Optimization of a Digital Self-guided Psychological Intervention for Insomnia: A Randomized Factorial Experiment

Optimization of a Digital Self-guided Psychological Intervention for Insomnia: A Randomized Factorial Experiment

In a previous pilot study, a digital self-guided intervention for insomnia showed preliminary positive effects on insomnia symptoms. In order to optimize the digital self-guided format, this study will evaluate the added value of three treatment features on treatment engagement and insomnia symptoms. The participants will be adults with insomnia. The trial will be a 2x2x2 randomized factorial experiment, where the following features/factors will be manipulated: an optimized graphical user interface (yes or no), an adaptive treatment strategy (yes or no), and daily prompts to use the intervention (yes or no). The factorial experiment will create 8 equally large groups (1:1:1:1:1:1:1:1), who will receive the different combinations of features. The main outcome will be the effect on treatment engagement.

Inclusion Criteria:

1. ≥ 18 years of age.
2. ≥ 15 points on Insomnia Severity Index.
3. Insomnia diagnosis, according to criteria in the Diagnostic and Statistical Manual of mental disorders-5 (somatic/psychiatric comorbidity is allowed).
4. Good understanding of the Swedish language.
5. No practical obstacles to participate in treatment and assessments.
6. Daily access to computer/smart-phone/tablet with Internet access.
7. Can receive phone calls and text messages during the study period.

Exclusion Criteria:

1. Sleep diseases, such as narcolepsy or sleep apnea.
2. Somatic or psychiatric illnesses that either are directly contraindicated for the treatment, require other treatment, or entail symptoms/a functional level making it too difficult to participate in the study.
3. Alcohol/drug abuse, or medication with side effects on sleep (however, sleep medication is allowed).
4. Working nights or night shifts.