Background: there are major disparities in health outcomes between indigenous and non-indigenous Australians. To address this, it is vital to understand key health priorities and knowledge gaps in the current landscape of trial activity in indigenous Australians.
Objectives: to provide an overview of trial activity in Australia focusing on indigenous Australians' health, and compare this to overall Australian trial activity.
Methods: we extracted data from all trials registered between 2008 to 2018 on the Australian New Zealand Clinical Trials Registry or ClinicalTrials.gov, recruiting only Australian participants, and identified trials with an indigenous focus by searching titles, eligibility criteria, study summary, intervention description and ethics committee name for relevant terms such as ‘indigenous’, ‘Aboriginal’ and ‘Torres Strait Islander’. We compared indigenous versus non-indigenous trials, and Australian trials overall, by sample size, conditions studied, intervention type, study design, sponsorship and funding.
Results: of the 9206 included trials, 139 (1.5%) focused on indigenous health. The three disease areas that had the greatest number of indigenous trials were ‘Public Health’ (n = 69, 50%), ‘mental health’ (n = 35, 25%) and ‘cardiovascular’ (n = 25, 18%; see Figure). Compared to other Australian trials, indigenous trials more frequently studied ear conditions (odds ratio (OR) 16.47, 95% confidence interval (CI) 8.43 to 29.99), public health (OR 4.87, 95% CI 3.65 to 6.41) and infection (OR 2.51, 95% CI 1.53 to 3.89), and were more likely to focus on early detection/screening (OR 3.57, 95% CI 2.10 to 5.70) and preventive interventions (OR 2.24, 95% CI 1.61 to 3.08) rather than treatment (OR 0.40, 95% CI 0.30 to 0.52). The majority of indigenous trials were randomised (n = 97, 70%) and this proportion was similar for other Australian trials (n = 6763, 76%). Indigenous trials were less likely to be blinded (OR 1.72, 95% CI 1.20 to 2.49). Only 16 (12%) indigenous trials had industry involvement compared to 2271 (25%) of other Australian trials (OR 2.52, 95% CI 1.54 to 4.43).
Conclusions: trials with indigenous health focus differ from other Australian trials in terms of health conditions studied, intervention focus, blinding and industry involvement. Understanding these differences can help inform research prioritization to address the high burden of disease in indigenous Australians. Relative to population size and burden of disease, the number of trials focusing on indigenous health is low, and therefore limited indigenous trial data are available for incorporation into systematic reviews and clinical guidelines. More trials are needed, particularly in the areas of cardiovascular disease, mental and substance use disorders, and injuries, which are the disease groups contributing most to the gap in total burden of disease between indigenous and non-indigenous Australians.
Patient or healthcare consumer involvement: this research was conducted in collaboration with an Indigenous representative (Alex Brown).