Australia is one of the most culturally diverse nations in the world. The 2021 Census found that 27.6% of the population was born overseas, 48.2% have a parent born overseas, and 22% spoke a language other than English at home.
For clinical trial sponsors and CROs, this diversity represents both an opportunity and a challenge. A participant pool that reflects the actual population produces more generalisable results, and reaching culturally and linguistically diverse (CALD) communities opens access to a significant portion of that population.
In practice, however, CALD communities remain consistently underrepresented in Australian clinical trials.
Lead Lists covers why that gap exists, what it costs in scientific and ethical terms, and what practical steps sponsors and site teams can take to improve CALD recruitment.
Why CALD underrepresentation matters
The problem with recruiting participants predominantly from English-speaking, majority-background populations is that trial results may not translate accurately to the broader population a treatment is intended to serve. According to this international study, failing to include diverse participants can result in treatments and interventions that are not accessible to all who need them.
Clinical trial participation among CALD populations should be understood as a dynamic, multi-level decision-making process rather than a single recruitment or informed consent event. That framing matters because it shifts the approach from a one-off communication task to a sustained, structured engagement effort.
Australia’s principal challenge is embedding, resourcing and evaluating culturally responsive practices across the clinical trial system. This implementation gap has important ethical as well as scientific implications.
Common barriers to CALD recruitment
Before addressing solutions, it helps to understand what is driving the gap. Research into CALD participation in Australian clinical trials consistently points to a cluster of recurring barriers.
Challenges identified as the most frequently perceived barriers to recruitment in a national survey of the Australian cancer clinical trials workforce include:
- Clinical trial design and exclusion criteria such as the ability to speak English
- Comorbidities and pre-existing health issues
- Health systems that require a high level of health literacy
- Financial barriers such as the cost of travelling to hospitals and taking time off work
- Lack of culturally appropriate resources and support
- Communication barriers, such as a lack of translated materials
- Opportunity-related barriers, such as exclusionary trial protocols
Beyond language, there are trust-related barriers that translate-only strategies do not address. Many CALD communities have historical reasons for wariness toward medical institutions, and building the kind of trust that supports informed participation in a clinical trial takes time and genuine community engagement.
Practical outreach strategies for CALD recruitment
Fortunately, there are ways clinicians and researchers can overcome these barriers to ensure there is a wide range of language, culture, and experience being represented in trials.
Translate materials early and completely
Translated participant information is a necessary starting point, but translation alone is not sufficient. Materials need to be translated before outreach begins, not retrofitted after initial recruitment falls short. Work with professional translators familiar with medical terminology in the target language, and have materials reviewed by community members or cultural consultants before use.
Engage community organisations and leaders
Recruitment should extend beyond translation of study materials to incorporate meaningful community partnerships, appropriate use of interpreters, consumer and carer involvement, and culturally responsive engagement throughout the research lifecycle.
Ethnic community councils, multicultural health services, religious organisations and community health centres all offer established trust relationships with CALD populations that clinical trial teams rarely have independently.
Building relationships with these organisations before recruitment opens, rather than approaching them when enrolment is already behind, is the more effective approach. Where possible, involve community representatives in study design and recruitment planning.
Work through CALD healthcare providers
GPs and specialists who serve high-CALD population areas are a valuable referral channel. Clinicians with established relationships within specific cultural communities can introduce clinical trial opportunities in a trusted context, which is particularly important where institutional trust is low. Providing multilingual referral materials and clear, simple study summaries that GPs can use with patients reduces friction in this channel.
Use geographic and demographic targeting for outreach
Suburbs with high CALD population concentrations are identifiable from ABS Census data and are well-represented within large Australian consumer databases. For direct-to-consumer outreach, postcode-level targeting allows research teams to focus direct mail, SMS and email campaigns on areas where the target community is concentrated, rather than running untargeted national campaigns.
This approach works well for trials targeting demographic profiles that correlate with specific communities, for example cardiovascular studies targeting older adults in areas with established Vietnamese, Chinese or Italian communities, or metabolic health studies targeting areas with high South Asian population density.
Accurate, opted-in consumer data filtered by age, gender, household type and geographic location gives recruitment teams a targeted starting point for direct outreach that reaches beyond the clinic-based GP referral channel. All outreach must be based on ethics-approved recruitment materials and comply with the Privacy Act 1988 and ACMA requirements.
Use multilingual digital and community channels
Ethnic media, including community radio stations, language-specific online publications and social media groups organised around specific cultural communities, can carry study awareness messages to audiences that mainstream digital advertising does not reach effectively. These channels require materials in the relevant language and messaging that have been reviewed for cultural appropriateness.
Social media advertising can also be targeted by language preference on some platforms, allowing teams to serve study awareness content to users who engage primarily in a specific language.
Account for family involvement in consent
Strategies that strengthen clinical trial literacy, support culturally responsive communication and acknowledge the influence of trust and family involvement may better support informed participation decision-making.
In many CALD communities, health decisions involve family members rather than being made individually. Consent processes and study information should be designed to accommodate this, including providing information in formats that can be shared with family members and allowing time for family consultation where appropriate.
The compliance and ethics framework
All recruitment outreach for clinical trials in Australia requires HREC approval before any materials are used or contacts made. All HRECs in Australia must operate in accordance with the National Statement on Ethical Conduct in Human Research, developed by the National Health and Medical Research Council (NHMRC).
Recruitment approaches targeting CALD communities, including translated materials, community partnerships and targeted outreach campaigns, should be described in your ethics application and approved before use.
The Privacy Act 1988 governs how personal information is collected and used throughout the recruitment process. Any consumer data used for participant outreach must be opted-in and compliant with Australian privacy law, and telemarketing outreach must comply with the Do Not Call Register Act 2006.
How consumer data supports CALD recruitment
For trials where direct-to-consumer outreach is part of the approved recruitment approach, accurate consumer data filtered by geographic location can help teams reach CALD communities at scale. Targeting postcodes and suburbs with known CALD population concentrations, combined with demographic filters such as age and household type, gives recruitment campaigns a more relevant starting point than broad national outreach.
Lead Lists supplies opted-in, compliant Australian consumer data across direct mail, telemarketing, email and SMS channels, drawn from a database of 21 million+ records.
For sponsors and CROs running participant outreach campaigns that need to reach specific geographic areas, including those with high CALD population density, we can supply targeted lists built to your campaign specifications. We can provide compliance documentation to support procurement and ethics review requirements.
Our data cleansing service can also be used to clean and update existing participant contact databases before a recruitment campaign launches.
Reaching CALD communities in clinical trial recruitment is not a communication problem that better translation alone solves. It requires earlier planning, genuine community partnerships and outreach strategies that go beyond the clinic. Consumer data targeted to the right geographies is one practical tool that supports broader reach when direct-to-consumer outreach is part of your approved recruitment approach.
Get in touch to discuss data options for your next recruitment campaign.
Disclaimer: This article is intended as general guidance and does not constitute legal, regulatory, or ethical advice. Recruitment activities must be conducted in accordance with your study’s HREC approval and applicable Australian regulations.
