Setting, noise have little impact on accuracy of BP measurement

Key takeaways:

• Researchers found similar BP readings when evaluated in public and private settings.
• The data show that loud public areas, such as schools or pharmacies, are acceptable for BP screening, a researcher said.

BP readings taken in public spaces vs. those taken in private offices appeared similar, results from a randomized crossover trial in the Annals of Internal Medicine showed.

Any differences in readings when comparing public vs. private or quiet vs. noisy settings lacked clinical significance, the researchers noted.

The ambient noise in these settings also had little effect on the measurements, while the researchers appeared “pleasantly surprised” by the observations, Tammy M. Brady, MD, PhD, a professor of pediatrics at Johns Hopkins University School of Medicine, told Healio.

“Based on the guideline recommendation that BP be obtained in a quiet, private space free of distraction, we expected to find BP to be significantly higher in the public market,” she said. “Our results suggest that many of the practical and convenient environments relied on by many for BP measurement — such as places of worship, pharmacies, schools, and even barbershops — are acceptable for CVD prevention efforts.”

In the trial, researchers randomly assigned 108 participants (mean age, 56 years; 41% women) to the order in which they had triplicate diastolic BP and systolic BP measurements in each of three settings:

• a private quiet office (private quiet);
• a noisy public space (public loud); and
• a noisy public space with earplugs (public quiet).

Differences in mean BP readings in public settings vs. those in the private setting served as the study’s primary outcome measurement.

The results revealed an average noise level of 37 dB in the private quiet setting and 74 dB in the public setting.

The researchers reported mean systolic BPs of 128.9 mm Hg in private quiet, 128.3 mm Hg in public loud and 129 mm Hg in public quiet.

They further noted diastolic BPs of 74.2 mm Hg in private quiet, 75.9 mm Hg in public loud and 75.7 mm Hg in public quiet settings.

Ishigami and colleagues noted minimal and not clinically significant differences between the BPs in the public settings and those in the private setting, while the results were generally consistent in the subgroup and sensitivity analyses.

The researchers acknowledged several study limitations. These included a relatively small sample size and a study cohort comprising predominantly Black adults.

Additionally, trained research staff took the BP measurement, meaning “it remains uncertain whether the differences in BP we observed would be similar in a real-world practice,” they wrote.

BP screening is critical for hypertension identification and ultimately preventing CVD, while “innovative uses of clinical space to screen greater numbers of people can help with prevention efforts,” Brady said.

“That said, while ambient noise and busy environment didn’t impact BP measurement accuracy in our study, it is important to remember to adhere to other key measurement steps such as individualized cuff size selection based on arm size and proper patient positioning, with the arm resting and mid-cuff at heart level, for measurement accuracy,” she told Healio.

Brady added that there are several additional measuring steps that may be challenging to adhere to in under-resourced areas and busy clinical settings.

“Determining the importance of these steps on measurement accuracy — and specifically, determining if any of these steps might be eliminated — could potentially help simplify BP measurement, which could ultimately make it easier for more people to be screened, diagnosed and treated,” she said.