A new study reveals that more than half of family doctors in Canada still use manual devices to measure blood pressure, an outdated technology that often leads to misdiagnosis. A study by researchers at the University of Montreal Hospital Research Centre (CRCHUM) showed that about 20 percent of people receiving treatment for hypertension do not actually have a problem and do not need medication. This is due mainly to the fact that their blood pressure was improperly measured," said lead author behind the study.
Blood pressure is defined as the pressure that the blood exerts on artery walls. Measured in the arm artery, it is expressed in two numbers: the value when the heart contracts (systolic blood pressure) and the value when the heart relaxes between two contractions (diastolic blood pressure). Blood pressure is considered normal when systolic pressure is below 140 mmHg and diastolic pressure is below 90 mmHg. Above these values, a person is said to have high blood pressure (hypertension) and below these values as low blood pressure (hypotension).
The technology behind sphygmomanometers, the devices used to measure blood pressure, has changed a great deal over the last 20 years. Today, automatic electronic measuring devices, known as oscillometric devices, are available. Yet, in the spring of 2016, when a survey as conducted by the CRCHUM researchers, 52 percent of the 769 respondents indicated that they still used the manual sphygmomanometers to measure blood pressure. Only 43 percent used an automatic device.
The study team recommended that despite it being more expensive, clinicians should adopt the electronic measuring devices as they take several measurements making them more precise. “Manual measurement is acceptable if it's properly done, but that's often not the case. To take blood pressure the right way, a 12- to 15-minute period is required. We know that the average visit to a family doctor lasts 10 minutes. We have to rethink how patient visits are organized so that the patient can be left alone in a room while the measurement is taken," said the author of the study.
Automated measurement also has the advantage of eliminating what is known as white-coat syndrome, which refers to artificially high blood pressure resulting from the stress of being in a doctor's office and human interaction.