| 1. |
- Almén, Niclas, 1971-
(författare)
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Intervening Stress Recovery Behaviors in Everyday Life
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. High levels of perceived stress and stress-related ill health, such as burnout, are common in many countries. Several theories postulate that stress behaviors promote adaption to environmental changes and if sustained they are potentially harmful for the body. In accordance, impaired stress recovery behaviors, i.e., psychophysiological deactivation after periods of stress behaviors, have been suggested to be a critical factor in explaining stress-related ill health. Whereas research shows that interventions targeting stress reactivity can have beneficial effects on stress-related variables, studies on interventions targeting stress recovery are surprisingly few. Also, the number of validated instruments for measuring behaviors important for stress recovery are few, in particular easily used self-rating scales. Aims. The primary aim of the thesis was to evaluate stress and health-related effects of an intervention targeting stress recovery behaviors in everyday life among people perceiving high levels of stress in life. A secondary aim was to validate a self-report scale measuring behaviors important for stress recovery in everyday life. Method. Three empirical studies were conducted to evaluate effects of the behavioral stress recovery intervention “balance in everyday life”, which solely aims at strengthening stress recovery behaviors in everyday life. First, a brief version of the intervention was investigated through a small pilot study in which a single-subject experimental design was used (study 1). After that, the intervention was exploratively tested in a group format in which a quasi-experimental design was used (study 2). Due to the positive results of these two studies, a larger scale study using a randomized controlled design was conducted in order to further investigate the effects of the intervention when delivered in a group format (study 3). To fulfill the secondary aim of the thesis, the Recovery Experience Questionnaire was translated into Swedish and analyzed using exploratory factor analysis and confirmatory factor analysis (study 4). Results. In study 1, data demonstrated immediate reduction of stress symptoms as a function of the intervention. The improvements were maintained at 1-year and 5-year follow-up assessments. In study 2, in comparison with a waiting-list-control group, the intervention yielded statistically significant improvements between pre- and postintervention assessment on eleven out of twelve stress and health-related variables. Medium to large between-groups effect sizes were demonstrated for the primary outcome measures covering (potential) recovery behaviors, perceived stress and rest and experiences of being recovered. In the third study, statistically significant improvements for all outcome measures at postintervention assessment and at the 3-month follow-up were demonstrated. The between-groups effect sizes for the primary measures - perceived stress, tension, and burnout - were medium-to-high at postintervention assessment and at follow-up. In addition, in all studies the intervention was associated with beneficial changes in levels of anxiety and depression. In the last study, support was found for the proposed four-factor structure of the Swedish version of the Recovery Experience Questionnaire. Conclusions. The results clearly indicate that the intervention “balance in everyday life” improves stress and health-related factors in a relatively satisfactory way among people perceiving high levels of stress in life. The empirical support is strongest for the reduction in tension, perceived stress, burnout, anxiety and depression, and to deliver the intervention in a group format. The studies demonstrated results that warrant further investigation of the effects of “balance in everyday life”, for example in different contexts, and to study other behavioral recovery interventions. To test (potential) recovery facilitating behaviors as mediators of intervention effects, such as reduction in burnout, the Swedish version of the Recovery Experience Questionnaire could be used.
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| 2. |
- Ingre, Michael, et al.
(författare)
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Sleep length as a function of morning shift-start time in irregular shift schedules for train drivers : self-rated health and individual differences.
