OBJECTIVES : Insomnia is associated with significant economic consequences, mainly due to work absenteeism. Although cognitive behavioral therapy for insomnia (CBT-I) has been shown to be effective for insomnia, general practitioners (GPs) do not regularly subscribe CBT-I as first line of treatment. Internet-delivered CBT-I presents an alternative to bridge this gap while efficiently using scarce resources. The aim of this study was to estimate the cost-effectiveness of a guided, internet-delivered intervention compared to care-as-usual for insomnia patients in general practice from a societal perspective.

METHODS : An economic evaluation was conducted alongside a randomized clinical trial with 26 weeks follow-up. Primary outcomes were insomnia severity (score on and clinically relevant response measured by the Insomnia Severity Index, ISI) and Quality-Adjusted Life Years (QALYs). Societal costs were assessed at baseline, and at 8 and 26 weeks. Missing data was imputed using multiple imputation. Statistical uncertainty around cost and effect differences and incremental cost-effectiveness ratios (ICERs) were estimated using bootstrapping, and presented using cost-effectiveness acceptability curves.

RESULTS : Mean societal costs in the intervention group were statistically non-significantly lower than in the care-as-usual group (-€318; 95% CI -1282 to 645). Cost-effectiveness analyses revealed a 95% probability of the intervention being cost-effective as compared to care-as-usual at ceiling ratios of €450/extra point of decrease in ISI and €7,000/additional response to treatment, respectively. At a ceiling ratio of 30,000 €/extra QALY gained, the probability of the intervention being cost-effective was 69%. Sensitivity analyses gave similar results.

CONCLUSIONS : The intervention was considered cost-effective in comparison with care-as-usual for patients with insomnia treated in general practice from the societal perspective. However, the probability of the intervention being cost-effective as compared to care-as-usual was lower for the QALY outcome. We conclude that internet-delivered CBT-I is a promising and efficient intervention to reduce the personal and societal burden associated with insomnia.