In 2016 New Zealand’s Perioperative Mortality Review Committee (POMRC) reported that, between 2009-2013, Māori New Zealanders were 62% more likely to die within 30 days following an elective or waiting list procedure (adjusted odds ratio [OR]: 1.62, 95% CI 1.33-1.97) – even after adjusting for age, gender, deprivation and physical status (‘ASA’ score). Māori were also more likely to die following an acute procedure, although not to the same extent (OR: 1.23, 95% CI 1.18-1.36). In their concluding remarks, the Committee highlighted the urgent need for further research into the drivers of this substantial disparity, emphasising the need for future work to assess the impact of comorbidity.
Despite these stark disparities, there had been very little research examining the potential drivers of postoperative mortality disparities between Māori and non-Māori and there was an urgent need to:
- describe in detail the extent to which disparities in postoperative mortality exist between Māori and non-Māori, particularly for surgical procedures that are major causes of postoperative mortality and/or morbidity, and
- measure the extent to which any observed disparities are explained by patient-level, surgical quality-of-care and/or health system level factors.
In 2018 we received funding from the Health Research Council of New Zealand to complete a national study of disparities in post-operative mortality between Māori and non-Māori. Over the course of this project, we observed substantial evidence of ethnic disparities in postoperative mortality across procedures for Māori compared to non-Māori ethnic groups. The evidence generated in this project provides a robust reinforcement for international findings from our recent systematic review of this topic, although the quality of international evidence has been sub-optimal. Our observed disparities are likely driven by structural factors including institutional racism acting through a combination of healthcare system, process and clinical team factors.
Our group remain interested and engaged in post-operative mortality research with other collaborators around Aotearoa New Zealand.
Key publications
Cameron Wells, Chris Varghese, Luke Boyle, Matthew J McGuinness, Celia Keane, Greg O’Grady, Jason Gurney, Jonathan Koea, Chris Harmston, Ian P Bissett (2023). ‘Failure to rescue’ following colorectal cancer resection: variation and improvements in a national study of postoperative mortality – Reducing Mortality after Colorectal Surgery. Annals of Surgery, 278(1), p87-95.
Gurney, J.K., McLeod, M., Thomas, C., Campbell, D., Dennett, E., Jackson, S., Ongley, D., Rumball-Smith, J., Stanley, J., Sarfati, D., Koea, J. (2022). Understanding disparities in post-operative mortality for indigenous patients. New Zealand Medical Journal, 135 (1565). p104-112.
Gurney, J., McLeod, M., Stanley, J., Robson, B., Campbell, D., Dennett, E., Ongley, D., Rumball-Smith, J., Sarfati, D., Koea, J. (2022). Regional variation in post-operative mortality in New Zealand. ANZ Journal of Surgery, 92(5), p1015-1025.
Gurney, J., McLeod, M., Campbell, D., Dennett, E., Jackson, S., Koea, J., Lash, N., Ongley, D. (2022). Anaesthetic choice for hip or knee arthroplasty in New Zealand: risk of post-operative death and variations in use. Anaesthesiology and Intensive Care, 50(3), p178-188.
Gurney, J., McLeod, M., Stanley, J., Sarfati, D., Campbell, D., Davies, C., Dennett, E., Himona, P., Jackson, S., Ongley, D., Robson, B., Rumball-Smith, J., Signal, V., Stairmand, J., Thomas, C., Koea, J. (2021). Disparities in post-operative mortality between Māori and non-indigenous ethnic groups in New Zealand. New Zealand Medical Journal, 134(1542), p15-28.
Gurney, J., McLeod, M., Stanley, J., Campbell, D., Dennett, E., Jackson, S., Koea, J., Ongley, D., Sarfati, D. (2020). Post-operative mortality in New Zealand following general anaesthetic: demographic patterns and temporal trends. BMJ Open, 10, e036451, p1-11.
McLeod, M., Signal, V., Gurney, J., Sarfati, D. (2020). Post-operative mortality of Indigenous compared to non-Indigenous populations: a systematic review. JAMA Surgery, 155(7), p636-656.
Gurney, J., Stanley, J., Rumball-Smith, J., York, S., Sarfati, D. (2018). Postoperative death following lower limb amputation in a national prevalent cohort of patients with diabetes. Diabetes Care, 41(6):p1204-1211.