Epidemiology of elevated blood pressure in the ED

Abstract

Objectives

To determine the prevalence and demographics of elevated blood pressure (BP) in emergency department (ED) patients.

Methods

Retrospective study at an academic ED. ED patients with any systolic blood pressure (SBP) ≥ 140 mm Hg or diastolic blood pressure (DBP) ≥ 90 mm Hg over a 1-year period were included. Data pertaining to frequency of elevated BP across different ethnic categories, age groups, days of the week, shifts, and gender were collected.

Results

A total of 44 435 patient records were accessed. Overall 47.6% (95% CI, 47.2%-48.1%) of patients had elevated BP (SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg). Fifty three percent (95% CI, 52%-54%) were women. Among patients with elevated BP, 18% (95% CI, 17.8%-18.9%) had severe BP elevation (SBP ≥ 180 or DBP ≥ 110). Overall, patients > 45 years old were more likely to have elevated BP in ED. Across all ethnic groups, BP increased with age. Significant differences were noted in the prevalence of elevated BP between whites (52%), and other ethnic groups (African Americans [45%] and Hispanics [31%]) (P < .01). Overall, 64% (95% CI, 63.3%-64.6%) of patients with elevated BP were discharged from the ED. Forty four percent (95% CI, 42.4%-45.5%) of patients with severe BP elevation were also discharged from the ED.

Conclusions

This study provides knowledge of distribution of elevated BP among different age, gender and ethnic groups in the ED which can be used to develop specific interventions to improve recognition, prevention, detection, and treatment of hypertension.

Introduction

Hypertension is a common condition, affecting approximately 67 million, or 1 in every 3, American adults [1]. The prevalence of hypertension is estimated to increase by 7.2% by 2030 [2]. The annual costs of hypertension which includes health care services, antihypertensive agents and missed days of work is approximately $47.5 billion [1]. Undiagnosed, untreated and uncontrolled hypertension can lead to stroke, renal failure and cardiovascular complications. High blood pressure (BP) is prevalent in approximately 69% of patients who have a first myocardial ischemic event, 77% who have a first stroke, and 74% who have congestive heart failure [2]. Early identification and intervention can prevent many of the long-term hypertension-related complications [3]. Approximately 1 in 5 individuals in the United States are unaware that they have hypertension and remain undiagnosed [1].

Elevated BP is often noted in emergency department (ED) patients. According to National Hospital Ambulatory Medical Care Survey, 30% of patients seen in the ED have high BP (> 140/90 mm Hg) [4]. Many individuals with undiagnosed hypertension are evaluated in the ED for an unrelated illness, and the ED visit may be the only time their BP was measured. It has been well documented in the literature that a significant proportion of ED patients (26%-77%) with high BP are indeed hypertensive, with persistently elevated BP during outpatient clinic follow-up [5], [6], [7], [8], [9]. The variation in prevalence is likely due to differences in the study setting (ED vs ED and urgent care), and data collection procedures (electronic medical records vs. self-reported patient data) [8]. The ED visit presents a unique opportunity for identifying individuals with undiagnosed or inadequately treated hypertension, providing BP counselling and arranging a referral for reevaluation and intervention. The American College of Emergency Physicians 2006 Asymptomatic Hypertension clinical policy guidelines on the evaluation and management of adult patients with asymptomatic elevated BP in the ED recommends that emergency physicians provide outpatient referral to patients with persistently elevated BP in ED for reassessment [10].

EDs are a major source of health care in the United States. Therefore strategies to identify individuals with undiagnosed hypertension and provide appropriate interventions are crucial to reduce morbidity and mortality from uncontrolled hypertension. Knowledge of distribution of elevated BP in ED patients is useful for developing ED based interventions for hypertension. To our knowledge, no prior studies reported the prevalence of elevated BP in different age groups, ethnic categories, across different shifts, and severity of elevated BP in ED patients. The objective of this study was to determine the prevalence and demographics of elevated BP in ED patients.