Internet-Delivered Cognitive-Behavioral Therapy for Insomnia in Breast Cancer Survivors: A Randomized Controlled Trial

Background: Insomnia is two to three times more prevalent in cancer survivors than in the general population, where it is estimated to be 10% to 20%. Cognitive-behavioral therapy for insomnia (CBT-I) is the recommended treatment for chronic insomnia, but meeting survivor needs remains a challenge. Internet-delivered CBT-I (iCBT-I) has been shown efficacious in otherwise healthy adults. We tested the efficacy of iCBT-I in breast cancer survivors with clinically significant sleep disturbance. Methods: Women from a national sample of Danish breast cancer survivors who experienced clinically significant sleep disturbance were randomly allocated to iCBT-I or waitlist control (55:45). The fully automated iCBT-I program consisted of six cores. Online measures of insomnia severity, sleep quality, and fatigue were collected at baseline, postintervention (nine weeks), and follow-up (15 weeks). Online sleep diaries were completed over two-week periods pre- and postintervention. Intention-to-treat analyses (time x group interactions) were conducted with mixed linear models and corrected for multiple outcomes. All statistical tests were two-sided. Results: A total of 255 women were randomly allocated to iCBT-I (n = 133) or waitlist control (n = 122). Statistically significant (P <= .02) time x group interactions were found for all sleep-related outcomes from pre- to postintervention. Effect sizes (Cohen's d) ranged from 0.33 (95% confidence interval [CI] = 0.06 to 0.61) for wake after sleep onset to 1.17 (95% CI = 0.87 to 1.47) for insomnia severity. Improvements were maintained for outcomes measured at follow-up (d = 0.66-1.10). Conclusions: iCBT-I appears to be effective in breast cancer survivors, with additional benefit in terms of reduced fatigue. This low-cost treatment could be incorporated in cancer rehabilitation programs.