Millions of US adults may be getting wrong blood pressure reads at home

In an effort to do the right thing for their health, around 17 million US adults could actually be getting poor blood pressure readings from at-home kits that aren't fitted correctly. This potentially has serious implications for nearly 7% of American adults.

Researchers at the Johns Hopkins Bloomberg School of Public Health have issued a warning over these over-the-counter devices that aim to make keeping tabs on blood pressure a simple and easy task to do at home.

And the primary issue is the size of the cuff required to fit the arm of the person using these convenient and otherwise reliable devices.

“The fact that millions of Americans are affected shows that this is not a small problem; and probably the easiest solution is for retailers just to offer a wider range of cuff sizes for no extra cost,” says study senior author Dr. Kunihiro Matsushita, a professor in the Bloomberg School’s Department of Epidemiology.

This form of keeping track of blood pressure is, for millions, the easiest and most inexpensive way of monitoring their health. But poorly fitting cuffs that don't offer a range of sizes has meant that ill-fitting devices won't work as they should. And the person using the device is generally none the wiser of how important this part of the test is.

The researchers found that around 6.7% of adults – or 17.3 million people – have arms that don't fit the industry 'standard' when it comes to cuff size. For 16.5 million individuals, the cuffs were too small – something that disproportionately impacted Black adults using these at-home devices. "This disparity is particularly concerning, Matsushita says, because Black adults have a significantly higher prevalence of hypertension than other major racial/ethnic groups: 57.1% versus 43.6% for white adults and 43.7% for Hispanic adults."

While there are many factors in getting an accurate read on blood pressure figures, such as the positioning of an arm and refraining from talking while measuring, cuff size is not often spoken of as a key factor in undertaking a home test.

In the study, the team homed in on 16 popular devices sold through Amazon in January 2024. Ten of these had cuffs, which were measured in comparison to the arm circumference sizes of 13,826 US adults from US National Health and Nutrition Examination Surveys (NHANES).

Of these 10, nine could fit arms that ranged from 8.6-16.5 inches (22-42 cm) in circumference. The one other device worked with arms that had a circumference of between 8.6 and 15.7 inches (22 and 40 cm). The NHANES data revealed that 6.7% of adults, according to 2023 census results, have arm circumferences outside of those ranges.

While some devices offered adjustable cuffs at additional cost, the researchers have urged health care providers to be doing more to help patients find machines with the correct fit to start with, in order for them to achieve the most accurate results at home. They also asked manufacturers to offer a wider range of cuff sizes, rather than a one-size-fits-all model, at no extra charge.

“Consumers should be able to buy the blood pressure cuff sizes they need just as they can buy clothing sizes they need,” said Dr. Matsushita.

The study was published in the journal Hypertension.

Source: Johns Hopkins Bloomberg School of Public Health via EurekAlert!