The Cost-Effectiveness of Cognitive Behavioral Therapy Versus Second-Generation Antidepressants for Initial Treatment of Major Depressive Disorder in the United States: A Decision Analytic Model

Abstract

Background: Most guidelines for major depressive disorder recommend initial treatment with either a second-generation antidepressant (SGA) or cognitive behavioral therapy (CBT). Although most trials suggest that these treatments have similar efficacy, their health economic implications are uncertain.

Objective: To quantify the cost-effectiveness of CBT versus SGA for initial treatment of depression.

Design: Decision analytic model.

Data sources: Relative effectiveness data from a meta-analysis of randomized controlled trials; additional clinical and economic data from other publications.

Target population: Adults with newly diagnosed major depressive disorder in the United States.

Time horizon: 1 to 5 years.

Perspectives: Health care sector and societal.

Intervention: Initial treatment with either an SGA or group and individual CBT.

Outcome measures: Costs in 2014 U.S. dollars, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

Results of base-case analysis: In model projections, CBT produced higher QALYs (3 days more at 1 year and 20 days more at 5 years) with higher costs at 1 year (health care sector, $900; societal, $1500) but lower costs at 5 years (health care sector, -$1800; societal, -$2500).

Results of sensitivity analysis: In probabilistic sensitivity analyses, SGA had a 64% to 77% likelihood of having an incremental cost-effectiveness ratio of $100 000 or less per QALY at 1 year; CBT had a 73% to 77% likelihood at 5 years. Uncertainty in the relative risk for relapse of depression contributed the most to overall uncertainty in the optimal treatment.

Limitation: Long-term trials comparing CBT and SGA are lacking.

Conclusion: Neither SGAs nor CBT provides consistently superior cost-effectiveness relative to the other. Given many patients' preference for psychotherapy over pharmacotherapy, increasing patient access to CBT may be warranted.

Primary funding source: Department of Veterans Affairs, National Institute of Mental Health.

Figure 1.. Model structure.

Structure of the model used for the analysis. Health states are represented by boxes, and transition probabilities between states are represented by arrows. Each group of boxes of the same color represents 1 treatment; treatments 3 through 8 are represented by a single box with a dashed outline. For clarity, mortality probabilities are omitted from the diagram; patients in every model state are subject to a probability of mortality with each time-step. Additional information on the mathematical structure of the model is provided in the Supplement.

Figure 2.. Scenario sensitivity analyses.

Bars show the percentage of 10 000 probabilistic model runs in which either SGA or CBT is the preferred treatment strategy (i.e., that which produces the greatest net monetary benefit), at a willingness-to-pay threshold of $100 000 per quality-adjusted life-year. Results are shown for both 1- and 5-year time horizons. The vertical axis shows the scenario being modeled, indicating a change in either parameter values or model structure relative to the base case. CBT = cognitive behavioral therapy; SGA = second-generation antidepressant; STAR*D = Sequenced Treatment Alternatives to Relieve Depression. Top. Results from a health care sector perspective. Bottom. Results from a societal perspective. Scenarios include increased or reduced cost uncertainty (SEs of first-line SGA and CBT cost estimates are increased or reduced to 30% or 10% of the mean); alternative cost data (annual background depression costs of $12 389 for remission and $17 551 for nonremission); SGA cost includes vilazodone (vilazodone is incorporated into SGA costing analysis, increasing annual cost of SGA from $48 to $72); individual or group CBT only (exclusively individual sessions or exclusively group sessions are used to calculate CBT costs); no STAR*D efficacy data (odds of remission and response are reduced by 19% with each successive treatment rather than using STAR*D data on remission and response rates); increasing relapse rate (by a relative 15% with each successive treatment); all-cause discontinuation (all-cause discontinuation [rather than discontinuation due to adverse events] is simulated; annual probability is 46.0% for SGA, with a relative risk of 1.00 [95% CI, 0.55 to 1.81] for CBT vs. SGA).