The untapped potential of physical activity monitoring for quality assurance of field-based walking tests in clinical respiratory trials

Field-based walking tests are well-established outcome measures in clinical research trials and in the evaluation of routine clinical services, including pulmonary rehabilitation. Despite widespread use, there has been little attention to, or reporting of, the quality assurance of these tests. Physical activity monitoring has become increasingly popular and data from activity monitors could be used for quality assurance of field-based walking tests. We provide examples in this article of data-driven insights possible with this approach, using data from waist-worn accelerometry, for the incremental shuttle walking test (ISWT), endurance shuttle walk test (ESWT) and six-minute walk test (6MWT). Given the multitude of devices to measure physical activity and the range metrics to describe physical activity, we also comment on some of the technical considerations to using activity monitors for walking test quality assurance. Data-driven approaches to quality assurance are already commonplace for other outcome measures in clinical respiratory trials, but little is known about this approach for field-based walking tests. The application of physical activity monitoring may be extended to other field-based exercise tests and additional rehabilitation services. This may be more challenging for self-paced walking tests such as the 6MWT. Future work should apply this approach to research trials and service evaluations to explore the impact of field-based walking test quality on performance (e.g. distance on the ISWT or time achieved for the ESWT), responsiveness to interventions (e.g. pulmonary rehabilitation) and effectiveness of training procedures (e.g. remote training for multi-site trials).