Improper Arm Placement During Blood Pressure Reading Could Lead to Inaccurate Results
Blood pressure readings could be off, thanks to your arm position when measuring. A study published on Monday in JAMA Internal Medicine revealed a potential issue with two common arm positions for blood pressure assessments, suggesting that they might lead to overestimates. According to the researchers, such flaws could possibly lead to incorrect diagnoses of hypertension.
Blood pressure is a crucial health indicator, with chronic high blood pressure — or hypertension — increasing the risk of heart disease, stroke, and even type 2 diabetes. This latest study, conducted by researchers at Johns Hopkins, unveiled a glaring issue in the way doctors and patients assess this essential health marker.
The study involved 133 adults aged between 18 and 80 years old who participated in the various conditions of the study, each in random order. Their blood pressure was measured via their arm in three ways: supporting their arm on a desk, having the arm dangling by the side unsupported, and having their hand rested on their lap.
Compared to the standard position (arm supported on a desk), the other two methods consistently resulted in higher blood pressure readings, the research team discovered. On average, using an arm resting on the lap led to a 3.9 mm Hg higher systolic (top) number and a 4 mm Hg higher diastolic (bottom) number. Using an unsupported arm led to a 6.5 mm Hg higher systolic measurement and a 4.4 mm Hg higher diastolic reading.
This overestimation could potentially result in misdiagnosing some patients with hypertension, as a reading of 130/80 is the threshold for determining hypertension. Similarly, patients taking their blood pressure at home might face the same issues.
ApThe researchers wrote, "This crossover randomized clinical trial showed that commonly used arm positions (lap or side) resulted in substantial overestimation of BP readings and may lead to misdiagnosis and overestimation of hypertension."
Prior research has hinted at subtle factors like arm positioning or support affecting blood pressure measurements, but this study appears to be one of the first randomized trials to attempt quantifying the difference. Other research suggests that even the location of a test can impact readings, such as "white coat hypertension," where people show higher blood pressure readings at a doctor's office than at home due to anxiety.
Senior researcher Tammy Brady, medical director of the pediatric hypertension program at Johns Hopkins Children's Center, emphasized the importance of proper blood pressure measurement techniques and urged patients to advocate for correct measurements in clinic settings.
"Healthcare providers need to be reminded about the importance of taking the time to do these steps properly," Brady suggested to CNN. "I also hope this study educates patients, empowering them to advocate for proper measurement when they're in a clinic setting."
- The study published in JAMA Internal Medicine suggests that incorrect blood pressure diagnoses might occur due to flaws in common arm positions, such as Supporting the arm on a desk, having the arm dangling, or having the hand rested on the lap.
- According to the research team, using an arm resting on the lap led to an overestimation of 3.9 mm Hg for the systolic reading and 4 mm Hg for the diastolic reading compared to the standard position (arm supported on a desk).
- Similarly, an unsupported arm resulted in a higher overestimation, with a 6.5 mm Hg increase in systolic measurement and a 4.4 mm Hg increase in diastolic reading.
- In light of these findings, the team advises healthcare providers to remind themselves about the proper blood pressure measurement techniques and encourages patients to request correct measurements in clinic settings.
