Cost-effectiveness of cognitive behavioral therapy for insomnia comorbid with depression: Analysis of a randomized controlled trial

Aim Although the efficacy of cognitive behavioral therapy for insomnia has been confirmed, dissemination depends on the balance of benefits and costs. This study aimed to examine the cost-effectiveness of cognitive behavioral therapy for insomnia consisting of four weekly individual sessions. Methods We conducted a 4-week randomized controlled trial with a 4-week follow up in outpatient clinics in Japan. Thirty-seven patients diagnosed as having major depressive disorder according to DSM-IV and suffering from chronic insomnia were randomized to receive either treatment as usual (TAU) alone or TAU plus cognitive behavioral therapy for insomnia. Effectiveness was evaluated as quality-adjusted life years (QALY) over 8 weeks' time, estimated by bootstrapping of the observed total scores of the Hamilton Depression Rating Scale. Direct medical costs for cognitive behavioral therapy for insomnia and TAU were also evaluated. We calculated the incremental cost-effectiveness ratio. Results Over the 8 weeks of the study, the group receiving cognitive behavioral therapy for insomnia plus TAU had significantly higher QALY (P = 0.002) than the TAU-alone group with an incremental value of 0.019 (SD 0.006), and had non-significantly higher costs with an incremental value of 254 (SD 203) USD in direct costs. The incremental cost-effectiveness ratio was 13 678 USD (95% confidence interval: -5691 to 71 316). Adding cognitive behavioral therapy for insomnia demonstrated an approximately 95% chance of gaining one more QALY if a decision-maker was willing to pay 60 000 USD, and approximately 90% for 40 000 USD. Conclusion Adding cognitive behavioral therapy for insomnia is highly likely to be cost-effective for patients with residual insomnia and concomitant depression.