The Characteristics and Outcomes of Patients Who Make an Emergency Department Visit for Hypertension After Use of a Home or Pharmacy Blood Pressure Device

Study objective: Emergency department (ED) visits for hypertension are rapidly increasing. Hypertension guidelines began recommending use of self-measurement blood pressure (BP) devices in the early 2000s, which could be contributing to the increase. We aim to examine the proportion of ED visits for hypertension that occurred after a BP measurement with a self-measuring device, and the associated outcomes.

Methods: This retrospective observational study included adults who made an ED visit and received a primary diagnosis of hypertension at 1 of 5 community and tertiary hospitals in Ontario, Canada, between April 2010 and March 2011. We categorized ED visits into 4 groups: those made after a home BP reading, a pharmacy reading, as a result of a physician referral, and all others (termed "not documented"). We examined rates of admission to the hospital, ED treatment (administration of antihypertensive medication and prescription provision), and post-ED clinical events (follow-up care, return ED visits, and long-term all-cause mortality) by group.

Results: Among 1,508 qualifying patients, median presenting ED BP was 182/97 mm Hg (interquartile range 164 to 200/85 to 109 mm Hg). The percentage of patients who presented to the ED after a reading at home, at a pharmacy, or by physician referral and the remaining patients not documented was 40.9%, 8.3%, 13.3%, and 37.5%, respectively. Overall, 109 patients (7.2%) were admitted to the hospital. The proportion of patients admitted after a home or pharmacy reading, after a physician referral, or who were not documented was 3.1%, 11.9%, and 11.0%, respectively. Two-year mortality rates were 5.4%, 0.0%, 6.5%, and 5.3% for the home, pharmacy, physician referral, and not documented groups, respectively. Among the 92.8% of patients who were discharged from the ED, 11% made another ED visit for hypertension within a year.

Conclusion: In this study, half of patients with an ED visit that was primarily for hypertension presented after elevated readings on self-measurement devices. Only 3% of these patients were admitted to the hospital.