Measuring Adherence to Control Hypertension

Despite the presence of numerous effective medications, one-half of the adults receiving
treatment for hypertension in the United States have uncontrolled blood pressure. At least
one-third of these hypertensive patients are not adherent to their blood pressure
medications. Given this high rate of non-adherence, clinicians will ideally consider whether
their patients are taking their pills before deciding whether to intensify a blood pressure
regimen. Yet, in practice, clinicians are often unsure about their patients' level of
adherence. This uncertainty limits clinicians' ability to optimally manage hypertension.
Electronic medication monitors represent the gold-standard for objectively measuring
day-to-day adherence. As a result, they have the potential to best reduce uncertainty
regarding medication adherence. The goal of this study is to test whether providing
clinicians with an objective measure of medication adherence obtained through electronic
monitoring can improve clinician management of uncontrolled hypertension. When data from
monitoring indicate poor adherence, it may motivate clinicians to counsel their patients on
adherence. Conversely, when data from monitoring indicate good adherence among patients with
uncontrolled hypertension, it may motivate clinicians to intensify treatment rather than
presume patients were non-adherent.

To test this hypothesis, this study will first enroll and randomize 30 primary care
clinicians. Clinicians randomized to the intervention will be trained in the use of a
quantitative report that summarizes their patients' adherence to blood pressure medications;
they will receive these reports during visits with patients who later get enrolled in the
study.

The study will then enroll 300 patients with uncontrolled hypertension from the same clinic.
These patients will then have their adherence to up to 4 blood pressure medications measured
by an electronic pillbox. The MedSignals® pillbox (LIFETECHniques Inc., San Antonio, TX) is
small (5"x3½"x1"), easily portable, and can simultaneous monitor adherence to up to four
medications. The device records a pill as taken each time the individual pillbox lid is
opened and closed. Data on adherence are easily uploaded (< 1 minute) by connecting the
pillbox to a telephone line.

Patients will return to the clinic after 1 month of taking their pills from the electronic
pillbox for a visit with a research assistant and their clinician. At this time, data from
the pillboxes will be downloaded and used to generate an adherence report. The report will
summarize the percent of days that blood pressure medications were taken as prescribed
during the monitoring period and will provide guidance on how to take action based on the
data. After the report is generated (< 5 minutes), patients will attend visits with their
clinicians. Clinicians in the intervention group will receive the adherence report at the
time of this visit whereas clinicians in the control group will treat patients according to
usual care (without report). Hypertension management during the 1-month clinic visit will be
assessed after the visit by 1) reviewing the medical note to determine if clinicians
intensified hypertension treatment and 2) surveying patients to determine if clinicians
counseled them on adherence. Hypertension management will then be compared between groups.

Inclusion Criteria:

- clinical diagnosis of hypertension

- prescribed at least one blood pressure medication

- uncontrolled blood pressure on at least 2 clinic visits (SBP ≥140 or DBP≥90 if no
diabetes mellitus (DM) or chronic kidney disease (CKD; glomerular filtration rate
<60mL/min); SBP ≥130 or DBP ≥80 if DM or CKD)

Exclusion Criteria:

- non-English, non-Spanish speaking

- live in institutional setting

- severe visual impairment

- terminal non-cardiovascular illness (<6 month prognosis)

- simultaneously enrolled in another cardiovascular trial

- unable to return for follow-up

- no access to a telephone

- age>80