mHealth Intervention for Work-Related Stress

Adherence was operationalized as a count variable coded 0-28 representing the number of days that a given participant used the intervention.

App Engagement was measured using The App Engagement Scale, a 7-item questionnaire designed to measure engagement with mobile applications, translated into Swedish by the research team. This translation has been used previously by the research team and has preliminary evidence of good reliability. Items (e.g. "I enjoyed using the app") are scored on a 1-5 ordered categories scale (1 = Not at all, 5 = Fully agree).

Stress was measured daily as the mean value of three items inspired by the Stress-Energy Questionnaire. This study used a Swedish translation which has been validated in a previous study by the research team. Items ("During the last day, to what extent have you felt tense / pressed / frustrated?") were rated on a 6-point ordered categories scale (1 = Not at all, 6 = Very much). This variable was measured daily during the intervention and was not included in the pre-, post-, and follow-up measures.

Acceptability was measured using a set of single-item measures evaluating whether the intervention was relevant to the user, if they would like to use it again, quality of the prompts, and technical stability. These items were only included in the post-intervention measure.

Anxiety was measured using the GAD-7 questionnaire, a 7-item instrument designed to assess generalized anxiety disorder. This study uses a Swedish translation. Items (e.g. "Feeling nervous, anxious, or on edge") were scored on a 1-4 ordered categories scale (1 = Not at all, 4 = Nearly every day).

Mindfulness was measured using the Mindful Attention Awareness Scale, a 15-item measure designed to assess attention and awareness of "what is occurring in the present moment". This study used a Swedish translation with six items centered around emotional self-awareness. Items ("I could be experiencing some emotion and not be conscious of it until some time later") are rated on a 1-7 ordered categories scale (1 = Almost never, 7 = Almost always).

Recovery was measured using the Recovery Experience Questionnaire, a 16-item questionnaire designed to measure four dimensions of recovery - detachment, relaxation, autonomy, and mastery - using four items for each dimension. This study uses a Swedish translation. Items ("In my free time I don't think about work") are scored on a 1-7 ordered categories scale (1 = Almost never, 7 = Almost always).

Exhaustion and disengagement from work was measured using the Oldenburg Burnout Inventory, an instrument designed to measure burnout in an occupational context including the dimensions exhaustion and disengagement. This study used a Swedish translation with a subset of 7 items. Items (e.g. "after work I often feel tired and exhausted") are scored on a 4-point ordered categories scale (1 = Not at all, 4 = Exactly).

Emotional exhaustion was measured using the Shirom-Melamed Burnout Questionnaire (SMBQ), an instrument designed to assess burnout symptoms. The study used a Swedish translation and subset of 6 items focused on the emotional exhaustion dimension of burnout. Items ("My batteries are empty") are rated on a 1-7 ordered categories scale (1 = Almost never, 7 = Almost always).