Wearable Device–Based Measurement of Physical Activity in Populations at Risk of Health Inequity: A Scoping Review

Background: Accurate and consistent measurement of physical activity (PA) is essential for evaluating interventions, informing clinical and public health decision-making, and enabling comparisons across populations. Wearable device–based measures are increasingly used to quantify PA, but the extent to which populations at risk of health inequity, as defined by established equity frameworks, are represented in wearable-based PA studies, and whether measurement protocols are appropriate and comparable across these groups, remains insufficiently characterised. Aim: To synthesise evidence on the use of wearable devices for measuring PA in populations at risk of health inequity, as defined by the PROGRESS-Plus and CORE20PLUS5 frameworks, and to identify methodological features relevant to equity in PA measurement. Methods: A scoping review was conducted in accordance with PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and grey literature were searched for peer-reviewed randomised controlled trials published between January 2020 and October 2025. Eligible studies quantitatively measured PA using pedometers, accelerometers, or smartwatches in populations at risk of health inequity. Data were extracted on study design, population characteristics, device type and placement, monitoring protocols, and equity-related considerations. Results: Of 1,027 records screened, 13 studies met inclusion criteria. Wrist-worn pedometers and hip-worn accelerometers were most common. Adaptations were minimal and largely limited to language translation. Several high-risk equity groups according to the frameworks used including LGBTQ+, people experiencing homelessness, those with learning difficulties, substance misuse, and justice system involvement were absent. Conclusions: This review demonstrates that wearable-based PA measurement has been applied to only a narrow subset of populations at risk of health inequity, with notable gaps across several key PROGRESS-Plus and CORE20PLUS5 groups. Methodological adaptations to support equitable measurement were uncommon and largely superficial, raising concerns about the appropriateness, acceptability, and comparability of PA data generated in these contexts. Addressing these methodological and reporting deficiencies is essential to strengthen the evidence base and prevent the widening of inequities in PA surveillance and intervention evaluation.