The real risks of wrong blood pressure readings

Missing the mark: why Australians are getting blood pressure checks wrong and what pharmacists can do to help.

More than one in three (34%) of Australian adults have high blood pressure. Of those diagnosed with hypertension, a staggering 68% have uncontrolled blood pressure. 

Effectively managing hypertension is the most powerful method of lowering the risk of cardiovascular disease; reducing blood pressure by 5 mm Hg can decrease the probability of adverse cardiovascular events by 10%.

Yet new research found that most Australians don’t know how to measure their blood pressure accurately, nor are they getting advice on how to do so from healthcare professionals – including pharmacists.

Lead researcher Dr Niamh Chapman, Senior Research Fellow at the University of Sydney, explains where patients are getting it wrong, and the vital role pharmacists can play in blood pressure management.

Improper measurement methods are skewing results

While most patients knew they should be seated, have their back supported and remain silent during blood pressure measurement to ensure accurate readings, they weren’t aware they should take multiple readings across different intervals conducted over several days.

‘They were doing it really frequently, (either) every week or every day,’ said Dr Chapman.

But the frequency of readings should depend on how they inform care. For example, if a patient needs a review of their blood pressure medications every 6 months, they could take their blood pressure at bi-annual intervals, following recommended steps, before visiting their GP for a script renewal, she said.

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When participants had a headache, felt unwell or were a bit stressed – this often served as a prompt for them to measure their blood pressure. However, all these factors can cause a variation in blood pressure results.

‘We know high blood pressure doesn't have any symptoms,’ said Dr Chapman. ‘To understand your risk of heart disease, stroke or dementia, that's not the best time to measure your blood pressure.’

Healthcare advice is lacking

Among people who measured their blood pressure at home, less than 20% received advice about how and when to do this from a doctor, nurse or pharmacist, said Dr Chapman.

The at-home devices patients used to measure their blood pressure were also not often clinically validated, which requires testing under an international protocol to assess the device’s reliability to deliver accurate blood pressure readings.

‘The [Therapeutic Goods Administration] only requires devices to be safe in terms of electrical safety, not [in accordance with] this rigorous accuracy testing,’ she said.

In further, as-yet-to-be-published research conducted by the University of Sydney, it was unearthed that most people buy blood pressure monitors from community pharmacists.

‘[But] only half of the devices that were purchased from pharmacies met this standard, and there's very little point-of-sale advice about what to do and what device to buy,’ said Dr Chapman.

Inaccurate readings could inform care decisions

Nearly 80% of people took often inaccurate at-home readings to their next doctor’s appointment. While not following the recommended steps is more likely to result in higher blood pressure readings, a tendency to opt for more favourable results was observed among respondents.

‘They were often taking lots of measurements, then trusting the lowest number, which was also a common [approach among] physicians,’ she said.

These readings were used to inform care decisions, such as confirming a diagnosis of hypertension or deciding whether to add or remove a medicine.

‘Often the home blood pressure measurements were valued by clinicians, because they can be performed more consistently and are more in-depth than one-off readings in a clinic,’ Dr Chapman added.

Pharmacists can improve the accuracy of blood pressure readings

As trusted healthcare providers, pharmacists have several opportunities to relay important messages to patients, said Dr Chapman.

‘Given most people buy their blood pressure device from pharmacies, it’s a great opportunity to provide basic training about how to use it, how to fit the cuff properly, what steps to follow, and when to take action,’ she said. 

‘They can also provide education when people are refilling scripts for anti-hypertensive medications.’

First and foremost, pharmacists should advise patients to obtain a validated device according to national and international clinical guidelines, said Dr Chapman. This online tool can be used to check the validation status of blood pressure monitors.

From there, pharmacists should explain how to take a structured approach to at-home blood pressure readings. For example, this could entail taking blood pressure readings once a month, over 3–5 days in the morning and evening, she said.

‘The person should be seated, have 5 minutes rest and take two readings each time they measure their blood pressure, using the average of those.’

This BP Toolkit helps patients take and record their blood pressure averages in a way that's easy for their doctor to digest.

‘To simplify things for both patients and doctors, we created a 10-steps guide for measuring blood pressure, with a report [format] that makes it easier to understand what number to use to inform care,’ said Dr Chapman.

An even bigger role is in the works for pharmacists

As part of the National Hypertension Taskforce to improve blood pressure control, a big part of Dr Chapman’s focus is working with pharmacists to take a team-based approach to hypertension management.

This includes conducting a randomised controlled trial in 2025, in collaboration with PSA, to test the 'BP Toolkit’ – an educational support package designed to improve blood pressure control. 

When patients visit the pharmacy for their blood pressure medication, they will be screened and offered a blood pressure check. Those in the intervention group will receive a counselling session with a pharmacist, covering medication adherence, lifestyle changes, action planning, and goal setting.

‘We'll look at delivering formal patient education and counseling, perhaps as part of a MedsCheck, to help improve blood pressure control,’ she said.

‘The goal is to deliver education that supports the patient to know whether or not they should go back to their doctor, and if they do go back to the doctor, what they should talk about.’

Dr Chapman is hoping to develop concrete evidence of the value pharmacists add to chronic disease management. 

‘We will be [funding] the pharmacy sites for undertaking the blood pressure measurement and providing an additional payment for delivering the education to the intervention group,’ she said.

‘With that information, we want to demonstrate a fundable model to deliver this [service] that mirrors what happens with [Medicare Benefits Schedule] and [Pharmaceutical Benefits Scheme] items.’

Evidence shows that team-based care involving pharmacists can significantly improve blood pressure control.

‘What we now need to do is demonstrate what an appropriate fee-for-service model is and how this is sustainable and scalable within the context of Australia at a national level,’ said Dr Chapman.

Working closely with local consumer advisors on this research, a key takeout for Dr Chapman is the peace of mind one patient, a stroke survivor, was able to achieve after following recommended at-home blood pressure measurement guidelines.

‘The [relief] they got from measuring their blood pressure in a structured way once a month, instead of every day where it jumps around and they don’t know what the numbers mean, is the most valuable thing as a stroke survivor – allowing them to relax and know that their blood pressure is under control and they're reducing their risk of stroke,’ she said.