Iltifat Husain MD contributed to this piece

According to the American Heart Association, hypertension affects nearly 78 million Americans and its prevalence is increasing.

As a major contributor to coronary artery disease, renal disease, and cerebrovascular disease, effective management of hypertension is of critical importance both on an individual level and from a public health standpoint. Like many chronic diseases, self-management is particularly important.

A commonly employed strategy is home blood pressure monitoring – an approach endorsed by the American Heart Association, American Society of Hypertension, and other professional societies. When you think about it, self-tracking of home blood pressure seems to be a task that should be particularly amenable to mobile health tools like smartphone or tablet applications.

As part of a focus on chronic disease self-management, iMedicalApps will be putting together several features on specific conditions that are intended to help clinicians understand (1) the evidence for use of smartphone applications and (2) available tools that they can recommend to their patients. First, we’ll start with hypertension.

Here we present the results of our literature review and share the insights we gained on what evidence-based features we believe should be included in patient-centric apps for hypertension self-management. In upcoming pieces, we’ll look at available apps as well as connected blood pressure monitors and try to provide a roadmap for integrating these tools into your practice.

Methods

We conducted an extensive literature review utilizing PubMed (search term available at the end of this article). We sought studies which included the use of a PDA, smartphone, or tablet app for the self-management of hypertension with the following filters:

  • Published within past five years
  • Abstract available
  • English

Results

We retrieved 1175 abstracts which were reviewed. A total of 15 abstracts were selected for further review of the full manuscript. Of these, 6 apps were excluded as they did not include an app in some way. Of note, we additionally reviewed several meta-analyses and reviews which we felt offered additional insights into the use of apps for hypertension self-management. The included studies and reviews were reviewed to identify features that were likely to contribute to more effective self-management of hypertension.

No studies were found which evaluated specific features of mobile apps. However, several studies and reviews addressed or incorporated components that are readily integrated into smartphone and tablet apps. As such, features that were assessed to be likely to contribute to more effective self-management apps were identified.

Evidence-Based App Features

Medication Reminder Function

Poor adherence to medical therapy is often cited as a major problem in the management of a variety of chronic medical conditions.

In one small study specifically using an app as a platform for medication reminders, Patel et al showed a trend towards improved adherence based on pharmacy refill data (1). While the study population was quite small (~50 patients), it is unique in that the intervention was based on patient entry of medications and automatic alarm reminders. McGillicuddy et al, in a study of poorly controlled hypertensive renal transplant patients, also showed improved adherence to medical therapy using smartphone-based reminders, though this study also included an electronic pillbox (2).

While these studies are small, some additional support is lent to the inclusion of this functionality by a recent systematic review by Verloet et al of electronic medication adherence systems. Of 13 studies identified for inclusion, the majority found positive effects on short-term medication adherence using tools like SMS-based reminders or dedicated reminder devices (3).

Measurement Reminder Function

Similar to the problem of medication nonadherence, a challenge in the clinical use of home blood pressure monitoring is actually measuring blood pressure at home.

Several studies tackled this problem using a functionality that reminded patients to measure their blood pressure, though none actually evaluated or compared specific strategies. McGillicuddy et al used a strategy of providing reminders every three days (2). In the protocol utilized by Logan et al, the app provided an alert whenever a planned measurement was missed (4).

Inclusion of this functionality is largely based on the assessment that available studies incorporated some sort of reminder function to encourage blood pressure measurement. We should note that we were not able to identify studies that compared specific reminder strategies. That being said, the flexibility offered by most apps will allow users to easily create and modify reminders until they hit on the right strategy for them.

Incorporation of Self-Care Messages

The typical 15 minute follow-up clinic visit every three months is not well designed for effective counseling. One opportunity offered by apps is the ability to deliver adjunctive automated counseling.

Logan et al utilized an automated, app-based messaging system in which educational messages were delivered in response to a patient monitoring their blood pressure (4). Using this tool, they achieved a relative 7 mm Hg decrease in systolic blood pressure. Improvements in blood pressure control were also seen in studies done by Park et al in which patients entered information into a web-diary and self-care messages were delivered via SMS (5-7).

Clinical experience tells us that getting patients to change long-standing behaviors to improve hypertension control is, in large part, dependent on making the numbers relevant. When a patient takes the time to measure their blood pressure, they are clearly engaging in their health – a moment that may be particularly opportune for delivery of educational messages.