How Is Cognitive Behavioural Therapy for Insomnia Provided in Randomized Controlled Trials? A Scoping Review

Cognitive behavioural therapy (CBT) in general has demonstrated efficacy in treating insomnia, but there is some variation in the content of CBT for insomnia (CBT-I) across studies. We therefore conducted a scoping review of randomized controlled trials on CBT-I to determine how CBT-I is usually provided in randomized controlled trials. This knowledge is essential for writing evidence-based treatment guidelines and ensuring that clinical practice reflects interventions with proven effectiveness. The search was performed in Pubmed, Embase and Web of Science. A total of 514 publications were included. Excluding the secondary analyses, this left 375 unique randomized controlled trials on CBT-I. A total of 197 focused on comorbid insomnia. The most frequently reported components were stimulus control (86.93%), time-in-bed restriction (84.53%), cognitive therapy (83.20%) and sleep hygiene (78.13%). In a few randomized controlled trials, CBT-I did not include its three core components time-in-bed restriction, stimulus control and cognitive therapy. The reasons for omitting one of these components were rarely reported. The intervention is generally delivered in six sessions, which is more than the previously identified ideal amount of four sessions. When delivered individually, sessions typically lasted 60 min. However, in a group format, they usually lasted 90 min and involved four to six patients. CBT-I was usually delivered in person and by a psychologist. Guidelines on the report of CBT-I in RCTs were formulated.