5th October 2018, Volume 131 Number 1483

Nina Scott, Helen Clark, Bridget Kool, Shanthi Ameratunga, Grant Christey, Donna Cormack

Injury, as a leading cause of morbidity and mortality, contributes to health inequity in New Zealand and is a major socio-economic burden.1,2 Health inequities are defined as “differences which are…

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Eliminating unfair differences in life expectancy between Māori and non-Māori is something the New Zealand government has signed up to. Part of this involves fixing unwarranted variations in healthcare that exist across a range of pathways. For this, we need good-quality ethnicity data to figure out where healthcare needs improving. We found that one-quarter (24%) of trauma patients who self-identified as Māori were misclassified as New Zealand European. We did this by asking patients to self-identify their ethnicity using the census ethnicity question. This is important because hospital data is used for national planning and budgeting and we need good-quality ethnicity data to guide efforts to implement the necessary steps for achieving equity.


Māori are disproportionately impacted by injury in New Zealand, therefore reliable ethnicity data are essential for measuring and addressing inequities in trauma incidence, care and outcomes.


To audit the quality of ethnicity data captured by the Waikato Hospital Trauma Registry and Waikato Hospital patient management system against self-identified ethnicity.


Self-identified ethnicity using the New Zealand Census ethnicity question was gathered from 100 consecutive trauma patients and compared with ethnicity recorded in their Trauma Registry record and in the hospital’s patient management database.


Twenty-nine (29%) participants self-identified as Māori, of whom six were classified as New Zealand European (NZE) only in the Trauma Registry and five as NZE on the hospital patient management database. Over half of Māori (n=18/29) reported more than one ethnicity compared with 4% (n=3/71) of non-Māori. Self-identified ethnicity matched Trauma Registry ethnicity for one quarter (n=7/29) of Māori versus 9% of non-Māori.


The degree of misclassification of Māori ethnicity data among patients in the Waikato Trauma Registry and the Waikato Hospital patient management system highlights a need for improvements to how ethnicity data is captured within these databases and potentially many other similar entities collecting ethnicity data in New Zealand. The release of revised standardised protocols for the collection of ethnicity data is timely given the recent establishment of a national trauma registry. Without quality data, the opportunity to investigate and address ethnic inequities in trauma incidence and management is greatly compromised.

Author Information

Nina Scott, Public Health Physician, Waikato District Health Board Hamilton;
Helen Clark, Medical Education Officer, Clinical Education and Training Unit; Waikato District Health Board, Hamilton; Bridget Kool, Senior Lecturer (Epidemiology and Biostatics), School of Population Health, The University of Auckland, Auckland; Shanthi Ameratunga, Professor of Epidemiology, School of Population Health, The University of Auckland, Auckland; Grant Christey, Trauma Director, Waikato District Health Board Hamilton; Donna Cormack, Senior Lecturer, Te Kupenga Hauora Māori, Faculty of Medical and Health Sciences, The University of Auckland, Auckland. 


Nina Scott, Waikato Hospital, Pembroke Street, Private Bag 3200, Hamilton 3240.

Correspondence Email


Competing Interests

Dr Cormack reports grants from the Ministry of Health during the conduct of the study.


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