Hypertension is known to increase the risk of cardiovascular disease. It was identified as one of the nine modifiable risk factors (along with smoking, lipids, diabetes, obesity, diet, physical activity, alcohol consumption and psychosocial factors) contributing to more than 90% of the risk of AMI in the INTERHEART study conducted in 52 countries.¹ To mitigate the risk, high BP has to be managed effectively and for this it has to be measured accurately.

Several factors influence the measurement of BP. These factors can be patient-related (such as drinking tea/coffee or engaging in physical activity just before measurement, acute meal ingestion, slouching, unsupported back/feet/arm, sitting with crossed legs, talking including on the phone, full bladder), procedure-related (patient’s legs are crossed at the knees, patient is talking, the arm is lower than heart level), physician-related (talking, using a wrong cuff size, tying the cuff over clothing, not taking multiple measurements) or equipment-related (non-validated automated devices, too small or too large cuff).² These factors yield readings that may be inaccurate and therefore unreliable. The consequences are missed diagnosis and therefore delayed or no treatment or inappropriate treatment. Attaining the treatment goals is difficult on account of the highly variable readings. Standardized measurement of office BP is essential to reduce errors.

Recently, 13 scientific global health organizations jointly published a consensus statement on standardized clinic BP measurement in the May 2023 issue of the American Journal of Medicine.³

The consensus statement has outlined four steps for implementing standardized clinic BP measurement relating to the equipment and the facility where BP is to be measured, staff measuring the BP, patient preparation and the procedure of measurement. The BP should be measured in a quiet room with a clinically validated BP device by trained healthcare professionals using an appropriately sized cuff over the bare upper arm. An automated device is recommended to eliminate the “human error associated with manual devices”. The aforementioned patient-related factors should be eliminated. If the patient has not been prepared, then the measurement should be deferred for later. The arm with the higher systolic BP readings should be used and more than 2 readings should be obtained in a gap of at least 30 seconds. The average of the readings should be recorded. Training and certification in proper office BP measurement followed by regular recertification will enhance accuracy.

The statement has also addressed the role of out-of-office BP measurement in control of hypertension. Because of the ambiguity of evidence supporting home BP monitoring (HBPM) or ambulatory BP monitoring (ABPM) to guide management, it considers them “complementary to standardized clinic BP measurements” to be used when clinic BP measurements are unavailable.

However, standardized measurement may particularly be difficult to implement in the resource-crunched parts of the world because of lack of availability of automated BP measuring devices or cuffs of different sizes or an optimal clinic environment or shortage of adequately trained staff. Moreover, measuring BP is not subjected to regulatory standards. All these act as hurdles to standardized BP measurements.

It has issued a “call to action” for all stakeholders to overcome the barriers to the implementation of standardized clinic BP measurement.

• All healthcare workersshould adopt the standardized measurement as part of the routine BP check in their clinics and also educate the patients and staff on the need to do so.
• The role of healthcare institutionsis to provide the proper validated equipment, staff and designate a proper clinic space. They must arrange for staff training and certification.
• Manufacturersshould provide BP measuring devices and cuffs at an affordable cost.
• Hypertension is a public health problem. Hence, the government regulatory agenciesshould devise strategies to educate the public, health care providers and institutions to meet the challenge. Training and certification should be mandated by the government.
• Professional societiesmust promote standardized clinic BP measurement among the fraternity and also engage in educating the general public.
• Financial incentives for standardized clinic BP measurements can be provided by healthcare funding agencies to enhance compliance.

Today is World Hypertension Day and the theme this year is “Measure your blood pressure accurately, control it, live longer”. Accurate measurement of BP using the standardized BP measurement technique is essential to control the rising prevalence of hypertension.

References

1. Yusuf S, et al, on behalf of the INTERHEART Study Investigators. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364:937-952.
2. https://www.ama-assn.org/delivering-care/hypertension/4-big-ways-bp-measurement-goes-wrong-and-how-tackle-them. Accessed on May 16, 2023.
3. Cheung AK, et al. International consensus on standardized clinic blood pressure measurement - a call to action. Am J Med. 2023 May;136(5):438-445.e1. doi: 10.1016/j.amjmed.2022.12.015.