COST-BENEFIT AND COST-UTILITY ANALYSES OF COGNITIVE-BEHAVIORAL THERAPY VERSUS LIGHT THERAPY FOR SEASONAL AFFECTIVE DISORDER

Costs, benefits, and effectiveness (Quality-Adjusted Life Years Gained or QALYGs) of Light Therapy (LT) versus Cognitive Behavioral Therapy (CBT) for treatment of Seasonal Affective Disorder (SAD) were examined at first- and second-winter follow-ups for 148 women and 29 men enrolled in a randomized clinical trial. Provider and patient costs of LT and CBT-SAD were contrasted to change in costs of health services in cost-benefit analyses. QALYG were calculated for each patient individually using health utility scores derived from changes on the Beck Depression Inventory – Second Edition and compared to patient costs in cost-utility analyses. No significant differences were found in benefits, i.e., in decreased cost or use of health services, following CBT-SAD or LT. After the next winter, estimated median benefits exceeded costs from the provider perspective for LT but not CBT-SAD ($169 and -$87 respectively), and estimated at the treatment, not patient, level. Patient perspective, as treated (AT) median costs significantly exceeded benefits for both treatments after next winter (LT = -$582, CBT-SAD = -$456) and second winter (LT = -$951, CBT-SAD = -$555), ps < .01, with CBT-SAD having significantly less negative net benefit after the second winter, p < .01. Patient perspective, AT median cost per QALYG was significantly less for CBT-SAD than LT after next winter (CBT-SAD = $5,421/QALYG/patient, LT = $9,008/QALYG/patient; p < .01) and second winter (CBT-SAD = $4,146/QALYG/patient, LT = $10,644/QALYG/patient; p < .01). From the patient perspective, CBT-SAD was better than LT in cumulative treatment costs, median net benefit, and cost per QALYG.