If we do not count it, it does not count: ethnicity in allogeneic haemopoietic stem cell transplant in Australia.

Race and ethnicity are important social determinants of health and may be associated with significant disparities in access to, quality of, and outcomes from health care. In the United States, racial disparities have been well-documented among patients with solid cancer, with Black patients experiencing the poorest outcomes for most cancers of any racial and ethnic group.1 In patients with acute myeloid leukaemia, mortality is strongly associated with ethnicity, with non-Hispanic Black patients faring worse than non-Hispanic White patients.2 In Australia, these disparities also exist for First Nations peoples, and patients from culturally, ethnically and linguistically diverse communities. These populations experience higher mortality and morbidity rates from cancer, greater levels of unmet physical, psychosocial and informational needs related to cancer treatment, lower quality of life following cancer diagnosis and treatment, and lesser access to and participation in clinical trials and cancer prevention and screening programmes.3-5 This occurs as a result of compounding inequities, including systemic cultural and racial discrimination, less access to primary and tertiary health care services and cancer therapy, lower health literacy and English language proficiency, cultural and religious barriers to help-seeking, geographic isolation and other social determinants of health that lead to worse health outcomes.2, 3, 5-8 Racial and ethnic disparities exist in solid organ transplantation with studies in Australia demonstrating that Aboriginal and Torres Strait Islander peoples with end-stage kidney disease, including children and young adults, experience poorer access to renal allo-transplant than White patients.9, 10 This was similarly noted among First Nations patients in New Zealand, Canada and the United States.11 Disturbingly, these disparities in outcomes and mortality, especially in cancer, have widened over the past two decades.12, 13 As with solid organ transplants, minority and underserved populations may also experience inequitable access to haemopoietic stem cell transplant (HSCT) and disparities in outcomes from HSCT14 – a highly specialised, complex and resource-intensive treatment only available at select metropolitan quaternary hospitals. Indeed, as with many health interventions, existing health disparities may act as barriers to access and referral for transplantation. For more than two decades, almost every single-centre, multicentre and registry study conducted in the United States that has explored social determinants of HSCT has consistently shown associations between age, sex, race/ethnicity, insurance coverage and socioeconomic status and utilisation of HSCT, repeatedly showing that many patients who may otherwise benefit from the treatment do not receive allogeneic HSCT.14-17 Importantly, the same disparities in relation to access to HSCT also influence short-term and long-term outcomes following HSCT. Empirical studies, again almost all from the United States, consistently note racial/ethnic disparities in outcomes following HSCT.18 White patients are more often referred for transplant, more often receive stem cells from an optimally matched donor and experience improved progression-free survival (PFS) and overall survival (OS) compared with patients from ethnic minorities (non-White/Hispanic peoples).18-20 A recent systematic review on racial disparities in HSCT utilisation and outcomes21 included 40 studies (all conducted in North America), consisting of registry reviews, surveys, cohort studies and qualitative studies. This review established that there is substantial variation in access to HSCT by patients from ethnic minority groups (Black, Hispanic or Asian patients) when compared with White patients. It also found racial/ethnic disparities in either OS, PFS, graft-vs-host disease, posttransplant relapse or transplant-related mortality – particularly in relation to outcomes experienced by Black American patients. Although worse survival and poorer transplant outcomes were partly related to differences in human leukocyte antigen matching, donor source, disease and performance status, time to transplant, socioeconomic status, insurance status and family income disparities in outcomes generally persisted after clinical and socioeconomic factors adjustment.21 This suggests that existing disparities, including nonreferral may relate to real and perceived racial bias and health-related stigma. In addition to disparities in access to and outcomes following HSCT, data from the Blood & Marrow Transplant Clinical Trials Network in the United States has also demonstrated that patients from minority groups have less access to HSCT trials, principally because they have less access to HSCT as a therapy, whether on trial or not.22 In summary, empirical studies make clear that racial/ethnic disparities in HSCT exist, and that there are complex, multifactorial and interrelated explanations for why they exist – including donor availability (with the major donor registries worldwide, including in the United Kingdom, United States, Canada and Germany, having restricted ethnic diversity as a result of which patients from ethnic minority populations are less likely to have an optimal donor and more often rely on alternative donor sources,23, 24 economic issues (cost, insurance coverage and socioeconomic status and geographic isolation), health care system issues (number and location of HSCT centres, procedural complexity and infrastructure), provider bias (based on judgements regarding age, sex, ethnicity and the indications for and safety of HSCT) and social factors (age, sex, education, intellectual capacity, mental and intellectual status, family support and social isolation, race and ethnicity).23-27 In contrast to solid organ transplantation, however, it has been established that the Australian Bone Marrow Donor Registry (ABMDR) does not align with the ethnic diversity of the Australian population, with relative