Supplementing sleep actigraphy with button pressing while awake.

Area of Science:

• Sleep science
• Biomedical engineering
• Human-computer interaction

Background:

• Wrist-worn sleep actigraphy has limitations in accurately assessing sleep, particularly for individuals who remain still while awake.
• Traditional sleep logs rely on subjective recall, introducing potential inaccuracies in perceived wakefulness duration.

Purpose of the Study:

• To evaluate the acceptability and accuracy of two methods for marking wakefulness: self-initiated button presses and vibration-signaled presses.
• To compare these methods against wrist-worn actigraphy for sleep scoring concordance.

Main Methods:

• Twenty-nine adults participated in a six-night study, wearing actigraphs.
• Participants used a marker button in response to vibration signals or self-initiated presses on different nights, with control nights involving no pressing.
• Sleep logs were completed daily to record perceived sleep quality.

Main Results:

• Vibration-triggered pressing was deemed unacceptable by 42% of participants due to sleep disturbance.
• Self-initiated pressing was universally acceptable but reduced reported sleep depth.
• Epoch-by-epoch sleep scoring showed poor agreement (kappa = 0.23) for self-initiated presses and moderate agreement (kappa = 0.46) for vibration-signaled presses compared to actigraphy.

Conclusions:

• Self-initiated button pressing is an acceptable and minimally disruptive method to augment actigraphy data.
• This method provides valuable information beyond standard actigraphy, especially for identifying wakefulness periods.
• While vibration-triggered pressing showed moderate concordance, self-initiated pressing offers a more practical approach for improving sleep assessment accuracy.