Call for Mandatory Ethnicity Reporting in Aotearoa New Zealand Clinical Trials to Uphold Health Equity

A comprehensive review of randomised controlled trials in Aotearoa New Zealand has identified significant challenges in measuring whether clinical research is meeting its health equity commitments under Te Tiriti o Waitangi.

A systematic review led by Dr Selwyn Te Paa at the Medical Research Institute of New Zealand examined ethnic representation in all randomised controlled trials (RCTs) undertaken in Aotearoa New Zealand between 2010 and 2020 and registered with the Australia New Zealand Controlled Trials Registry (ANZCTR).

The findings show that more than one-third of published trials reported no ethnicity data at all, and that in studies where ethnicity was reported, over 70% of participants could not be clearly classified using Statistics New Zealand’s standard ethnicity categories.

Across 239 trials reporting ethnicity or race data, involving more than 295,000 participants, only 2.9% were identified as Māori and 1.4% were identified as Pacific Peoples — figures that sit well below population proportions and highlight a critical gap in representative research participation.

“Randomised controlled trials are the gold standard for evaluating treatments, but they can only inform equitable care if the populations most affected by disease are meaningfully represented,” says Dr Selwyn Te Paa. “Without consistent and standardised ethnicity reporting, we simply cannot assess whether clinical research in New Zealand is serving Māori communities equitably.”

The review also found substantial variation in how studies described participant demographics. Nearly half of publications categorised participants using the term ‘race’, others used ‘ethnicity’, some used both interchangeably, and many applied international or non-standard groupings that could not be aligned with New Zealand’s official ethnicity classifications.

The authors note that lack of cultural safety in trial design, historical trauma, concerns around data sovereignty, and unclear governance over how data is used may all contribute to under-representation. Without accurate data, it is impossible to track progress or design interventions that genuinely meet Māori health needs.

The study’s authors recommend that ethnicity information be collected and reported in a standardised way for all clinical trials conducted in New Zealand. Using Statistics New Zealand’s recognised ethnicity categories would ensure that participant data is recorded consistently and reflects the communities the research is intended to serve.

Requiring this information at the ethics approval stage, during trial registration, and when results are published would make it possible to see who is — and who is not — being included in research, and whether progress is being made toward equitable participation.

“Standardised ethnicity reporting is not an administrative burden — it is a foundational requirement for equitable, high-quality research,” says Professor Alex Semprini. “New Zealand has a strong clinical trials ecosystem with international reach. Aligning our reporting standards with our equity commitments is both achievable and necessary.”

The findings provide a clear roadmap for strengthening accountability and transparency in clinical research, while also offering a model for other countries grappling with inequities in Indigenous and marginalised population health.