Randomised controlled or comparative trials of CBT techniques that delivered at least 50 per cent of the intervention via the internet were eligible for inclusion if they were aimed at changing behaviour in patients with existing disorders or health problems. Studies of patients with mental disorders and studies that focused on preventative interventions for lifestyle factors such as smoking and obesity were not eligible.
Included studies were conducted in Sweden or the USA. Most patients were women. Children were also recruited from the community. Mean age ranged between 12 and 57 years. Patients presented with pain, headache or other health problem (tinnitus, physical disability, chronic disease, breast cancer, insomnia and paediatric brain injury). Interventions were either self help (with or without support) or individual/group online therapy, and compared CBT (including psychoeducation, exercise/relaxation or problem solving) with a control (mostly waiting-list). Interventions were delivered over four to 20 weeks.
The authors did not state how many reviewers selected studies for relevance.