A University of Otago researcher says Māori and Pasifika patients are being failed by a heart abnormality diagnosis that is not fit for purpose.
A stethoscope and heart monitor. File photo. Photo: AFP / Science Photo Library
A new study shows Māori and Pasifika patients could be missing out on critical heart treatment because of diagnosis methods that are not fit for purpose.
The University of Otago paper says the normal range used to gauge heart abnormalities has been developed for white Americans.
When applied to Māori and Pacific people, this could result in incorrect diagnoses and potentially delay treatment.
"I think this is an example of a failure of the health system to respond to their needs" - Study author Professor Gillian Whalley
One of the study's authors, Professor Gillian Whalley told First Up the calculation used to measure heart size was not fit for purpose for Māori and Pasifika people.
In the past, best medical practice has encouraged doctors to divide a person's various measurements by their body surface area.
"When you go and have an ultrasound scan of your heart, the sonographer who does it will take a lot of measurements and of course if someone is five-foot-five their heart will be smaller than someone who is six-foot tall because your heart is obviously proportional to the rest of your body and how much blood flow it needs," Whalley said.
Professor Whalley said that taking measurements using the current diagnoses assumed the person's underyling body composition was made up of fat rather than muscle.
However, extensive evidence has shown that Māori tend to have a greater muscle mass than non-Māori.
"Lots of evidence, 20 plus years of evidence has shown us that if you take two people of the same height and weight one who's Māori and one who's non-Māori the Māori patient will have a lot more muscle mass in their body than the non-Māori patient," she said.
The correlation between muscle mass and heart size suggested Māori possessed larger hearts than non-Māori but the medical profession had failed to factor this into its calculations, Whalley said.
It was difficult to know if this meant Māori and Pasifika patients diagnosed using this formula had been underprescribed medicines to help with their conditions but it was possible, she said.
"Often people talk about Māori patients and Pacific patients presenting late for surgery and other treatments and I think this is an example of a failure of the health system to respond to their needs."
Māori women were the most affected by the implied bias of existing heart size calculations, mainly due to body composition.
Whalley said this was unsurprising as a lot of medical research focused on white American men, a demographic which represented a wealthy target audience for medical companies.
Professor Whalley said the ineffective heart treatment diagnoses represented another reminder that the health system stacked the odds against Māori and Pasifika people.
"This is my profession so I'm as bad as anyone, I for many years before I started to think about this, which was about 15 to 20 years ago, I followed the international guidelines it seemed like best practice.
"And individually none of us are racist ... we all care about our patients ... but systematically it is racist. Once you understand that and once you see it there's no coming back from it if that makes sense you can't unsee it anymore once you realise this is just blatant systemic racism really."
A stronger approach was needed to recognise higher risks and biases in cardiology practices, she said.
She urged the Cardiac Society of Australia and New Zealand to come together to develop a set of guidelines to recognise higher risk of heart disease in certain demographics and do all they can to alleviate any inequality.
Whalley said it was likely there were other medical practices which discriminated against minority populations that had yet to be discovered.
*This story was updated on 18 July 2022 to correct reference to sonographer in a quote.