0369 A RANDOMIZED CONTROLLED INTERVENTION OF WORKPLACE-BASED GROUP COGNITIVE BEHAVIOURAL THERAPY FOR INSOMNIA: THE MODERATING EFFECT OF CHRONIC STRESS

Abstract

Introduction: Sleep disturbance is common in the working population, often associated with work stress, health complaints and impaired work performance. This study investigated if a group intervention at work, based on Cognitive Behavioral Therapy (CBT) for insomnia, may improve sleep and if the effects were moderated by burnout levels at baseline. Methods: This is a randomized controlled intervention with a waiting list control group. Participants were employees working at least 75% of full time, reporting self‐perceived moderate sleep problems (N=51, 63% women). The intervention consisted of five group sessions at the workplace plus homework. Data were collected at baseline, post‐intervention and at a three‐month follow‐up through diaries, wrist actigraphy and questionnaires including the Insomnia Severity Index (ISI) and the Shirom‐Melamed Burnout Questionnaire (SMBQ). Results: A multilevel mixed model showed no significant interaction effects for sleep. However, by adding burnout levels at baseline into the model, a moderating effect on insomnia symptoms was observed through a significant three‐way interaction (Coeff.=3.28; p=0.009; C.I.=0.82‐5.75). Individuals in the intervention group with low to moderate levels of burnout at baseline (SMBQ<3.75) displayed significantly reduced ISI score at follow‐up as compared to individuals with high levels of burnout at baseline (Coeff.=2.51; p=0.005; C.I.=0.77‐4.24). Conclusion: Group CBT for insomnia given at the work place did not reduce sleep problems, while there were some indications that the intervention reduced symptoms of insomnia in employees with low burnout levels. The results suggest that group CBT may improve sleep in individuals with primary insomnia.