Ethnic Diversity in Clinical Trials: Systematic Review Reveals Underrepresentation of Māori and Pacific in NZ RCTs

The Critical Need for Ethnic Diversity in New Zealand Clinical Trials

Randomized Controlled Trials (RCTs), considered the gold standard in medical research for testing the efficacy and safety of interventions, play a pivotal role in shaping healthcare practices worldwide. In Aotearoa New Zealand, where health disparities persist among different ethnic groups, ensuring diverse representation in these trials is not just a scientific imperative but a matter of social justice. Māori, the indigenous Tangata Whenua, and Pacific peoples, who together form a significant portion of the population, experience higher burdens of chronic diseases such as cardiovascular conditions, diabetes, and certain cancers. Yet, treatments developed primarily from European-centric data may not translate effectively across ethnicities due to genetic, metabolic, and socio-cultural differences. 73 43

This underrepresentation perpetuates inequities, undermining the principles of Te Tiriti o Waitangi—the Treaty of Waitangi—New Zealand's foundational document that mandates equitable health outcomes for Māori. The economic toll is staggering, with Indigenous health inequities costing the nation an estimated NZ$863.3 million annually, compounded by over NZ$1 billion in underfunding for Māori primary healthcare.

A Groundbreaking Systematic Review Exposes Gaps in Ethnic Reporting

Published on 30 January 2026 in the New Zealand Medical Journal (NZMJ), a systematic review titled "A systematic review of ethnic diversity in clinical trial participation in Aotearoa" led by Selwyn Te Paa and colleagues from the Medical Research Institute of New Zealand (MRINZ) has shone a light on these issues. Affiliated with Te Herenga Waka—Victoria University of Wellington, the research team analyzed RCTs registered in the Australia New Zealand Clinical Trials Registry (ANZCTR) from 2010 to 2020. 73

The methodology was rigorous: screening 1,040 trials, 342 met initial criteria, and 239 provided ethnicity data on 295,254 participants. Ethnicity was categorized using Stats NZ level one codes: European, Māori, Pacific peoples, Asian, Middle Eastern/Latin American/African (MELAA), and Other. Shockingly, 103 trials (30%) published no ethnicity data at all, highlighting a systemic flaw in reporting. 73

Alarming Disparities: Trial Participation vs National Census Data

Juxtaposed against the 2023 Stats NZ Census—European 67.8%, Māori 17.8%, Asian 17.3%, Pacific peoples 8.9%, MELAA 1.9%—the trial data reveals profound mismatches. Across all participants, only 6.1% were classified as European, 2.9% Māori, 1.4% Pacific peoples, 7.5% Asian, 2.5% MELAA, 9.0% Other, with a staggering 70.6% falling into a 'residual' category due to poor categorization like 'non-Hispanic' or 'white'. Mean enrollment per study: 23.2% European, 2.7% Māori, 1.8% Pacific peoples. 73 54

These figures suggest potential severe underrepresentation, particularly for Māori and Pacific groups, though cautioned by reporting inadequacies. Industry-sponsored trials dominated, often lacking local cultural alignment. 73

Root Causes: Barriers to Māori and Pacific Participation

Historical trauma from colonization, medical mistrust, and lack of cultural responsiveness deter involvement. Data sovereignty concerns—control over whakapapa (genealogy)—and inconsistent collection methods exacerbate issues. A related Kaupapa Māori study on pregnancy trials found strong researcher relationships key to recruitment success for Māori and Pacific women. 2

• Mistrust: Past unethical research erodes confidence.
• Accessibility: Urban bias excludes rural iwi (tribes).
• Cultural mismatch: Trials ignore kaupapa Māori frameworks.
• Reporting flaws: 46.9% used 'race' vs 'ethnicity', misaligning with Stats NZ standards.

Universities like the University of Auckland are addressing this through initiatives to boost Māori and Pasifika in research. 33

Implications for Health Equity and Te Tiriti Obligations

Underrepresentation risks ineffective treatments for priority populations, widening gaps. The review underscores obligations under Te Tiriti to protect (rongoā) and participate (kanohi ki te kanohi—face-to-face). Policymakers must act, as inaccurate data hampers equity monitoring. For higher education, this highlights the need for diverse research teams; Victoria University Wellington's involvement exemplifies academic contributions.Explore research jobs advancing health equity at NZ universities.

Read the full study. 73

University Initiatives Driving Change

New Zealand universities are pivotal. The University of Auckland's study on rural, Māori, and Pasifika trial inclusion and Victoria University's biological sciences collaborations with MRINZ foster culturally safe research. Programs like MAPAS support Māori and Pacific health students, building future researchers. Clinical research jobs and postdoc opportunities emphasize diversity. 33 34

• Co-design with communities for trust-building.
• Whānau-centered recruitment models.
• Training in Kaupapa Māori methodologies.

Recommendations: Toward Standardized and Mandatory Reporting

The review advocates mandatory Stats NZ ethnicity recording in protocols, HDEC approvals, ANZCTR, and journals. For multicenters, add NZ-specific data. Integrate cultural worldviews early. Steps: 1) Align forms with Stats NZ; 2) Prospective collection; 3) Regulatory enforcement. 73

Academics can lead by prioritizing equity in grant applications. Check academic CV tips for equity-focused researchers.

Global Context and Future Outlook

Globally, FDA mandates diversity plans; NZ can follow. Projections show Asian growth to 34% by 2048, demanding adaptive strategies. Optimism lies in growing Indigenous-led research. By 2030, expect policy shifts via Health Research Council. 55

Stakeholders: government, unis, industry must collaborate. View Stats NZ projections. 53

Empowering the Next Generation of Diverse Researchers

Higher education must train Māori and Pacific researchers. Initiatives like Te Kāhui Amokura showcase uni successes. Aspiring academics, leverage scholarships and higher ed jobs in NZ. Share experiences on Rate My Professor.

Photo by CDC on Unsplash

Conclusion: Time for Action in NZ Health Research

This review catalyzes change toward inclusive trials, honoring Te Tiriti. Researchers, policymakers, and universities: standardize, diversify, equitize. Explore university jobs, higher ed careers, career advice, professor ratings, and post jobs to join the movement.