Walking limitations are debilitating symptoms in many chronic diseases, and are highly related to quality of life, fall risk, and economic burden. Unsurprisingly, walking ability is a common target of pharmacological or behavioural intervention. Thanks to advances in wearable sensor technologies, it is now possible to objectively monitor how, and how much, patients walk in the real world. Digital mobility outcomes (DMOs), such as walking speed or step variability, pose great potential as ecologically-valid, meaningful measures to evaluate the efficacy of novel therapies. Unfortunately, these measures require further validation before they can be used regularly as treatment outcomes or in clinical practice. To date, fragmentation in terminology and methodology across disease areas and research disciplines limits our understanding of DMOs’ potential.
To address this gap and prepare for our upcoming validation studies, researchers from Mobilise-D have initiated a large, multi-disciplinary scoping review to map the existing literature and bridge gaps across this fragmented field. This review, whose protocol was recently published in BMJ Open will help us understand which DMOs are best-suited for use as clinical measures and how these DMOs might be meaningful in practice. We will address four main properties of DMOs which are critical to the validation process:
- Discriminant ability: How do DMOs differ between healthy people and those with chronic conditions?
- Construct validity: What relationships exist between DMOs and common measures of disease severity and physical function?
- Prognostic value: Do DMOs provide useful information about how health status might change over time?
- Responsiveness: Are we able to observe changes in DMOs due to treatment?
The review is ongoing, and is expected to be published in 2021.