- 2008
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Ingår i: Chronobiol Int. - : Informa UK Limited. - 1525-6073 .- 0742-0528. ; 25:2, s. 349-58
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Tidskriftsartikel (refereegranskat)abstract
- Sleep length as a function of morning shift-start time in irregular shift schedules for train drivers: self-rated health and individual differences.Ingre M, Kecklund G, Akerstedt T, Söderström M, Kecklund L.Stress Research Institute, Stockholm University, Sweden. michael.ingre@stressforskning.su.seForty-six male train drivers (mean age = 46.5, SD = 5.1) were recruited to participate in a diary study for 14 consecutive days with questions about their sleep and working hours. A polynomial mixed-effect regression model showed a curvilinear relation ( p < .001) between shift-start time and sleep duration for shifts starting at 03:00-12:00 hand with a near linear increase for ones starting between 04:30 and 09:00 h of approximately 0.7 h for every 1 h the shift was delayed. The longest sleeps were estimated at approximately 8 h before shifts that started at approximately 10:00 h. The shortest sleeps were found for shifts that started before 04:30 h and were estimated at approximately 5 h. Individual differences were estimated with a random-effect standard deviation of 0.51 h, independent of shift start time ( p = .005). One-half of the between-subject variance was explained by subjective health. A one-step decrease in health was associated with a 26 min increase in sleep length. The results have practical implications for constructing shift schedules. Early morning shifts reduced sleep length substantially and should be mixed with later start hours to avoid the accumulation of sleep dept. Delaying the shift-start past 10:00 h had little effect on sleep opportunity; however, delaying shift-start to between 04:30 and 9:00 h had a strong impact on sleep length, with 70% of the extra time used for sleep, suggesting large positive effects for this range of shift-start times.
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| 3. |
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| 4. |
- Kecklund, Lena, et al.
(författare)
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The TRAIN-project: Effects of Organizational Factors, Automatic Train Control, Work Hours, and Environment: Suggestions for Safety-Enhancing Measures
- 2003
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Ingår i: Proceedings of the Human Factors and Ergonomic Society, 47th Annual Meeting. ; , s. 1835-1839
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Konferensbidrag (refereegranskat)abstract
- The purpose of the TRAIN project was to describe and analyse the train drivers information environment, working hours, work situation and work environment and their effect on drivers' behaviour and the train driver system safety as well as to propose safety enhancing measures. The results indicate several problems of significance to the train driver system safety, which have been grouped into three main areas; organizational support functions, information environment including cognitive ergonomics and ATC and also working hours, work situation and work environment.
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| 5. |
- Santoft, Fredrik, et al.
(författare)
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Mediators of Change in Cognitive Behavior Therapy for Clinical Burnout
- 2019
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Ingår i: Behavior Therapy. - : Elsevier BV. - 0005-7894 .- 1878-1888. ; 50:3, s. 475-488
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Tidskriftsartikel (refereegranskat)abstract
- Evidence supporting the effectiveness of cognitive behavior therapy (CBT) for stress-related illness is growing, but little is known about its mechanisms of change. The aim of this study was to investigate potential mediators of CBT for severe stress in form of clinical burnout, using an active psychological treatment as comparator. We used linear mixed models to analyze data from patients (N = 82) with clinical burnout who received either CBT or another psychological treatment in a randomized controlled trial. Potential mediators (i.e., sleep quality, behavioral activation, perceived competence, and therapeutic alliance) and outcome (i.e., symptoms of burnout) were assessed weekly during treatment. The results showed that the positive treatment effects on symptoms of burnout favoring CBT (estimated between-group d = 0.93) were mediated by improvements in sleep quality, ab = -0.017,95% CIasymmetric [-0.037, -0.002], and increase in perceived competence, ab = -0.037, 95% CIasymmetric [-0.070, -0.010]. Behavioral activation, ab = -0.004 [-0.016, 0.007], and therapeutic alliance, ab = 0.002 [-0.006, 0.011], did not significantly mediate the difference in effects between the treatments. Improving sleep quality and increasing perceived competence may thus constitute important process goals in order to attain symptom reduction in CBT for clinical burnout.
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| 6. |
- Santoft, Fredrik, et al.
