements, using Bluetooth connectivity through Apple and Android smartphones. Patients in the HBPM program demonstrated significantly greater improvement in BP control compared to a matched control population.

In 2016, Lee and Park noted, “One of the major determinates of low BP control results from therapeutic inertia of the physician and suboptimal compliance of patients.”¹⁵ Just as patients need strategies to integrate BP monitoring into their daily lives, healthcare professionals need to develop strategies to integrate technology sources of communication into their normal workflow. At the study site, with assistance from a nurse navigator, an NP evaluated the results and consulted the patient's primary care provider if communication of patient information advice was needed. Providers responded to communication from the NP with changes in medication, lifestyle recommendations, nurse recheck, and/or referral to other healthcare resources 59% of the time. This process addressed the problem of both too much and too little information, that is, providers are either overwhelmed with patient information or must wait for a subsequent visit to receive any patient information. Other studies have reported that self-monitoring with supportive intervention from a case manager/advanced practitioner, or the implementation of patient-centered protocols for self-titration where appropriate, led to improved BP control.^{9,10,15
–17} This was directly addressed by involvement of a nurse navigator who facilitated improved workflow and interprovider, as well as patient-provider, communication.

Therapeutic inertia may also be enabled by misaligned incentives. In traditional fee-for-service-based payment models, physicians were only reimbursed when a patient was seen in person, hence healthcare providers were reluctant to manage chronic disease “on the fly.”^10,18 In today's environment, characterized by a shift toward value-based payment models, control of chronic diseases is paramount. Providers will increasingly need to rely on the patient and supportive technology for timely and actionable information. In addition, improved BP control translates to improved quality measures and potential shared savings for healthcare organizations who are required to report measures like BP control under the 2015 Medicare Access and Chip Reauthorization Act (MACRA).

This study differed from previous studies in that patients were not responsible for uploading or transferring data.^9
–11 Instead, data were directly transferred to a secure network from the device at the time of BP measurement. This mitigated the potential issue of patients selecting readings for their provider. However, patients could still choose to take as many or as few readings as they liked, leaving open the possibility of “noncompliance.” As demonstrated in previous studies, we found improved BP control over time with this technology. Overall, the HBPM program, punctuated by involvement of a nurse navigator, facilitated patients taking a more active role in their care and lifestyle and physicians responding to the results in a more frequent and timely manner.^8,18

One barrier to providers was that the EHR vendors would not allow direct transfer of data from an outside device. “Work around” processes were implemented at all sites. At the study site, the nurse navigator used a password-protected secure website to download and review patient data and calculated mean, maximum, and minimum BP values to share with participating providers. Integration into EHRs would ensure sustainability. Patient barriers included technical issues, particularly among older patients; however, only a minority of patients reported problems.

Study limitations included potential selection bias due to purposive patient sampling and the requirement that they have a smart device, resulting in limited generalizability of results. In addition, some results are limited to one smaller study site. However, conclusions derived from the additional three sites were consistent with those from the study site. Furthermore, inclusion of these sites broadens the generalizability of the findings as they represent both independent medical groups, as well as integrated delivery systems, in three U.S. states and covering three distinct geographic regions with diverse patient populations. Costs of equipment and staff and patient training were minimal and could be considered an investment in prevention and improved quality measures.

The type of collaborative, patient-supported HTN management demonstrated in this study proved to be invaluable in controlling BP as it addressed both physician therapeutic inertia and patient medication adherence. It might also be used for short-term patient monitoring during medication changes or times when BP may fluctuate or may require closer monitoring. Ultimately, this work supports Merrell and Doarn's statement, “Seamless, continuous, coherent management of chronic disease is becoming the expected mode of care in these conditions…with telemedicine as a tool for such care.”¹⁹

Conclusions

HBPM enabled by smartphone technology is a feasible and affordable method to improve HTN control among patients to improve population health, meet quality measure requirements, and may become a necessity under new value-based payment systems. The potential for direct transfer of BP measurements through smart technology advances the use of home monitoring devices. In 2017, the Pew Research Center reported that over three quarters of Americans (77%) own smartphones.²⁰ The smartphone application is free and the home monitor costs around $90 on Amazon, equivalent to most home monitors, and loaner programs can be implemented in primary care practices. Training of patients and staff is minimal and the workflow required can be integrated into a nurse navigator's or care coordinator's population health activities, and other healthcare personnel, such as medical assistants, could be trained to fill this role to reduce costs. The greatest barrier is integration into local EHRs and needs to be addressed with each individual vendor; however, the device manufacturer has designed the monitors for universal integration.

Footnotes

Acknowledgments

The authors acknowledge the four clinics that participated in the study or in parallel qualitative improvement projects aimed at improving blood pressure control in their patient's populations: Billings Clinic, Billings, MT; Cornerstone Health Care, P.A., Highpoint, NC; Community Physician Network, Indianapolis, IN; and Wilmington Health, Wilmington, NC. The authors also wish to acknowledge Optum Analytics for their collaboration, data provision, and support during this initiative.

Disclosure Statement

No competing financial interests exist.

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