- Accurate blood pressure (BP) measurement is the foundation of optimal screening, diagnosis, and treatment of hypertension.
- Many family physicians continue to use techniques for diagnosis that are not
recommended by the Canadian Hypertension Education Program (CHEP) leading to misdiagnosis.
- To diagnose hypertension, 24-hour Ambulatory BP monitoring should be done whenever feasible otherwise home BP measurement should be performed with electronic device.
Getting one's blood pressure taken during a visit to the doctor is a routine procedure. It also provides crucial medical data. In Canada, one adult in five suffers from hypertension which represents the greatest global risk factor for death and disability.
A study by researchers at the University of Montreal Hospital Research Centre (CRCHUM) shows that more than half of family doctors in Canada are still using manual devices to measure blood pressure, a dated technology that often leads to misdiagnosis.
‘More than half of the family physicians in Canada are still using manual devices to measure blood pressure, a dated technology that often leads to misdiagnosis.’
"About 20% of people receiving treatment for hypertension don't 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 Janusz Kaczorowski, a medical sociologist, is a CRCHUM researcher and professor in the Department of Family and Emergency Medicine at Université de Montréal.
Measuring Blood Pressure
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 120 mmHg and diastolic pressure is below 80 mmHg
. Above these values, a person is said to have high blood pressure (hypertension).
The technology behind tensiometers or sphygmomanometers, the devices used to measure blood pressure, has changed a great deal over the last 20 years. Automatic electronic measuring devices, known as oscillometric devices, are now available. In 2016, The Canadian Hypertension Education Program (CHEP) Guidelines recommended that electronic measurement is preferable to manual measurement
Automated Electronic Devices are Better
An increasing number of medical clinics are equipped with automatic electronic devices. Yet in the spring of 2016, Kaczorowski's team conducted a survey among Canadian family doctors: 52% of the 769 respondents indicated that they used a manual tensiometer to measure blood pressure. Only 43% used an automatic device.
"Clinicians should use automatic devices," Kaczorowski said. "They are more expensive but more precise because they take several measurements. 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."
Automated measurement has the advantage of eliminating what's 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. The researchers believe that clinicians should adopt these devices to detect individuals likely to suffer from high blood pressure, in accordance with the Canadian guidelines.
In Canada, healthcare costs attributable to hypertension were evaluated at more than $13 billion in 2010. "If people who take high-blood-pressure medication had their blood pressure measured incorrectly, the financial implications are considerable, in addition to the side effects, which could be avoided," said Kaczorowski.
Facts on Hypertension
- Blood pressure monitor readings must be taken at different times of the day to determine average blood pressure over a period.
- In 90 - 95% cases of high blood pressure, there is no specific underlying medical condition.
- An estimated 35.3 million men and 38.3 million women in the United States suffer from hypertension.
- Hypertension is often referred to as 'the silent killer' and accounts for nearly 6% deaths worldwide.
- Almost one in every three people suffers from this condition and this may be related to our modern lifestyle and dietary changes.
- Janusz Kaczorowski et al., How do family physicians measure
blood pressure in routine clinical practice?, Canadian Family Physician (2017)