The landscape of clinical trial activity focusing on Indigenous health in Australia from 2008-2018

Article type
Authors
Hunter KE1, Xu G1, Modi D1, Askie LM1, Jamieson L2, Brown A3, Seidler AL1
1National Health and Medical Research Council (NHMRC) Clinical Trials Centre, University of Sydney
2Australian Research Centre for Population Oral Health, The University of Adelaide
3South Australian Health and Medical Research Institute
Abstract
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 Indigenous trial activity.

Objectives: To provide an overview of trial activity in Australia focusing on Indigenous health, and compare this to overall Australian trial activity.

Methods: We extracted data from all trials registered between 2008-2018 on the Australian New Zealand Clinical Trials Registry or ClinicalTrials.gov, which only recruited participants in Australia. Trials with an Indigenous focus were identified by searching titles, eligibility criteria, study summary, intervention description and ethics committee name for relevant terms such as ‘Indigenous’, ‘Aboriginal’ and ‘Torres Strait Islander’. Indigenous versus non-Indigenous trials and Australian trials overall were compared 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 (OR 16.47, 95%CI=8.43-29.99), public health (OR 4.87, 95%CI=3.65-6.41) and infection (OR 2.51, 95%CI=1.53-3.89), and were more likely to focus on early detection/screening (OR 3.57, 95%CI=2.10-5.70) and preventive interventions (OR 2.24, 95%CI=1.61-3.08) rather than treatment (OR 0.40, 95%CI 0.30-0.52). 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 1.20-2.49). Only 16 (12%) Indigenous trials had industry involvement compared to 2271 (25%) of other Australian trials (OR 2.52, 95%CI 1.54-4.43).

Conclusions: Trials with an 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 prioritisation 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. Trial registries are a freely available and valuable resource for evaluating trends in trial activity, which can be used to inform future research and ensure it addresses diverse and vulnerable populations such as Indigenous Australians.

Patient or healthcare consumer involvement: This research was conducted in collaboration with an Indigenous researcher (Alex Brown).