Stress and sleep problems are common in the working population and cause considerable costs for society. Sleep is the most important part of recovery, and poor sleep has a negative impact on overall functioning, which might have important consequences for both the employee, the employer and society. In order to find strategies to alleviate this contemporary public health concern of stress and poor sleep in the working population, this thesis evaluated interventions performed at the workplace to target these issues.

The first intervention is a randomized controlled trial of a 25% work time reduction for full-time workers within the public sector in Sweden. Study I evaluated the impact of work time reduction on subjective sleep quality, sleep duration, sleepiness, perceived stress, and bedtime worries. Assessments included diary data from one week at three occasions over 18 months. Study II investigated time-use patterns through activity reporting sheets used during the work time reduction by evaluating the amount of total workload, paid work, non-paid work and recovery activities. Both studies investigated workdays and days off separately as well as the importance of gender, family status and work situation (only Study II). The second randomized controlled intervention of the thesis is a group cognitive behavioral therapy (CBT) intervention at the workplace targeting sleep disturbances among employees within the retail sector in Sweden (Study III). Data were collected through questionnaires, diaries and objective sleep measurement (actigraphy) over a period of ten days before and after the intervention, as well as at a three-month follow up. The study evaluated the effects of the intervention on sleep and explored the moderating effect of burnout-levels at baseline.

In our studies, an economically fully compensated reduction of work hours for full-time workers lead to long-term positive effects on sleep duration and sleep quality, sleepiness and levels of perceived stress. During this work time reduction, the total workload of both paid and non-paid work was reduced and time spent in recovery activities increased. The results indicate that a more balanced relation between effort and recovery was established. The second intervention, which targets the individual through a group CBT-intervention for insomnia at the workplace, was shown to improve insomnia symptoms in daytime workers who did not suffer from concurrent burnout. Such an intervention could support the individual in handling sleep problems and preventing the development of more severe and chronic sleep disorders, as opposed to interventions aimed at making environmental changes at the workplace. However, the CBT-intervention evaluated within this thesis will need to be further developed in order to be beneficial for more groups of employees. The positive effects of these interventions might be beneficial for public health and help improve employee’s life satisfaction, daily functioning and health development.​