Addressing Uncontrolled Hypertension in America

High Blood Pressure, or Hypertension, is a significant health issue in the United States. About half of American adults have high blood pressure, but less than half manage to control it effectively. When blood pressure is not controlled, individuals face increased risks for serious health problems such as stroke, heart attacks, kidney disease, heart failure, and memory issues. Therefore, it is essential to identify those who are not controlling their hypertension and understand their treatment and health outcomes to improve public health efforts.

Electronic Health Records (EHRs) can help us learn more about uncontrolled hypertension because they provide detailed patient health information over time. However, defining and identifying patients with uncontrolled hypertension using EHR data can be challenging. There is no specific code for uncontrolled hypertension, and doctors usually require multiple visits to diagnose it properly. This complexity creates a need for clear definitions based on EHR data to help identify these patients.

#Study Goals

The primary goal of this study is to identify patients with controlled and uncontrolled hypertension using data from two large health systems. We also want to compare their characteristics, treatment patterns, and health outcomes.

We developed two different methods to define uncontrolled hypertension, applying them to data from two health systems. This research is part of a larger effort to gather real-world evidence that can improve health care for patients with hypertension.

#Project Background

This research is funded by a group known as the National Evaluation System for health Technology Coordinating Center (NESTcc). NESTcc works with various health care providers, research centers, and insurance companies to collect and analyze real-world health data.

This particular study was proposed by Medtronic, a medical device company studying a device to treat hypertension. After reviewing the proposal, NESTcc decided to fund the project. Two health systems, Yale-New Haven Health System (YNHHS) and OneFlorida, partnered in this research due to their experience with EHR data.

#Data Collection

The study uses electronic health records from YNHHS and OneFlorida. YNHHS serves about two million patients yearly and includes several hospitals and clinics in Connecticut and Rhode Island. OneFlorida is a research network that covers 40% of Florida's population and includes 16 partner health systems.

Both systems worked to standardize their data according to the National Patient-Centered Clinical Research Network model, ensuring that the data could be easily compared and analyzed. Data quality checks were done regularly to ensure accurate and reliable information was used for the study.

#Study Population

The study focused on adults aged 18 and older who had high blood pressure between October 1, 2015, and December 31, 2018. Patients were included if they had a hypertension diagnosis code or if they had two high blood pressure measurements taken on different days within six months.

Patients were excluded if they had less than three months of follow-up, were pregnant, or were on dialysis. We only included blood pressure measurements from outpatient visits, as these are more reliable indicators of hypertension.

#Defining Controlled and Uncontrolled Hypertension

To classify patients as having controlled or uncontrolled hypertension, we created two methods. In the first approach, we considered patients to have controlled hypertension if more than half of their blood pressure readings were below the target levels. If half or more of their readings were above these levels, they were classified as having uncontrolled hypertension.

In the second approach, we defined controlled hypertension as having both blood pressure readings below the target levels at the most recent visit. Uncontrolled hypertension was if one or both readings were above those levels.

#Key Characteristics of Patients

We collected information on several characteristics of the patients, including age, race, gender, health insurance type, smoking status, body mass index (BMI), and any existing health issues like diabetes or heart disease.

We noted differences in characteristics based on whether patients had controlled or uncontrolled hypertension. For instance, we found that uncontrolled hypertension was more common among younger age groups and certain racial groups. However, patients with uncontrolled hypertension tended to have fewer other health issues compared to those with controlled hypertension.

#Medication Patterns

Looking at medication prescriptions, we found that a significant number of patients were not taking any blood pressure-lowering medications in the year leading up to the study. Among those who were prescribed medication, we noted a variety of drug classes used to treat hypertension, such as ACE inhibitors, beta-blockers, and calcium channel blockers.

Across both health systems, we found that the rates of patients not taking medication were high, suggesting that some individuals may have achieved control over their blood pressure through lifestyle changes rather than medication.

#Health Outcomes

We examined patients’ health outcomes over time, including rates of serious health events like heart attacks and strokes. We found that both patients with controlled and uncontrolled hypertension experienced similar rates of these serious health issues over the follow-up periods.

The study also noted differences in healthcare utilization between the two groups. Patients with uncontrolled hypertension had higher rates of emergency room visits and hospitalizations.

#Challenges in Identifying Patients

As we worked on this project, we faced challenges in accurately identifying patients with uncontrolled hypertension. The lack of a specific diagnostic code made it difficult to create a consistent definition. Additionally, relying solely on diagnosis codes was not enough, as many patients identified with high blood pressure did not have accompanying codes in their records.

We developed multiple ways to define uncontrolled hypertension using various data points from the EHRs, which helps enhance the accuracy of our findings.

#Limitations of the Study

There are several limitations in our study. The methods used to measure blood pressure could vary between clinics, which may impact the accuracy of the readings. We also only reviewed prescription data and did not track whether patients actually took their medications. Furthermore, we relied on healthcare encounters within the specific networks to identify health outcomes, which may have caused some events to be missed if patients sought care elsewhere.

Our analysis was mostly descriptive and did not adjust for possible differences in patient characteristics that might affect health outcomes. Additionally, while the findings are valuable, they may not apply to other health systems due to differences in patient populations and practices.

#Conclusion

This study highlights the potential for using EHR data to improve our understanding of uncontrolled hypertension and the treatment patterns for these patients. By using clear definitions and analyzing data from two large health systems, we found significant information about the prevalence and outcomes of uncontrolled hypertension.

Recognizing the challenges faced in defining and identifying patients with uncontrolled hypertension is important for ongoing research. This information will aid in developing better strategies to manage hypertension and enhance care for individuals at risk of serious health issues.

The findings call for more comprehensive efforts in managing high blood pressure by targeting patients who could benefit from additional treatments or lifestyle modifications to improve their health outcomes. In the future, leveraging EHR data can help researchers and healthcare providers better understand and address the needs of patients with high blood pressure.