Anxiety disorders are highly prevalent and among the leading causes of the global disease burden. Cognitive behaviour therapy (CBT) is an effective treatment, but demand is high and resources to deliver CBT are scarce. Embracing new technologies to meet these growing needs, there is an emergent evidence base of the efficacy of internet-based CBT (ICBT).

Evaluating (1) treatment effects, (2) cost-effectiveness and (3) cost-utility of ICBT for panic disorder.

To evaluate clinical effectiveness and health economics of ICBT for patients within regular psychiatric care.

Longitudinal analysis of 570 patients diagnosed with panic disorder that have been treated between 2007 and 2012 at an ICBT unit within regular psychiatric care. The ICBT was therapist-guided and lasted for three months. Clinical outcome measures were improvements in symptom severity and health related quality of life. Economic outcome measures were direct and indirect costs and incremental cost-effectiveness ratios (ICER).

Analyses of treatment outcome suggest significant reductions in primary symptoms of panic disorder and that ICBT is an economically and clinically effective treatment for panic disorder leading to improvement of symptom severity and quality of life for these patients.

The findings of this study can aid decision makers when considering options of evidence-based treatment delivery formats within psychiatric care.