Abstract
Introduction: Maori are disproportionately affected by cardiovascular disease (CVD), which is the main reason for the eight year difference in life expectancy between Maori and non-Maori. The primary care-based IMPACT (IMProving Adherence using Combination Therapy) trial evaluates whether fixed dose combination therapy (a "polypill") improves adherence to guideline-based therapy compared with current care among people at high risk of CVD. Interventions shown in trials to be effective do not necessarily reduce ethnic disparities, and may in fact widen them. Indigenous populations with poorer health outcomes are often under-represented in trials so the effect of interventions cannot be assessed for them, specifically. Therefore, the IMPACT trial aimed to recruit as many Maori as non-Maori to assess the consistency of the effect of the polypill. This paper describes the methods and results of the recruitment strategy used to achieve this.
Methods: Experienced Maori researchers were involved in trial governance throughout trial development and conduct. The trial Steering Committee included leading Maori researchers and was committed to equal recruitment of Maori and non-Maori. Additional funding and Maori research nurses were sought to allow home-based assessment, establishment of the relationship between research nurse and participant, more family involvement prior to enrollment, continuity of the research nurse-participant relationship, and acknowledgement of other Maori culturally important procedures, interactions, language and manners. Primary care practices with high enrollment of Maori were targeted, with over-sampling of potentially eligible Maori patients, lower thresholds for screening of Maori and 6 months continued Maori recruitment after non-Maori recruitment had finished.
Results: A total of 257 Maori and 256 non-Maori participants were randomized. Four Maori and eight non-Maori participants were randomized per research nurse per month. Potentially eligible Maori were more likely than non-Maori to proceed to subsequent stages of recruitment. Differences between randomized Maori and non-Maori were evident (e. g. Maori were less likely to have established coronary artery disease).
Conclusions: Recruitment of equal numbers of indigenous and non-indigenous participants is possible if it is prioritised, adequately resourced and self-determination is supported.
Trial registration: The trial is registered with the Australian New Zealand Clinical Trial Registry (ACTRN12606000067572).