Stress and Sleep Study

Primary outcomes

1. Acceptability of the Combined tVNS + Mindfulness Intervention as Assessed by Participant Self-report of Acceptability Using the Acceptability of Intervention Measure (AIM)

   Time frame: Assessed in the tVNS + mindfulness groups and sham + mindfulness groups at Week 2

   The AIM (Weiner et al., 2017) is a brief 4-item scale measuring the degree to which participants believe an intervention is acceptable. The response scale for each item ranges from 1 (completely disagree) to 5 (completely agree). Responses from the 4 items are averaged to yield total scores ranging from 1-5, with higher scores indicating greater acceptability.

2. Sleep Quality as Assessed by Participant Self-report on the Pittsburgh Sleep Quality Index (PSQI)

   Time frame: Assessed at the end of the intervention phase (Week 4)

   The PSQI (Buysse et al., 1989) contains 19 self-rated items that are combined to form seven component scores, each of which has a range from 0-3 points. For each component, a score of 0 indicates no difficulty, while a score of 3 indicates severe difficulty. The seven component scores are then added to yield one "global" score, with a range from 0-21 points (0 = best sleep quality, 21 = poorest sleep quality).

3. Perceived Stress as Assessed by Participant Self-report on the Perceived Stress Scale (PSS)

   Time frame: Assessed at the end of the intervention phase (Week 4)

   The PSS (Cohen et al., 1994) is a 10-item questionnaire measuring the degree to which situations in one's life are appraised as stressful. In particular, it gauges how unpredictable, uncontrollable, and overloaded respondents find their lives. Participants rate each item on a scale of 0 (never) to 4 (very often), and total scores range from 0-40 (0 = least perceived stress, 40 = most perceived stress).