JMIR Publications

ABSTRACT

Background:

Sleep complaints are among the most prevalent health concerns especially amongst workers which may lead to adverse effects on health and work. Internet-delivered cognitive-behavioral therapy for insomnia (iCBT-I) offers the opportunity to deliver effective solutions on a large scale. While, the efficacy of iCBT-I for clinical samples has been demonstrated in recent meta-analyses, evidence is missing that iCBT-I is also an effective tool for universal prevention among the general working population. There is increasing evidence that cognitive activation may be a key factor for the development and maintenance of insomnia, but little is known about how iCBT-I reduce cognitive activation before sleep.

Objective:

This study examined the efficacy of a self-help web-based recovery training, based upon principles of iCBT-I tailored to the work-life domain, among the general working population in the context of universal prevention and investigated general and work-related cognitive activation as potential mediators of the intervention’s effect.

Methods:

A sample of 177 workers was randomized to either the iCBT-I (n = 88) or to care as usual (n = 89). The intervention is a 6-week web-based training consisting of 6 one-week modules. Since the training was conducted in self-help, participants received nothing but technical support via email. Web-based self-report assessments were scheduled at baseline, at eight weeks and six months following randomization. The primary outcome was insomnia severity. Secondary outcomes included measures of mental health and work-related health and cognitive activation. General and work-related cognitive activation, measured as worry and work-related rumination, were investigated as mediators.

Results:

An intention-to-treat analysis of covariance showed that, relative to controls, treated subjects reported significantly lower insomnia severity scores, at post treatment (F1,174 = 64.26, P < .001; Cohen´s d = 0.97, 95% CI 0.66 – 1.28), and at six-month follow-up (F1,174 = 49.19, P < .001; Cohen´s d = 0.83, 95% CI 0.52 – 1.14). Significant differences, with small-to-large effect sizes, also were detected for cognitive activation, and for mental and work-related health, but not for absenteeism. Mediation analysis demonstrated that work-related rumination (indirect effect : a1b1 = -0.99, SE =.35, 95% Boot CI -1.80 – -0.41) and worry (indirect effect: a2b2 = -0.26, SE = 0.35, 95% Boot CI -0.68 – -0.04) mediate the intervention’s effect on sleep, the indirect effect being larger through work-related rumination than worry.

Conclusions:

A self-help web-based recovery training, grounded in the principles of iCBT-I, can be effective as a universal prevention approach, both short- and long-term, in the general working population. Work-related rumination may be a particularly crucial mediator of the intervention´s effect, suggesting that tailoring interventions to the workplace, including components to reduce the work-related cognitive activation, might be important when designing recovery interventions for workers. Clinical Trial: Trial Registration: German Clinical Trials Register (DRKS): DRKS00007142 (DRKS00004700; DRKS00004984)