Problems and Solutions in Implementing the World Hypertension League Recommendations for Automated Office Assessment of Blood Pressure

Hypertension is the main risk factor for heart disease and stroke in Brazil and most other countries.1 The Global Burden of Disease Study estimated that increased BP was the leading risk for death and disability in 2010, accounting for 7% of all disability‐adjusted life years and 18% of deaths.1 Worldwide, hypertension is estimated to impact more than 1 billion people.2

Approximately 40% of adults older than 25 years have hypertension.2, 3, 4, 5 Optimized control of hypertension through lifestyle changes and pharmacologic treatment can reduce morbidity and mortality from cardiovascular disease.6 However, appropriate management of hypertension starts with diagnosis and that requires accurate assessment of BP. Unfortunately, adherence to recommended techniques for obtaining an accurate blood pressure (BP) assessment is rare in clinical practice.7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18

The World Hypertension League (WHL)19 and World Health Organization (WHO)13 have advocated the use of automated BP devices especially in low‐resource settings as a partial solution to improve the accuracy of BP assessment. Use of an automated device removes the need for accurate hearing and interpretation of Korokoff sounds, standardizes cuff deflation rates, and provides a reading to the closest 1 mm Hg.19 Depending on the degree of automation, other technical aspects such as cuff inflation are also addressed. Nevertheless, several critical technical aspects of BP assessment (cuff selection and arm support and position) and patient preparation (eg, rest and not smoking for 30 minutes) still require the observer to be trained and to apply recommended techniques during readings. This editorial describes some of the difficulties in implementing the WHL policy to transition to automated devices in Brazil, addresses additional problems the authors have encountered, and proposes some recommended solutions. The issues identified and solutions proposed are likely applicable in many if not most countries.

In contrast to the WHL and WHO recommendations to use automated BP devices, healthcare professionals in Brazil are taught to assess BP by auscultation and almost uniformly use this technique in clinical practice.20 Hence, one of the first steps toward implementing increased use of automated BP devices needs to be integration of their use into training programs and continuing health education. The WHL is proposing to develop a core curriculum to teach healthcare professionals how to accurately use automated devices as a stimulus for this badly needed paradigm shift in training. The WHL has also developed resources to aid screening of hypertension and a tool (http://www.whleague.org/images/Blood_Pressure_Training_Assessment.pdf) to assist in testing the ability to properly assess BP with an automated device that could be used in training programs.21 Accreditation programs requiring training in automated BP assessment with accuracy testing would further aid the transition away from auscultatory readings.

Automated BP devices may not have passed international validation standards and therefore may not provide accurate readings. Further, to obtain accurate readings, a cuff size that is appropriate to the arm size of the person being assessed needs to be used. In Brazil, BP cuffs are often not marked to easily determine whether they are an appropriate size. Clinicians can be trained to purchase only devices that have passed international validation standards and cuffs that are accurately marked for easy identification of the sizes appropriate for individual patients. Training to mark the cuffs for the range of arm they should be used on or to assess the arm sizes in individual patients is cumbersome and not an optimum long‐term solution. Advocating to government to more appropriately regulate the devices that are sold and to device companies to produce and sell only “validated” devices and accurately marked cuffs should be a role for national hypertension organizations and the WHL. Regulating the sale of validated devices and appropriate BP cuffs would allow training on accurate assessment of BP to be more focused and will likely result in more accurate BP readings.

Currently, the Brazilian Guidelines in Arterial Hypertension recommend that BP measurement be performed either using the auscultatory technique with an aneroid sphygmomanometer or mercury column or oscillometric technique using automatic devices.22 This recommendation, which is supported by multiple Brazilian heath and scientific organizations, facilitates an evolution toward the automated technology but may not provide adequate motivation for clinicians to change to a technology they may be less familiar with and that may increase their costs. Changing the recommendation wording to a preference for automated technology over auscultation in subsequent recommendations might aid the transition. Further, it is anticipated that in the future there should be a clear recommendation not to use auscultation for routine BP assessment once this is feasible in the context of the country.

In low‐resource settings, many clinicians cannot afford to purchase automated BP devices, which are more expensive than aneroid devices and require periodic replacement. The United Nations/WHO has a target of 80% availability in public and private settings for essential medications and technology to reduce noncommunicable disease by 2025.23 The United Nations/WHO target is supported by most national governments and can be used by national hypertension organizations to advocate for financial incentives to support implementing the WHO recommendation to utilize automated BP devices in low‐resource settings. Further, the WHL and others are strongly encouraging device companies to develop robust inexpensive semiautomated devices.

In reality, lack of a basic electrical power supply persists as a limiting step for oscillometric automatic device acceptance in very low‐resource settings. Automated devices require power sources and batteries, which can be highly problematic in very low‐resource countries. With Bill & Melinda Gates Foundation funding support, Microlife has recently developed a robust semiautomated device that is inexpensive and that uses a cell phone charger (Microlife 3AS1‐2; Widnau, Switzerland). Omron developed a robust solar‐powered device (Omron HEM‐SOLAR; Omron Healthcare, Inc, Lake Forest, IL) in response to a request from the WHO, although production costs have made the device expensive, threatening the complementary goals of affordability and availability.13, 24 Despite these important developmental steps, there are unresolved issues. Solutions are vulnerable, whether due to an unreliable to nonexistent electrical power grid or the high cost and limited access to battery sources, even if rechargeable by solar, generator, or other intermittent external power sources. One potential catalytic innovation may allow the development of completely self‐powered semiautomatic devices requiring no external or battery power. Low‐cost solutions harvesting vibrational energy from the bulb squeezing action could eliminate completely the need for external power, while preserving the validation of oscillometric measurement accuracy.25

Conclusions

There is a need to transition to automated BP devices from manual devices that rely on auscultation. To be fully implemented, especially in low‐resource settings, this requires a change in the training of healthcare professionals, regulatory changes regarding the production and sale of BP devices, and technological advances to make less‐expensive robust devices that are less reliant on electrical power sources. Hypertension organizations and experts can aid this long overdue and important transition by advocating to government, the private sector, and healthcare professional training centers. National hypertension organizations need to take up this challenge and also evolve their hypertension recommendations to support the change while at the same time reflecting what is feasible within the national context.

Disclosures

The authors report no specific funding in relation to this research and have no financial conflicts of interest to declare. Lyne Cloutier has received funding for the pilot projects related to blood pressure screening from the Agence Universitaire de la Francophonie.