A Proactive Intervention Promoting Strategies for Sleep and Recovery in Nurses

Change in insomnia symptoms (subjective measure)

Insomnia Severity Index (ISI) which consists of 7 questions related to sleep e.g. "How satisfied are you with your current sleep pattern?" (0 = very satisfied, 4 = very dissatisfied). The total score is summarised with a minimum score 0, maximum score 28. Higher scores indicate more sleep problems.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in sleep quality (subjective measure)

Karolinska Sleep Questionnaire (KSQ) from which a sleep quality index was formed based on four questions e.g. "Have you had problems falling asleep the past month"? etc : Minimum score 1, maximum score 6. Lower scores indicate worse sleep quality.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in Dysfunctional beliefs and attitudes about sleep (subjective measure)

Dysfunctional Beliefs and Attitudes about Sleep (DBAS) consists of 10 statements regarding beliefs and attitudes to sleep e.g. "I am concerned that chronic insomnia may have serious consequences on my physical health"; "When I have trouble sleeping, I should stay in bed and try harder" (strongly agree - strongly disagree): Minimum score 0, maximum score 10. Higher scores indicate more dysfunctional sleep-related cognitions.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in sleep (subjective measure)

Karolinska Sleep Diary (KSD). KSD includes bedtime; time of awakening; sleep latency (the time it takes to fall asleep); feelings of worry and stress at bedtime (1 very worried/aroused - 5 very calm/relaxed); and the following questions: Did you have difficulties falling asleep? (1 = very; 5 = not at all) How did you sleep? (1 = very badly; 5 = very good); Did you have a restless sleep? (1 = very much so; 5 = not at all); Did you wake up very early without being able to fall asleep? (1 = much too early; 5 = no). These four latter questions constitutes a sleep quality index, minimum score 1, maximum score 5: Lower scores indicate worse sleep quality.

Time frame: In order to detect change measures were made at baseline to 4 weeks after the intervention. Measured seven days at baseline and seven days at follow up.

Change in satisfaction with sleep

Self-rated sufficient sleep (5=very insufficient 1=fully sufficient)

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in subjective sleep quality

Self-rated general sleep quality (1=very good 5=very bad).

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in sleep (objective measures)

Actigraphy (wrist-watch). Measuring of movements during sleep through a sensitive accelerometer in the wrist-watch. The value, which is described as the amount of movements per minute, is saved in the memory of the actigraph. Preprogrammed algorithms make it possible to classify if the participant has slept or not. Measured seven nights at baseline and seven nights at follow up. Example of measures: Actual sleep time: The total time spent in sleep according to the epoch-by-epoch wake/sleep categorisation. Actual sleep %: Actual sleep time expressed as a percentage of the assumed sleep time. Actual wake time: The total time spent in wake according to the epoch-by-epoch wake/sleep categorisation. Wake bouts: The number of contiguous sections categorised as wake in the epoch-by- epoch wake/sleep categorisation. Sleep fragmentation: The sum of the "Mobile time (%)" and the "Immobile bouts \<=1min (%)". This is an indication of the degree of fragmentation.

Time frame: In order to detect change measures were made at baseline and at 4 weeks after the intervention. Measured seven days at baseline and seven days at follow up.

Change in work home interference (subjective measures)

Work-Home Interference (WHI) measured with four items: "I come home from work too tired to do things I would like to do."; "My job makes it difficult to maintain the kind of personal life I would like."; "I often neglect my personal needs because of the demands of my work."; "My personal life suffers because of my work." Rated on a 5-graded scale ranging from 1=not at all to 5=almost always.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in fatigue and recuperation (subjective measures)

Single items (self-ratings): Frequency of recovery behaviours (e.g. micro breaks (1 = every shift, 5 = Never); routine for winding down before bedtime (1 = never, 5 = Always); Satisfaction regarding rest and recuperation during spare time (1 = fully sufficient, 5 = no, far from sufficient); Use of strategies for optimizing sleep and recuperation (1 = never, 5= always); General satisfaction with spare time (1 = very good, 5 = very bad); Use of free time before evening shifts (1 = never, 5 = always); Frequency of breaks during work shifts (1 = every shift, 5= never).

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in diurnal levels of sleepiness (subjective measures)

Karolinska Sleepiness Scale (KSS): A nine-graded scale with values ranging from 1=very alert to 9=very sleepy, fighting sleep. Measured every third hour during wake time seven days at baseline and seven days at follow up.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in symptoms of sleepiness and fatigue (subjective measures)

Single items measuring symptoms of fatigue e.g. "sustained fatigue", "unfocused" and "engaged", on a five-graded scale ranging from 1=not at all, and 5=very much. Measured seven days at baseline and seven days at follow up.