(författare)
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Processes in cognitive behavior therapy for social anxiety disorder : Predicting subsequent symptom change
- 2019
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Ingår i: Journal of Anxiety Disorders. - : Elsevier BV. - 0887-6185 .- 1873-7897. ; 67
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Tidskriftsartikel (refereegranskat)abstract
- Although cognitive behavior therapy (CBT) is an effective treatment for social anxiety disorder, little is known about the processes during treatment that bring about change. The aim of this study was to investigate whether the proposed processes of change according to the cognitive model of social anxiety disorder predicted subsequent symptom reduction in CBT delivered as therapist-guided bibliotherapy. We analyzed data from patients with social anxiety disorder (N = 61) who participated in an effectiveness trial of CBT in primary care. Seven putative processes and outcome (i.e., social anxiety) were assessed on a weekly basis throughout treatment. We used linear mixed models to analyze within-person relations between processes and outcome. The results showed a unidirectional effect of reduced avoidance on subsequent decrease in social anxiety. Further, we found support for reciprocal influences between four of the proposed processes (i.e., estimated probability and cost of adverse outcome, self-focused attention, and safety behaviors) and social anxiety. The remaining two processes, (i.e., anticipatory and post-event processing) did not predict subsequent social anxiety, but were predicted by prior symptom reduction. The findings support that several of the change processes according to the cognitive model of social anxiety disorder are involved in symptom improvement.
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| 7. |
- Ahlström, Christer, et al.
(författare)
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Fit-for-duty test for estimation of drivers sleepiness level: Eye movements improve the sleep/wake predictor
- 2013
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Ingår i: Transportation Research Part C. - : Elsevier. - 0968-090X .- 1879-2359. ; 26, s. 20-32
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Tidskriftsartikel (refereegranskat)abstract
- Driver sleepiness contributes to a considerable proportion of road accidents, and a fit-for-duty test able to measure a drivers sleepiness level might improve traffic safety. The aim of this study was to develop a fit-for-duty test based on eye movement measurements and on the sleep/wake predictor model (SWP, which predicts the sleepiness level) and evaluate the ability to predict severe sleepiness during real road driving. Twenty-four drivers participated in an experimental study which took place partly in the laboratory, where the fit-for-duty data were acquired, and partly on the road, where the drivers sleepiness was assessed. A series of four measurements were conducted over a 24-h period during different stages of sleepiness. Two separate analyses were performed; a variance analysis and a feature selection followed by classification analysis. In the first analysis it was found that the SWP and several eye movement features involving anti-saccades, pro-saccades, smooth pursuit, pupillometry and fixation stability varied significantly with different stages of sleep deprivation. In the second analysis, a feature set was determined based on floating forward selection. The correlation coefficient between a linear combination of the acquired features and subjective sleepiness (Karolinska sleepiness scale, KSS) was found to be R = 0.73 and the correct classification rate of drivers who reached high levels of sleepiness (KSS andgt;= 8) in the subsequent driving session was 82.4% (sensitivity = 80.0%, specificity = 84.2% and AUC = 0.86). Future improvements of a fit-for-duty test should focus on how to account for individual differences and situational/contextual factors in the test, and whether it is possible to maintain high sensitive/specificity with a shorter test that can be used in a real-life environment, e.g. on professional drivers.
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| 8. |
- Ahlström, Christer, 1977-, et al.
(författare)
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Real-Time Adaptation of Driving Time and Rest Periods in Automated Long-Haul Trucking : Development of a System Based on Biomathematical Modelling, Fatigue and Relaxation Monitoring
- 2022
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Ingår i: IEEE transactions on intelligent transportation systems (Print). - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1524-9050 .- 1558-0016. ; 23:5, s. 4758-4766
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Tidskriftsartikel (refereegranskat)abstract
- Hours of service regulations govern the working hours of commercial motor vehicle drivers, but these regulations may become more flexible as highly automated vehicles have the potential to afford periods of in-cab rest or even sleep while the vehicle is moving. A prerequisite is robust continuous monitoring of when the driver is resting (to account for reduced time on task) or sleeping (to account for the reduced physiological drive to sleep). The overall aims of this paper are to raise a discussion of whether it is possible to obtain successful rest during automated driving, and to present initial work on a hypothetical data driven algorithm aimed to estimate if it is possible to gain driving time after resting under fully automated driving. The presented algorithm consists of four central components, a heart rate-based relaxation detection algorithm, a camera-based sleep detection algorithm, a fatigue modelling component taking time awake, time of day and time on task into account, and a component that estimates gained driving time. Real-time assessment of driver fitness is complicated, especially when it comes to the recuperative value of in-cab sleep and rest, as it depends on sleep quality, time of day, homeostatic sleep pressure and on the activities that are carried out while resting. The monotony that characterizes for long-haul truck driving is clearly interrupted for a while, but the long-term consequences of extended driving times, including user acceptance of the key stakeholders, requires further research.
