Turning a Self-Report Questionnaire into a Wearable Device

Well-defined and reliable tools are needed for objective diagnosis and to measure clinically relevant outcomes of treatment for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The 2015 Institute of Medicine (IOM) report “Beyond ME/CFS: Redefining an Illness” defines these symptoms for us namely, a substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities, that persists for more than six months and is accompanied by fatigue, post-exertional malaise (PEM), unrefreshing sleep along with cognitive impairment or orthostatic intolerance.

Our goal at BHC is to take these criteria one-by-one and develop ways to measure them. Our medical experience over the past 17 years with ME/CFS patients has shown that asking patients to report the amount of time they spend in an upright position (defined as having lower legs vertical with feet on the floor) over a 24 hour period provides insight to their disease severity and degree of functional impairment. Our goal was to turn this self-report questionnaire about upright activity into a wearable device that could accurately and passively measure upright activity. We coined this measure “UpTime”.

The results have just been published in the Journal of Translational Medicine in a paper titled, “Accurate and Objective Determination of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Disease Severity with a Wearable Sensor”. The authors demonstrated that UpTime accurately and passively measure the percent of time an individual spent in a upright posture with feet on the floor over a 24 hour period. Severely ill ME/CFS patients had 20% or less UpTime, moderately ill patients had between 20-30% UpTime while healthy volunteers had greater than 30% UpTime. Importantly, the UpTime sensor was more precise than self-reported hours of upright activity (HUA) which were over-estimated by patients. The authors concluded that because UpTime accurately and passively monitors upright activity it has potential to improve objective diagnosis and be used as a reliable outcome measure for evaluating ME/CFS treatment efficacy.