overrepresentation of Northern and Western European donors and relative underrepresentation of donors of Aboriginal and Torres Strait Islander, Maori, Pacifika and Asian ancestry, no Australian studies have explored the impact of racial and ethnic disparities in access to or outcomes following HSCT. This may be because of current structural deficiencies in the data collected on patients undergoing HSCT in Australia.28 Although the Australia and New Zealand Transplant and Cellular Registry (ANZTCT, formerly the ABMTRR) documents whether a patient identifies as an Aboriginal or Torres Strait Islander, it does not routinely collect data on race or ethnicity. In addition, individual transplant centres that do capture more comprehensive data on ethnicity to satisfy reporting responsibilities to the Centre for International Blood and Marrow Transplantation (CIBMTR) do so inconsistently and according to ethnic taxonomies that may be unreliable and/or contextually and culturally invalid.29 The other challenge in studying the impact of race and ethnicity in HSCT relates to a series of conceptual complexities associated with their definition, categorisation, reporting and analysis.30, 31 First, race and ethnicity may be surrogates for other (related) sociodemographic factors that may influence disease incidences, health care utilisation and treatment outcomes, such as socioeconomic status, health literacy and education status. Second, ethnic categorisations are region- and context-specific and are not fixed in time but are dynamic social constructs that reflect prevailing power structures and social norms. Third, because race and ethnicities themselves, both for communities and individuals, are not fixed, but become more complex over time, some may declare one or another racial/ethnic identity while others may choose to say ‘mixed’ or multiple identities. Fourth, racial/ethnic assignment may be unreliable, relying, as it does, on self-attribution on the one hand and on changing definitions and taxonomies of race/ethnicity on the other. Finally, examination of racial and ethnic differences in health may oversimplify or dichotomise peoples and communities and fail to account for other complex social determinants of health, including the influence of culture (best understood as integrated patterns of human behaviours that include the language, thoughts, communications, actions, customs, beliefs, values and institutions of racial, ethnic, religious or social groups).29, 30 Despite these challenges, there is no option but to improve our understanding of the impacts of ethnicity on access to and outcomes from HSCT if we are to meet the health care needs of the Australian population. Australia is one of the most ethnically diverse countries in the world. According to the 2021 Australian Bureau of Statistics Census, Australia comprises 3.2% Aboriginal and Torres Strait Islander peoples and 29.1% overseas-born and 51.5% first- or second-generation Australians. Australian residents speak over 300 distinct languages, 22.8% do not speak English in the home and increasing numbers of Australians are identifying as having ‘blended’ ethnicities.32 However, the impact of this diversity and the health care experience of people with different ethnicities remains insufficiently understood. As with the ANZTCT, many health registries collect minimal data on ethnicity, with the most commonly collected data points limited to identification as an Aboriginal or Torres Strait Islander person, country of birth and language spoken at home. This is highly inadequate, making it impossible to truly understand the identities and experiences of Australia's population – directly impacting the generalisability of research, health care planning and delivery and evaluation of outcomes. As the title of the Federation of Ethnic Communities’ Councils of Australia (FECCA) 2020 white paper states, ‘If We Don't Count It, It Doesn't Count!’.28 What is required is the codevelopment of standardised categories, taxonomies and indicators of cultural, ethnic and linguistic diversity that can then be adopted in donor, disease, administrative and research databases. In the longer term, this will enable proper evaluation of outcomes and facilitate equitable care, but, even in the short term, it may give greater insights into who we are and how we experience health care. In the United States, for example, when improvements were made to how the US Census Bureau collected data on racial and ethnic composition, a 276% increase in those identifying as multiracial was reported between 2010 and 2020.33 In recent years, Australia has taken small steps to address its past and the structural inequities that continue to impact the lives of First Nations peoples. Later this year Australians will vote to alter the Constitution to recognise the First Peoples of Australia by establishing an Aboriginal and Torres Strait Islander Voice to Parliament. Constitutional recognition is long overdue for Australia's First Peoples – and is a huge step towards achieving equity in many areas of policy and government. But action to improve inclusion and responsiveness to need should also be extended to all those who experience marginalisation, disadvantage and exclusion in Australia. In health care, we can take steps towards decolonisation and inclusion by changing how data are collected, and reporting on the experience and outcomes of cultural, ethnic and linguistically diverse groups, giving a voice to all. This is true irrespective of whether the data sets are population-wide or relate to specific diseases or therapies – such as HSCT. Although increasing the ethnic and HLA diversity of donors available on the ABMDR is an imperative, we also need to understand better the full range of factors that impact access to and outcomes of HSCT. This can only be done by including, respecting and working with all those people and communities that make up Australia. It is time that we now take seriously the need to include culture and ethnicity in assessments of outcomes in HSCT and other cancers in Australia to help create better outcomes for all.