Short-term cost-effectiveness of psychodynamic therapy and cognitive-behavioral therapy in social anxiety disorder: Results from the SOPHO-NET trial

Background: To investigate the short-term cost-effectiveness of cognitive-behavioral therapy (CBT) and psychodynamic therapy (PDT) compared to waiting list (WL).

Methods: The analysis was conducted alongside the SOPHO-NET multi-center efficacy trial. Patients were randomly assigned to CBT (n=209), PDT (n=207), or WL (n=79). Resource use was assessed prior and during treatment to determine direct and absenteeism costs. Unadjusted incremental cost-effectiveness ratios (ICERs) were calculated based on remission and response rates. To visualize statistical uncertainty, cost-effectiveness acceptability curves (CEACs) were constructed based on adjusted net-benefit regression. Different values for the society׳s willingness to pay (WTP) were assumed.

Results: Both interventions were more efficacious than WL but were associated with increased direct costs besides intervention costs. Unadjusted ICERs per responder were €3615 for CBT and €4958 for PDT. Unadjusted ICERs per remitted patient were €5788 and €10,733. CEACs revealed a high degree of uncertainty: applying the 97.5% probability threshold, CBT proved cost-effective at a WTP ≥€16,100 per responder and ≥€26,605 per remitted patient. Regarding PDT cost-effectiveness only was certain for response at a WTP ≥€27,290.

Limitations: The WL condition is assumed to represent untreated patients, although the expectation to start treatment in the near future probably affects symptom severity and health care utilization.

Conclusions: At the end of treatment cost-effectiveness of CBT and PDT compared to WL is uncertain and depends on the societal WTP. The interventions may induce a more adequate utilization of other health care services - involving increased costs. Development of costs and effects in the long-run should be considered.