A total of 2,238,308 ED patients were identified from 18 of 20 DHBs in NZ between 2006 to 2012. This includes 365,282 (16.3%) Māori and 1,873,026 (83.7%) non-Māori patients.

Despite some ED process measures favouring Māori e.g. arrival to assessment time (mean difference:-2.14 mins, 95% CI:-2.42 to -1.86) and access block (odds ratio [OR]:0.89, 95% CI:0.87 to 0.91), others showed no difference e.g. self-discharge (OR:0.98, 95% CI: 0.97 to 1.00). Despite this, Māori mortality (OR:1.60, 95% CI: 1.50 to 1.71) and ED re-presentation (OR: 1.11, 95% CI: 1.09 to 1.12) were higher than non-Māori.

To our knowledge, this is the most comprehensive investigation of acute outcomes by ethnicity to date in Aotearoa New Zealand. We found ED mortality inequities that are unlikely to be explained by ED process measures or comorbidities. Our findings reinforce the need to investigate health professional bias and institutional racism within an acute care context.