Medication Guideline Adherence Among Patients with Markedly Elevated Blood Pressure in A Real-World Setting
Authors: Lu Yuan , Huang Chenxi , Liu Yuntian , Caraballo César , Mahajan Shiwani , Massey Daisy , Spatz Erica S. , Onuma Oyere , Ross Joseph S. , Schulz Wade L. , Krumholz Harlan M. 
Published: February 2022

Objective

To evaluate medication guideline adherence among ambulatory patients with markedly elevated blood pressure (BP), overall and by patient characteristics.

Design

Population-based, retrospective cohort study.

Setting

Yale New Haven Health System.

Participants

Adult patients aged 18-85 years with markedly elevated BP (defined as two consecutive outpatient visits with systolic BP ≥160 mmHg or diastolic BP ≥100 mmHg) between October 1st, 2015 and December 31st, 2018.

Main outcome measures

We assessed the number and class of antihypertensive drugs (previously taken and newly prescribed) prior to 90 days of the second visit with BP ≥160/100 mmHg. Among patients treated with two-drug class regimens, we assessed the proportion of patients on guideline-recommended two drug classes, overall and stratified by documentation of prior myocardial infarction (MI), diabetes, chronic kidney disease (CKD), and uncomplicated hypertension (i.e., without MI, coronary artery disease, diabetes, CKD, and cerebrovascular disease).

Results

We identified 16,377 patients with markedly elevated BP. They had a mean age of 65.8 (SD: 14.5) years; 54.0% were female; and 69.4%, 19.6%, and 9.6% were White, Black, and Hispanic, respectively. Prior to 90 days of the second visit, 29.8% had no active antihypertensive drug prescription, 20.0% had one drug class prescribed, and 50.2% had two or more drug classes prescribed. Among patients prescribed one antihypertensive drug class, the most common drug class was angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB), followed by calcium channel blocker (CCB). Among patients prescribed two antihypertensive drug classes, the most common treatment combinations were ACEI or ARB and thiazide diuretic (21.0%), followed by ACEI or ARB and CCB (20.6%). Guideline-recommended two-drug class combination therapy were prescribed in 54.3% of the treated population, with the highest proportion of 67.0% in patients with a prior MI and the lowest proportion of 48.2% among patients with CKD. Older age, lower body mass index, and lower BP were associated with lower prescription of guideline-recommended combination therapy.

Conclusion

Only half of patients with markedly elevated BP were prescribed guideline-recommended antihypertensive combination drugs. Major opportunities exist for improving the guideline adherence of antihypertensive drug prescription in this population.

What this Paper Adds

Section 1: What is already known on this subject?

Hypertension affects nearly one in two adults in the United States, of whom 20% have markedly elevated blood pressure (BP; defined as BP ≥160/100 mmHg). People with markedly elevated BP have increased risks of adverse cardiovascular and kidney events. Clinical guidelines recommend prescribing combination therapy with two or more antihypertensive agents for patients with markedly elevated BP.

Section 2: What this study adds

This study quantified the real-world medication guideline adherence among ambulatory patients with markedly elevated BP, using electronic health record data from a large health system in the United States. Prior to 90 days of the second visit with BP ≥160/100 mmHg, nearly 30% of patients had no active antihypertensive drug prescription. Among patients prescribed at least one antihypertensive drug class, guideline-recommended two-drug class combination therapy were prescribed in 54% of patients, with the highest proportion of 67% in patients with a prior myocardial infarction and the lowest proportion of 48% among patients with chronic kidney disease. These findings highlight a large missed opportunity for improving the guideline adherence of antihypertensive drug prescription in this population.