Factors influencing the effectiveness of digital cognitive behavioural therapy for chronic insomnia in clinical practice.

Digital cognitive behavioural therapy for chronic insomnia (D-CBT-I) has been shown to be as efficacious as traditional CBT-I. However, not all patients achieve insomnia remission after treatment. We explored the factors influencing the effectiveness of D-CBT-I in a clinical practice. A total of 414 Asian chronic insomniacs were studied during a 6 week D-CBT-I intervention. All patients were assessed at baseline and posttreatment and were determined to be remitters or non-remitters, responders or non-responders by posttreatment criteria; Insomnia Severity Index (ISI <8) or ISI reduction ≥8, to examine whether remission and response status were associated with patient baseline characteristics. The average baseline ISI score in all subjects was 16.29 points. At posttreatment, 192 (46.4%) patients achieved ISI remission and 218 (52.7%) patients demonstrated an ISI response. An increased baseline early morning awakening time and ISI score were independently associated with a lower odds for remission (OR, 0.995 and 0.991, respectively). Increased baseline Patients Health Questionnaire-9 score was independently associated with higher odds for response (OR, 1.114). Our results suggest that D-CBT-I can be recommended as the first-line treatment for chronic insomnia, particularly in insomniacs with milder insomnia symptoms and more severe depressive symptoms. Meanwhile, the effectiveness of D-CBT-I was adversely affected by longer early morning awakening time and higher insomnia severity at pretreatment, which may be improved by more intense intervention and greater therapeutic support or by traditional CBT-I.