Results Summary

What was the research about?

Uncontrolled blood pressure, or BP, affects tens of millions of Americans. Lowering BP to recommended levels can reduce the risk of heart attack and stroke. Support from a medical team can help patients lower their BP, but questions remain about the best way to provide care.

In this study, the research team compared two ways of providing care:

  • Clinic-based care, or CBC. In this group, patients had regular, in-person visits with a doctor or medical assistant.
  • Telehealth. In this group, patients received home-based and telephone care from pharmacists or nurse practitioners who had special training to manage patients’ medicines.

What were the results?

After one year, the two groups didn’t differ in how much their BP changed. Both groups had lower BP.

After six months, compared with CBC, patients in the telehealth group:

  • Were more satisfied with their care
  • Reported that visits by phone were more convenient

The two groups didn’t differ in their confidence in self-care or side effects from BP medicine.

Who was in the study?

The study included 3,071 patients with uncontrolled BP. All received care at one of 21 clinics in Minnesota and Wisconsin. Among patients, 69 percent were White, 19 percent were Black, 7 percent were Asian, 1 percent were American Indian/Alaska Native, and 4 percent were another race; 2 percent were Hispanic. The average age was 60, and 53 percent were women.

What did the research team do?

The research team assigned 21 clinics by chance to one of the two groups. In CBC, patients had a BP checkup with a medical assistant in the clinic within two to four weeks. Patients then had regular, in-person follow-up visits until their BP was controlled.

In the telehealth group, doctors referred patients to have a one-hour, in-person visit within two to four weeks. At the visit, patients learned how to measure their BP. Patients then measured their BP at home six times per week. Pharmacists or nurse practitioners received a report with patients’ BP every two weeks and also got alerts if BP was too high or too low. Patients had regular visits with pharmacists or nurse practitioners by phone about how to make medicine and lifestyle changes.

The research team looked at patient BP at the start of the study and again 12 months later. Patients took surveys about their care at the start of the study and again 6 months later.

Patients, doctors, and health system administrators gave input during the study.

What were the limits of the study?

In both groups, only one in three patients had their follow-up visit within two to four weeks as planned. Also, in the telehealth group, pharmacists and nurse practitioners managed patients’ care. Results may have differed if more timely follow-up visits had occurred or if doctors or nurses had managed telehealth care.

Future research could examine telehealth care managed by other clinicians.

How can people use the results?

Patients and doctors can use the results when considering ways to help manage uncontrolled BP.

Final Research Report

View this project's final research report.

More to Explore...


Helping Patients Better Control High Blood Pressure
Principal Investigator Karen Margolis speaks about this study, which is comparing two methods of monitoring high blood pressure to determine whether telehealth offers an edge over more traditional clinic-based care.

More Telehealth Research Needed
Principal Investigator Karen Margolis says more research is needed to determine whether telehealth offers an advantage to patients as it becomes more widely available.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers questioned how well the interventions in the study could be tested given the low rate of attendance for blood pressure checks at the six-week mark. The reviewers also felt that the high nonadherence to the intervention protocols was an important finding in this study and had large implications for implementing the interventions in real-world settings.  The researchers pointed out that the low rate of attendance referred to blood pressure checks with the specific healthcare professional (HCP) listed in the intervention protocol, and this specificity led to the impression of low adherence to the interventions. In fact, a much higher percentage of patients completed the required follow-up if the researchers looked at patients receiving the care from other available HCPs. In response, the researchers added this information in their results and limitations sections, indicating that preferentially directing patients to specific follow-up choices limited adherence to the study protocol.
  • The reviewers asked whether the researchers applied multiple imputation techniques to account for the large amount of missing data for the primary outcome, systolic blood pressure, at the six-month follow-up. The researchers explained that the primary outcome was change in systolic blood pressure over 12 months, and almost all of the study participants had at least one more blood pressure reading during that time period. Change in outcomes in the first six months was the secondary outcome, and the researchers applied statistical methods to account for the missing data.
  • The reviewers expressed concern about the study conclusions because two graphs relaying the study results seemed to indicate that both systolic and diastolic blood pressure decreased before the start of the interventions. The researchers revised the two graphs to increase the precision of the blood pressure measurements taken, which showed that the sharp drop in blood pressure took place in the 1-15 days after the study start. The researchers attributed this early drop to the alert system incorporated into the electronic health record. This alert meant that clinicians were more likely to identify high blood pressure as a concern at the first study visit and therefore begin treating the condition before the study interventions started. The researchers added this information to their descriptions of clinic referral and follow-up care procedures. The researchers further justified the strength of their results by noting that if the effect was actually due to regression to the mean, the change in blood pressure would be several times smaller.

Conflict of Interest Disclosures

Project Information

Karen L. Margolis, MD, MPH
HealthPartners Institute
Pragmatic Trial Comparing Telehealth Care and Optimized Clinic-Based Care for Uncontrolled High Blood Pressure

Key Dates

April 2016
January 2023

Study Registration Information


Has Results
Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: September 24, 2023