Clinical trial NCT04485637: Helping Hypertension Patients to Interpret Blood Pressure Readings and Motivate Blood Pressure Control
Official title: Helping Hypertension Patients to Interpret Blood Pressure Readings and Motivate Blood Pressure Control
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypertension
Lead sponsor: University of Southern California
Sponsor class: OTHER
Collaborators: name: University of Pittsburgh
First posted: 2020-07-24
Enrollment: 542
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: Hypertension is a major risk factor for cardiovascular disease, and a leading cause of death worldwide. Only about 50% of hypertension patients have good blood pressure control, perhaps because they find it hard to understand their blood pressure readings. The investigators will evaluate ways to help hypertension patients to interpret their blood pressure readings and motivate blood pressure control.

Aim 1: Based on existing communications, the investigators will create 3 blood pressure communications:

(A) a basic table showing only the normal blood pressure range, which is often used in clinical practice and online communications about blood pressure, but may make it hard to interpret numbers outside of the normal range, potentially undermining behavior change intentions; (B) an enhanced table showing how combinations of diastolic and systolic blood pressure reflect normal, elevated and hypertension ranges, from the American Heart Association; (C) an enhanced graph to be adapted from Blood Pressure UK to show the same color-coded ranges as the enhanced table, with diastolic blood pressure on the x-axis and systolic blood pressure on the y-axis.

Aim 2: : Among 650 diagnosed hypertension patients recruited through the University of Pittsburgh Medical Center (UPMC) Pitt+Me Patient Registry, the investigators will evaluate whether being presented with the enhanced table or graph (vs. basic table) affects patients' self-reported blood pressure measurement (as averaged across two measurements taken at the time of the survey at least 1 minute apart, as per directions of the American Heart Association), and improves interpretations of these two blood pressure readings and of hypothetical blood pressure readings, as well as behavior change intentions.

Aim 3: The investigators will examine whether Aim 2 findings vary by health literacy, age, and SES.

Detailed description: BACKGROUND Hypertension is a major modifiable risk factor for cardiovascular disease, and a leading cause of death worldwide. Lifetime risk of hypertension is 70-90%, but it is higher among adults who are older and of low socio-economic status (SES). Older age and lower SES are also associated with low health literacy, which undermines understanding of health information. Yet, low health literacy in hypertension patients is an independent predictor of poor blood pressure control, with only about 50% of hypertension patients having controlled blood pressure. Possibly, patients with lower health literacy find it harder to interpret whether blood pressure readings are high or low, reflect good or bad blood pressure control, and indicate a need for behavior change or medication use. Even college-educated hypertension patients who have bought home blood pressure monitors may struggle to interpret blood pressure readings that are outside the normal range, undermining their intentions to improve their blood pressure control.

BEHAVIORAL SCIENCE INSIGHT Lab studies in behavioral science have found that individuals' ability to interpret numbers (likely including blood pressure readings) is improved by showing the range or distribution - also called 'reference information'. In preliminary work, the PI showed that many people struggle to interpret credit card APRs, because they do not know what numbers are good or bad. In line with the behavioral science insight, the PI found that providing graphs with ranges of existing APRs helped recipients to see which credit cards posed a bad deal, and reduced their intentions to get such credit cards. It has been posited that providing reference information (e.g. normal and abnormal blood pressure ranges) should also help hypertension patients to interpret blood pressure readings, and help them to control their blood pressure.

If reference information is used when communicating blood pressure readings in clinics and online health records, it often involves a basic table that only shows the normal range (e.g., \<120 for systolic and \<80 for diastolic blood pressure). In one behavioral science study, 106 university staff performed similarly when using this basic table or when using a color-coded horizontal bar graph (showing the normal range in white and values outside the normal range in black). However, neither format followed the American Heart Association's communication, which shows more reference information for interpreting blood pressure readings outside of the normal range. Hypertension patients may need to see such enhanced reference information, because they are more likely to encounter blood pressure readings outside of the normal range. Moreover, those readings can be harder to interpret - perhaps especially for hypertension patients with low health literacy. The investigators propose to evaluate 2 formats for providing the more enhanced reference information from the American Heart Association, in either a table (as used by the American Heart Association), or a graph (as used by Blood Pressure UK, to be adapted to show the information from the American Heart Association). The behavioral science literature suggests that tables facilitate reading specific numbers, but that graphs help more with interpreting numbers as high or low, and good or bad - though that could depend on recipients' health literacy.

SPECIFIC AIMS The American Heart Association has called for broad-based efforts to improve the proportion of hypertension patients with controlled blood pressure, by "further engaging individuals in the hypertension control process" with "adequate representation of \[specific\] populations" including those with lower health literacy, older age, and lower SES. Therefore, the investigators propose to conduct an NIH Stage I primary data collection project, to evaluate the efficacy of interventions to facilitate blood pressure readings and motivate blood pressure control, in a sample of hypertension patients varying in health literacy, age, and SES.

Aim 1: Based on existing communications, the investigators' communication expertise (see below), and pilot tests with up to 10 hypertension patients, the investigators will generate 3 blood pressure communications:

(A) a basic table showing only the normal range, which is often used but may make it hard to interpret numbers outside of the normal range, potentially undermining behavior change intentions; (B) an enhanced table with more reference information, showing how combinations of diastolic and systolic blood pressure reflect normal, elevated and hypertension ranges, from the American Heart Association; (C) an enhanced graph to be adapted from Blood Pressure UK to show the same color-coded ranges as the enhanced table, with diastolic blood pressure on the x-axis and systolic blood pressure on the y-axis.

Aim 2:: In a sample of 650 diagnosed hypertension patients recruited through the Pitt+Me Patient Registry at the University of Pittsburgh Medical Center (UPMC), the investigators will evaluate whether being presented with the enhanced table or graph (vs. basic table) affects patients' self-reported blood pressure measurement (as averaged across two measurements taken at the time of the survey at least 1 minute apart, as per directions of the American Heart Association), and improves interpretations of these two blood pressure readings and of hypothetical blood pressure readings, as well as behavior change intentions.

Aim 3: The investigators will examine whether Aim 2 findings vary by health literacy, age, and SES.

Eligibility criteria: Inclusion Criteria:

* Diagnosed with hypertension
* Proficient in English

Primary outcomes:
measure: Number of Participants Who Measured Blood Pressure as Instructed (Assessed on Questionnaire)
timeFrame: Questionnaire completed immediately after receiving communication
measure: Number of Participants Who Understood Blood Pressure Readings (Assessed on Questionnaire)
timeFrame: Questionnaire completed immediately after receiving communication
measure: Evaluation of Blood Pressure Reading (Provided on Questionnaire)
timeFrame: Questionnaire completed immediately after receiving communication
measure: Behavioral Intention Index (Provided on Questionnaire)
timeFrame: Questionnaire completed immediately after receiving communication
Secondary outcomes:
Other outcomes:
Locations:
city: Pittsburgh
country: United States
facility: Pitt+Me Patient Registry
state: Pennsylvania
Study officials:
affiliation: University of Southern California
name: Wandi Bruine de Bruin, PhD
role: PRINCIPAL_INVESTIGATOR
References: