nzRISK: Understanding Surgical Risk based on New Zealand’s Unique Population
Deciding whether to have major surgery can be difficult for patients and clinicians alike. The benefits and risks need to be weighed up through a shared decision-making process. This is particularly true for high-risk populations.

In Aotearoa New Zealand, Māori experience different outcomes compared to the rest of the population across nearly all areas of health. This includes mortality (risk of death) following surgery; for Māori, mortality within one month is higher than for non-Māori.
In order to achieve better health outcomes for Māori and New Zealand’s other high-risk populations, a tailored solution has been developed to help patients and clinicians make surgery decisions based on local research, which has been interpreted alongside Māori health experts.
New Zealand clinicians previously relied on risk assessment tools that are based on a small number of patients’ data from either the UK or USA, and many of which have been in place for up to 30 years. These tools weren’t tailored to New Zealand, and didn’t reflect the uniqueness of our population.
To address this, Dr. Doug Campbell of the Department of Anaesthesia at Auckland City Hospital set out to develop a surgical risk calculator in 2017 through the Precision Driven Health research partnership, working with researcher Luke Boyle.
The result is nzRISK, an easy-to-use online risk calculator that allows for a more informed decision-making process. Patients and clinicians can use nzRISK to enter risk factors including age, gender, ethnicity and the procedure they’re having to get a 30 day, one- and two-year estimate of mortality.
nzRISK has been created using data from over 270,000 New Zealand patients aged 18 or over undergoing non-cardiac surgery. This focus on local data gives New Zealanders – and in particular New Zealanders at higher risk, such as Māori – the information they need to inform their decision making.
In order to further develop nzRISK, additional research has been undertaken to improve its initial modelling, and uncover more information related to ethnic inequities in healthcare outcomes.
Luke is currently completing his PhD by undertaking this work and is working with Māori health advisors and researchers – including Taia Te Hauora, a University of Auckland Māori research advisory group – to ensure a Māori health lens is applied.
Collaboration is key to the ongoing adaptation and adoption of nzRISK and its associated research, allowing information to always be interpreted by relevant experts and translated for the patients they’re working with. By tuning nzRISK to represent New Zealand’s unique population, patients and clinicians can make more informed decisions about their health.