Cost-effectiveness and cost-utility of an Acceptance and Commitment Therapy intervention vs. a Cognitive Behavioral Therapy intervention for older adults with anxiety symptoms: A randomized controlled trial

Background: A previous randomized controlled trial in older adults with anxiety symptoms found no differences between a brief blended Acceptance and Commitment Therapy (ACT) intervention and brief face-to-face Cognitive Behavior Therapy (CBT) regarding anxiety symptom severity at posttreatment and 12-month follow-up. A health-economic evaluation comparing these interventions has not yet been conducted. Objective: This study examined the one-year cost-effectiveness and cost-utility of blended ACT compared to face-to-face CBT for older adults with anxiety symptoms. Methods: The economic evaluation was embedded in a randomized controlled trial comparing blended ACT to CBT in 314 older adults with mild to moderately severe anxiety symptoms. Data were collected at baseline and 3, 6 and 12 months post baseline. For the cost-effectiveness analysis, treatment response was defined as a reliable improvement in anxiety symptom severity (measured with the Generalized Anxiety Disorder-7) between baseline and 12-month follow-up. To assess cost-utility, quality-adjusted life years (QALYs) were computed using EuroQol-5 Dimensions-5 Levels-5 utility scores. Analyses took the societal perspective, including both healthcare costs and productivity costs. Incremental cost-effectiveness ratios were calculated using 2500 bootstraps of seemingly unrelated regression equations of costs and effects. Sensitivity analyses were performed to assess the robustness of the findings. Results: Differences between the blended ACT group and CBT group in treatment response and QALYs were statistically insignificant and clinically irrelevant. The ACT intervention was associated with an average per-participant cost reduction of €466 ($593) compared to CBT, which resulted from lower productivity costs in the blended ACT group. From a healthcare perspective, the ACT intervention was associated with higher costs (by €71 ($90)) than CBT. Conclusions: The results do not indicate that from a health-economic perspective blended ACT should be preferred over CBT in the treatment of older adults with anxiety symptoms. The findings support a model of shared decision making, where clinicians and patients collaboratively decide on the preferred intervention, based on ethical-medical, practical and personal considerations. Trial registration: Netherlands Trial Register: TRIAL NL6131 (NTR6270); https://www.trialregister.nl/trial/6131.