Time frame: In order to detect change measures were made at baseline to 4 weeks after the intervention.

Change in burnout (subjective measure)

Shirom-Melamed Burnout Questionnaire (SMBQ): Minimum score 1, maximum score 7. Higher scores indicate more burnout.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in perceived stress (subjective measure)

Perceived Stress Scale (PSS-10) which consists of 10 statements e.g.. "In the last month, how often have you felt nervous and "stressed"; "In the last month, how often have you found that you could not cope with all the things that you had to do"? etc: Answers on 0 = never, 4 = very often. These are summarised. Minimum score 0, maximum score 40. Higher scores indicate more stress.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in stress and energy (subjective measures)

Stress-Energy rating questionnaire: Minimum score 0, maximum score 5. Higher scores indicate more stress and more energy.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in stress symptoms (subjective measures)

Self-ratings of stress symptoms/absence of stress symptoms (single items): "Tense"; "Irritated"; "Exhausted"; "Hard to disconnect from thoughts of work during spare time"; "Emotional burden"; "Relaxed/calm" on a scale ranging from 1=not at all, and 5=very much. Measured every day during seven days at baseline and seven days at follow up.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in diurnal levels of stress (subjective measures)

Self-rated stress scale for repeated measurement, measured one a nine-graded scale with values ranging from 1=very low stress to 9=very high stress. Measured every third hour during wake time seven days at baseline and seven days at follow up.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in stress (objective measures)

Hair cortisol based on 2 cm segments (pg/mg)

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in somatic symptoms

Somatic Symptoms Scale-8 (SSS-8): Minimum score 0, maximum score 32. Higher scores indicate higher somatic symptom burden.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in health

Single items: Self-rated health on a scale ranging from 1=very good to 7=very bad. Self-rated use of medical drugs the past three months (frequency as 1 = never, 5 = always), coffee consumption during a work day (1 = none, 5 = 7 cups or more); how often do you do 30 minutes of physical exercise (1 = never, 5 = 3 times of more/week).

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in psychological health

Single items (self-ratings): How often have you during the past 7 days felt "depressed"; "stated"; "sad"; "worried"; "nervous"; "unsure" on a scale ranging from 0=not at all to 5=very much.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in self rated health

Self-rated health on a scale ranging from 1=very good to 7=very bad. Measured daily during seven days at baseline and seven days at follow-up.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention.

Change in performance and cognitive symptoms (subjective measures)

Ratings (single items): Self-rated work performance through the following items: During the past month how often have you during you work .... "in risk of mistakes"; "found it hard to make decisions"; "been present during interaction with others"; "had to make corrections or double-check work tasks" (1 = never, 5 = Always). Sub-indices from SMBQ (described above) will also be used as measures of cognitive symptoms.

Time frame: In order to detect change measures were made at baseline, 4 weeks after the intervention and 6 months after the intervention.

Change in performance and cognitive symptoms (subjective measures)

Self-ratings (single items) of how well the participant managed to (at work) make decisions; keep things in their head; keep track of the overall picture; perform tasks in a safe way; being present during interaction with others. Rated on a 5-graded scale ranging from 1=very well to 5=very badly.

Time frame: In order to detect change measures were made at baseline and 4 weeks after the intervention. Measured seven days at baseline and seven days at follow up.

Change in performance, arithmetic ability (objective measures)

Cognitive tests measuring executive functioning, performed on the participant's mobile phone. In the arithmetic ability task, the participant is presented with simple arithmetical addition questions and required to calculate the answer and type it into the phone. New questions are presented until the time is running out (duration 2 minutes). Performance is measured in terms of total score (correct responses during 2 minutes) and the speed of correct responses (in ms).

Time frame: In order to detect change tests were made at baseline (one day, during and after work) and 4 weeks after the intervention (one day, during and after work).

Change in performance, episodic memory (objective measures)

Cognitive tests measuring executive functioning, performed on the participant's mobile phone. In the episodic memory task, participants are presented with a list of 12 words for 12 seconds, which they are asked to remember. A fixation cross then appears for 5 seconds. Following this, participants are shown a list of 24 words, which contains the original 12 words, and an additional 12 dummy words, and are asked whether each word was previously shown (yes/no). The task is performed twice. Performance is assessed as percentage correct.

Time frame: In order to detect change tests were made at baseline (one day, during and after work) and 4 weeks after the intervention (one day, during and after work).