(317) Feasibility of the E4 Wristband to assess sleep in adults with and without fibromyalgia

There is a growing body of evidence linking sleep and pain. Efforts to characterize this association and examine mechanistic links between sleep and pain are hindered by a lack of valid, reliable, and accessible measure of sleep. We tested the feasibility of the E4 Wristband, which continuously collects actigraphy, heart rate variability (HRV), and electrodermal response data, to measure autonomic nervous system activity during sleep in people with and without fibromyalgia (FM). Twenty adults with FM and 20 age- and sex-matched controls wore the E4 continuously for 7 days (removing 1 hour/day for charging/download) and then completed a feasibility/acceptability interview. Most (80%) participants were female with mean age = 38.79±14.85 (min-max=18-70 years). Of a possible 140 nights of sleep data, the FM group had data for 119(85%) nights and the control group had data for 115(82%) nights. Across both groups, 19.9% of heartbeats were missing due to noisy signals or failure of the E4 in detecting beats. Data were divided into 5 minutes’ windows for HRV analysis; windows with more than 15% missing peaks were eliminated. This led to exclusion of 30.9% of the windows. For one night, all windows were excluded, resulting in 114(81%) usable nights for the control group. The groups did not differ in terms of E4 acceptability ratings; 84.7% reported that it was “easy to use”, 53.8% agreed/strongly agreed that it was “comfortable to wear”, and 75% reported they would be likely/extremely likely to participate in a study that involved wearing the E4 for 28 days. There were low rates of missing data associated with participant protocol non-compliance; signal noise resulted in some additional missing HRV data. With generally good participant acceptability ratings these data suggest the E4 Wristband is a feasible device to examine sleep and autonomic nervous system activity in FM.