Technology
Clarissa Chan, PharmD
“Not all blood pressure kiosks are created equal,” said Josh Sarkis, general manager and chief strategy officer at PharmaSmart International, LLC, in Rochester, NY. He said it’s up to pharmacy leadership and consumers to make informed decisions about using high-quality, clinically validated devices.
“The good news is that information is now readily available in the form of the U.S. National Validated Device List (VDL),” Sarkis said. VDL was created by the American Medical Association (AMA) and the American Heart Association, and it is administered by NORC (an independent research organization at the University of Chicago) and a panel of independent expert peer reviewers as a universal standard for manufacturers to use in determining the accuracy of devices.
“The VDL [at www.validatebp.org] was created to fill the gap left by the FDA’s 510(k) program and inform the public how to select a validated device,” said Sarkis.
Many self-service BP kiosks are not independently verified to be accurate, potentially resulting in poor BP management. All noninvasive BP devices—like home, kiosk, and office devices as well as thousands of other products like contact lenses and surgical gloves—are Class II medical devices, which are “cleared” under the FDA 510(k) program. However, the 510(k) program requires no independent testing, nor does FDA directly test or even approve these devices.
“They review an application claiming that the device is ‘substantially equivalent’ to a device that is already on the market,” said Sarkis. “You can see how this regulatory structure allows the continued entry of inadequate blood pressure devices into the market.”
Importance of clinically accurate and validated blood pressure kiosks
Many BP devices are not formally tested for accuracy using an accepted validation protocol, said Tammy M. Brady, MD, PhD, a cochair on AMA VDL and associate professor of pediatrics at Johns Hopkins University.
“The real issue is that there is little competitive advantage to ensuring that a device is accurate, as unbelievable as this sounds,” said Raj Padwal, MD, MSc, FRCP(C), general internal medicine professor at the University of Alberta in Edmonton. “But there is increasing advocacy on this issue and scrutiny of these dubious practices, and so it is our hope that over time all companies will perform clinical validation.”
Fortunately, some companies like PharmaSmart take the accuracy of their blood pressure kiosks seriously, and they are currently the only blood pressure kiosk that has been validated to meet the VDL’s standards.
“VDL is an excellent resource,” said Padwal. However, “one drawback is that not all the validated devices are captured on [it] because not all companies that have validated devices apply to be on the listing.”
Readings from validated devices can be used to help manage BP appropriately. “Otherwise, the devices are just a gimmick—[they] may or may not be accurate and should not be used for clinical care delivery,” said Padwal.
Cuff size matters
Kiosks only use one cuff size, so it’s important that the cuffs are validated on a wide range of arm sizes that reflects the general public.
Too-small cuff sizes overestimate BP and too-large cuff sizes underestimate BP, said Brady. “In fact, I just completed a study that showed when an individual who requires an extra-large cuff size—based on their arm circumference—has their blood pressure measured with a regular adult cuff, their systolic blood pressure can be overestimated by almost 20 mm Hg,” she said. Inaccurate results due to cuff limitations can cause confusion and mismanagement of BP.
Historically, BP kiosks are designed for average- or medium-sized arms, and people with large arm sizes—those most at risk for hypertension—are unknowingly using traditional BP kiosks off-label.
“Unfortunately, the FDA’s 510(k) regulations allow for this, and many people using public kiosks are unaware of the situation,” said Sarkis.
Additionally, wrist BP devices are less accurate because they are further away from the heart, more difficult to hold at the level of the heart, and the measurement site is not the same artery (radial artery for wrist devices) as the artery site used for all of the field-seminal data collected in clinical studies (brachial artery).
“So, it’s always best to use an upper arm device unless one cannot be found that fits around the upper arm,” said Padwal.
Security and maintenance of blood pressure devices
For companies like PharmaSmart, HIPAA compliance is a priority. Patients can identify themselves at the kiosk through a simple mobile phone scan—most commonly a retailer’s mobile app, which involves patient consent. The user’s biometric data is then often stored in a cloud-based server and is available to patients from an app which is also available for integration with pharmacy software systems, physician electronic health records, and other partner systems. For devices from his company, Sarkis said data are encrypted locally and in transit.
“The digital oscillometric devices [unlike analog devices] used in kiosks don’t usually require [routine manual] calibration unless there is some type of physical damage,” said Padwal.
Pharmacists should stock sanitary wipes next to kiosks so patients can sanitize the machines and their hands before and after using devices for public use.
How pharmacists can help
Pharmacists should first ensure that the device in their pharmacy is clinically validated, not just FDA “cleared.” They should also provide clearly written and, if necessary, verbal instructions to guide patients in proper BP measurement technique.
Patients should seek kiosks located in a quiet environment. It is also recommended that patients rest 3 to 5 minutes prior to measurement and that they position their arm properly, per instructions located on the kiosk. These and other preparatory steps can improve accuracy of the results, said Brady.
“In fact, we showed that while taking a blood pressure [reading] without antecedent rest was acceptable for those with a systolic blood pressure of ≤ 140 mm Hg, rest remains important for blood pressure measurement accuracy among individuals who have higher systolic blood pressure of ≥ 140 mm Hg,” Brady said, referring to the American Heart Association/American College of Cardiology’s Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults.
“Advise patients to take multiple readings over several days or purchase a clinically validated home blood pressure device to take measurements at home; blood pressure should never be managed based on a single reading alone,” said Padwal. “[Hypertension] is a highly variable physiologic parameter, changing every second of the day, and therefore multiple readings are needed—ideally two to four readings taken each day for three to seven days—in order to best understand an individual’s true blood pressure.”
Pharmacists should monitor patients with high BP readings and work with the patient and their primary care provider to manage their BP. Focus on high-risk patients with cardiovascular disease or diabetes who have high BP greater than 160/100 mm Hg and help those patients get treated, said Padwal.
If one’s local pharmacy does not have a validated BP kiosk and patients do not have their own BP device for home use, kiosks can also be found in medical clinics, employer worksites, senior living facilities, and fitness centers. Patients can also ask their pharmacist to take their BP reading.
Awareness brings impact
Pharmacies providing validated BP kiosks equip pharmacists with valid and actionable patient data allowing pharmacists to turn the tide on health care’s most dangerous risk factor: high BP. According to CDC, nearly half of all Americans have hypertension. By delivering better cardiovascular outcomes, pharmacies can carve out new revenue models and assure their seat at the table as critical health care stakeholders, said Sarkis. ■