Cognitive behavioral therapy for chronic insomnia in occupational health services: Analyses of outcomes up to 24 months post-treatment

Our results indicate that CBT-I delivered by OHS leads to long-term improvements among both daytime and shift workers. Two groups were identified according to the degree of improvement of insomnia; one comprising two thirds of the participants with a moderate response and the other comprising one thirds of the participants with a modest response. The results need to be interpreted cautiously as insomnia was mild (ISI was on average under 15 points at all measurement points) and improvements were relatively small in the sample, and the study design was non-randomized.