Effects of Noise and Public Setting on Blood Pressure Readings, A Randomized Crossover Trial

Junichi Ishigami, MD, MPH; Hairong Liu, MHS; Di Zhao, PhD; Ahmed Sabit, MS; Chathurangi H. Pathiravasan, MS, PhD;
Jeanne Charleston, RN, BSN; Edgar R. Miller III, MD, PhD; Kunihiro Matsushita, MD, PhD; Lawrence J. Appel, MD, MPH; and
Tammy M. Brady, MD, PhD

BACKGROUND
Guidelines emphasize quiet settings for blood pressure (BP) measurement.

OBJECTIVE
To determine the effect of noise and public environment on BP readings.

DESIGN
Randomized crossover trial of adults in Baltimore, Maryland. (ClinicalTrials.gov: NCT05394376)

SETTING
Study measures were obtained in a clinical research office and a public food market near Johns Hopkins University School of Medicine in Baltimore, Maryland.

PARTICIPANTS
108 community-dwelling adults from the Baltimore, Maryland, area recruited through measurement-screening campaigns, mailings to previous study participants, and referrals from hypertension clinics.

INTERVENTION
Participants were randomly assigned to the order in which they had triplicate BP measurements in each of 3 settings: 1) private quiet office (private quiet [reference]); 2) noisy public space (public loud); and 3) noisy public space plus earplugs (public quiet).

MEASUREMENTS
Differences in mean BP readings obtained in public loud and public quiet versus private quiet, overall and stratified by baseline systolic BP (SBP), age, and recent health care utilization.

RESULTS
Of the 108 randomly assigned participants, mean age was 56 years (SD, 17), 84% were selfreported Black, 41% were female, and 45% had an SBP of 130 mm Hg or more. The average noise level in public loud was 74 dB and in private quiet
was 37 dB. Mean SBPs were: 128.9 mm Hg (SD, 22.3) in private quiet, 128.3 mm Hg (SD, 21.7) in public loud, and 129.0 mm Hg (SD, 22.2) in public quiet. Corresponding diastolic BPs (DBPs) were 74.2 mm Hg (SD, 11.4), 75.9 mm Hg (SD, 11.6), and 75.7 mm Hg (SD, 12.0), respectively. Public-loud and public-quiet BPs had minimal, non–clinically important differences from private quiet BPs: public loud: DSBP,
0.66 mm Hg (95% CI,
2.25 to 0.93 mm Hg) and DDBP, 1.65 mm Hg (CI, 0.77 to 2.54 mm Hg); public quiet: DSBP, 0.09 mm Hg (
1.53 to 1.72 mm Hg) and DDBP, 1.45 mm Hg (0.64 to 2.27 mm Hg). The patterns were generally consistent across subgroups.

LIMITATIONS
Single-center trial. Imbalance in the numbers and characteristics across the randomly assigned groups.

CONCLUSION
The BP readings obtained in public spaces were minimally different from BPs obtained in a private office, suggesting that public spaces are reasonable settings to screen for hypertension.

Primary Funding Source: Resolve to Save Lives.