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| 9. |
- Akerstedt, Torbjörn, et al.
(författare)
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Accounting for partial sleep deprivation and cumulative sleepiness in the Three-Process Model of alertness regulation.
- 2008
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Ingår i: Chronobiol Int. - : Informa UK Limited. - 1525-6073 .- 0742-0528. ; 25:2, s. 309-19
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Tidskriftsartikel (refereegranskat)abstract
- Accounting for partial sleep deprivation and cumulative sleepiness in the Three-Process Model of alertness regulation.Akerstedt T, Ingre M, Kecklund G, Folkard S, Axelsson J.Stress Research Institute, University of Stockholm, Stockholm, Sweden. torbjorn.akerstedt@ki.seMathematical models designed to predict alertness or performance have been developed primarily as tools for evaluating work and/or sleep-wake schedules that deviate from the traditional daytime orientation. In general, these models cope well with the acute changes resulting from an abnormal sleep but have difficulties handling sleep restriction across longer periods. The reason is that the function representing recovery is too steep--usually exponentially so--and with increasing sleep loss, the steepness increases, resulting in too rapid recovery. The present study focused on refining the Three-Process Model of alertness regulation. We used an experiment with 4 h of sleep/night (nine participants) that included subjective self-ratings of sleepiness every hour. To evaluate the model at the individual subject level, a set of mixed-effect regression analyses were performed using subjective sleepiness as the dependent variable. These mixed models estimate a fixed effect (group mean) and a random effect that accounts for heterogeneity between participants in the overall level of sleepiness (i.e., a random intercept). Using this technique, a point was sought on the exponential recovery function that would explain maximum variance in subjective sleepiness by switching to a linear function. The resulting point explaining the highest amount of variance was 12.2 on the 1-21 unit scale. It was concluded that the accumulation of sleep loss effects on subjective sleepiness may be accounted for by making the recovery function linear below a certain point on the otherwise exponential function.
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| 10. |
- Akerstedt, Torbjörn, et al.
(författare)
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Disturbed sleep in shift workers, day workers, and insomniacs.
- 2008
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Ingår i: Chronobiol Int. - : Informa UK Limited. - 1525-6073 .- 0742-0528. ; 25:2, s. 333-48
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Tidskriftsartikel (refereegranskat)abstract
- Disturbed sleep in shift workers, day workers, and insomniacs.Akerstedt T, Ingre M, Broman JE, Kecklund G.Stress Research Institute, University of Stockholm, Karolinska Institutet, Stockholm, Sweden. torbjorn.akerstedt@ki.seVery little is known about differences in sleep between day and shift workers in representative samples of the population. This study compared a national representative sample (N=3400) of shift (with night shifts) and day workers regarding the different types of sleep disturbances and also the level of sleep symptoms with that of insomnia patients. The results showed very few differences between shift and day workers; only "too little sleep" and "nodding off at work" were marginally higher among shift workers. The results also showed that the complaints of insomnia patients for most sleep disturbances corresponded to the 2nd-16th percentile of the shift workers' levels of complaints. The results suggest, at least with the present questionnaire methodology, that shift work does not appear to be a major source of sleep disturbances and that their complaint levels bear no resemblance to those seen in insomniac patients.
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