Shayla Scott Claringbold

Objective: Both Indigenous and non-Indigenous governments and organizations have increasingly called for improved Indigenous health data in order to improve health equity among Indigenous peoples. This scoping review identifies best practices, potential consequences and barriers for advancing Indigenous health data and Indigenous data sovereignty globally. Methods: A scoping review was conducted to capture the breadth and nature of the academic and grey literature. We searched academic databases for academic records published between 2000 and 2021. We used Google to conduct a review of the grey literature. We applied Harfield’s Aboriginal and Torres Strait Islander Quality Appraisal Tool (QAT) to all original research articles included in the review to assess the quality of health information from an Indigenous perspective. Results: In total, 77 academic articles and 49 grey literature records were included. Much of the academic literature was published in the last 12 years, demonstrating a more recent interest in Indigenous health data. Overall, we identified two ways for Indigenous health data to be retrieved. The first approach is health care organizations asking clients to voluntarily self-identify as Indigenous. The other approach is through data linkage. Both approaches to improving Indigenous health data require awareness of the intergenerational consequences of settler colonialism along with a general mistrust in health care systems among Indigenous peoples. This context also presents special considerations for health care systems that wish to engage with Indigenous communities around the intention, purpose, and uses of the identification of Indigenous status in administrative databases and in health care settings. Partnerships with local Indigenous nations should be developed prior to the systematic collection of Indigenous identifiers in health administrative data. The QAT revealed that many research articles do not include adequate information to describe how Indigenous communities and stakeholders have been involved in this research. Conclusion: There is consensus within the academic literature that improving Indigenous health should be of high priority for health care systems globally. To address data disparities, governments and health organizations are encouraged to work in collaboration with local Indigenous nations and stakeholders at every step from conceptualization, data collection, analysis, to ownership. This finding highlights the need for future research to provide transparent explanation of how meaningful Indigenous collaboration is achieved in their research.

The capillary module (CM), consisting of parallel capillaries from terminal arteriole to post‐capillary venule, is classically considered to be the building block of complex capillary networks. In skeletal muscle, CMs form interconnected columns spanning thousands of microns, which we recently described as the capillary fascicle. However, detailed evaluation of CM haemodynamics has not been described, and may provide insight into mechanisms of blood flow regulation in the microcirculation. We used intravital videomicroscopy from resting extensor digitorum longus muscle in rats (n = 9 networks, 112 capillary modules), as well as dual‐phase computational modelling of blood flow in simulated CM geometries. We found that the mean driving pressure across CMs was 3.236 ± 1.833 mmHg. Red blood cell (RBC) flow was independent of CM resistance, and the ratio of blood flow in adjacent modules was not correlated with their ratio of resistances. In simulated CM geometries, increases to driving pressure produced a direct linear increase to RBC and plasma flow, with no changes to RBC distribution; increases to arteriolar inflow haematocrit resulted in increased RBC flow, but with viscosity‐dependent increases to CM resistance. CM RBC flow heterogeneity was higher than plasma flow heterogeneity in experimental data, in contrast to simulated geometries, suggesting that time‐dependent flow variability may have important consequences for RBC distribution. In summary, these findings suggest that CMs are active participants in microvascular flow regulation, likely achieved through adjustments to CM driving pressure using pre‐ and post‐capillary loci of flow control. Increases to CM viscosity may be important during the regulation of functional hyperaemia.Key points: The capillary module (CM), consisting of parallel capillaries from the arteriole to venule, is classically considered to be the building block of capillary networks in skeletal muscle. A detailed evaluation of module haemodynamics may provide insight into mechanisms of blood flow regulation in the microcirculation. Using experimental data from resting skeletal muscle in rats, as well as dual‐phase computational models of blood flow, we analysed haemodynamic relationships and the impact of variations to boundary conditions on red blood cell and plasma distribution. We showed that driving pressure across CMs is low, and that simulated increases to inflow haematocrit have important viscosity‐dependent effects on module resistance. We found that red blood cell flow was independent from module resistance, which strongly suggests the regulation of driving pressure at the level of the capillary module using pre‐ and post‐capillary loci of flow control. These findings place CMs as central participants in microvascular flow regulation, with important consequences for disease and functional hyperaemia.