Doctors may raise blood pressure more than nurses

Do you want to get an accurate blood pressure reading? Then, new research suggests you may not want to have a doctor take that reading. The "white coat" effect -- called so because of the traditional doctor's uniform -- is the term used to describe a spike in blood pressure that some patients experience in a medical setting. The theory is that patients are more anxious when visiting the doctor's office, so pressure rises. A new study found that doctors in particular, as opposed to nurses, triggered a higher blood pressure measurement. Christopher Clark, PhD, a clinical research fellow at the University of Exeter Medical School in Devon, England, and fellow investigators reviewed blood pressure levels of 1,019 patients whose readings had been taken by both doctors and nurses during the same visit. Based on results from 15 studies in 10 different countries, Dr. Clark and team found that blood pressure readings of an individual patient taken by doctors were on average higher by 7/4 mm Hg compared to readings taken by nurses. While this "white coat" effect has been known about for decades, Dr. Clark's team claimed that this study is the first comprehensive research to put a number on the average blood pressure rise. High blood pressure is typically defined as a measure of 140/90 millimeters of mercury (mm Hg) or higher. The top number is systolic pressure, which is a measurement of maximum force of the blood in the arteries, while the lower number, or diastolic pressure, is the pressure measurement when the heart is relaxed. The American Heart Association defines normal blood pressure as less than 120 for systolic and less than 80 for diastolic. "Doctors should continue to measure blood pressure as part of the assessment of an ill patient or a routine check-up, but not where clinical decisions on blood pressure treatment depend on the outcome," said Dr. Clark in a press release. "The difference we noted is enough to tip some patients over the threshold for treatment for high blood pressure, and unnecessary medication can lead to unwanted side-effects." Dr. Clark added that some patients may have been asked in error to steadily monitor their blood pressure at home. This can build anxiety and keep pressure readings high. "These inappropriate measures could all be avoided by the simple measure of someone other than a doctor taking the blood pressure recording," said Dr. Clark in a statement. This study was published March 25 in the British Journal of General Practice. The research was supported by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care in the South West Peninsula (NIHR PenCLAHRC).