Comparison of an in-pharmacy automated blood pressure kiosk to daytime ambulatory blood pressure in hypertensive subjects

Comparison of an in-pharmacy automated blood pressure kiosk to daytime ambulatory blood pressure in hypertensive subjects

Context

High blood pressure, or hypertension, affects 40% of adults worldwide, 30% of Americans, and 22% of Canadians. Despite being highly treatable, it is the leading cause of death or disability in the world.

Accurate blood pressure measurement is critically important to ensuring that hypertension is optimally diagnosed and managed. Because in-office, manual blood pressure measurements taken in everyday clinical practice are poorly standardized and consequently, inaccurate, the use of out-of-office blood pressure measurements have been strongly endorsed.

The two most widely used and endorsed out-of-office methods are: ambulatory monitoring, where readings are taken at regular intervals from individuals performing daily life activities in a real-world setting; and home blood pressure monitoring, with the former considered to be the gold standard. A third out–of–office measurement modality, the blood pressure kiosk, has received considerably less attention. These devices are commonly found in retail pharmacies and worksites in North America and convenient to access. They are used frequently by both patients with a diagnosis of hypertension and by the general public, with an estimated one million measurements performed daily in the United States.

To date, hypertension experts and health care providers have not widely endorsed their use, and they have not been integrated into clinical practice on a widespread scale. Concerns have been raised regarding their accuracy; however, their results have never before been compared to the results obtained by ambulatory blood pressure monitoring.

One such device that has met clinical guidelines, and is incorporated into the study, is the PharmaSmart PS–2000.

Objectives

The objective of this study was to compare a series of blood pressure readings from an automated in–pharmacy kiosk, to those taken at regular intervals from individuals performing daily life activities in a real-world setting – otherwise referred to as ambulatory blood pressure monitoring. The purpose of this comparison was to determine the accuracy and reliability of in-pharmacy kiosks as an out-of-office method of measuring blood pressure.

A total of 100 adults with hypertension underwent three baseline automated office readings, three in–pharmacy readings on each of four visits (12 total) using the PharmaSmart PS– 2000 kiosk at a Rexall pharmacy; and  24–hour ambulatory BP monitoring (once) between in–pharmacy visits two and three.

Results

In this study of 100 hypertensive subjects, serial readings taken on automated in–pharmacy blood pressure kiosks over four visits were very similar to the mean daytime ambulatory blood pressure readings and were also similar to automated office readings. The 12–reading in–pharmacy average was closest to the mean daytime ambulatory blood pressure value.

Conclusions

Blood pressure readings at in–pharmacy devices were similar to automated office results. The PharmaSmart PS–2000 closely approximated results from mean daytime ambulatory blood pressure readings. This demonstrates that serial readings from this device in measuring blood pressure can be considered accurate and reliable.

Not all in-pharmacy kiosks can be recommended for patients, but properly validated kiosks capable of serialized reporting have the potential to fill an important gap in hypertension management. Our findings indicate that serial PharmaSmart PS–2000 kiosk measurements taken in a pharmacy setting are clinically useful and should be integrated into clinical practice, where available. We also advocate for more validity studies of all in–pharmacy kiosk devices.

Research by: Mark Gelfer, MD, Raj S. Padwal, MD, MS, Raymond R. Townsend, MD, Luc Trudeau, MD, Peter G. Hamilton, MD

Published in the Journal of the American Society of Hypertension